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Showing posts with label Vitamin E. Show all posts
Showing posts with label Vitamin E. Show all posts

Friday, 22 March 2019

Hepatitis B Health Protocol - Life Extension


Hepatitis B

Hepatitis B is an infectious liver disease caused by the hepatitis B virus (HBV) (A.D.A.M Editorial Board 2010; Merck 2007; Mayo Clinic 2011b). While most adults infected with HBV recover, a portion can develop chronic hepatitis B, risking serious illness or death from cirrhosis, hepatocellular carcinoma (liver cancer), or liver failure (El-Serag 2012; Nebbia 2012; WHO 2009; Lee 2008).


According to 2009 World Health Organization estimates, greater than 2 billion people have been exposed to the hepatitis B virus and 360 million are chronically infected worldwide (WHO 2009). It has been estimated that 12 million people In the U.S. have been exposed to HBV, with roughly 700,000 being chronically infected (Ioannou 2011).

Chronic HBV infection often does not cause symptoms in its early stages, so only about 33% of adults with chronic hepatitis are aware they are infected. Of those eligible for treatment for chronic HBV, only about 12.5% are receiving it (Scaglione 2012).

While the availability of HBV vaccination has decreased the incidence of HBV infection in the U.S., about 43,000 cases of acute hepatitis B still occur each year (Mitchell 2010). Rates of vaccination are relatively low among high-risk populations (eg, illicit IV drug users, individuals with HIV, and hemophiliacs); according to a 2007 CDC survey, over 51% of high risk adults remained unvaccinated in the U.S. (Ladak 2012).

Standard therapies for chronic HBV infection and hepatitis are limited, and are not effective in all cases (Scaglione 2012; Mutimer 2012). Additionally, the unique lifecycle of the HBV allows it to evolve and develop resistance to antiviral drugs (Billioud 2011).

Overlooked is an abundance of published research documenting potent anti-viral and liver-protecting properties of easy-to- obtain nutrients.

Fortunately, minimization of risk factors for HBV can reduce transmission of the virus, while new diagnostics and emerging treatments continue to advance the ability to combat this disease. This protocol will review these conventional treatments, as well as discuss nutritional approaches for addressing HBV infection and chronic liver disease progression.


Development and Progression of HBV Infection


HBV Biology. The hepatitis B virus infects humans and higher primates, entering and replicating within liver cells (hepatocytes), and secreting new virus particles into circulation (WHO 2009; Gish 2012). HBV is extremely effective at targeting hepatocytes; less than 10 individual virus particles are sufficient to establish an infection (Protzer 2012). Upon infection, HBV DNA enters the nucleus of the hepatocyte, where it serves as the reservoir for formation of virus particles for the lifetime of the cell and makes treatment of HBV challenging (Wilson 2009; Nebbia 2012). Replication of HBV requires the activity of a viral reverse transcriptase enzyme, which is prone to introducing mutations into the viral genome and potentially allowing the virus to become resistant to some treatments (Liaw 2009; Nebbia 2012).

Following an incubation period of 1-4 months, acute symptomatic hepatitis occurs in about one-third of infected adults, 10% of young children, and rarely in infants (Nebbia 2012). Acute hepatitis B resolves on its own in over 95% of adult cases (Liaw 2009). The acute infection is considered resolved when hepatitis B surface antigen (HBsAg) can no longer be detected in the blood within 6 months of infection (Nebbia 2012). HBsAg, a lipoprotein that forms part of the protective coating of the virus particle, is a marker for disease progression. Many individuals with HBV infection (7–40%) who are HBsAg-positive may also carry the hepatitis B e-antigen (HBeAg), a viral protein associated with high infectivity (WHO 2009). After resolution of an acute infection, an individual generally develops lifelong immunity against HBV-associated hepatitis, although the virus itself is not cleared from the liver (Nebbia 2012). Small amounts of viral DNA can be detected in blood years after recovery from acute hepatitis B (Liaw 2009). Thus, immunosuppression (eg, corticosteroid therapy) has the potential to reactivate an HBV infection.

There are several genetic strains of HBV (genotypes A-H), which vary in geographic distribution, response to treatment, and risk of progression to advanced liver disease (Liaw 2009; Tanwar 2012). In the United States, HBV genotypes A and D are more common in African-Americans and Caucasians, whereas HBV genotypes B and C are more common among persons of Asian ancestry (El-Serag 2012). Severe liver disease and hepatocellular carcinoma is more likely from infection with genotypes C and D. Response to interferon treatment (a conventional therapy; see below) is greater in genotypes A and B (than C or D), and thymosin treatment (see below) is twice as effective in genotype B than C (Chien 2006; Tanwar 2012). Although not yet standard for HBV treatment, genotyping could enable clinicians to identify and provide appropriate therapy for those at increased risk of disease progression (Tanwar 2012).

Transmission and Infectivity. HBV is transmitted through the skin (eg, injection) or via mucosal exposure to infected blood or other body fluids, mainly semen or vaginal fluid (WHO 2009). In geographic areas with low HBV prevalence (such as the United States), sexual transmission and use of contaminated needles by illicit drug users are major risk factors for infection (Daniels 2009).

In areas of high HBV prevalence (such as the Asia Pacific region), the virus is most commonly spread from infected mother to child at birth or child to child during early childhood. About 90% of mothers with high viral load will infect their babies with HBV (Liaw 2009). HBV can also infect sperm, enabling possible transmission from infected father to embryo during conception (Kang 2012). The likelihood of parent-to-child transmission can be reduced by vaccination (Lee 2006) (see below).

Individuals with acute or chronic HBV infection should be considered infectious any time HBsAg is present in the blood. HBsAg can be found in blood and bodily fluids for 1–2 months before and after the onset of symptoms. HBsAg can be identified in serum 30 to 60 days after exposure to HBV. Other markers of infectivity include HBeAg (hepatitis B e antigen) and HBV DNA (Hepatitis B DNA). HBeAg is a viral protein that indicates ongoing viral replication and increased infectivity. HBV DNA is a marker of viral replication; higher viral loads correlate with greater infectivity (CDC 1990, WHO 2009, Byrd 2012).

Outcomes of HBV Infection:


Asymptomatic or acute HBV infection. Acute HBV infection is asymptomatic in most individuals (symptomatic acute hepatitis B occurs in only about one-third of infected adults, 10% of children, and rarely in infants) (Nebbia 2012). Symptoms are similar to other viral hepatitis’ and include loss of appetite, fatigue, nausea, vomiting, abdominal pain, joint pain, mild fever, dark urine, and jaundice (yellowing of the skin and eyes due to accumulation of bilirubin secondary to liver dysfunction) (Merck 2007). The majority of acute hepatitis cases resolve, and the infected person eventually develops immunity to the virus (Liaw 2009; Nebbia 2012).

