Does the Mediterranean diet prevent heart attacks? NEJM retracts (and replaces) high-profile paper

The New England Journal of Medicine has retracted a 2013 paper that provided some proof that the Mediterranean diet can directly prevent heart attacks, stroke, and other cardiovascular problems.

The original paper, “Primary Prevention of Cardiovascular Disease with a Mediterranean Diet,” has been cited 1,759 times, according to Clarivate Analytics’ Web of Science.

But the findings haven’t disappeared — the authors have replaced the paper with a new version, which softens its earlier claims. 

To find out more about what happened — and who discovered the issues with the paper (someone whose name will be familiar to some of our readers) — read more in our story, our first for NPR’s Shots. (See article below:)

Source: https://retractionwatch.com/2018/06/13/does-the-mediterranean-diet-prevent-heart-attacks-nejm-retracts-and-replaces-high-profile-paper/

Errors Trigger Retraction Of Study On Mediterranean Diet's Heart Benefits

June 13, 2018  5:03 PM ET  ALISON MCCOOK

Flaws in a study of the Mediterranean diet led to a softening of its conclusions about
health benefits. But don't switch to a diet of cotton candy just yet. Westend61/Getty Images
Ask just about anybody, and you'll probably hear that a healthy diet is one full of fruits and vegetables, olive oil, nuts and fish — what's called Mediterranean diet. A lot of research has suggested people who eat this way tend to be healthier, but it's been harder to prove whether that is because of the diet or some other factor.

So in 2013, many took notice of a study in the New England Journal of Medicine that seemed to provide some proof. The study found that people eating the Mediterranean diet supplemented with olive oil were 30 percent less likely to experience a heart attack, stroke, or death from cardiovascular causes than people assigned to a low-fat diet. People who stuck with a Mediterranean diet supplemented with mixed nuts had a 28 percent lower risk than those asked to follow a low-fat diet.

The results got wide media attention, including from NPR.

But the New England Journal of Medicine retracted the paper Wednesday because of problems in the way the study was carried out.

A retraction is a last resort for medical and scientific journals, a sign to readers that the results are no longer trustworthy and are beyond correcting. Although retractions are relatively rare — taking down fewer than 1 in 1,000 published articles — the rate is increasing.

The authors of the NEJM paper are replacing the 2013 paper with a corrected version that shows people following the diet had a similarly reduced level of heart attacks and strokes. The major change is softer language about the conclusions.

The revised paper says only that people eating the Mediterranean diet had fewer strokes and heart attacks, not, as the original paper claimed, that the diet was the direct cause of those health benefits.

Of course, a change in one paper — even a high-profile one — doesn't mean that researchers have lost faith in the benefits of the Mediterranean diet. "I don't know anybody who would turn around from this and say, 'Now that this has been revealed, we should all eat cotton candy and turn away from the Mediterranean diet,' " says David Allison, dean of the School of Public Health at Indiana University in Bloomington.

Still, without the strong language touting the benefits of the diet in the original paper, "the legs have been kicked out from under it, in some sense," says Allison, a longtime nutrition researcher whose research has at times been partially funded by the food industry.

What prompted the Mediterranean diet researchers to soften their language?

A persistent British anesthesiologist named John Carlisle.

He knew very little about analyzing the details behind clinical trials until a few years ago, when he wrote a letter to an anesthesiology journal bemoaning the fact that his field was polluted by one researcher's data that many suspected were problematic. The journal editor told Carlisle, a practicing anesthesiologist at Torbay Hospital in Torquay, England, to prove it.

So Carlisle did. He read up on statistical methods and looked over more than 160 trials by the researcher, Dr. Yoshitaka Fujii, and analyzed how likely it was that the people had been randomized to different treatments. Randomization is part of the gold standard for clinical studies because it reduces the risk of bias and allows researchers to determine cause-effect relationships.

Carlisle found the odds were infinitesimally small that Fujii had randomized people properly. Since Carlisle's findings were published in 2012, medical journals have retracted more than 160 papers by Fujii — the most retractions for any one researcher, by a large margin, according to Retraction Watch.

Carlisle's analysis drew accolades — and added him to the ranks of a small but growing number of such sleuths. The success of the approach prompted Carlisle to expand his scope to include randomized trials from other researchers and in other fields.

After the Fujii paper, he spent two years applying the "Carlisle method" to thousands of clinical trials published in eight journals. In 2017, he reported that roughly 2 percent showed signs of problems.

Among the more than 5,000 trials Carlisle analyzed, 934 were published by the New England Journal of Medicine. He flagged 11. One was the 2013 study showing the Mediterranean diet was responsible for the reduced rates of heart attack and stroke.

Today, NEJM is replacing the 2013 study and correcting five others on different topics. The Mediterranean diet paper is being retracted because it turns out Carlisle was correct. When the lead author of the paper, Dr. Miguel Ángel Martínez González of the University of Navarra Medical School, saw Carlisle's analysis, he conducted a detailed audit of the study and quickly noticed some problems.

