Is soy healthy?
In my practice I have encountered a widely-held belief that eating tofu/soy can be unhealthy. Soy contains phytoestrogens. Phytoestrogens are chemically similar to the mammalian hormone estrogen. The idea is that consuming soy could cause the body to react to phytoestrogens the way it would to estrogen. In men, claims have been made that soy consumption leads to low sperm count and generalized feminization including breast development. In fact studies have not borne this out, and even consumption of very high amounts of soy or soy-based products have been shown to have no such effects on humans. Another common myth about soy is that it could promote or accelerate the growth of certain types of cancer cells that are estrogen sensitive (such as breast cancer). In fact, studies have shown that soy does not elevate the risk of estrogen-sensitive cancers but it does lower the risk for several other types of cancer. Conclusion: soy is a safe and wonderful source of complete protein. The only downside to soy, it seems, is that most of the soy now grown in the U.S. has been genetically modified. Try to buy only soybeans or soy-based products that are labeled ‘organic’ and/or ‘Non-GMO.’
READ ON: Healthy Animal Protein
In April, a presentation at the American Society for Nutrition's Scientific Sessions at Experimental Biology 2016 showed that certain dietary habits are associated with increased risk for breast and prostate cancer (April 2-6, 2016; San Diego, CA). More than 3,000 adults were followed for more than 20 years. About 25% were diagnosed at some point during this time with cancer. Those who regularly consumed carbohydrate-dense foods (CDFs) such as fruit juices and other sugary soft drinks had three times as much prostate cancer as those who took in less. CDFs (foods that cause spikes in blood sugar) were associated with increased risk for prostate cancer. Men who regularly consume processed foods (bread, pizza, deli meats, hot dogs, hamburgers, etc.) had double the risk for prostate cancer.
Women whose diets were high in vegetables, whole fruits, and legumes were two-thirds less likely to develop breast cancer than women whose diets were high in CDFs like whole wheat bread, cereal, pasta, juices, and sweets.
Many studies have shown that carrying extra belly fat and diets high in CDFs or red meat increase risk for diabetes, strokes, heart attacks, sexual dysfunction, and various cancers especially of the digestive system. (British Journal of Cancer, Jan 4,2011;104 (1): 6–11 and European Journal of Clinical Nutrition, 2007;61(Suppl 1):S112–S121). Diets high in CDFs cause belly fat to accumulate. Belly fat, CDFs and red meat all cause inflammation and inflammation is a driver of all forms of chronic disease, including cancers.
How Inflammation May Cause Cancer
When a germ gets into your body, your immunity recognizes that the germ cells have proteins on their outer surfaces that are different from your body's own cells. Your immunity produces cells and proteins that attack and kill these invading germs. However, as soon as the invading germs are gone, your immunity is supposed to calm down and stop producing all the proteins and cells that did the attacking and killing. Chronic inflammation means that your immunity stays active and starts to attack and damage your own cells and the DNA/genetic material inside them.
Normal cells live only a certain number of days and then die. Our cells are constantly being replaced by new, healthy cells. However, if your immunity damages your DNA, the cells may be changed so they forget to die and try to live forever, which is cancer. The "immortal" cancer cells overgrow and invade other tissues to destroy them and kill you. For example, breast cancer cells do not kill you as long as they stay in the breast, but the breast cancer cells can become so numerous that they spread to your brain, lungs, bones and other tissues and kill you by destroying these essential tissues.
High Blood Sugar Causes Inflammation
The same cells and chemicals that kill germs also start the healing process, so damage to any tissue in your body turns on your immunity in the same way that infections do and therefore can cause inflammation. When blood sugar levels rise too high, sugar sticks to the outer membranes of all the cells in your body and damages them, causing sugar-protein-fat complexes called AGEs or plaques. Plaques in arteries cause atherosclerosis, plaques in joints cause arthritis, and plaques in the brain cause dementia.
All the harmful effects of diabetes, such as impotence, dementia, blindness, deafness, heart attacks and cancers, are caused by high blood sugar turning on your immunity, and you don't have to be diabetic to suffer this damage. A review of the world's literature shows that non-diabetics with high blood sugar levels suffer a marked increase in breast, colon, liver, stomach, pancreatic and endometrial cancers. (Diabetologia, September 8, 2014). Furthermore, high blood sugar levels cause high insulin levels that also increase cancer risk (JCI May 2013;4(3)). High blood sugar levels can be caused by any of the high-glycemic-load foods, including all sports drinks, protein bars, granola, fruit juices, baked goods (including whole wheat and whole grain breads, muffins, cereals), white rice, potatoes, pastas (including whole wheat and whole grain pastas), and sauces and batters made with flour (Cancer Epidemiology, Biomarkers & Prevention, March 3, 2016). Other studies show that high blood sugar levels are associated with increased risk for prostate cancer (Horm Cancer, April 2016;7(2):75-83) and breast cancer by causing inflammation through the 12-Lipoxygenase (12-HETE) pathway (Cancer Res, Jan 1, 2016;76(1);24–29).