Chronic HBV infection. Some acutely infected individuals will progress to chronic HBV infection. Chronic HBV carriers are identified by the presence of hepatitis B surface antigen (HBsAg) in their blood for over 6 months, a HBV DNA blood level of 2000-20 000 IU/ml, and persistent or intermittent increases in liver enzymes. People with viral DNA loads of less than 2000 IU/ml are considered inactive carriers (Chevaliez 2012).

Age of infection has a significant effect on persistence of HBV (WHO 2009; Nebbia 2012); 90% of children infected at birth will develop chronic HBV, compared to 20-30% of children aged 1-5 and 1-5% of adults (Nebbia 2012). Chronic HBV infection increases the risk of serious liver disease, including cirrhosis and hepatocellular carcinoma (El-Serag 2012). Dysbiosis (detrimental changes in intestinal flora) is also possible (Xu 2012).

Cirrhosis. Cirrhosis, the end stage of any chronic liver disease (Garcia-Tsao 2009), involves functional liver tissue being replaced by fibrous tissue and scarring. Ascites (buildup of fluid in the abdomen), hepatic encephalopathy (depressed brain function due to accumulation of toxins in the brain), bacterial infection of the abdomen, and cancer are complications of cirrhosis (Garcia-Tsao 2009; Mayo Clinic 2011a). Cirrhosis is generally irreversible, although studies suggest that some HBV-mediated cirrhosis may be reversible with treatment (Scaglione 2012).

Hepatocellular carcinoma. Liver cancer is the fifth most common cancer in men and seventh most common in women worldwide. Hepatocellular carcinoma (HCC) is the most common form of liver cancer. Approximately 80% of HCC cases are associated with chronic HBV or HCV infection (El-Serag 2012). HCC risk increases with viral load. In the REVEAL-HBV study of liver disease in chronic HBV patients, individuals with the highest viral loads at study entry (over 1 million copies of HBV DNA per ml in blood) had almost 11 times the risk of HCC than those with viral loads of less than 10 000 copies/ml of blood (Chen 2006).

Fulminant Hepatitis. Fulminant hepatitis is an acute hepatitis leading to acute liver failure and hepatic encephalopathy within a rapid period of time (less than 8 weeks after the onset of jaundice) (Ichai 2011). Between 7 and 33.7% of fulminant hepatitis cases stem from HBV infection (Ichai 2011). Fulminant hepatitis is rare in HBV-infected children, and develops in 0.1-0.6% of acute hepatitis cases in adults (Nebbia 2012). HBV-mediated fulminant hepatitis has a mortality rate of about 70% (WHO 2009).

Causes and Risk Factors for Hepatitis B and HBV Infection


Risk factors for HBV transmission or the progression of HBV disease include:

Gender. Chronic hepatitis B progresses more rapidly in males than females; cirrhosis and HCC predominate in men and postmenopausal women (Shimizu 2007; El-Serag 2012). High serum levels of testosterone have been associated with increased HCC risk in HBV carriers (Yuan 1995). Additionally, among 42 men who underwent liver resection for HCC between 1995 and 1999, those whose preoperative testosterone levels were in the upper half of the distribution had greater disease recurrence and poorer survival rates over 5-year follow up (Lin 2007). In contrast, premenopausal women have lower liver iron stores and reduced production of pro-inflammatory cytokines, both reducing risk of liver disease; this also suggests a potential protective role of estrogens (Shimizu 2007).

HIV infection. An estimated 10% of the 40 million people infected with HIV worldwide are also infected with HBV. HIV infection significantly increases the risk of developing cirrhosis and HCC in individuals carrying both viruses (WHO 2009), and HBV increases the rate of mortality in HIV patients on antiretroviral therapy (Nikolopoulos 2009).

Alcohol use. A few studies investigating the association between alcohol intake, HBV infection, and the progression of liver disease found a 1.2 to 3 times increased risk of HCC among heavy alcohol users (El-Serag 2012).

Sexual behavior. Hepatitis B is considered a sexually transmitted disease (STD), and in areas with low HBV incidence such as the U.S., sexual transmission represents a major route of infection. While homosexual men have the highest risk of infection (70% infected after 5 years of activity), heterosexual transmission has been increasing in frequency. In heterosexuals, multiple or high-risk partners (such as HBV carriers or illicit IV drug users), history of STD, and long duration of sexual activity all increase risk of transmission (Hou 2005).

Intravenous (IV) illicit drug use. Injection of illicit IV drugs is a major route of HBV infection in areas of low HBV incidence. In the U.S. and Western Europe, 23% of hepatitis B patients were infected by needles (Hou 2005).

Contact with infected fluids. Individuals in frequent contact with potentially contaminated blood products or bodily fluids (eg, health care workers, lab technicians, police, firefighters, and patients requiring frequent transfusions or hemodialysis) are at increased risk of HBV infection. Contaminated instruments (eg, those used for surgery, body piercing, acupuncture, or tattooing) also represent possible sources of infection (Hou 2005).

Parent-to-child transfer. As mentioned earlier, mother-to-child transfer is a significant source of viral transmission in both high-prevalence and low-prevalence geographic areas. In contrast to transmission by sexual contact, drug use, or contact with infected blood (which all have a

Diagnosis

There are several tests for diagnosing HBV infection; the tests monitor either viral load or liver function.

Tests for HBV Viral Load. Quantification of HBV DNA in the blood by polymerase chain reaction (PCR) or newer real-time PCR tests are indicative of the activity of HBV replication. Levels above 2000 IU/ml indicate active or chronic infection, while levels below this indicate inactive carriage of the virus (Chevaliez 2012).

Serum hepatitis B surface antigen (HBsAg) level is also a marker of infected liver mass and the amount of HBV DNA in infected hepatocytes. When combined with PCR testing, a blood test for HBsAg levels can be used to monitor progression of chronic HBV infection or identify inactive carriers (Chevaliez 2012).

Other serological tests for viral load include quantification of HBeAg, a marker for high-infectivity HBV, as well as the detection of antibodies to HBV antigens (anti-HBs, anti-HBe, and anti-HBc, an antibody to the HBV core antigen), which can indicate a prior or chronic infection (WHO 2009; Chevaliez 2012). Testing for anti-HBc IgM antibody can identify acute HBV infection (Gitlin 1997).

Liver function tests. There are several blood tests that are not specific to HBV and nonspecifically assess liver function, but are important in the diagnosis of infection; these include ALT (alanine aminotransferase, a marker of liver cell damage), bilirubin (an indicator of liver excretion function), and albumin levels & prothrombin time (indicators of liver synthesis function) (Liaw 2009). Most of these markers can be measured in routine blood tests. Fibrometers (ie, liver-fibrosis-specific blood panels), which combine some of these markers with other liver-specific markers, are also available (Castera 2012).

Liver biopsy. Liver biopsy is an important, but invasive technique for grading liver damage. Newer non-invasive methods use imaging techniques to assess liver stiffness (a direct physical property of the liver that increases as the liver is filled with connective tissue during fibrosis). These include transient elastography (an ultrasound technique) and magnetic resonance elastography (Castera 2012).

