A superfood to 'keep death away'

Japan's most polarising superfood?

The Japanese have long hailed natto as a superfood – but its ammonia-like smell and mucus-like consistency make the fermented soybean dish a turnoff for many.

BBC Future

• By Erika Hobart

28 July 2020

Every day without fail, my 65-year-old mother prepares a dish that many people would say looks, smells and tastes revolting.

Nattō is very stinky. You definitely notice the smell.

Nattō is a traditional Japanese food made from fermented soybeans. It has an ammonia-like smell and mucus-like consistency that makes it polarising, even among people who grow up with it. A 2017 survey by Nifty, a Japanese internet service provider, found that only about 62% of Japanese people actually enjoy nattō. It also revealed that 13% actively dislike the taste. Regardless, many eat it anyway because of the health benefits.

Nattō is a fermented soy-based food that’s often served with spring onion and raw egg (Credit: Hungryworks/Getty Images)

“Nattō is very stinky. You definitely notice the smell,” said Yuki Gomi, a Japanese chef who runs the cooking school Yuki’s Kitchen in London. “But I always have it in my fridge.” She says it’s a staple in her home, the same way that cheese and yoghurt is readily available in many Western households.

The Japanese have long hailed nattō as a superfood and believe that consumption is linked to improved blood flow and reduced risk of stroke – factors that are particularly appealing in a country that is home to one of the world’s oldest populations. My mother often boasts that nattō keeps her blood “sara sara” (silky). Japanese news site SoraNews24 has gone as far as to declare that "a pack of natto a day keeps the death away”. Hitoshi Shirakawa, professor of nutrition and food science at Tohoku University's Graduate School of Agricultural Science in Sendai, muses this is “probably true”.

He cites a long-term study published in the British Medical Journal earlier this year: researchers at the National Cancer Center in Tokyo found that men and women who ate fermented soy-based foods like nattō on a daily basis reduced their risk of dying from a stroke or heart attack by 10%. 

Japan is one of the world’s most elderly societies, with senior citizens accounting for more than 28% of the nation’s population (Credit: bee32/Getty Images)

“Fermented soybean foods are less likely to lose [nutritional] components during processing, which is considered to be one of the reasons for the clear association between nattō consumption and [a reduced] risk of cardiovascular diseases,” Shirakawa said. Those nutritional components include plenty of protein, iron and dietary fibre, which have positive effects on blood pressure and weight.

Nattō might even help people feel and look younger. One serving (roughly 40-50g) has the same levels of vitamin K as the daily requirement set by the Japanese government and may help prevent osteoporosis. Nattō is also packed with vitamin B6 and vitamin E, which Shirakawa says boosts cell turnover and slows skin aging.

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But fermented soybeans were an integral part of the Japanese diet long before its nutritional benefits were understood. Dr Samuel Yamashita, professor of Japanese history at Pomona College in Claremont, California, says the food was first introduced to Japan from China during the Nara period (710-784AD).

“The historical record in Japan suggests that although nattō was introduced in the 700s, it became popular among both aristocrats and warriors in the Kamakura period (1192-1333) and became important, together with tofu, in the Buddhist-inspired vegetarian cuisine that emerged in the succeeding Muromachi period (1338-1573),” he said.

A set of nattō typically contains three small polystyrene foam containers, each with a single serve of the fermented soybeans (Credit: Yankane/Getty Images)

Yamashita says nattō evolved into a staple in the Japanese diet by the Edo period (1603-1867), when it appeared in cookbooks and started being prepared in the home. Soybeans were soaked in water, boiled or steamed, then blended with the bacterium Bacillus subtilis. They were then wrapped in straw and left to ferment for about a day, depending on the season and temperature.

When you add nattō to your recipes, it manages to add both rich and mellow notes to the food

Today nattō involves far less preparation and is available in convenience stores and supermarkets throughout Japan. A set of nattō, typically containing three small polystyrene foam containers, costs about 100 to 300 yen (£0.75 to £2.25). Each container has a single serving of nattō and tiny packets of tare (a soy sauce blend) and karashi (hot mustard).