Overweight Causes Inflammation
Full fat cells also produce the same cells and chemicals that turn on your immunity, which is why obesity is a major cause of inflammation (International Journal of Cardiology, April 14, 2016;215:318-324). Many studies show that obesity causes inflammation by increasing interleukin-6, BP and insulin insensitivity (International Journal of Cardiology, April 14, 2016;215:318-324 andJ Clin Endocrinol Metab, Mar 2001;86(3):1154-9). Overweight causes high blood sugar levels; blood sugar levels rise with increases in body weight, BMI and waist circumference (Cardiovasc Diabetol, Feb 6, 2012;11:13). Excess weight also increases risk for metabolic syndrome and diabetes (Nutrition, Metabolism & Cardiovascular Diseases, November 12, 2015). Storing fat in your belly raises markers of inflammation: C–reactive protein, leptin and insulin (Nutr Metab Cardiovasc Dis, February 2016;26(2):114–122) and many different cancers (Cancer Prev Res, March 2013 6; 177). Excess belly fat is directly caused by diets high in CDFs.
For two million years, humans evolved and adapted to a diet that is high in fiber, moderate in protein, low in fat, and very low in CDFs. I call this the Human Diet. For more information on the Human Diet, please contact the office and we will send you a copy of part I of my series on health: Health Part I; Nutrition which can be sent to you by email. Or simply link to the article here.
Plant protein is less abundant. There are several plant sources of protein but the only plant source of complete protein is soybean. That’s one of the reasons that it is such an important part of vegetarian and vegan diets, and one of the reasons that I recommend soy products be included as a dietary staple. Soybean is a very versatile plant food that can be eaten on its own (edamame), added as a healthy filler to other foods, or used to make soy milk, tempeh, and tofu (which is made by boiling soy milk). Tofu can be soft and delicate or firm and sturdy, and it tends to take on the flavor of whatever it is cooked with, enabling it to be used in a wide variety of ways including as a substitute for meats of various kinds.
Other sources of plant-based protein (which are not complete proteins) include: beans, nuts, lentils, hemp, chia, seeds, quinoa, and spirulina. But not all plants are necessarily healthy foods, even if they do contain protein. As you will read later, a lot of today’s GMO plants are very high in carbohydrates, and CDFs, as stated above, make blood sugar levels soar. Keeping our blood sugar levels relatively stable may be the single most important of the nine Rules of Healthy Eating. We should try to limit carbohydrate intake to about 15g per meal. More about this later, but as in illustration, one cup of quinoa contains 24g of protein but a whopping 109g of carbohydrate! Compare this to a cup of leafy greens like spinach which provides about 1g of carbs.
READ ON: Is Soy Healthy?
In the Human Diet about one third of our calories should come from protein. Children and young (still growing) adults, as well as adults with special nutritional needs (such as endurance athletes), may require even a little more protein for growth and the formation and restoration of healthy muscles, joints, bones and connective tissues. If you are eating animal-based protein, the thing you most want to consider is this: How healthy was the animal whose proteins you are eating? Pasture raised, organic animals and animal products are healthy sources of protein to which we are well-adapted. However, commercially raised animals are routinely confined in small spaces where they are made to suffer. This causes their bodies to produce high amounts of stress hormones. They are also fed a high carbohydrate diet (corn and grains) to make them big and fat. What’s more, this feed is routinely laced with hormones to make them even bigger and with antibiotics to keep infectious diseases at bay. Such animals are not particularly healthy and their flesh, fat, and milk reflect this. If you eat meat, eggs, or dairy, it is important to choose healthy animals.
READ ON: Plant Based Sources of Protein
Red Meat and Cancer:
In addition to its role in promoting heart disease, numerous studies have also linked red meat consumption to cancers of various kinds, and especially colon cancer. All mammals except for humans contain on the surfaces of their cells a sugar, called Neu5Gc. When humans eat the meat of cows and pigs, we are consuming Neu5Gc, causing this sugar to stick to the outsides of our cells. Because it is not a sugar that humans are meant to have stuck on our cells, our bodies mount an immune response against the cells with surface Neu5Gc, making antibodies that attack those cells. Daily consumption of red meat causes an ongoing immune response resulting in a state of chronic inflammation. Chronic inflammation is now understood to be the chief driver of heart disease, diabetes, and cancers, among other chronic diseases. Dr. Ajit Varki, at UCSD, has shown that this chronic inflammatory state results in spontaneous cancer tumors in mice genetically engineered to not produce Neu5Gc (like humans) when they are fed meat.
There are many reasons to cut down or avoid eating meat, including animal cruelty, pollution effects of cattle, and the various hormones, antibiotics, and grain feeds on which commercial cattle are raised. My recommendation for optimal health is this: if you are going to eat red meat, do so no more than one to three times per month, and buy only organic, pasture raised, animal-centered, grass-fed beef.