Conventional Treatment for Hepatitis B

Acute hepatitis B typically resolves on its own and may not require treatment (Liaw 2009). The goal of chronic hepatitis B treatment is to suppress HBV viral replication, which may limit hepatitis progression and may lower the risk of some complications, such as cirrhosis or cancer (Gish 2012).

Antiviral therapy. There are 7 drugs approved for treatment of chronic hepatitis (Mutimer 2012). Interferon (IFN) is a signal protein produced by infected or cancerous cells to bolster the immune response of neighboring cells (Marieb 2010). Interferon alpha (IFN-α) therapy is an approved antiviral for HBV and HCV infection. Both standard IFN-α and pegylated IFN-α (an IFN derivative with a longer half-life in the body) (Grimm 2011) are administered via subcutaneous injection (Nebbia 2012). INF-α, either alone or in combination with the nucleoside analog lamivudine, lowers viral load and normalizes ALT levels (Scaglione 2012). IFN alone may reduce the incidence of cirrhosis, hepatocellular carcinoma, and liver-related deaths (Scaglione 2012). Side effects of IFN include fatigue, flu-like symptoms, mood changes, bone marrow suppression, and development or exacerbation of autoimmune illnesses (Scaglione 2012). IFN-α may be better for achieving a sustained virological response than nucleotide analogs (see below) (Nebbia 2012).

Nucleotide and nucleoside analogs. Nucleotide and nucleoside analogs (NUCs; lamivudine, telbivudine, entecavir, adefovir dipivoxil, and tenofovir disoproxil fumarate) interfere with HBV viral replication. Trials of NUCs in HBV patients demonstrate a decrease in viral load, ALT levels, and hepatocellular carcinoma incidence, as well as the possible reversal of HBV-mediated cirrhosis. As oral medications, NUCs are more convenient to take than IFN, but the eventual development of resistance to these drugs limits their long-term utility. Side effects, which vary by drug, include myopathy and peripheral neuropathy (telbivudine), kidney toxicity and dysfunction (tenofovir and adefovir), decreased bone mineral density (tenofovir), and lactic acidosis in patients with liver disease (entecavir) (Scaglione 2012).


Novel and Emerging Therapies


Heteroaryldihydropyrimidines. Heteroaryldihydropyrimidines (HAPs) are antiviral compounds that have been shown to inhibit HBV replication in isolated cells and animal models. In contrast to nucleotide and nucleoside analogs, which interfere with the replication of the viral genome, HAPs prevent the proper assembly of the protein capsule that surrounds the mature virus and serves as the site of DNA replication (Deres 2003; Stray 2005). They are effective against HBV mutant strains resistant to nucleotide/nucleoside analog drugs (Billioud 2011). Bay 41-4109, the best studied HAP, reduced HBV viral load by about 2 to 3-fold in a humanized mouse model (mice with livers that contain human liver cells) (Billioud 2011; Weber 2002). These compounds await human trials.

RNA interference (RNAi) is a cellular mechanism for controlling gene expression; it is used by cells to regulate cell development and metabolism, but can also be used to turn off the expression of foreign genes, such as those of an invading virus. Since the life cycle of HBV relies on RNA intermediates for its replication, it is sensitive to inhibition by RNAi (Grimm 2011). Therapeutic RNA inhibitors have been designed to interrupt HBV DNA replication, and turn off the genes that produce the structural and regulatory proteins required for assembly of infectious HBV particles. They have shown success in decreasing virus replication in cell cultures (Wilson 2009). Early results of a safety trial of the small interfering RNA NUC B1000 appear promising (Gish 2011).

Thymosin α1. Thymosin α1 (Tα1) is an immunomodulatory peptide derived from the thymus that stimulates T-cells (one of the principle immune cells) to mature and produce cytokines, as well as increases the ability of the immune system to recognize invading pathogens (Delaney 2002; Yang 2008). In several studies of Tα1 therapy in chronic, HBeAg-negative (low-infectivity) HBV patients, thymosin lowered the liver enzyme ALT and increased the rate of HBV DNA clearance (Yang 2008). It is better tolerated than IFN-α. While treatment with Tα1 alone does not appear to be superior to current HBV therapies (Grimm 2011), it may enhance the effectiveness of antivirals and IFN when used as a combination therapy (Mao 2011; Zhang 2009), especially in difficult-to-treat HBeAg-positive patients. Tα1 is approved for use as a hepatitis B treatment in 30 countries, but is not yet available in the U.S. (SciClone 2012).


Prevention

Vaccination. The availability of HBV vaccine and anti-HBV antibodies has significantly lowered HBV infection rates throughout the world. The first HBV vaccine was introduced in 1982, along with official recommendations for its use in high-risk groups (Rich 2003). Recommendations for childhood (CDC 1991) and adolescent (CDC 1996) vaccination programs were published within the decade. A synthetic version of the vaccine was introduced in 1986, replacing blood-derived versions of the vaccine (WHO 2009), and a thimerosal-free version has been available since 1999 (CDC 1999).

Immunization may be one way to prevent mother-to-child transmission of HBV. In an analysis of several trials of children born to infected mothers, immunization reduced likelihood of mother-to-child transfer by 72% (Lee 2006). This protective effect decreased significantly when the initial dose of vaccine was delayed more than 7 days following birth (Marion 1994, WHO 2009).

As mentioned above, rates of vaccination are relatively low among high-risk populations in the U.S. (Ladak 2012). Healthcare workers at risk of HBV infection are recommended to receive the vaccine. However, in a study of matriculating healthcare students at U.S. University, only about 60% had been vaccinated (Tohme 2011).


Nutritional Strategies for Hepatitis B

Although research on specific nutritional strategies for HBV infection is not as broad as for HCV infection, evidence suggests that natural compounds can be of benefit for both conditions (See the Hepatitis C protocol for more information).

Selenium. Selenium is an essential trace element with protective roles in the defense against free radicals, liver detoxification reactions, and immunity (Rauf 2012). Chronic hepatitis patients (as well as those infected with hepatitis C virus) tend to be selenium deficient compared to their uninfected counterparts. The degree of deficiency relates to the severity of HBV infection (in one study, selenium levels dropped by 50% in HBV-infected men) (Khan 2012).

Adequate selenium may also be associated with less liver damage in HBV-infected patients (Abediankenari 2011). It is suggested that HBV and HCV patients be tested for selenium adequacy and supplemented if deficient (Khan 2012). Long-term selenium treatment reduced HBV infection by 77% and liver lesions by over 75% in an animal model. In an 8-year trial, treatment reduced the incidence of liver cancer in HBV patients by 35% (Yu 1997).

Coffee and related compounds. Evidence from several European and Japanese studies suggests coffee consumption is associated with reduced risk of liver cancer in. Heavy coffee consumption (defined in the studies as over 3 cups daily by Europeans, or over 1 cup daily by Japanese) reduced hepatocellular carcinoma (HCC) risk by an average of 55% over 10 observational studies (Bravi 2007; Larsson 2007). Moderate coffee consumption (4 or more cups weekly) in HBV carriers reduced hepatocellular cancer incidence by almost 60% in a separate study (Leung 2011).