It turns out approximately 14 percent of the more than 7,400 study participants hadn't been assigned randomly to either the Mediterranean diet or a low-fat one. When couples joined the study together, both had been picked to follow the same diet. At one of the 11 participating study sites, the lead investigator had assigned the same diet to an entire village and didn't tell the rest of the investigators.

"This affected only a small part of the trial," says Martínez González. When the researchers reanalyzed the data excluding the nonrandomized people, the results were the same, he adds.

Still, because everybody wasn't randomly assigned to different groups, the study can no longer claim the diet directly caused those health benefits. "We need to tone down the results, but it is just a little bit," he says.

Many other studies have shown that people eating the Mediterranean diet have lower risks of various ailments, without claiming cause and effect.

But would the New England Journal of Medicine, one of the world's most selective and prestigious journals, have published the Mediterranean diet paper from Martínez González if the randomization issues and softened conclusion had been included in the first place?

"It is difficult to answer hypothetical questions," New England Journal of Medicine spokeswoman Jennifer Zeis says. "We believe the evidence [in favor of the diet] is still strong, but not as strong as a randomized study in which the randomization was executed flawlessly."

Carlisle praised the journal's response. "I think that the NEJM editorial team responded very maturely to my paper," he says. "They took the possibility of a problem seriously and acted quickly and thoroughly."

Alison McCook is the editor of Retraction Watch, a website that reports on scientific retractions and related issues. It is a project of The Center for Scientific Integrity, a nonprofit organization that has been funded by the John D. and Catherine T. MacArthur Foundation, the Laura and John Arnold Foundation and the Helmsley Charitable Trust.

This story is a partnership with Retraction Watch, which you can find on Twitter: @retractionwatch

Source: https://www.npr.org/sections/health-shots/2018/06/13/619619302/researchers-soften-claim-that-mediterranean-diet-prevents-heart-attacks?live=1

(npr = National Public Radio (NPR, stylized as npr) is an American privately and publicly funded non-profit membership media organization based in Washington, D.C. that was founded on a mission to create a more informed public.)

Extra-virgin olive oil prevents dementia by prompting the brain to clear out harmful debris

... reveal scientists as they hail 'exciting' breakthrough

• Oil is a key ingredient of a Mediterranean diet, which has many health benefits
• Study found olive oil prompts the brain to remove harmful clutter in the brain
• Olive oil reduces the amount of amyloid-beta plaques and neurofibrillary tangles
• These structures increase a person's likelihood of getting Alzheimer's disease

By Daisy Dunne For Mailonline

PUBLISHED: 13:30, 21 June 2017 | UPDATED: 21:57, 21 June 2017

Extra-virgin olive oil preserves memory and protects the brain against dementia, according to new research. 

The oil is a key ingredient of the Mediterranean diet, which is associated with a variety of health benefits, including a lower dementia risk.

Now scientists have discovered that olive oil reduces the risk of dementia by prompting the brain to clear out harmful debris.

Regularly eating olive oil can protect your memory and your ability to learn new things as you age, according to the new study.

The discovery has been hailed as an 'exciting' breakthrough in the battle against Alzheimer's disease.

+2

Extra-virgin olive oil preserves memory and protects the brain from dementia, research shows

How does olive oil protect against dementia?

Cosuming olive oil reduces the formation of harmful structures in the brain, including amyloid-beta plaques and neurofibrillary tangles.

Previous research has shown the presence of these structures in the brain increases a person's likelihood of getting Alzheimer's disease.

The researchers also identified the mechanisms underlying the protective effects of extra-virgin olive oil.

Lead researcher Professor Domenico Pratico, from Temple University in Pennsylvania, said: 'We found that olive oil reduces brain inflammation but most importantly activates a process known as autophagy.' 

Autophagy is the process by which cells break down and clear out unwanted debris left in the body.

Mice with induced Alzheimer's who were fed a diet of olive oil had higher levels of autophagy in the brain, according to researchers.

Professor Pratico said: 'Brain cells from mice fed diets enriched with extra-virgin olive oil had higher levels of autophagy and reduced levels of amyloid plaques and phosphorylated tau.' 

+2

Oil is a staple of the Mediterranean diet, which is associated with a variety of health benefits

Phosphorylated tau is responsible for neurofibrillary tangles, which are suspected of contributing to the poor memory of Alzheimer's patients.

Previous research has suggested that the widespread use of extra-virgin olive oil in the Mediterranean diet is key to its health benefits. 

Professor Pratico said: 'The thinking is that extra-virgin olive oil is better than fruits and vegetables alone, and as a monounsaturated vegetable fat it is healthier than saturated animal fats.'

How was the study conducted? 

To investigate the relationship between extra-virgin olive oil and dementia, Professor Pratico and his colleagues tested mice with induced Alzheimer's.

Known as a 'triple transgenic model', the animals developed three key characteristics of the disease: memory impairment, amyloid plagues and neurofibrillary tangles.

The researchers divided the animals into two groups, one that received a chow diet enriched with extra-virgin olive oil and one that received the regular chow diet without it.

The olive oil was introduced into the diet when the mice were six months old, before symptoms of Alzheimer's begin to emerge in the animal model.

At first, there was no difference between the two groups of animals.

