General Wellness

Benefits of Soy

The topic of soy products and their impact on health is very hotly debated in the nutrition world. Some say it causes a variety of ailments including breast cancer, infertility, allergies, autoimmune issues and even “man boobs”. But these rumors are mostly nonsense. There is a lot of fear mongering and misinformation which I would like to clarify.

First of all, what is soy? Soybeans are in the legume family which also includes black beans, chickpeas and lentils. As a class of food, they are extremely healthy and are one of the staples of all the longest lived and healthiest populations in the world. In Asian countries, soybeans, in one form or another, have been consumed for thousands of years, having been domesticated around 3000 years ago. It’s been grown in the US since the 1700’s. Today, 95% of the soy grown in the US, and about 80% worldwide, is fed to animals. The majority of this is non-GMO and heavily pesticide laden. Remember that you are not just what you eat. You are also what you eat eats!

Soybeans are very nutritious with lots of vitamins and minerals as well as protein, fiber and plant compounds called phytochemicals. The most hotly discussed phytochemicals are isoflavones, which are also called phyto-estrogens. These are compounds which have a similar configuration to human estrogen and are blamed for causing breast cancer. But this is not true. In fact, these phyto-estrogens are protective against hormonal cancer like breast cancer and prostate cancer.

In mammals, there are 2 kinds of estrogen receptors, alpha and beta. The alpha receptor is the one which stimulates breast cancer cells to grow and also causes inflammation. The beta receptor downregulates breast cancer cell growth and reduces inflammation. Phytoestrogens are what are called selective estrogen receptor modulators. They bind preferentially to the beta receptor rather than the alpha receptor by 1600% greater affinity. There has only been one study showing a link between breast cancer and soy and it was done in rats many years ago. Massive doses of soy were used and the receptors were overwhelmed so it was not surprising that there was a link. But humans are not rats, and humans don’t consume massive quantities of soy. No human studies have shown any link. In fact, the opposite has been shown. Soy has a protective effect. 

Dairy, on the other hand, is full of mammalian estrogen. Just think of what milk is. It’s a cow’s breast milk. Just like human breast milk, it is produced to grow babies. Except cow’s milk is designed to grow a baby calf from 100 to 1000 pounds, a tenfold growth, in only 1 year. It contains almost 10x more protein and massive amounts more of other growth hormones than human milk. It is also full of mammalian estrogens which do preferentially bind to those breast cancer promoting alpha receptors. 

Prostate cancer also is significantly influenced by estrogen hormones and unnecessary growth factors. The prostate epithelial cells actually have estrogen receptors, mostly beta, which down-regulate prostate cell growth.

One need only look at what happened in Japan and China. In those countries, where soy has been consumed for thousands of years, there was virtually no breast or prostate cancer. In fact in Japan in the early 1970’s, prostate cancer rates were in the single digits! But as soon as the American diet, consisting of more processed foods as well as dairy and meat, was introduced, those cancer rates started to climb and now are similar to what we see in the West. 

The preferential binding of estrogen receptors also helps with many perimenopausal symptoms like hot flashes. Hot flashes are a rare symptom in soy-consuming cultures.

Soy is also a great source of calcium and increases bone density. It is a much better source of calcium than dairy, which is actually linked to poor bone health, despite its health claims. The societies like the US and Sweden who consume the most dairy also have the highest osteoporosis rates.

As compared with women who did not consume any soy products, regular soy consumers had 30-40% less breast cancer. Only 1 cup of soy milk or 1/2 cup of tofu led to a 30% decreased risk of breast cancer. By blocking the animal estrogen receptor, soy acts like a “natural Tamoxifen”, the most commonly prescribed chemotherapy agent used as a maintenance drug in breast cancer patients. Tamoxifen’s principal mechanism of action is  by its binding to the estrogen receptor and the blocking of the proliferative actions of estrogen on mammary epithelium. Studies have shown that regular consumption of soy products results in a 60% drop in occurrence and recurrence of breast cancer and a 29% drop in death from breast cancer which is the same as the results from taking tamoxifen, without all the side effects. This also includes estrogen negative breast cancers. Soy, bound to the beta receptor, also inhibits the enzyme aromatase. This enzyme, which is found in fat cells, converts various other hormones like testosterone and estradiol, made in the adrenal glands, into estrogen. So, not only do soy isoflavones block the harmful estrogen receptor site but they actually help to decrease the amount of estrogen your body produces. 