Chlorogenic acid, a compound isolated from coffee, was shown to inhibit HBV viral replication in
isolated liver cells, and reduce blood levels of HBV in an animal model. Its efficacy was comparable to the nucleoside analog lamivudine (Wang 2009a). Special coffee roasting procedures can retain chlorogenic acid, which is normally depleted by Dian roasting procedures. Chlorogenic acid is also supplied by green coffee extract supplements.

Green tea. Green tea and its major antioxidant component epigallocatechin gallate (EGCG) reduce the levels of HBV DNA and hepatitis B antigens in isolated liver cells by inhibiting the replication of HBV DNA (Xu 2008; He 2011). A study of 204 HCC cases in Chinese individuals with HBV infection revealed that green tea consumption reduced the risk of cancer progression by nearly half (Li 2011). But a Japanese study of 110 cases of HCC could not determine any effect of green tea consumption on cancer risk (Inoue 2009).

Zinc. Zinc, which is found in various enzymes, has a role in immunoregulation (Balamtekin 2010). Clearance of viral infection requires the activity of T-cells, which are highly dependent on zinc (Kuloğlu 2011). Levels of zinc (as well as molybdenum, manganese, and selenium) are reduced in HBV-infected children compared to healthy subjects (Balamtekin 2010).

Low serum zinc is associated with elevated blood levels of liver enzymes (aspartate aminotransferase and alanine aminotransferase; markers of liver damage) in adults (Abediankenari 2011). In one study, children with higher serum zinc levels had a better response to interferon (IFN) therapy (Ozbal 2002). In another study, the response to combination therapy of zinc and IFN-α in HBV infection was not significantly different than IFN-α alone. However, researchers speculate that the lack of response may have been due to the low dose of zinc administered (7.5 – 10 mg) (Kuloğlu 2011).

Lactoferrin. Lactoferrin is an antimicrobial protein with inhibitory activity against several viruses, possibly through interactions with host cells or direct binding to the invading virus. The antiviral activity of lactoferrin (a major protein in milk) may partially explain the low incidence of mother-to-child transfer of HBV through breastfeeding in humans (Petrova 2010). Isolated human liver cells pre-treated with bovine or human lactoferrin were resistant to HBV infection (Hara 2002). Bovine lactoferrin, as well as zinc- and iron-saturated lactoferrin, inhibited HBV replication in infected human liver cells in culture (Li 2009).

Iron-sequestering compounds. High serum and hepatic iron have been associated with a reduced response to IFN treatment and increased risk of disease progression in chronic hepatitis B patients (Fiorino 2011). While their efficacy in HBV treatment has not been examined, several compounds have been shown to reduce iron absorption from the gut or chelate iron from cells or body fluids; these include several flavonoids (Mladěnka 2011), pectin (Monnier 1980), silybin from milk thistle (Borsari 2001) and curcumin (Thephinlap 2011). Lactoferrin (Brock 1980) and green tea (Mandel 2006) may also have iron-sequestering activity in addition to their anti-viral activity. More information is available in the Iron Overload Disorders protocol.

B Vitamins. Patients with chronic hepatitis B exhibit marked increases in oxidative stress and lipid peroxidation along with decreased antioxidant status (Duygu 2012). Vitamin B1 (thiamine) is required for the formation of dihydrolipoate, an important antioxidant and cofactor in iron metabolism, two functions with relevance to HBV disease mitigation.

A small study on Chinese children with chronic HBV demonstrated similar reductions in HBV DNA and hepatitis B e-antigen (HBeAg) between thiamine and standard IFN therapies. But a second study in the same population showed no effect of thiamine on HBV (Fiorino 2011).

Chronic HBV infection reduces levels of vitamins B2 (riboflavin) and B6 (pyridoxine) in red blood cells (Lin 2011). Supplementation with these vitamins may be helpful in HBV patients, although their effects on mitigating HBV disease are unknown (Lin 2011).

Vitamins C and E. Vitamin C and E stores are also reduced in chronic HBV patients (Tasdelen Fisgin 2012). Three small studies of vitamin E therapy in HBV-infected children and adults suggest a possible role for the antioxidant in the clearance of HBV DNA, adaptation of immune response to the viral antigen, and normalization of liver enzymes levels (Fiorino 2011).

Resveratrol. In an animal model of HBV-associated liver disease resveratrol reduced fatty changes in the liver and structural alterations of liver cells (such as degradation of mitochondria), raised cellular glutathione levels, and decreased reactive oxygen species. Additionally, resveratrol reduced incidence of HCC by 5-fold, and enhanced liver cell proliferation and liver regeneration (Lin 2012).

Curcumin. Curcumin reduces viral replication and expression of HBV genes in isolated human hepatocytes by inhibiting the activity of the metabolic regulator PGC-1α (Kim 2009; Rechtman 2010). PGC-1α, which is activated during starvation and turns on genes involved in glucose production, also increases the replication of HBV (Rechtman 2010).

N-acetyl-cysteine. N-acetyl-cysteine (NAC) is derived from L-cysteine, a conditionally essential amino acid. This powerful antioxidant diminishes free radicals and raises glutathione levels (Nguyen-Khac 2011). It reduces viral load in experimental models by disrupting the assembly of HBV virus particles (Weiss 1996).

The few studies of NAC in HBV patients have had mixed results. Dosages of 1200 to 8000 mg/day were able to raise glutathione levels in chronic HBV patients or lower levels of bilirubin (high bilirubin can indicate liver dysfunction), but did not significantly affect most other markers of liver function (Shohrati 2010; Wang 2008; Shi 2005).

Neither oral nor intravenous NAC significantly affected HBV viral load or time to patient recovery, although differences in dosages and small study populations may preclude any conclusions about NAC therapy for HBV (Gunduz 2003; Weidenbach 2003).

Phyllanthus. Phyllanthus, a genus of plant used to treat chronic liver disease in traditional Chinese and Indian medical systems, has demonstrated inhibition of HBV viral replication and antigen synthesis in isolated cells as well as in animal models (Cui 2010).

A review of several small clinical trials suggests some positive effects of Phyllanthus on parameters of HBV infection and significant reductions in serum HBV antigen. Several species of Phyllanthus were used in these trials; one of the most commonly used is Phyllanthus amarus at a dose of 600 to 1200 mg daily (Liu 2001).

Fifteen trials have investigated combinations of Phyllanthus and antiviral drugs (INF-α, lamivudine, adefovir dipivoxil, thymosin, vidarabine), and demonstrated significant improvements associated with combination therapy over antiviral drugs alone, such as reducing blood levels of HBV DNA & HBV antigen, and increasing immune response to HBV (Xia 2011).