But, at age nine months and 12 months, mice on the extra virgin olive oil-enriched diet performed 'significantly better' on tests designed to evaluate working memory, spatial memory, and learning abilities.

What did the study find? 

Studies of brain tissue from both groups of mice revealed dramatic differences in nerve cell appearance and function.

Professor Pratico said: 'One thing that stood out immediately was synaptic integrity.'

He said the integrity of the connections between neurons, known as synapses, were preserved in animals on the extra-virgin olive oil diet.

And, compared to mice on a regular diet, brain cells from animals in the olive oil group showed a 'dramatic' increase in nerve cell autophagy activation.

This was ultimately responsible for the reduction in levels of amyloid plaques and phosphorylated tau.

Professor Pratico said: 'This is an exciting finding for us.

'Thanks to the autophagy activation, memory and synaptic integrity were preserved, and the pathological effects in animals otherwise destined to develop Alzheimer's disease were significantly reduced.

'This is a very important discovery, since we suspect that a reduction in autophagy marks the beginning of Alzheimer's disease.' 

http://www.dailymail.co.uk/health/article-4625116/Extra-virgin-olive-oil-prevents-dementia-memory-loss.html

Why Aged Cheese and Mushrooms Are so Good for Your Heart (and Make You Live Longer Too)

Until recently, it's been vetoed by health experts, but could this forbidden food actually help you manage your health, improve cholesterol levels,...

May 08, 2017

Story at-a-glance-

• Polyamines such as spermidine, spermine and putrescine are derivatives of amino acids, found both in food and your gut microbiota, and are critical for cellular growth and survival
• Polyamines have potent anti-inflammatory activity, protect your DNA against free-radical damage and have been linked to longevity
• In one recent study, those who had the highest spermidine levels had a 40 percent lower risk of heart failure

By Dr. Mercola

Cheese can be an excellent source of nutrition, especially if made from unpasteurized grass fed milk and aged according to tradition. Among the many valuable nutrients in real cheese is vitamin K2, which is important for heart, brain and bone health. The highest amounts of vitamin K2 can be found in Gouda, Brie and Edam. Other cheeses with lesser but still significant levels of K2 include cheddar, Colby, hard goat cheese, Swiss and Gruyere.

Cheese also provides a cornucopia of other vitamins (including vitamins A, D, B2 and B12), minerals (including calcium, zinc and phosphorous), amino acids and protein, as well as high-quality saturated and omega-3 fats. In recent years, a number of studies have exonerated cheese (especially full-fat cheese), showing higher cheese consumption results in improved health and aids weight management. For example:

• High-fat cheese has been shown to raise your high-density lipoprotein (HDL) cholesterol,1,2 thought to be protective against metabolic diseases and heart disease
• Cheese consumption also helps prevent fatty liver and improves triglyceride and cholesterol levels3 — parameters used to gauge your cardiovascular disease risk
• Full-fat cheese can be useful for weight management,4 in part by ramping up your metabolism5
• Roquefort cheese in particular has been linked to cardiovascular health and improved longevity, courtesy of its anti-inflammatory properties6,7

Now, researchers have discovered yet another major compound in many cheeses that helps explain its beneficial impact on your health.

Polyamines in Cheese Linked to Longevity and Lower Disease Risk

Polyamines are derivatives of amino acids, found both in food and your gut microbiota, and are critical cellular growth and survival. Polyamines in turn contain chemicals such as spermidine and spermine (thus named as they were originally discovered in human semen) and putrescine. As noted by the Royal Society of Chemistry: 8

“Spermine derives from spermidine. And, spermidine, with the help of spermidine synthase, arises from another polyamine originally named for its role in rotting meat, called putrescine … [T]hese polyamines are the reason why sperm and, in the springtime, some species of trees, give off a spunky [odor] …”

Spermidine, spermine and putrescine all have potent anti-inflammatory activity, protect DNA against free-radical damage, and have been linked to longevity in animal studies — even when the animals were given the polyamines starting in middle age. As a group, polyamines are positively charged molecules that strongly interact with negatively charged molecules such as DNA, RNA and proteins. This is why they’re so important for cellular processes involving growth, division, differentiation and survival.

Spermine Protects Against Heart Disease

Studies have repeatedly demonstrated that when you increase levels of polyamines in an organism (including humans), cellular activity goes up and mortality goes down,9 in part by improving cardiovascular function and lowering blood pressure.10 In one recent study, which included 800 cheese-loving Italians, those who had the highest spermidine levels had a 40 percent lower risk of heart failure.11

In another,12 spermine was not only found to offer potent protection against heart disease in both animals and humans, it was even found to counteract the adverse effects of a high-salt diet in salt-sensitive mice:

“[O]ral supplementation of the natural polyamine spermidine extends the lifespan of mice and exerts cardioprotective effects, reducing cardiac hypertrophy and preserving diastolic function in old mice. Spermidine feeding enhanced cardiac autophagy, mitophagy and mitochondrial respiration, and it also improved the mechano-elastical properties of cardiomyocytes in vivo, coinciding with … suppressed subclinical inflammation …  

In Dahl salt-sensitive rats that were fed a high-salt diet, a model for hypertension-induced congestive heart failure, spermidine feeding reduced systemic blood pressure, increased titin phosphorylation and prevented cardiac hypertrophy and a decline in diastolic function, thus delaying the progression to heart failure.