Consuming soy products is particularly important for adolescents, especially girls, with respect to minimizing the risks for developing breast cancer as adults. Studies clearly show that there is a decreased risk of breast cancer and prostate cancer in adults who consumed soy products when they were much younger.

By the way hops, a plant used to brew beer, has a much higher concentration of phytoestrogens than soy products which partly explains the “man-boobs” heavy beer drinkers get. 

Soy products also lower LDL cholesterol and improve blood pressure. The highest soy consumers had the lower all-cause mortality risk by 21% as compared with non soy consumers in one study.

Soy also contains a naturally anti-angiogenic compound called genisteine. This helps reduce the formation of new blood vessels by all cancerous tumors, leading to shrinkage and even disappearance of tumors.

As far as soy and fertility are concerned, again, just look at Asian countries. Their populations have gradually risen for thousands of years and their diet is based on soy. There is no evidence that soy causes fertility problems. On the other hand, studies have shown that me who consume the most dairy have the poorest sperm counts and motility.

Soy consumption can affect thyroid function, but only in people who already have thyroid issues and have borderline or low iodine intake, the most common cause of thyroid disease to begin with.

Some people are allergic to soy. It is actually the third most common food allergen, after dairy which is #1, followed by eggs. Soy allergy is still pretty uncommon only affecting 1 in 2000 people. This is 40x less frequent than dairy allergy which affects 1 in 50. This is a separate issue from lactose intolerance which affects 1 in 3 Americans but 70% of the population worldwide. Soy allergy is also 10x less common than the other common food allergies like fish, eggs, shellfish, nuts, wheat and peanuts. 

You should always buy organic, non-GMO soy. 80% of the soy grown in the US is genetically modified (GMO), not organic and is heavily sprayed with chemicals. In addition, processed foods that contain soy usually contain non-organic and genetically modified soy so please READ LABELS! If it doesn’t say it’s organic, assume it is laden with chemicals. Non-GMO alone is not enough. 

And not all allergies are truly allergies. Another reason to avoid non-organic products, especially soy, is that the chemicals used to grow them, can cause allergy-like reactions. It’s the chemicals.

Soy contains lectins known as soybean agglutinins (SBAs) which have been shown to cause inflammation and increase gut permeability. Furthermore, the phytic acid and other protein inhibitors in soy inhibit nutrient absorption. But just like other beans, proper cooking, fermentation and sprouting eliminates up to 95% of the lectins and acids, leaving just enough to actually be beneficial to human health.

Soy comes in many forms. The healthiest are edamame, the actual soy bean pods, and fermented forms such as miso, tempeh and natto. Tofu and soy milk are also good but a little more processed. Regardless of the form you consume, again, make sure it is organic and non-GMO. It is better to stay away from hyper-processed forms of soy such as soy isolates, often found in processed foods and plant protein powders.

All plants contain all amino acids, essential or not. Some foods have higher concentration of the essential ones, which are amino acids we can;t produce ourselves and must consume. Soy is one of those foods, high in essential amino acids. Other plant sources of complete protein include quinoa, hemp, buckwheat, mycoprotein (quorn, a type of mushroom grain), rice and beans, humus and pita bread and even a peanut butter sandwich with whole grain bread.

Only ½ a cup of soy milk or ½ serving of tofu, provides enough phytoestrogens to lower breast cancer risks by up to 10%. The higher the “dose”, the greater the benefit.

In addition to having a beneficial impact on hormonal cancer rates, other cancers were also reduced, including: esophageal, stomach, colon and even lung cancers, not to mention the improvement in the cardiovascular system.