Whey protein. In addition to its anabolic benefits, long-term supplementation with whey protein may increase antioxidant status and reduce markers of liver damage (Marshall 2004). An open label study of 8 chronic hepatitis B patients revealed that 12 grams twice daily of undenatured whey protein reduced alanine aminotransferase (ALT) activity in 6 of the patients and raised glutathione in 5 after 12 weeks of supplementation. Additionally, markers of lipid oxidation significantly decreased, while interleukin-2 levels and natural killer (NK) activity (both involved in immune response) significantly increased (Watanabe 2000).

Astragalus. Astragalus root has a history of traditional usage in Chinese medicine for immune and liver health. It inhibited secretion of HBV antigens from isolated human liver cells infected with the virus, and reduced levels of HBV DNA in a hepatitis B animal model (Wang 2009b).

A mixture of astragalus polysaccharide and another plant extract called emodin demonstrated significant reductions in HBV DNA and HBV antigens (HBsAg, HBeAg and HBcAg) in a hepatitis B mouse model (Dang 2009).

A Chinese study examined the effectiveness of astragalus and adjuvant compounds (Bupleurum chinenseSalviae miltiorrhizae, curcumin, peony and paeoniae) (116 grams daily as a tea) in 116 chronic HBV patients. Two months of treatment with the tea was clinically effective (defined as improvement in clinical symptoms -- fatigue, anorexia, abdominal distension, jaundice -- and partial or full recovery of liver function) in 91% of patients, compared to 70% of controls (who took a low-dose mixture of silibinin, oleanic acid, and the herb Yi-Gan-Ling) (Tang 2009).

Schizandra. Members of the genus Schizandra inhibited the secretion of virus antigens from isolated human liver cells by up to 76.5% in one experiment (Ma 2009a,b; Wu 2003). A Schizandra-containing herbal formulation reduced the production and secretion of HBsAg and HBeAg surface antigens (a measurement of virus particle secretion) from isolated liver cells, and reduced the growth of isolated hepatocellular carcinoma cells (Loo 2007).

In a Phase I trial, 23 volunteers with HBV infection took the herbal formulation daily for 10 weeks. The average number of monocytes (a type of circulating immune cell) in the blood decreased over the course of the study, which the authors suggested may lower self-inflicted host immune response and liver cell destruction (Yip 2007).

Milk Thistle. Milk thistle is a traditional liver tonic; the active compound in milk thistle (silymarin) has antioxidant and antifibrotic activity (Abenavoli 2010). Although it does not affect HBV viral replication, and has yet to demonstrate a significant effect on virus-related mortality in clinical trials (Rambaldi 2005), milk thistle may be beneficial in reducing the inflammation inherent to hepatitis that may precipitate complications such as cirrhosis or cancer (Abenavoli 2010).

Silibinin, a component of silymarin, slows the growth of isolated human hepatocellular carcinoma cells, and exhibits the strongest inhibition towards cancer cells positive for the hepatitis B virus (Varghese 2005). In an animal model of hepatitis B infection, silymarin prevented the progression of pre-cancerous lesions into hepatocellular carcinoma, but had no effect on existing cancer. Cancer developed in 80% of control animals (Wu 2008). A small trial in mixed hepatitis patients demonstrated that 480 mg silibinin daily for 7 days could significantly reduce aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltranspeptidase (GGT), and bilirubin, all markers of liver dysfunction (Buzzelli 1993).

Life Extension Suggestions



In addition, the following blood tests may be helpful:
Refer to the protocols on Cirrhosis and Liver Disease and Iron Overload Disorders for additional information relevant to hepatitis B.

Safety Caveats


Zinc
  • Supplemental zinc can inhibit the absorption and availability of copper.
  • If more than 50 mg of supplemental zinc is taken daily, 2 mg of supplemental copper should also be taken to prevent deficiency.
  • Chronic ingestion of more than 100 mg of zinc daily may be toxic.
Curcumin
  • Do not take if you have gallbladder problems or gallstones.
  • If you are taking anti-coagulant or anti-platelet medications, or have a bleeding disorder, consult your healthcare provider before taking this product.
pyridoxine (Vitamin B6)
  • Some people have reported temporary symptoms of peripheral neuropathy (tingling, numbness sensation, decreased sensation to touch or balance difficulties) when taking vitamin B6 in doses above 300 mg daily, especially if the nutrient is taken without other B complex vitamins.
  • This vitamin should not be taken without co-ingestion of equivalent doses of other B-complex vitamins.
  • Consult your physician before taking this vitamin if you are taking levodopa (L-dopa).
Resveratrol
  • If you are taking anti-coagulant or anti-platelet medications, or have a bleeding disorder, consult your healthcare provider before taking this product.
N-acetyl-cysteine (NAC)
  • Those who supplement with NAC should drink six to eight glasses of water daily to prevent cysteine renal stones.
  • Cysteine renal stones are rare but do occur.
Astragalus membranaceus
  • Do not take this product if you have gallstones or a bile duct obstruction, or if you are allergic to ragweed, chrysanthemums, marigolds or daisies.
  • If you are pregnant or nursing, consult your health care professional before using any herbal product.
 http://www.lef.org/protocols/infections/hepatitis_b_01.htm#introduction


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Tuesday, 25 April 2017

Thoughts on superfoods (and antioxidants) – Part 2

Not all free radicals are bad, and in fact, they are actually critical to life – for example, phagocytes in the body’s immune system rely heavily on producing free radicals to destroy invading bacteria (pathogens).


Thoughts on superfoods (and antioxidants) – Part 2
Outcomes from hundreds of research papers on combating oxidative stress suggests strongly: Eat more vegetables – and then eat some more. Filepic


Read PART 1

Nitric oxide (NO) is used as an intercellular semaphore (or messenger) to modulate blood flow, thrombosis and neural activity – and NO is also used as a general defence mechanism to eliminate tumours and cells damaged by pathogens.
It also seems a low level of free radicals is needed to induce mitosis, the important process of cell division. Overall, the body depends on having a moderate level of free radicals to function properly.

Down with (some) antioxidants!

And interestingly, ingesting too many antioxidants can also be bad news. A small study on 40 people in Germany found that antioxidant supplements reduce some of the benefits of exercise, in particular the sensitivity of the body to insulin (which is usually a dividend of exercising).
A US trial of antioxidant supplements called the Beta-Carotene and Retinol Efficacy Trial (CARET) involving over 18,000 smokers (and people exposed to asbestos) had to be halted 21 months early in 1996 because subjects ingesting high doses of beta-carotene and Vitamin A had a very significant 28% increase in the incidence of lung cancers.
This confirmed the earlier findings of a Finnish study on over 29,000 smokers who developed an 18% increase in lung cancer rates after ingesting antioxidant supplements – the main culprit appears again to be beta-carotene.
This does not leave Vitamin E off the hook though. The Selenium and Vitamin E Cancer Prevention Trial (SELECT) conducted on over 35,000 men across the United States found a 17% increase in prostate cancer rates in men taking Vitamin E supplements – the interesting thing is that prostate cancer rates accelerated only after a year or more of taking Vitamin E supplements, so long-term exposure to certain supplements appears to be a possible factor.
To sum it up succinctly, one of the major (and terse) conclusions of the SELECT study is: “Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men.”