In humans, high levels of dietary spermidine, as assessed from food questionnaires, correlated with reduced blood pressure and a lower incidence of cardiovascular disease. Our results suggest a new and feasible strategy for protection against cardiovascular disease.”

Polyamines Help Combat Visible Signs of Aging and Increase Lifespan

Previous research showed transgenic mice bred to not produce spermine and spermidine suffered hair loss, developed more skin wrinkles and died at an earlier age than normal mice,13 suggesting polyamines play an important role in combating both visible signs of aging and early death.

Importantly, polyamines encourage cellular autophagy,14,15 which has serious implications for longevity. Autophagy means "self-eating" and refers to the processes by which your body cleans out debris, including toxins, and recycles damaged cell components — processes that tend to decline with age.

Lifetime feeding studies using rodents have linked spermidine-rich diets to as much as a 25 percent increase in lifespan.16,17,18 In human terms, that equates to an average lifespan of 100 rather than 81.

Animals given spermidine at a later age gained about 10 percent in longevity, which can still amount to several years’ worth of life for a human. As noted by Leyuan Liu, Ph.D., assistant professor at the Texas A&M Institute of Biosciences and Technology's Center for Translational Cancer Research:19

"Only three interventions — severely cutting the number of calories consumed, restricting the amount of methionine (a type of amino acid found in meat and other proteins) in the diet and using the drug rapamycin — have been shown to truly prolong the lifespans of vertebrates, but eating less and not eating meat will not be welcomed by [the] general population, while rapamycin has shown to suppress the human immune system. Therefore, spermidine may be a better approach."

Aside from its general anti-aging influence, autophagy is also one of the mechanisms by which polyamines help protect against cancer (specifically liver cancer20,21) and Alzheimer’s disease.

Polyamines Correct Your Internal Body Clock

Interestingly, recent research22 has also shown that polyamines have the ability to restore your internal body clock, suggesting it might serve as a natural sleep aid. Improving sleep also helps lower your risk of chronic disease — including cancer and Alzheimer’s — and is important for longevity. According to the authors:

“Polyamines are … present in all living cells. Polyamine levels are maintained from the diet and de novo synthesis, and their decline with age is associated with various pathologies. Here we show that polyamine levels oscillate in a daily manner.

Both clock- and feeding-dependent mechanisms regulate the daily accumulation of key enzymes in polyamine biosynthesis … In turn, polyamines control the circadian period in cultured cells and animals by regulating the interaction between the core clock repressors PER2 and CRY1.

Importantly, we found that the decline in polyamine levels with age in mice is associated with a longer circadian period that can be reversed upon polyamine supplementation in the diet. Our findings suggest a crosstalk between circadian clocks and polyamine biosynthesis and open new possibilities for nutritional interventions against the decay in clock’s function with age.”

Fermentation Boosts Polyamine Content

Polyamines are found in many different foods, including the following (see listing below):23,24,25 As a general rule, fruits and cheese contain the highest levels of putrescine, vegetables have the highest levels of spermidine, and meat products have the most spermine.26 Research also shows polyamine levels are further increased through fermentation.

The Mediterranean diet, high in fresh vegetables and seafood, typically contains twice the amount of polyamines found in the average diet27 (which tends to be high in processed foods), and some scientists suggest the high polyamine content may be why the Mediterranean diet has such a positive influence on health and longevity.

Aged (fermented) cheese such as blue cheese, cheddar, Swiss, Brie, Gruyere, Manchego, Gouda and Parmesan28,29	Shell fish, including squid, oysters, crabs and scallops	Fermented foods such as sauerkraut and miso	Cruciferous veggies such as broccoli, cauliflower
Leafy greens	Pears	Mushrooms	Green peas
Wheat germ	Matcha green tea	Nuts and seeds, including hazelnuts, almonds, pistachios and peanuts	Chicken liver

Potential Contraindications

Some scientists and oncologists do warn that polyamine-rich diets may be contraindicated for those with psoriasis, as rapid skin cell regeneration may worsen the condition,30 and certain polyamine-sensitive cancers, such as prostate cancer. As noted in one study,31

“… [D]ifferences in biological [behavior] of prostatic (cancer) cells are associated with changes in polyamine levels and/or the activity of their metabolic enzymes. Faulty antizyme regulation of polyamine homoeostasis may play an important role in the growth and progression of prostatic carcinoma. Treatment of human prostate carcinoma cells with inhibitors of polyamine metabolic enzymes or polyamine analogues induces cell growth arrest or (apoptotic) cell death.”

Eat Real Food for Optimal Health

If you love cheese, there’s plenty of evidence to suggest real cheese is a boon to your health, and there’s no reason to avoid it for fear of its fat content. The healthy fats found in real cheese will neither pack on pounds nor contribute to heart disease. On the contrary, these fats will actually boost your weight loss success and lower your cardiovascular health risks.