To prepare nattō, you simply stir the three items and then pour the sticky concoction over a bowl of steamed white rice. Other ingredients commonly used to spruce up the dish are chopped negi (spring onions) and raw egg. When you lift your chopsticks to eat the end result, each bite is trailed by sticky strings.

Nattō is commonly available in convenience stores and supermarkets throughout Japan (Credit: Recep-bg/Getty Images)

In Japan, it’s most common to eat nattō for breakfast. My mother isn’t particularly fond of the taste, but consumes a bowl each morning, solely for its nutritional benefits. Akemi Fukuta, a jewellery salesperson in Tokyo’s Ginza district, says she eats it several times a week because she finds it both healthy and delicious. Gomi likes to make nattō for her four-year-old daughter’s dinner and says it’s a godsend for busy mothers.

Some people, like Mayuko Suzuki, have an entirely different level of appreciation for the simple dish. She eats nattō two to three times a day and has made a career out of being a “nattō influencer”. Known on YouTube and Instagram as Nattō Musume (Nattō Girl), Suzuki promotes restaurants serving unusual nattō-inspired dishes and shares her own recipes containing the slimy soybeans. She regularly shares photos of dubious combinations like nattō pasta, nattō pizza and even nattō gelato.

“I like the unique taste that the fermentation brings,” she explained. “When you add nattō to your recipes, it manages to add both rich and mellow notes to the food.”

Nattō’s sticky, slimy texture is a natural result of the fermentation process (Credit: Kuppa_rock/Getty Images)

Given her enthusiasm, it’s no surprise that Suzuki has made three visits to Sendai-ya, an all-you-can-eat nattō restaurant in Tokyo. For about 900 yen (£6.75), customers can devour several variations on the dish, including edamame nattō, goma (sesame) nattō and wakame (seaweed) nattō. The business also sells an unlikely dessert: nattō doughnuts.

Sendai-ya president Itō Hidefumi is the third generation of his family to take over the business, which was established in the Yamanashi prefecture in 1961. He says Sendai-ya expanded to Japan’s capital as a response to customer demand. There are also several vending machines containing Sendai-ya’s nattō products in the city.

"It’s very rewarding to take over a family business that provides people with such a healthy product,” he said.

Despite its reputation as a superfood, however, nattō has failed to gain popularity outside of Japan. It has, however, attracted enough attention to end up in the Disgusting Food Museum in Malmö, Sweden.

Variations on the dish include natto sushi and even natto doughnuts (Credit: Ma-no/Getty Images)

“The two things that most people find problematic with nattō are the sliminess and the smell,” said museum director Andreas Ahrens. “It does contain bacteria that’s also found in dirt, so it has that earthy kind of smell to it.”

What we find disgusting and delicious is very cultural

The Disgusting Food Museum features nattō alongside dishes like cuy (roasted guinea pigs from Peru) and casu marzu (maggot-infested cheese from Sardinia). The exhibit also includes American snacks like Pop-Tarts and Twinkies.

“What we find disgusting and delicious is very cultural,” Ahrens said. “It all depends on what we grew up with and what we are conditioned to like. Something like nattō is a very good example of that.”

Gomi understands that sentiment all too well. She remembers being hesitant to include a recipe for nattō maki (sushi rolls) in her 2013 book Sushi at Home: The Beginner’s Guide to Perfect, Simple Sushi. “I was scared that people wouldn’t like such stinky stuff. I was almost embarrassed,” she admitted.

Traditionally, the steamed soybeans were wrapped in rice straw to initiate the fermentation process (Credit: KPS/Getty Images)

But Gomi says that she’s since seen an uptick in students who come to her cooking classes and want to know more about nattō.

“More people are traveling to Japan and staying in ryokan (traditional Japanese inns) that serve nattō for breakfast,” she said. “They come back and tell me they had some strange, sticky stuff… some of them hate it. I don’t blame them. But some of them say they quite like it and want to know where they can buy it.”

Gomi says it makes her hopeful that her non-Japanese peers will come to appreciate nattō as much as she does.