Now what?

So where does all this information leave us? Well, hopefully with a little less enthusiasm for overdosing on “superfoods” and especially antioxidant supplements – the evidence suggests that they won’t fix any major health issues induced by bad habits, and indeed might make things worse.

fried chicken
If you are inclined to smoke or binge daily on oily fried foods, you are simply very likely heading for chronic oxidative stress. Photo: Reuters
If, for example, you are inclined to smoke or pig out daily on oily fried foods, you are simply very likely heading for chronic Oxidative Stress (OS), and ingesting additionally some green tea or superfood supplement pills probably would not prevent faster ageing and OS-related diseases.
In short, some sanity in life choices and diet are the keys to a healthy (or at least, healthier) life.
Factors known to help the body counter OS are quite straightforward. Life choice factors include avoiding unnecessary poisonous compounds such as tobacco smoke, car fumes, air pollutants, insecticides, inorganic fertilisers, household chemicals, unnecessary skin or hair bleaching treatments, et cetera.
Basically, use some common sense and do not go around inhaling, coming in contact with or ingesting nasty environmental factors such as dirty air and icky chemicals.
Regarding diet, if you are fond of tasty but less healthy foods (perhaps even junk food), then a suggestion is to cut down on portion sizes and substitute the missing calories with some vegetables if possible.
The reason is outcomes from hundreds of research papers on combating OS suggests strongly: Eat more vegetables – and then eat some more.
Also, eat more fruits – any kind of fruit. The EU recommends eating five portions of different vegetables and fruits every day – and if you can, try to double that number as research at Imperial College has found significantly better health benefits from 10 different portions a day.
The reasons are not known – and it may be vegetables and fruits have as yet unidentified antioxidants or compounds which enhance the efficacy of the known antioxidants.

antioxidants and fried food
If you are fond of tasty but less healthy foods (perhaps even junk food), then a suggestion is to cut down on portion sizes and substitute the missing calories with some vegetables if possible. Photo: Reuters
There is as yet no definitive list of all antioxidants or antioxidant adjuvants found in food items – almost all research has been focused on the main known antioxidants.
As an example, polyphenols such as hydroxybenzoic acids, anthocyanins, flavonols, flavones, flavanones, isoflavones, hydroxycinnamic acids, monomeric flavanols, et cetera, have been identified in various fruits and quite a few have been found to be effective antioxidants.
So if you are really looking for superfoods, it would appear that they have always been around you – just go to your local market and eat as large a variety of vegetables and fruits as possible and this would seem to be the best superfood known to science at the moment.
I appreciate that such comments might sound glib to modern workers who cannot spare the time and effort to buy so many different foods – so a suggestion is to stock up on frozen vegetables and fruits, as even 2.5 portions a day confer some discernible benefits.
As a personal example, instead of a 300g steak, I might now order a 200g steak plus some broccoli and spinach sides. It actually makes meals tastier due to the variety and contrasts of the various foods.
And for meals at home, it is really easy to microwave up, for example, frozen peas and chopped carrots as complementary dishes. This way, the body gets helpful doses of natural antioxidants for very little effort.
Also, be aware of what you are REALLY ingesting. A pot marketed with pretty labels like “low-fat”, “added vitamins”, “no added …”, “free from …” actually does not mean much – read the nutritional panel on the packaging.
Then you might realise that only a few percent of a pot of “healthy” fruit compote is actually fruit with the rest made up of sugar, artificial flavours, stabilisers, preservatives and processed gunk. However, please note that this is not meant to be disparaging against all packaged foods.
In fairness, there are food suppliers who do make the effort to provide healthy convenience foods – it is a matter of identifying good suppliers who one can trust and reading the nutritional panels is a positive way to start.

Lessons

If you are one of those who believe in expensive pseudoscience stuff like emu oil, goat milk whey, fermented cod liver oil, et cetera, I have only one question: Why?
Homo sapiens have never needed the stuff for over a million years and people living in the small region of Acciaroli, Italy (where between 10 to 15% of the population is over a hundred years old), have never heard of them either and would probably laugh at the idea of ingesting these products.

fried food
A man eats a piece of a fried chicken at a pub in Seoul, South Korea. Photo: Reuters
This incredulous reaction would be the same for most of the people of Japan, the country with the highest statistical probability of living to be 100 years old (according to the WHO).
So a good question would be: what do these old people eat? The answer appears to be, lots of stuff. Despite their wide geographical differences, they generally consume a broad range of local vegetables, legumes, fish, and in the case of the Acciarolians, fruits, olive oil, local game and rosemary.
The Acciarolians also apparently indulge in a lot of sex, an activity rather rewarding with the right partner but regrettably not so much so with the wrong companion – that is just a subjective hypothesis by the way.
What both populations have in common is that they both eat less red meat than average, seldom touch industrially-processed foods, and certainly they do not ingest any superfood supplements.
Studies into the pockets of the world where people live longer lifespans than average have not yet come up with any hugely significant conclusions – but a few plausible theories have arisen from the research.
One is that ageing is directly related to OS and providing the body with simple nutrients and natural antioxidants is sufficient to mitigate some of the effects of OS.
Another looked into the calorific intake of various old-age populations, in particular the Okinawans, who have the longest lifespans of all the Japanese – and it appears that they tend to ingest foods with fewer calories, less than 1 calorie for each gram of food (the Western average is over 50% higher).
It appears that some populations have suffered from severe famines in the past and their dietary patterns have adapted to historic periods of food scarcity – and the theory is that a calorie restricted diet can promote longevity (it is a long, complex hypothesis perhaps suited for another article when more validated evidence is available).
Another theory looked into the holistic aspects of living in various locations – a common factor is that old age populations tend to live in relatively stress-free environments and the good fortune of having a variety of nutritious foods available in their local diets may have augmented their lifespans.
Studies have also found that advantageous genetic adaptations of mitochondrial DNA may also promote longevity.
What has also been recognised is that recent lifestyle changes brought to Okinawa in the guise of American supermarkets and fast food chains have already decreased the lifespans of modern Okinawans – so it would seem that the added fats, sugars, salt and other components of modern diets is having a measurable, deleterious effect on longevity, at least in Okinawa.
However, to be objective, I have to caution that correlation does not mean causality (even though the same pattern has been observed in other communities) – and it could be that a modern lifestyle (with side effects such as pollution, stress, changes in working patterns, et cetera) might be having an adverse effect.