One caveat is to make sure you’re eating real cheese. Natural cheese is a simple fermented dairy product made with just a few basic ingredients — milk, starter culture, salt and an enzyme called rennet. Salt is a crucial ingredient for flavor, ripening and preservation.

You can tell a natural cheese by its label, which will state the name of the cheese variety, such as “cheddar cheese,” “blue cheese” or “Brie.” Real cheese also requires refrigeration. Processed cheeses are typically pasteurized and otherwise adulterated with a variety of additives that detract from their nutritional value. The tipoff on the label is the word “pasteurized.”

A lengthier list of ingredients is another way to distinguish processed cheese from the real thing. Velveeta is one example, with additives like sodium phosphate, sodium citronate and various coloring agents. A final clue is that most processed cheeses do not require refrigeration. So, be it Velveeta, Cheese Whiz, squeeze cheese, spray cheese or some other imposter — these are not real cheeses and have no redeeming value.

Even if you don’t like cheese, there are plenty of other foods rich in polyamines, as you can see from the list above, with fermented foods and beverages having some of the highest levels. Following a Mediterranean-style diet is one way to ensure you’re getting plenty of these anti-inflammatory, anti-aging compounds.

http://articles.mercola.com/sites/articles/archive/2017/05/08/polyamines-cheese.aspx

Is Your Olive Oil Counterfeit?

Olive oil is a critical part of the Mediterranean diet. Higher consumption of extra virgin olive oil has been shown to reduce risk of all-cause mortality by 23%, cardiovascular events by 28%, and stroke incidence 40%. Startling findings reveal many brands are diluted with cheap omega-6 fats. These fats not only create health problems, but deprive consumers of beneficial polyphenols from pure extra virgin olive oil.

September 2016

By Michael Downey

 

The Mediterranean diet with its high content of olive oil is well-documented to reduce cardiovascular disease and overall mortality.1-3

Scientists have discovered a range of beneficial compounds naturally found in extra virgin olive oil, depending on the brand selected.

Recent research shows that olive oil’s potent effects are dependent not only on its monounsaturated fatty acids, but also on constituents known as polyphenols. Levels of polyphenols vary with the source and method of olive fruit processing.

Compared to other food oils (corn, cottonseed, safflower, etc.), olive oil is more expensive. This has created a situation whereby olive oil is being diluted with cheaper oils to generate greater profits at the expense of public health.

As we found when investigating this scandal, a large percentage of products labeled as “extra virgin olive oil” are not what consumers think and some are outright counterfeit.4-6

Fortunately, a source of extra virgin olive oil has emerged that is tested to deliver high polyphenols—and to have zero adulteration or mishandling.

Researchers continue to confirm that those who follow a Mediterranean diet have a longer life expectancy and a lower risk of heart disease, high blood pressure, and stroke.1-3

Olive oil has built a strong reputation for defending against diabetes, cancer, rheumatoid arthritis, and other diseases. Newly released studies demonstrate that incorporating olive oil into one’s daily diet may protect against other conditions such as Alzheimer’s, osteoporosis, and skin aging as well as premature death.7-14

A 2013 study found that these benefits are greater when extra virgin olive oil is substituted for regular olive oil.15 This study found that many of the beneficial effects of the Mediterranean diet can be ascribed largely to the quality of its extra virgin olive oil.7

Results from a 2015 study point to the superiority of extra virgin olive oil for cooking. A comparison of different cooking methods found that the use of extra virgin olive oil for cooking not only preserved the antioxidants found in vegetables, it also boosted their content.16

Extra virgin olive oil is a rich source of monounsaturated fatty acids, along with various polyphenol compounds such as oleocanthal, oleuropein, hydroxytyrosol, and tyrosol.7 These substances are believed to modulate nearly 100 human genes8 that favorably control cell signaling9 and age-associated processes.7

The health benefits of olive oil consumption vary widely, however, depending on the choice of product. Those not consuming the right type or amount of olive oil might not be getting much benefit at all.

This is due to two problems. First is that the overall polyphenol content of any olive oil is inconsistent among brands. Second, most olive oil products on the market have been shown to be seriously adulterated.

Let’s delve into each of these two issues, which are critical to understanding biological effects of this remarkable oil.

WHAT YOU NEED TO KNOW

The Benefits of Extra Virgin Olive Oil

• Scientists are finding varying cardiovascular benefits from extra virgin olive oil, depending on the brand tested.
• Olive oil’s potent effects have now been shown to be dependent on its levels of constituents known as polyphenols.
• Vast differences in polyphenol levels are due to extraction and handling differences, as well as to widespread adulteration of olive oil products. Up to 80% of oils sold in the US as extra virgin olive oil are adulterated.
• Fortunately, an extra virgin olive oil has been identified that is tested to be vastly superior in polyphenol content as well as 100% adulteration-free.