SOY and the Environment.

I mentioned above that soy is one of the most pesticide-laden food crops (cotton is actually the most contaminated crop in general) and you should look for organic soy to consume. Some people accuse soy of being very environmentally unfriendly because of the the land use required to grow it. It is true that soy crops destroy a huge amount of land however, 80% of that soy goes to feed animals. Most of the soy which humans consume is in the form of unhealthy soy oil and only 4% goes towards foods like tofu, seitan, soy milk and other soy products. 

Soy is very healthy and switching from animal protein sources to plant protein sources, including soy, is healthier for you, as well as very positively impactful on the planet. Not to mention, animals don’t die in the production of soy!

For more about soy and breast cancer, and breast health in general, look up breast surgeon Dr. Kristi Funk’s book “Breasts: The Owner’s Manual“. 

This is a transcript f a radio show post I did. At the bottom, I’ve included the Dementia Risk Factors handout I give patients with a link to the PDF.

Hello everyone. Dr. Chuma here once again and I would like to talk to you today a bit about dementia.

Dementia is the 7th leading cause of death in the US but more concerningly, it’s the fastest rising chronic disease. I am finding myself having more and more conversations with patients about dementia. People want to talk about it so much that I am working on a short handout summarizing the most common and reversible risk factors. I’ll include this handout in the transcript of this show which I post on my website doctorchuma.com and my facebook page. 

You may be wondering why an Ear, Nose and Throat doctor would be having such conversations. The reason has to do with how intimately linked hearing loss is with dementia.

A study in 2020 published in the renowned medical journal the Lancet, reported that hearing loss was the most important of all the 12 modifiable risk factors they identified. 

Someone in middle age with a mild hearing loss which is unaddressed doubles their risk of dementia. A moderate loss can result in a tripling of the risk. But doing something about it, meaning getting hearing aids and wearing them all the time, significantly reduces  that risk. Those who only wear them when they think they need to, do not get the benefit. You need to wear them most of the time.

The reason hearing loss is so connected with cognitive decline is very complex. Hearing is essentially the body’s ability to perceive vibrations around us. Our brain is constantly listening for the vibrations which produce sound as a means of gathering information about our surroundings, essentially to protect us. The parts of the brain which process sound are always on, and always analyzing. The auditory cortex is almost as active when you are asleep as when you are awake. When you don;t hear things around you, those areas are not active and deteriorate. Use it or lose it.

In most people, hearing deteriorates very slowly, often starting decades before a patient appreciates they have an issue. People also erroneously feel that if they are able to communicate well, their hearing must be good enough, but this is not the case. Our brains process everything we hear, and again, this analysis provides us with protection. You may not be aware of a sound, but if your auditory system hears the sound, it processes the sound. A good comparison is how when someone moves into the city from the country, they initially can’t sleep very well because they are not used to the background sounds of the city. Our brain is telling us that something is new and we need to be aware. But after a few weeks, the brain realizes that this is a non threatening sound and they get used to it and their sleep improves. They may not be aware of the sound anymore, but they hear it and their brain processes it as something they do not need to worry about.

Anyone over 50, or even sooner if you have had any amount of noise exposure, should have their hearing tested and consider wearing hearing aids if they have a significant amount of loss. Online or smartphone apps may provide a good hearing screen, but a formal test with an audiologist is much better because they can also test your ability to understand what you hear, which deteriorates much sooner than your ability to hear the beeps of a test.

Some of the other reversible risk factors associated with dementia were not surprising. Smoking, cardiovascular disease and diabetes all cause inflammation and vascular changes in all our organs, including the brain, leading to deterioration of brain tissue. Alcohol is a toxin to all our cells, including the brain. Traumatic brain injury also significantly increases dementia risk. And it is not just the obvious concussions. Soccer and football players all have low levels of injuries to their heads all the time. Helmet hits and heading a soccer ball directly injure the frontal lobe of the brain, which continues to develop well into our 20s. This area of the brain controls executive function like impulse control and decision making. 