“I'd love to see it more widely available in places like a farmer's market,” she said. “There is certainly a trend towards fermented food [and drink], such as kimchi, kefir and kombucha. It feels like nattō’s time is just around the corner.”

BBC Travel’s Well World is a global take on wellness that explores different ways that cultures the world over strive for a healthy lifestyle.

http://www.bbc.com/travel/story/20200727-japans-most-polarising-superfood

Is Soy Good or Bad for Your Health?

Soy or soybeans are a legume native to Asia and for thousands of years have been included in Asian diets with evidence showing soybeans were grown as far back as 9,000 BC in China reports Melissa Hargroves a Registered Dietition for HealthLine.

Posted by Elaine Iseri on Nov 28th, 2018 // Comments off

As a legume, soy is a plant based protein and is widely consumed for that purpose and many processed foods have it as an ingredient.

Although it’s a popular food, there are many controversies surrounding it as to its benefits — is it healthy or bad for you? There are arguments for both sides.

Melissa lists the different types of soy.

Whole soy products include the whole soybean or edamame (immature, green soybeans) which are a favorite high-protein appetizer. Whole soybeans are used to make soy milk and tofu as well.

For people who wish to avoid milk, soy milk is a good substitute.

Tofu is great for vegetarian diets as it provides a good source of plant-based protein.

Fermented soy products are made using traditional methods. They include soy sauce, tempeh, miso and natto.

Soy sauce is a liquid condiment used to flavor or marinate foods. Tempeh is a source of protein used in vegetarian diets like tofu though not as popular. Miso is a traditional paste used to season soups and other dishes.

Soy-based processed foods include vegan meat substitutes, yogurts and cheeses, as well as soy flour, texturized vegetable protein and soybean oil and all are use in many packaged foods.

Soy supplements such as soy protein isolate is a highly processed derivative of soy and made into a protein powder and used in protein bars and shakes. Other soy supplements are available in capsule form such as soy isoflavones and soy lecithin.

The Benefits of soy are that they are high in nutritional content of protein, fat, fiber, 9 vitamins, 7 minerals, prebiotic fiber, and beneficial phytochemicals, all beneficial for the proper function of the human body.

Studies have shown other soy benefits such as lowering of bad cholesterol, improving fertility outcomes, protecting effect against BPA (a chemical found in plastic), and reducing menopause symptoms.

Negative effects of soy have been found in animal studies on the possible effect on breast cancer, on thyroid function and on male hormones, however human studies suggest otherwise.

Also 90% of soy grown in the US is genetically modified and there’s a lot of debate on the safety of GMO soy affecting increase risk of cancer and birth defects. So eat organic soy if you want to avoid GMOs.

Overall, studies have shown that the benefits of soy in the diet outweigh any potential risks, so eat whole or fermented soy foods in moderation.

https://www.modernreaders.com/news/2018/11/28/is-soy-good-or-bad-for-your-health.html

Five Common Mistakes That Steal Testosterone

It’s one of the first—and most upsetting—casualties of aging… Testosterone levels start to drop as men get older. And it doesn’t wait until retirement. It can start as early as your 30s.

INH ResearchOctober 3, 2014

But age isn’t the only threat. There are some common—and sneaky—factors that drain this hormone from you no matter how old you are.

Here are five common mistakes that steal testosterone:

1. Going Low-Fat: You know all the myths about eating fat… But heart health and a slim waistline aren’t the only reasons to add more of it to each meal. Research shows that it only takes six weeks of reducing fat intake to lower your testosterone levels. Just dropping from 40% to 25% fat a day means around 15% less T.

So if you have been one of the millions of people in the U.S. afraid to touch fat, your testosterone levels could be suffering. Try adding avocados, coconut oil, and grass-fed butter to your meals. These clean fats will help set the table for healthy, natural production.

2. Skipping Sleep: It isn’t always easy to get a good night’s sleep… But if it’s happening more than a night or two a week, it could put your hormones in jeopardy. Just one full week of getting five or less hours of sleep each night can drop T levels by up to 15%.1 And that’s only one week. If you’re making a habit of burning the midnight oil—or have sleep problems you need to address—the damage could be even worse over time. Trying natural sleep aids will help you fall asleep easier—and keep your testosterone levels from sinking.