Polyphenol Levels are Critical

Originally, olive oil’s high content of monounsaturated fatty acids was credited with its health benefits. Abundant levels of one particular monounsaturated fatty acid known as oleic acid have been demonstrated to increase high-density lipoprotein (HDL) or “good” cholesterol and decrease low-density lipoprotein (LDL) or “bad” cholesterol.17

Scientists initially thought that if oleic acid were responsible for the bulk of olive oil’s cardiovascular and other health benefits, they would see the same benefits with oleic acid itself. But that is not what they found.18

Instead, an explosion of research strongly suggests that many of olive oil’s benefits are attributable to its polyphenols, which are compounds naturally occurring that inhibit oxidation and extend shelf-life. The presence of disease-fighting polyphenols in olive oil appears to explain why other monounsaturated-rich oils don’t come close to matching olive oil’s health benefits.19

Hydroxytyrosol is one of the polyphenols found in the highest amounts in olive oil—and it has been demonstrated to provide key cardiovascular benefits.20,21 This polyphenol and others that are abundant in extra virgin olive oil—including tyrosol and verbascoside—neutralize free radicals, lower blood pressure, and slow atherosclerosis.21 Over 30 different polyphenols (also called phenolics) are found in extra virgin olive oil, including lignans and the secoiridoids known as oleuropein and oleocanthal.21,22

A recent meta-analysis, including 32 studies and 841,211 subjects, clarified that the benefits of olive oil consumption far exceed the benefits of other rich sources of monounsaturated fatty acids—underscoring that olive oil’s beneficial effects derive from polyphenols.23

This meta-analysis showed that when evaluating olive oil separately, olive oil itself reduced the risk for all-cause mortality by 23%, cardiovascular events by 28%, and stroke incidence by 40%. Monounsaturated fatty acid intakes that came from a general mix of animal and plant origins did not reveal any significant risk reduction for all-cause mortality, cardiovascular events, or stroke.23

As University of California at Davis scientists reported regarding this meta-analysis, extra virgin olive oil “… is the only oil that is high both in monounsaturated fat and phenol content, and comparable health benefits would not be provided by other oils or foods.”24

As a result, it is now broadly recognized that the high polyphenol content of extra virgin olive oil (not its high monounsaturated fat content) is an important driver of its documented reduction in cardiovascular disease risk and other benefits.18,19,23

THE VASCULAR PROTECTIVE EFFECTS OF OLIVE OIL POLYPHENOLS

Recent focus on the link between extra virgin olive oil’s polyphenol content and its potent health effects has cast new light on its cardiovascular benefits—highlighting the critical impact of the polyphenols.

Higher-polyphenol olive oil shows a better ability to boost beneficial HDL cholesterol.26

A human crossover study provided the first direct evidence that high-polyphenol olive oil enhances HDL function. A three-week intake of 25 ml/d (about 1.7 tablespoons) of high-polyphenol olive oil produced a 3.05% increase in what is known as cholesterol efflux capacity, while a low-polyphenol olive oil produced only a 2.34% decrease.28 Cholesterol efflux capacity is a measure of how well HDL cholesterol removes bad cholesterol from white blood cells (macrophages) so that it can be eliminated from the body, reducing overall cholesterol.35 Another human trial revealed that olive oil polyphenols enhance the expression of genes that trigger this process.36

High-polyphenol olive oil was also shown to make HDL particles bigger, enhancing their ability to remove cholesterol from arterial plaque.28

A group of researchers found that 2 tablespoons of high-polyphenol olive oil daily for four months substantially improved endothelial function in adults with atherosclerosis.37 Endothelial dysfunction interferes with arteries’ ability to maintain healthy blood flow and normal blood pressure.38

In another human study, scientists determined that a higher polyphenol intake over one year, as a result of increased extra virgin olive oil consumption, decreased blood pressure in participating adults aged 55 to 80. Higher polyphenol intake, confirmed by increased urine polyphenol excretion, was linked directly to increases in plasma nitric oxide, which signals blood vessels to relax and thus lower blood pressure.39

Beyond cardiovascular effects, the polyphenols in extra virgin olive oil have been found to suppress cancer.40,41 For instance, the major extra virgin olive oil polyphenols have been shown to cause cells with the breast cancer-promoting gene HER2 to self-destruct.41

Although not specifically tied directly to polyphenols, olive oil also quells inflammation, protects stomach health, and inhibits other diseases—including Alzheimer’s and premature death.7-14

Olive Polyphenols Regulate Blood Lipids

The amount of cholesterol in one’s blood and its breakdown of “bad LDL” and “good HDL” remains a hallmark by which conventional authorities assess vascular disease risk.

Olive oil favorably modulates these blood lipid levels.

A flurry of studies reveals differences between higher-polyphenol and lower-polyphenol olive oils for a variety of cardiovascular markers. Olive oils richer in polyphenols were found to produce:

• Reduced LDL,25
• Improved LDL density,25
• Increased HDL,26,27
• Improved HDL function,28
• Reduced LDL oxidation,26,29 and
• Improved postprandial hemostatic (blood flow-inhibiting) profile to a less thrombogenic (clot-promoting) state.30,31

These favorable changes in blood markers of cardiovascular risk show the value of ingesting lots of olive oil polyphenols.