Some of the more surprising risk factors were level of education, air pollution and depression. Lack of physical activity was also significantly linked.

Although diet was mentioned as important, it did not make the top twelve. But in my opinion, diet is the most important since it impacts directly on almost all of the other risk factors. A healthy, minimally processed plant-based diet can reverse diabetes and heart disease. It improves mood and can ease depression. It improves sleep quality, another dementia risk factor. 

And, it even impacts the expression of genes.

Dr. Dean Ornish is one of the pioneers of lifestyle medicine. His mantra “Eat well, move more, love more and stress less” is pretty close to perfect. His studies have shown that adopting healthy lifestyle habits can reverse prostate cancer, heart disease and most recently, even some early symptoms of dementia, something no drug has ever done.

A fantastic book about dementia prevention is “The Alzheimer’s Solution” by Drs. Dean and Ayesha Sherzai, both neurologists. It’s an easy read and available on Amazon.

Just to change gears a little, Covid is still out there. Numbers have not changed much but one concerning trend is that the proportion of hospital admissions is rising most rapidly in kids, no doubt as a result of going back to school with virtually no Covid rules anymore.

Please get vaccinated and be careful.

See you next time.

 

DEMENTIA RISK FACTORS HANDOUT (This is a link to the PDF DEMENTIA RISK FACTORS)

Cardiovascular disease has been the #1 cause of death worldwide for the last 100 years, but dementia is #7 and is the most rapidly increasing chronic disease in the developed world. There are over 200 types of dementia. Alzheimer’s Disease is the most common (~ 60%), followed by Vascular Dementia (20%) and Lewy Body Dementia (5%). Other common types include Fronto-Temporal Dementia, Alcohol Induced Dementia and Parkinson’s Related Dementia. In the US, Alzheimer’s Disease is by far the costliest disease to manage since people can live with it for many years and rely almost 100% on help.

Billions have been spent on developing drugs but not even one has improved let alone cured any form of dementia. The most recent drug at best slows progression but it comes at a great cost, both financially ($50-100,000 a year) and from side effects like bleeding in the brain (10% of patients). Prevention is key and now is the time to start since the damage leading to dementia starts 30 years before symptoms develop.

A 2020 Lancet study reviewed the factors contributing to dementia. They reported that 40% of the risk is attributable to 12 factors we have direct control over, called “modifiable risk factors”. 60% of the risk is attributable to age (the older you are, the greater the risk) as well as genetics. Clearly, you can’t do anything about age. As we learn more about how our lifestyle choices can impact how genes are expressed, even inherited genes are not as important as the modifiable risk factors. Dr. Dean Ornish showed that in just a few weeks, improving lifestyle factors like diet, stress management, exercise and social interactions, can alter the expression of over 500 genes, inhibiting genes which cause harm and expressing the genes which are protective. He also showed in a 2024 trial that those lifestyle changes can actually reverse some early dementia symptoms. This has never been seen before.

Below is a list of the 12 identified modifiable risk factors in order of their impact on the development or progression of cognitive decline and dementia. The additional 3 impact greatly on all the previous 12.