READ ON: How Healthy Was the Animal Whose Proteins You are Eating?
Begin reading from the beginning of this series about Food and Nutrition
A few words here about red meat.
We have all heard for decades that red meat is unhealthy. The original recommendation by the medical community to reduce red meat consumption was based on the (now false) assumption that dietary animal fat was the chief cause of obesity, and heart disease. However, while it is now clear that animal fat (including the fat in beef) is actually healthy in small amounts, good studies continue to link regular consumption of red meat with increased risk of cardiovascular disease. Why?
Red meat is high in a particular compound called carnitine which is synthesized from two amino acids (methionine and lysine). Certain gut bacteria feed on carnitine producing a waste product which is turned into something called TMAO. Recent studies have shown that high levels of TMAO cause tiny puncture wounds form along the cells lining our arteries (the endothelium). These endothelial wounds are the initiating event for plaque formation (atherosclerosis). Humans and animals who eat red meat regularly have higher levels of TMAO which is directly associated with atherosclerosis and increased risk of heart attack.
Should we avoid carnitine then? Not so fast. Carnitine is an essential compound used by all cells of the body for energy and for fatty acid metabolism. It helps muscles heal after injury and intense workouts. Carnitine plays a vital role in health. But like any healthy substance, too much of it can become a problem. Too much carnitine over time results in too much TMAO.
TMAO levels do not go up after eating red meat in people who only eat it occasionally. Vegans given meat/carnitine do not show a rise in TMAO levels because the bacteria which feed off of carnitine die off after prolonged periods without carnitine to sustain them. Animals fed a diet rich in carnitine over time show the same rises in TMAO and the same endothelial ulcers as do humans. However, if these animals are given bacteria-killing antibiotics prior to being fed carnitine, TMAO levels remain low, supporting the idea that gut bacteria are the source of the TMAO.
In a nutshell, certain gut bacteria feed on carnitine which leads to production of TMAO, which in turn damages our blood vessels. This is what makes regular consumption of red meat (the most potent source of carnitine) a risky dietary behavior.
READ ON: Red Meat and Cancer
Fish, beef, pork, chicken, turkey, and lamb meats are also sources of complete protein. In fact, any food that comes from an animal (eggs, meats, yogurt, cheese, etc.) is a good source of protein. Chicken meat is high in healthy protein, but chicken fat is not so healthy. High in Omega-6 fatty acids (O-6FAs), the fat from chicken is converted into a pro-inflammatory acid (arachadonic acid) which promotes aging and disease. This will be discussed below in the section on fats.
Read On: A Few Words About red Meat
Are eggs really good for me?
You may have been told (possibly even by a doctor) that eggs are to be limited because their yolks contain cholesterol. However, data over the last 25 years has proven that the amount of cholesterol in eggs is tiny compared to the amount that we manufacture (in our livers) naturally each day. What’s more, cholesterol/fat from our diet is not the cause of high serum cholesterol (the cholesterol measured by blood tests which is associated with chronic diseases). In fact, fat from healthy animals is healthy to eat in small to moderate amounts, is not a contributor to high blood cholesterol, and can even be helpful in lowering serum cholesterol and reducing our risk for chronic diseases. I will speak about this in some detail later in this essay in the section on fats.
Read on about Protein in the next article: Animal Sources of Protein
Protein Biochemistry and Nutrition
Protein biochemistry: Proteins are big molecules made up of smaller molecules called amino acids linked together to form long chains. Each protein is defined by its unique sequence of amino acids repeated over and over in its chain. Each repetition of a protein’s unique amino acid sequence causes the chain to bend or fold and this determines the shape (and function) of the protein. Some proteins give structure to cells and tissues like the collagen and keratin that give smoothness and elasticity to our skin and strength to our hair; others are for mechanical functions like the actin and myosin which enable muscles to contract and relax; proteins called enzymes help chemical reactions to take place throughout the body; immunoglobulins are proteins that help carry out the work of our immune systems. And these examples form just the tip of the protein iceberg. Virtually every important function of the body is run by proteins which in turn are made up of repeating sequences of amino acids.
Protein and nutrition: There are 20 different amino acids. Some amino acids can be made inside our own cells, while others have to be captured through our diets. Amino acids that we cannot make ourselves are called essential amino acids. There are 9 essential amino acids that we must consume regularly in order for our bodies to make all the different types of proteins necessary for optimal health. Some foods contain what are called complete proteins. Complete proteins contain all 9 essential amino acids in their sequences. From a dietary standpoint, foods with complete proteins are especially healthy. Eggs are the best example of a food containing complete protein, and eggs from an organic, pasture-raised chicken are among the healthiest foods in the Human Diet.
Read the next article :
Are eggs really good for me?
THE 9 RULES OF HEALTHY EATING
Okay, now the details...
Read Part 4 of this series: FOOD: Protein, Fat, Carbs and Fiber; What are They? PROTEIN