What’s been overlooked until recently is the variation in polyphenol content among olive oil products on the market. A key study that measured levels of one particular polyphenol demonstrated that some olive oil brands on the United States market provide five times as much of this polyphenol as some others.32

In response to data indicating the importance of olive oil polyphenols, a specific source of extra virgin olive oil has been identified that contains consistently high levels of total polyphenols.

We’ll return to this exciting and potentially life-saving oil later. But first, let’s examine the other hurdle when it comes to deriving olive oil’s full benefits—rampant product adulteration.

WHAT ARE POLYPHENOLS?

Polyphenols are naturally occurring compounds found largely in fruits, vegetables, tea, wine, and cocoa. They are secondary metabolites of plants, generally defending them against ultraviolet radiation or aggression by pathogens. More than 8,000 polyphenolic compounds have been identified in various plant species.42

The polyphenolic content of foods is greatly affected by environmental factors such as soil type, sun exposure, and rainfall. The degree of ripeness considerably affects the concentrations and proportions of polyphenols. A critical factor affecting polyphenol content of any food is storage time and type, which affects polyphenol oxidation. Exposure to light, heat, or air can destroy polyphenols.43

Polyphenols are anti-inflammatory and free-radical scavengers. Some have anticarcinogenic and cardioprotective effects. Polyphenols have beneficial effects on the endothelial lining of blood vessels by increasing the availability of nitric oxide and by preventing the lipid oxidation underlying atherosclerosis.

Numerous studies suggest that polyphenols from different plants may work synergistically to protect against cardiovascular disease, cancer, diabetes, endothelial dysfunction, osteoporosis, and neurodegenerative and other chronic diseases—without any known side effects.42

The typical Western diet lacks sufficient amounts and variety of plant polyphenols to be of optimal benefit.

Polyphenols give extra virgin olive oil its unique fresh-fruity and spicy-peppery taste and improve its shelf life, with some versions containing several times the polyphenols of others. So potent are these compounds that, cooking with extra virgin olive oil not only fully preserves the antioxidant value of the food, it also boosts the food’s antioxidant content.

Do you want to know what polyphenols “feel” like? Take a slow sip of extra virgin olive oil and wait for the sudden tingling at the extreme back of the throat. This is the tell-tale sign of an extra virgin olive oil that’s polyphenol-rich.

Olive Oil Adulteration is Widespread

The United States is the world’s third-largest consumer of olive oil, and standards for the top grade—“extra virgin”—have been established by the International Olive Council and United States Department of Agriculture (USDA).33

However, there are numerous ways to cheat, and enforcement is virtually nonexistent. An estimated 50% of extra virgin olive oil brands sold in Italy—and 75% to 80% of extra virgin olive oil brands sold in the United States—do not even meet the legal grades to be called extra virgin.6

The most common fraud involves diluting extra virgin olive oil with lower-quality oils from North Africa and other areas. Worse, many bottles labeled extra virgin olive oil contain almost no olive oil at all—just a seed oil such as sunflower, altered with chlorophyll and beta-carotene to convey the same appearance and fragrance.6 Some use an inert liquid fat as a base, adding just a little olive oil to pass it off as genuine. Others deodorize rancid oil using chemicals and heat, killing off its health properties.34

In addition to laboratory measured standards for “extra virgin,” the International Olive Council and USDA have established sensory standards—indicators that detect when oils are oxidized, low-quality, lacking characteristic fruity flavor, or adulterated with cheap, refined oils.33

Using these sensory tests, University of California at Davis scientists analyzed 186 extra virgin olive oil samples from several countries, all selected randomly from retail shelves in California. They found that 73%—imported and local—failed. The extent to which each failing brand failed its sensory tests ranged from 56% to 94%. The majority of samples tested exhibited one or more of the following:33

• Oxidation by exposure to high temperatures, light, or aging,
• Adulteration with cheaper, refined olive oil, or
• Poor quality from processing flaws, improper storage, or use of damaged and overripe olives.

Experts advise consumers to check for the authentic fresh-fruity and spicy-peppery tastes, but how can people be fully certain that they’re unleashing the potency of the real thing?

Fortunately, our scientific investigators have identified a source that surpasses the lab measurement and sensory standards of pure, fresh, extra virgin olive oil—while delivering polyphenols at the highest end of the scale!

COOKING AND STORAGE CONDITIONS FOR EXTRA VIRGIN OLIVE OIL

There is a great deal of confusion amongst consumers as to what is the best oil to cook with. In order to make the best decision, we need to discuss two things: first, smoke point, or the temperature at which an oil begins to break down, loses its taste and nutritional benefits and releases harmful chemicals, and second, the tendency to oxidize or go rancid.

There’s a general belief that regular olive oil isn’t an optimal oil for sautéing due to having a low smoke point. But high quality extra virgin olive oil has a high smoke point of 400ºF. If olive oil in general has gotten a bad rap for use in cooking, it’s probably because up to 80% of the oils sold in the US as extra virgin olive oil are counterfeit. Most people who think they’re using it are actually using inferior oils.

