Animal Products and Health
Table of Contents–Jump Links
- Protein, Fat, and Early Dietary Guidelines
- Why Limit Saturated Fat?
- Understanding Inflammation
- Read This Before You Go “Carnivore”
- Animal Products and Insulin Resistance
- The Animal Protein “Difference”—the Branched Chain Amino Acids and Methionine
- Vascular Disease and Safety Talk
- Atherosclerosis, TMAO and Red Meat
- Body Fat and Cancer Risk
- Your Cholesterol: Good, Bad, and Ugly
- Protein Sources and Hazard Ratios
Dating from the mid 1940’s, various schemes, “pyramids” and “plates” have been used to help people understand what is “healthy.” These efforts by the United States Department of Agriculture (U.S.D.A.) have largely been a history-making disaster. Today’s recommendations and graphical interpretations are healthier and recommend lower intake of animal products, but especially red and processed meats. Lower levels of dairy foods are also recommended.
ABOVE RIGHT: the Harvard School of Public Health “Healthy Eating Plate”–in effect the Mediterranean Diet that Harvard promotes as being healthy and protective.
The Vegan Plate graphic shows several necessary supplements for those choosing to avoid meat. Vitamin B12 is produced by bacteria — our primary sources are bacterial contamination on or within meat. The upshot is that those who don’t eat meat (or don’t play in the dirt and lick their fingers), don’t get B12.
Similarly, without fish or intentional supplementation, the Vegan diet-style will be insufficient in omega-3 polyunsaturated fats (see Fats, Oils and Health) In general, vitamin-D needs to be supplemented by all who live in higher latitudes. Vitamin-D is created when the sun shines on the skin—provided that sun is warm.
Health, weight-loss, and animal cruelty are among the common reasons people choose to eat less meat, but there are global reason too. Diets based on animal products have a much higher climate-change impact.
Animal-agriculture produces a vast amount of methane, the green-house gas 28-times more potent than carbon-dioxide. As a source of climate-changing atmospheric pollution, animal-agriculture rivals the transportation sector.
Protein, Fats, and the Early Dietary Guidelines
The food labelling and regulation that began in the late 1970’s was supposed to improve consumer health and knowledge. Unintentionally, the exact opposite occurred and we compounded some nutritional myths that had been with us since the late 1800’s.
The U.S.D.A. guidance we receive today is far better than in the past, but still suffers from political influence. Health-science isn’t “rocket-science;” rather, it’s vastly more complex. Health-scientists and those who study human disease-causation refer to correlation, relative risk, and probability—not proof.
In the absence of proof there are tremendous effort by special interests. They lobby to change recommendations and the science itself. Some of these powerful groups include agri-business, food processors, and trade associations. Yet, there is still good science! Lots of our “free speech” is just commercial BS that leads good people astray, so consumers have to be very careful.
Debunking the Protein Myth
Among the most persistent and myths about animal (human) nutrition, one the U.S.D.A. helped create, is that the protein in animal products is “complete,” while the protein in plants is “incomplete.” For the record, that is not true. This one protein myth, which the U.S.D.A. began to promote in the early 20th Century, caused us to over-consume animal products and under-consume plant foods. This single falsity is perhaps responsible for millions of premature U.S. deaths.
My mother and father were both secondary Health/P.E. teachers. They learned and repeated the above tragic myth to their high school students. Their university nutrition textbook: Rose’s Foundations of Nutrition (1944 ed) was their source. Today, dad’s copy, proudly signed “Dean P. Sheldon, P.E. Major,” sits on my bookshelf. The ultimate source of erroneous notion might also be European scientists.
Health-science debunked the animal-protein-completeness-myth about five decades ago. It seems that none of the early “experts” pondered how a mountain gorilla, a species genetically close to humans, could become so large and awesomely powerful eating shoots, leaves, and bugs.
Protein is made from amino acids and the amino acids in, say, rice are certainly fewer than the amino acids in a porterhouse steak or kale, but all nine “essential” amino acids — those found only in food — are found in all three. Plants, like legumes, nuts, seeds and dark greens have plenty of protein and people who eat a careful vegan or vegetarian diet get all the protein their bodies require..
An interesting factoid from author Brenda Davis, RDN: about half of the protein intake for Earth’s 8-billion human inhabitants comes from grain—absolutely complete protein[i] Yet, variety is the spice of life and food diversity is healthful. We complement all the amino acids by eating a variety of whole foods, be they from plants or animals.
Robert Cheeke, Vegan Bodybuilder
A vegan diet-style provides all the amino acids and complete protein.
Saturated Fat and the Diet-Heart Hypothesis
Back in the 1960’s and 70’s, a prevailing nutritional hypothesis was that our steadily growing rate of heart disease could be slowed by lowering saturated fat—most of the fat in eggs, dairy, and meat. This idea had been around since the 1950s and has generally been validated, with a caveat. This “diet-heart hypothesis” was only part of the heart disease story—one that will claim just under 700,000 U.S. lives this year. A vocal group in the heath science field continue to question the relative risk of eating saturated fat — still an active controversy after all these years.