Binges and why I do them

My personal view is that food should be enjoyed, even to excess occasionally if necessary – it is simply a major part of enjoying life.
As such, I am likely to binge on really good food and wine perhaps two to three times a month – however, I also allow time for the body to recover by having lots of sensible food in between the benders.
Perhaps some “clean eating” purists would not approve but this is part of my approach to nutrition, having done some research in trying to understand the subject rather than behave like dietary despots who have more opinions than knowledge or sense.
As a little aside, on my recent return to the UK, I was compelled to eat at some fast food chains for convenience – and the result was not good, especially for the intestines.
A lot of modern fast food now reminds me of the prayers before mealtimes at the home of a very bad Catholic cook: “O Lord, for what we are to receive, may it pass through us peacefully. Amen.”
http://www.star2.com/food/food-news/2017/04/23/thoughts-on-superfoods-and-antioxidants-part-2/

Thursday, 2 February 2017

Why Vitamin Pills Don't Work, And May Be Bad For You

We dose up on antioxidants as if they are the elixir of life. At best, they are probably ineffective. At worse, they may just send you to an early grave.


For Linus Pauling, it all started to go wrong when he changed his breakfast routine. In 1964, at the age of 65, he started adding vitamin C to his orange juice in the morning. It was like adding sugar to Coca Cola, and he believed – wholeheartedly, sometimes vehemently  – that it was a good thing.
Before this, his breakfasts were nothing to write about. Just that they happened early every morning before going to work at California Institute of Technology, even on weekends. He was indefatigable, and his work was fruitful.
At the age of 30, for instance, he proposed a third fundamental way that atoms are held together in molecules, melding ideas from both chemistry and quantum mechanics. Twenty years later, his work into how proteins (the building blocks of all life) are structured helped Francis Crick and James Watson decode the structure of DNA (the code of said building blocks) in 1953. 
The next year, Pauling was awarded a Nobel Prize in Chemistry for his insights into how molecules are held together. As Nick Lane, a biochemist from University College London, writes in his 2001 book Oxygen, “Pauling… was a colossus of 20th Century science, whose work laid the foundations of modern chemistry.”
(Credit: Getty Images)
Linus Pauling was one of our most influential scientists, yet his belief in the power of antioxidants may have set us down a dangerous path (Credit: Getty Images)
But then came the vitamin C days. In his 1970 bestselling book, How To Live Longer and Feel Better, Pauling argued that such supplementation could cure the common cold. He consumed 18,000 milligrams (18 grams) of the stuff per day, 50 times the recommended daily allowance.
In the book’s second edition, he added flu to the list of easy fixes. When HIV spread in the US during the 1980s, he claimed that vitamin C could cure that, too.
In 1992, his ideas were featured on the cover of Time Magazine under the headline: “The Real Power of Vitamins”. They were touted as treatments for cardiovascular diseases, cataracts, and even cancer. “Even more provocative are glimmerings that vitamins can stave off the normal ravages of ageing,” the article claimed.
Sales in multivitamins and other dietary supplements boomed, as did Pauling’s fame.
But his academic reputation went the other way. Over the years, vitamin C, and many other dietary supplements, have found little backing from scientific study. In fact, with every spoonful of supplement he added to his orange juice, Pauling was more likely harming rather than helping his body. His ideas have not just proven to be wrong, but ultimately dangerous. 
(Credit: Getty Images)
Antioxidants were meant to delay the ravages of ageing, but there's little evidence that supplements bring any noticeable benefits (Credit: Getty Images)
Pauling was basing his theories on the fact that vitamin C is an antioxidant, a breed of molecules that includes vitamin E, beta-carotene, and folic acid. Their benefits are thought to arise from the fact that they neutralise highly reactive molecules called free-radicals.
In 1954, Rebeca Gerschman then at the University of Rochester, New York, first identified these molecules as a possible danger – ideas expanded upon by Denham Harman, from the Donner Laboratory of Medical Physics at UC Berkeley in 1956, who argued that free radicals can lead to cellular deterioration, disease and, ultimately, ageing.
Throughout the 20th Century, scientists steadily built on his ideas and they soon became widely accepted.
Here’s how it works. The process starts with mitochondria, those tiny combustion engines that sit within our cells. Inside their internal membranes food and oxygen are converted into water, carbon dioxide, and energy. This is respiration, a mechanism that fuels all complex life.
‘Leaky watermills’
But it isn’t so simple. In addition to food and oxygen, a continuous flow of negatively charged particles called electrons is also required. Like a subcellular stream downhill powering a series of watermills, this flow is maintained across  four proteins, each embedded in the internal membrane of the mitochondria, powering the production of the end product: energy.
This reaction fuels everything we do, but it is an imperfect process. There is some leakage of electrons from three of the cellular watermills, each able to react with oxygen molecules nearby. The result is a free radical, a radically reactive molecule with a free electron. 
Oxygen is the breath of life, but it also holds the potential to make us old, decrepit, and then dead
In order to regain stability, free radicals wreak havoc on the structures around them, ripping electrons from vital molecules such as DNA and proteins in order to balance its own charge. Although inconceivably small in scale, the production of free radicals, Harman and many others posited, would gradually take its toll on our entire bodies, causing mutations that can lead to ageing and age-related diseases such as cancer.
In short, oxygen is the breath of life, but it also holds the potential to make us old, decrepit, and then dead.
(Credit: Alamy)
Clinical trials are the only ways to reveal the effects of a drug - and investigations into antioxidants have produced some shocking results (Credit: Alamy)
Shortly after free radicals were linked to ageing and disease, they were seen as enemies that should be purged from our bodies. In 1972, for example, Harman wrote, “Decreasing [free radicals] in an organism might be expected to result in a decreased rate of biological degradation with an accompanying increase in the years of useful, healthy life. It is hoped that [this theory] will lead to fruitful experiments directed toward increasing the healthy human lifespan.” 
He was talking about antioxidants, molecules that accept electrons from free radicals thereby diffusing the threat. And the experiments he hoped for were sown, nurtured, and replicated over the next few decades. But they bore little fruit.
The results were the largely the same: an excess of antioxidants didn’t quell the ravages of ageing, nor stop the onset of disease
In the 1970s and into the 80s, for example, many mice – our go-to laboratory animal – were prescribed a variety of supplementary antioxidants in their diet or via an injection straight into the bloodstream. Some were even genetically modified so that the genes coding for certain antioxidants were more active than non-modified lab mice. 
Although different in method, the results were the largely the same: an excess of antioxidants didn’t quell the ravages of ageing, nor stop the onset of disease.
“They never really proved that they were extending lifespan, or improving it,” says Antonio Enriquez from the Spanish National Centre for Cardiovascular Research in Madrid. “Mice don’t care for [supplements] very much.”
(Credit: Alamy)
Far from protecting us from disease, one study found that vitamin supplements increased the incidence of lung cancer among smokers (Credit: Alamy)
What about humans? Unlike our smaller mammalian kin, scientists can’t take members of society into labs and monitor their health over their lifetime, while controlling for any extraneous factors that could bias the results at the end. But what they can do is set up long-term clinical trials.