3. Drinking Too Much Alcohol: A glass of red wine with dinner can be good for your heart and help boost your health. But if you’re having more than two drinks a day, you’re helping your body convert testosterone into estrogen.2 That’s the female sex hormone. It’s true that men need this hormone in small amounts… But when it comes from sacrificing testosterone, it can put out your fire fast.

If you’re a beer drinker, it only gets worse… The hops in beer are estrogenic. They may even help women avoid hot flashes during menopause.3 Your best bet is to limit your alcohol to a glass of wine. If you prefer to sip the hard stuff instead, limit it to a drink or two on the weekends. This helps prevent inflammation and spares testosterone.

4. Over-Exercising: Health Watch readers know that less is more when it comes to exercise. But spending less time in the gym—and turning up the intensity—doesn’t just help keep your heart in top shape. A study at the University of British Columbia found that long-distance runners had at least 20% less testosterone.4 But it’s not just about running less. It’s about greater intensity.

Another study reveals that high-intensity interval training causes bigger testosterone spikes after workouts that normal running.5 It may not be as easy as a jog… But high-intensity interval training (HIIT) can cut your gym time in half—and brings your T levels to where they need to be to fight aging.

5. Eating Soy: It not only lowers your sperm count,6 eating soy depletes your testosterone. It may even prevent your body from being able to make more of it over time. One study found that taking a soy protein supplement led to a 19% drop in serum levels of this hormone in only two weeks.7 But avoiding soy isn’t always easy. That’s because it’s a popular filler ingredient in processed foods. It’s a cheap way to help foods—especially powders—emulsify. That’s why many protein supplements contain soy even though it isn’t being used as a protein source. But even “healthy” foods aren’t immune. Most of the salad dressings you’ll find—even the organic ones—use soybean oil as their base. Always make sure to read the labels on the foods and health products you buy to avoid this testosterone killer.

You don’t need dangerous hormone therapy or an expensive doctor’s prescription to start reclaiming your youthful vigor. There are natural ways to do it. But you need to protect any gains you make. Fixing these simple mistakes is the first step to reigniting your fire—no matter how low the candle may be burning.

Testosterone levels decline about 1% a year after age 30. This is just one more symptom of what we call “Male Aging Syndrome.” Most men think problems like lack of energy or libido are a natural consequence of getting older… when it may actually be an easy to fix chemical imbalance! See the four ways you can break free of Male Aging Syndrome here.

References:
1http://www.uchospitals.edu/news/2011/20110531-sleep.html
2http://www.fammed.wisc.edu/sites/default/files//webfm-uploads/documents/outreach/im/handout_testosterone.pdf
3http://www.ncbi.nlm.nih.gov/pubmed/20167461
4http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1724199/
5http://www.ncbi.nlm.nih.gov/pubmed/23310924
6http://www.ncbi.nlm.nih.gov/pubmed/18650557
7http://cebp.aacrjournals.org/content/16/12/2796.full

https://www.institutefornaturalhealing.com/2014/10/five-common-mistakes-that-steal-testosterone/

Is soya bad for women's health?

Soy's isoflavones have oestrogenic properties — and have been blamed for raising the risk of breast cancer (as well as prostate cancer for men). But is this really the case?

• By Jessica Brown

19 August 2019

Consumed in many traditional Asian populations for millennia, soya has only been a common part of the Western diet for around 60 years. Now, many of our supermarkets are full of soy milk alternatives, soy burgers and other soya-based meat replacements – not to mention traditional soy-based products like tofu, tempeh, soya milk, miso and soya sauce.

In the meantime, soya has been linked to a lower risk of heart disease compared to other diets. As a good source of protein, unsaturated fatty acids, B vitamins, fibre, iron, calcium and zinc, it is becoming increasingly popular in the West as a healthy substitute for meat. But despite more people associating soya with health over the last decade, one fear has come to the fore: the idea that soya can disrupt our hormones.