The low acidity of high quality extra virgin olive oil allows it to have a longer shelf life since it tends to oxidize more slowly.44,45 Even so, proper storage conditions are important in order to minimize oxidization. Accordingly, high quality extra virgin oil should be kept in a cool, dark place and in a dark bottle away from light, oxygen, and heat as these factors can reduce the nutritional value of the oil in the long run. Cooking with genuine, unadulterated high quality extra virgin olive oil presents no problem for general cooking.

High-Polyphenol, Adulteration-Free Olive Oil

Refining causes a reduction in the polyphenol content of olive oil. Extra virgin olive oil is less refined.

Even among authentic extra virgin olive oils, a host of factors interact to determine polyphenol content. These include olive variety, weather type, timing of harvest, promptness of pressing, pressing method, handling, distance to market, and storage.32

An investigation has found an olive oil brand that is both polyphenol-packed and completely pure and unadulterated, making it possible for Americans to derive the full health benefits of extra virgin olive oil.

This is especially critical in light of research reporting that it is the polyphenol content of olive oils that unleashes the full health benefits, including reduction in all-cause mortality.18,23,25-31

This California-derived extra virgin olive oil meets all conditions for purity. The olives are grown on a family farm, providing the Mediterranean-like climate needed for nutrient-rich olives while avoiding the long transit time involved in importing Mediterranean-derived oil. The non-GMO olives are harvested early in the season and handpicked to exclude leaves and avoid the bruising caused by mechanical harvesters. They are crushed within hours of harvest rather than days, and the resulting oil is then cold-extracted and not filtered, which preserves its raw qualities, after which it is stored in temperature-controlled stainless steel tanks until it’s poured into dark bottles to protect it from light.

NEW ANALYSIS HIGHLIGHTS THE CARDIAC DANGERS OF CORN OIL

Over thirty years ago, Life Extension® identified corn oil, which is loaded with the omega-6 fatty acid linoleic acid, as pro-inflammatory.

The journal The BMJ (formerly The British Medical Journal) published a recently rediscovered clinical data set from between 1968 and 1973, with a study population of more than 9,000 people.46

Control subjects were fed saturated-fat rich meals that included red meat, milk and cheese. The intervention group had most of their saturated fats replaced by corn oil rich in the pro-inflammatory omega-6 fatty acid linoleic acid. The goal of the analysis was to evaluate the theory that omega-6 rich corn oil would protect people against heart disease and lower their mortality. What the researchers found, however, was that the use of corn oil to replace saturated fats in the diet lowered cholesterol but increased the risk of death from heart disease.

This new analysis of old data validates what Life Extension pointed out over thirty years ago, when we warned the public to select vegetable oils with care in order to avoid the pro-inflammatory omega-6 fatty acids like linoleic acid found in corn oil and other high omega-6 vegetable oils.

Heart-healthy vegetable oils with low amounts omega-6 linoleic acid and low saturated fat are far better options than corn oil rich in omega-6 linoleic acid.47 Whenever possible, be sure to look for extra virgin, cold pressed in order to receive the full benefits of these healthy oils. For salad dressings, olive oil and flaxseed are reasonable options. Flaxseed oil should always be refrigerated, and should never be used for frying. For sautéing, olive oil is a far better choice than corn oil.48

• Extra virgin olive oil contains oleic acid and is rich in heart-healthy polyphenols including oleuropein, hydroxytyrosol, tyrosol, and verbascoside.17,20,21
• Avocado oil, rich in monounsaturated fatty acids, carotenoids, and phytosterols is a healthy option.49
• Flaxseed oil, high in healthy omega-3, alpha-linolenic acid is another healthy option.50

Summary

Olive oil’s beneficial effects are highly dependent on its polyphenols.

There are huge differences in polyphenol content of commercially sold olive oil brands. This can occur because of variable growing conditions and from extraction and handling differences.

Most troubling, however, is widespread adulteration. Studies show that between 75% and 80% of oils sold in the United States as “extra virgin olive oil” are adulterated or diluted.

A California grown extra virgin olive oil has been identified that is lab-tested to be superior in polyphenol content with no adulteration.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.

IMPACT ON BODY WEIGHT

A new study published in the journal Lancet Diabetes & Endocrinology lends further credence to the sterling reputation of extra virgin olive oil and its remarkable benefits for health and weight loss.51

In a randomized, controlled study, scientists analyzed the waist circumference and weight of 7,447 subjects who consumed three different diets over five years. They concluded that a Mediterranean diet, in which extra virgin olive oil is heavily featured, is more conducive to weight loss than low-fat diets. The findings held true for a variety of different groups, including those with type II diabetes, the elderly and people who are overweight or even obese.

Subjects were divided into three groups. One group had a Mediterranean diet featuring extra virgin olive oil, the second group had a Mediterranean diet that featured a mix of nuts, and the third group was instructed to simply avoid all fats. In the end, the olive oil group lost the most weight—an approximate two pounds, while the low-fat group averaged a 1.3-pound loss. The group that ate a Mediterranean diet with nuts lost an amount comparable to the low-fat group.

What may not be appreciated by this study is that adults tend to gain significant weight as they age. The fact that those who consumed the most extra virgin olive oil lost weight over a 5-year period makes it clear that olive oil is the type of fat to consume for those concerned about body weight.

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