The premise is pretty simple. First, find a group of people similar in age, location, and lifestyle. Second, split them into two subgroups. One half receives the supplement you’re interested in testing, while the other receives a blank – a sugar pill, a placebo. Third, and crucially to avoid unintentional bias, no one knows who was given which until after the trial; not even those administering the treatment. 
The incidence of lung cancer increased by 16% in the group given vitamin supplements
Known as a double-blind control trial, this is the gold standard of pharmaceutical research. Since the 1970s, there have been many trials like this trying to figure out what antioxidant supplementation does for our health and survival. The results are far from heartening.
In 1994, for example, one trial followed the lives of 29,133 Finish people in their 50s. All smoked, but only some were given beta-carotene supplements. Within this group, the incidence of lung cancer increased by 16%.
A similar result was found in postmenopausal women in the U.S. After 10 years of taking folic acid (a variety of B vitamin) every day their risk of breast cancer increased by 20% relative to those women who didn’t take the supplement. 
It gets worse. One study of more than 1,000 heavy smokers published in 1996 had to be terminated nearly two years early. After just four years of beta-carotene and vitamin A supplementation, there was a 28% increase in lung cancer rates and a 17% increase in those who died.
These aren’t trivial numbers. Compared to placebo, 20 more people were dying every year when taking these two supplements. Over the four years of the trial, that equates to 80 more deaths. As the authors wrote at the time, “The present findings provide ample grounds to discourage use of supplemental beta-carotene and the combination of beta-carotene and vitamin A.”
Fatal ideas
Of course, these notable studies don’t tell the full story. There are some studies that do show benefits of taking antioxidants, especially when the population sampled doesn’t have access to a healthy diet. 
But, according a review from 2012 that noted the conclusions of 27 clinical trials assessing the efficacy of a variety of antioxidants, the weight of evidence does not fall in its favour.
Just seven studies reported that supplementation led to some sort of health benefit from antioxidant supplements, including reduced risk of coronary heart disease and pancreatic cancer. Ten studies didn’t see any benefit at all – it was as if all patients were given the sugar pill also (but, of course, they weren’t). That left another 10 studies that found many patients to be in a measurably worse state after being administered antioxidants than before, including an increased incidence of diseases such as lung and breast cancer.
The idea that antioxidant supplements are a miracle cure is completely redundant – Antonio Enriquez
“The idea that antioxidant [supplementation] is a miracle cure is completely redundant,” says Enriquez. Linus Pauling was largely unaware of the fact that his own ideas could be fatal. In 1994, before the publication of many of the large-scale clinical trials, he died of prostate cancer. Vitamin C certainly wasn’t the cure-all that he cantankerously claimed it was up until his last breath. But did it contribute to a heightened risk? 
(Credit: Alamy)
Dosing up on vitamin C does not even help us fight the common cold (Credit: Alamy)
We’ll never know for sure. But given that multiple studies have linked excess antioxidants to cancer, it certainly isn’t out of the question. A study published in 2007 from the US National Cancer Institute, for instance, found that men that took multivitamins were twice as likely to die from prostate cancer compared to those who didn’t. And in 2011, a similar study on 35,533 healthy men found that vitamin E and selenium supplementation increased prostate cancer by 17%.
Ever since Harman proposed his great theory of free radicals and ageing, the neat separation of antioxidants and free radicals (oxidants) has been deteriorating. It has aged.
Antioxidant is only a name, not a fixed definition of nature. Take vitamin C, Pauling’s preferred supplement. At the correct dose, vitamin C neutralises highly charged free radicals by accepting their free electron. It’s a molecular martyr, taking the hit upon itself to protect the cellular neighbourhood. 
But by accepting an electron, the vitamin C becomes a free radical itself, able to damage cell membranes, proteins and DNA. As the food chemist William Porter wrote in 1993, “[vitamin C] is truly a two-headed Janus, a Dr Jekyll-Mr Hyde, an oxymoron of antioxidants.”
Thankfully, in normal circumstances, the enzyme vitamin C reductase can return vitamin C’s antioxidant persona. But what if there’s so much vitamin C that it simply can’t keep up with supply? Although such simplifying of complex biochemistry is in itself problematic, the clinical trials above provide some possible outcomes.  
Divide and conquer
Antioxidants have a dark side. And, with increasing evidence that free radicals themselves are essential for our health, even their good side isn’t always helpful.
Without free radicals, cells would continue to grow and divide uncontrollably
We now know that free radicals are often used as molecular messengers that send signals from one region of the cell to another. In this role, they have been shown to modulate when a cell grows, when it divides in two, and when it dies. At every stage of a cell’s life, free radicals are vital.
Without them, cells would continue to grow and divide uncontrollably. There’s a word for this: cancer.
We would also be more prone to infections from outside. When under stress from an unwanted bacterium or virus, free radicals are naturally produced in higher numbers, acting as silent klaxons to our immune system. In response, those cells at the vanguard of our immune defense – macrophages and lymphocytes – start to divide and scout out the problem. If it is a bacterium, they will engulf it like Pac-Man eating a blue ghost.
It is trapped, but it is not yet dead. To change that, free radicals are once again called into action. Inside the immune cell, they are used for what they are infamous for: to damage and to kill. The intruder is torn apart.
From start to finish, a healthy immune response depends on free radicals being there for us, within us. As geneticists Joao Pedro Magalhaes and George Church wrote in 2006: “In the same way that fire is dangerous and nonetheless humans learned how to use it, it now appears that cells evolved mechanisms to control and use [free radicals].”
Put another way, freeing ourselves of free radicals with antioxidants is not a good idea. “You would leave the body helpless against some infections,” says Enriquez.
(Credit: Getty Images)
Few would dispute that a balanced diet is essential for good health, but most of us don't need supplements to meet our nutritional needs (Credit: Getty Images)
Thankfully, your body has systems in place to keep a your inner biochemistry as stable as possible. For antioxidants, this generally involves filtering any excess out of the bloodstream into urine for disposal. “They go in the toilet,” says Cleva Villanueva from Instituto Politécnico Nacional, Mexico City, in an email.
“We’re very good at balancing things out so that the affect [of supplementation] is moderate whatever you do, which we should be grateful for,” says Lane. Our bodies have been selected to balance the risk of oxygen ever since the first microbes started to breathe this toxic gas. We can’t change billions of years of evolution with a simple pill.
No one would deny that vitamin C is vital to a healthy lifestyle, as are all antioxidants, but unless you are following doctor's orders, these supplements are rarely going to be the answer for a longer life when a healthy diet is also an option. “Administration of antioxidants is justified only when it is evident that there is a real deficiency of a specific antioxidant,” says Villanueva. “The best option is to get antioxidants from food because it contains a mixture of antioxidants that work together.”
“Diets rich in fruits and vegetables have been shown generally to be good for you,” says Lane. “Not invariably, but generally that’s agreed to be the case.” Although often attributed to antioxidants, the benefits of such a diet, he says, might also hail from a healthy balance of pro-oxidants and other compounds whose roles aren’t yet fully understood.
After decades of unlocking the baroque biochemistry of free radicals and antioxidants, hundreds of thousands of volunteers, and millions of pounds spent on clinical trials, the best conclusion that 21st Century science has to offer is also found within a child’s classroom – eat your five-a-day.

http://www.bbc.com/future/story/20161208-why-vitamin-supplements-could-kill-you