The controversy around soya comes down to its uniquely high content of isoflavones. These compounds have oestrogenic properties, which means they act like oestrogen, the primary female sex hormone, and bind to oestrogen receptors in the body – and oestrogen can fuel the growth of some types of breast cancer.

But while scientists have extensively researched the compound’s effects in the body over the last few decades, the answer about whether isoflavones themselves can contribute to cancer risk isn’t straightforward.

And often, it seems soya protects against cancer risk – rather than making it worse. But exactly why that is isn’t certain.

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To start, there are the observational findings. High soya intake among women in Asian countries has been linked to their 30% lower risk of developing breast cancer compared to US women, who eat much less soya. (The average person’s intake of isoflavones in Japan, for example, is between 30 and 50mg, compared to less than 3mg in Europe and the US.)

High soya intake among women in Asian countries has been linked to their 30% lower risk of developing breast cancer (Credit: Getty Images)

 

Soya also has been correlated with reducing breast cancer’s severity. Fang Fang Zhang, associate professor at Tufts University in Massachusetts, carried out population research among 6,000 women with breast cancer living in the US and found a 21% reduction in mortality among those who consumed more soya. 

Population research among 6,000 women with breast cancer found a 21% reduction in mortality among those who consumed more soya

Its benefits were strongest in women with hormone-receptor-negative breast cancer, a more aggressive type of breast cancer where tumours lack oestrogen and progesterone receptors, and therefore doesn’t respond well to hormone therapies.

“Our findings suggest that, for women with hormone-receptor-negative breast cancer, soya food consumption may potentially have a beneficial effect to improve survival,” Zhang says.

Not soy easy

Even so, it’s difficult to conclusively isolate soya’s benefits – if there are any.

Soya is often consumed as part of a healthy diet and as a substitute for red meat, which is associated with a higher risk of heart disease and cancer.

Soya products often replace foods like red meat, which could be why soya intake is associated with healthier outcomes (Credit: Getty Images)

“No one has given people soya foods, then looked at whether they’re more or less likely to get breast cancer over time than those not given soya,” says Leena Hilakivi-Clarke, professor of oncology at Georgetown University School of Medicine in Washington DC.

One review of evidence into soya’s effect on breast cancer risk found that studies that adjusted for body mass index (BMI), a common marker of health, showed a weaker association for soya than those that didn’t.

This means a reduced risk of breast cancer could have been due to lower BMI, not to soya consumption.

If soya does lower breast cancer risk, it may be because its isoflavones can enhance apoptosis: a genetically programmed mechanism that tells cells to self-destruct when they get DNA damage they’re not able to repair. Without this process, damaged cells can form into cancer.

If products like soya milk lower breast cancer risk, it may be by bolstering the mechanism that tells cells to self-destruct when they get DNA damage (Credit: Getty Images)

 

So where did the concern that soya causes cancer come from?

It’s true that soya has been found to fuel the growth cancer cells in lab research. In one experiment from 2001, mice with inhibited immune systems and with cancerous tumours were fed isoflavones. Their tumours were measured for 11 weeks. The researchers found that the isoflavones resulted in increased cell growth. The mice were then switched to an isoflavone-free diet – and their tumours regressed over the following nine weeks. Meanwhile, in a study from 1999, researchers implanted human breast cancer cells into mice, and some were fed isoflavones. They also found that dietary isoflavones enhance the growth of cancerous tumours.

But a more recent, 2010 review of more than 100 studies concluded that, overall, lab experiments have shown no significant increased risk of breast cancer.

One reason there isn’t a more definitive answer is because isoflavone either acts like oestrogen in the body, or its opposite

One reason there isn’t a more definitive answer is because isoflavone either acts like oestrogen in the body, or its opposite. When we eat soya, isoflavone either binds to the alpha oestrogen receptor in the body, which stimulates a tumour’s growth rate, or the beta receptor, which decreases growth rate and induces apoptosis.

Isoflavone prefers to bind to beta receptors, says Bruce Trock, professor of epidemiology and oncology at Johns Hopkins School of Medicine in Maryland in the US. That makes it more likely to reduce potential cancer risk.