1. HEARING LOSS. In addition to the lack of brain stimulation, the isolation hearing loss causes is very bad for brain health. Someone in mid-life with only a mild untreated hearing loss doubles their risk of developing dementia. Hearing aids have also been shown to improve balance and reduce fracture risk. Consider getting hearing aids even if your loss is mild.
2. LESS EDUCATION. The greater your education level, the lower the risk. However, continuing to learn new skills as we age such as a new job, languages, musical instruments, sports… are very important when it comes to staving off cognitive decline and dementia.
3. SMOKING. Every single disease process is negatively impacted by this terrible habit. Because it causes cardiovascular disease, it impairs blood flow to the inner ear, in addition to being directly toxic to the inner ear nerve endings and all blood vessels in your body.
4. DEPRESSION. The link is partly age and duration related. Changes in brain structure, such as the hippocampus, the memory center, are seen in chronic depression, making dementia worse.
5. SOCIAL ISOLATION. Humans evolved in societies. Social isolation was not sustainable for the vast majority of us. Lack of human interaction and stimulation is a significant factor. Married couples and those involved in social organizations like religion have lower dementia rates.
6. TRAUMATIC BRAIN INJURY. Concussions and other brain trauma such as bleeding or strokes, result in damage to brain tissue as well as disrupting millions of neuronal connections in the brain. Even the “minor” recurrent trauma from heading a soccer ball or playing football has an effect.
7. AIR POLLUTION. Poor air quality contributes to various conditions like dementia, heart disease and cancer. Breathing the air in Beijing, China causes the same health risks of smoking 1 pack of cigarettes a day. But it’s not just smog. Burning wood in the winter also increases rates of chronic disease. Get a good HEPA air filter for your bedroom, even if you have a whole house filter.
8. HYPERTENSION. The number one killer worldwide, elevated blood pressure, damages arteries leading to poor blood flow and reduced oxygen and nourishment supply to all our organs, including the inner ear and the brain. The second most common type of dementia is vascular dementia, a direct result of arterial disease affecting the brain
9. PHYSICAL INACTIVITY. There is a clear relationship between lack of physical activity and dementia. Most of the populations who live the longest and are the healthiest, with the least amount of dementia, don’t actually exercise, but they move constantly. Most of don’t live in such environments but the good news is that regular exercise improves cognitive function. Do whatever you like, just do it regularly.
10. DIABETES. The most common complications and cause of death of diabetics is cardiovascular disease. This contributes to vascular disease in the brain. In addition, elevated blood sugars are toxic to all tissues and organs. Lastly, insulin has a significant impact on brain tissue directly as well as glucose management in the brain.
11. OBESITY. The rate of obesity in the US amongst adults is 42%, with 20% of kids being obese. Adding up those who are overweight, 75% of Americans have an unhealthy weight. Fat doesn’t just sit there, doing nothing. Fat cells produce inflammatory compounds and hormones like estrogen, increasing cancer risk of various hormone related cancers like breast and prostate. The good news is that even losing just a few pounds leads to reduced dementia risk.
12. ALCOHOL. Simply put, alcohol is a toxin to every cell in your body, including brain cells. There is a clear relationship between excessive alcohol consumption (more than an average of 1 drink a day for women and 2 drinks a day for men) worsens all diseases, especially dementia.
13. SLEEP. Chronically reduced and poor-quality sleep is associated with various chronic diseases, especially cognitive decline and dementia. Sleep is when our brains clean up and remove the damaging proteins which build up during the day. And sleep medications do not reduce the risks because, although they may cause you to sleep longer, the quality of your sleep is poor.
14. STRESS. To be alive is to be stressed, however how we deal with stress is the key. If you deal with it poorly, excessive stress hormones and inflammatory compounds are produced.
15. DIET. Listed last, this is the MOST IMPORTANT of all the lifestyle habits which reduce the risks of all chronic diseases, including cognitive decline and dementia.

–         Focus on a predominantly whole foods, plant-based diet.

1.     Fruit, especially berries (not fruit juice which is equivalent to soda).
2.     Greens (arugula, kale, cruciferous vegetables…).
3.     Whole grains. The more they are processed, the worse they are for you.
4.     Nuts and seeds. They do contain a good amount of fat so don’t overdo it.
5.     Beans. They’re all good, especially soy, lentils, chickpeas and black beans.
6.     Water. Filtered, just avoid plastic bottles since they leach chemicals.

–         Eliminate processed foods. The more processed it is, the worse it is for you.

–         Minimize added sugar, including honey and artificial sweeteners, and salt.

–         Minimize fat and cholesterol, the majority of which comes from animal products like meat, fish, dairy and eggs. In other words, minimize eating animal products.

 

A great reference is “The Alzheimer’s Solution” by Drs. Dean and Ayesha Sherzai.