The impact of soya on breast cancer risk may depend on when we start eating it.

Most studies on Asian populations included women who have eaten it since early childhood and were probably also exposed to it in the uterus, says Trock, compared to Western studies involving women who mostly didn’t eat soya until later in life. 

Starting to consume soya products at an earlier age may make soya more beneficial (Credit: Getty Images)

 

“Giving soya to animals at the equivalent of middle age doesn’t seem to reduce risk or growth rate of tumours,” he says.

“But if researchers feed mice [soy] prior to puberty, then expose them to carcinogens, they get fewer and smaller tumours than if you don’t give them soya.”

Soya cycle

Meanwhile, clinical and population data shows daily soya intake can halve the frequency and severity of hot flashes even when the placebo affect is taken into consideration, says Mindy Kurzer, professor of nutrition at the University of Minnesota. (Taking oestrogen medication, on the other hand, brings hot flushes down by 75%.)

Some research has found that these benefits are largely determined by a woman’s ability to produce equol, a bacteria that around 30 to 50 percent of adults produce in their intestines after eating soy. One study found that giving equol supplements to menopausal women who don’t produce it themselves significantly lowered the incidence and severity of hot flushes.  

It could be that a person’s ability to produce equol, rather than the equol itself, is responsible for the benefits of soya. One paper argues that Chinese populations, for example, may be better able to digest and extract nutrients from soya because their ancestors have been eating it for thousands of years.

This could explain why research has found that, while people who move from Asian countries to the US have an increased risk of breast cancer by the second generation, their risk remains lower than Westerners even when they adopt a Western diet.

Soya intake could reduce the risk of cardiovascular disease (Credit: Getty Images)

 

Early soya intake has also been found to reduce the risk of cardiovascular disease. In fact, population studies suggest isoflavone intake could be responsible for the different rates of cardiovascular disease between Asian and Western countries. This is because soya has been found to reduce levels of harmful low-density lipoprotein (LDL) cholesterol in the blood, which is a risk for heart disease.

But may have nothing to do with soya, per se – it could simply be because diets higher in soya are lower in unhealthier foods.

“Soya foods are normally eaten in place of other higher saturated fat foods, such as fatty meat and full-fat dairy products,” says JoAnn Pinkerton, professor of obstetrics and gynaecology at the University of Virginia Health System. “Whereas most soya foods are naturally low in saturated fat.” 

There are also concerns soya could be linked to prostate cancer. However, a review of evidence last year found that regular soya food intake was associated with an almost 30% reduction in risk of developing prostate cancer. Soya doesn’t affect testosterone levels in men, so how this happens isn’t yet known – except that a diet containing more soya is often healthier overall.

We maintain the current conclusion that soya is beneficial in preventing prostate cancer – Catherine Applegate

“Throughout the years and despite the constant emergence of new research that could contain potentially conflicting results, we maintain the current conclusion that soya is beneficial in preventing prostate cancer,” says the study’s author Catherine Applegate, a predoctoral fellow from  the University of Illinois's Tissue Microenvironment Training Program.

Unprocessed soya, like edamame beans, has higher isoflavone levels than processed versions, like soya milk (Credit: Getty Images)

 

Soya’s benefits also depend on the type we consume. Isoflavone content varies in unprocessed soybeans, such as edamame beans, compared to processed soya foods – and the closer the food is to the soyabean, the higher its isoflavone levels. Edamame has around 18mg of isoflavones per 100g, while soya milk has between 0.7 and 11mg.

“The only thing we can say is that women should be safe to consume soya foods in amounts consistent with Asian diet, including tofu, fermented soya foods and soymilk, but studies shown that the more soya is processed, the lower the level of isoflavones, which we think are protective elements,” says Trock.

Soya has been extensively researched over the last few decades. No single study has been perfect, and as with other nutritional research, findings often show correlation – they don’t prove causation.

Even so, the consensus clearly indicates health benefits from eating soya – even if that’s simply because it replaces unhealthier foods.

http://www.bbc.com/future/story/20190816-is-soy-bad-for-womens-health