Concerning saturated fat, protein and carbohydrate intake, on this website I reference the current dietary recommendations of U.S.D.A., the U.S. Centers for Disease Control, the World Health Organization, and Harvard’s T.H. Chan School of Public Health. These institutions continue to recommend reducing the intake of saturated (animal) fat.
Long story short, starting in the late 1970’s the reduction of saturated fat intake and complying with the (mistaken) U.S.D.A. dietary guidelines became a colossal marketing opportunity for food producers. They expanded and redesigned product formulas and refined their promotional spin. You might say, “low fat” went straight to the bank. On net, in the decades that followed we lowered saturated fat somewhat, but we ended up eating more total calories because we replaced the missing saturated fat with:
Omega-6 polyunsaturated fat (also inflammatory)
Refined carbohydrates (white flour), and
Sugar
To summarize: we swapped-out saturated fat and swapped-in cheaply produced seed oil, sugar, and nutrient-poor starch. Bada-bing! Consumers still get smacked up-side the head with half-truths. For instance, “2% milk” means two-percent of the total volume of the liquid is fat. Dairy foods are fatty. Thirty-five percent of calories in two-percent milk come from fat—65-percent of which is saturated.
Whole milk (4%) gets about half of its calories from fat. Grocers cashed in because of thousands of new, more shelf-stable processed food products with addictive, ultra-palatable allure. The page Fats, Oils and Health dives into this slippery subject — the world’s most caloric food, 120 calories-per-tablespoon. Below, are some ideas I repeat in several places — ways to keep calories and fat low:
Choose healthy fats
Cook with steam, rather than frying in oil
Find alternatives to fatty-sweet store-bought sauces
Grab fruit or whole nuts at the store, rather than fatty-sweet deli/hot-case junkola
Lower animal product intake
The Cart Before the Horse—early dietary guidelines
When the U.S.D.A. crafted the 1980 (disastrous) food pyramid and guidelines, some core facts about human metabolism still remained hidden. For example, we still didn’t understand how the body metabolized fructose (fruit sugar)—which by weight is about half of your honey and “added sugar.” That wasn’t discovered until 1985, after the new guidelines went into effect and food processors had boosted sugar consumption. We also thought the trans-fats in margarine and fryer grease were heather than saturated fat — not deadly — as Dutch scientists discovered in 1990.
Why Limit Saturated Fat?
Saturated fat remains controversial to many, however I don’t view it as a such. My comments relating to saturated fat, here and below under Understanding Inflammation, are consistent with major U.S. and European academic, governmental, and lifestyle medicine sources. I highlight this last group because lifestyle medicine practitioners are: a) on the cutting-edge of applied nutritional science and b) are today’s heretics of mainstream medicine. That is, they are the medical doctors trying not to prescribe pills and are laser-focused on helping patients achieve permanent lifestyle modification (and they actually reverse chronic disease).
The body makes its own saturated fat and a low level is found in plant foods. Avoiding or limiting high sources is considered healthy. A full understanding of why optimal health demands its limitation requires a discussion of the relationship between disease and the immune response — inflammation.
Understanding Inflammation
Inflammation means the immune response is triggered. It is present where ever there is disease. When inflammation never stops, the rough-and-tumble inflammatory response (immune system) itself elevates disease risk and causes damage. It’s like a S.W.A.T. team, where sometime good people can get hurt. For example, our immune response actually produces plenty of free-radicals that damage cells, so being constantly inflamed is very unhealthy and life-shortening. Of course, the immune system is protecting you from being eaten by hungry microbes every second.
Inflammation can be external, like a cut or a swollen wrist after a fall. It can also be internal — the kind of inflammation that can be caused by diet. Walter Willett, Ph.D, M.D. of the Harvard T.H. Chan School of Public Health considers saturated fat, to be the most inflammatory form of dietary fat. The omega-6 polyunsaturated fats (vegetable oil) are also inflammatory, but for very different reasons — described in Fats, Oils, and Health.
Three types of food in the modern diet (below) stand out as being especially inflammatory when routine; that is, consumed on a daily basis for individual or family nutrition:
Refined carbohydrates–meaning sugar and refined white flour (mostly)
Saturated fat
Poly-unsaturated oils high in omega-6 fats.
Of course, fiber and the antioxidants in salads and veggies LOWER your inflammation, but the more you eliminate the above from your diet, the healthier you will be. “Refined” and “highly processed” are synonymous with SAD — foods deficient in the anti-inflammatory omega-3 polyunsaturated fats. At the factory, super-cheap, shelf-stable omega-6 polyunsaturated fat (seed-oils) have replaced the natural omega-3.
The Jones Family who favors the pre-packaged heat-and-eat and boxy cereals and pop — and skips the whole plant nutrition–will have an (inflammatory) imbalance between the omega-6 and omega-3. It’s a fact. Their bodies respond to the elevated omega-6 fat with faster, spikier inflammation and more aggressive clotting — a condition that leads to much higher disease-risk, higher medical expenses, and pain. Why? you’ll have to see for yourself under: Fats, Oils, and Health.
The lusty “carnivore,” immoderately consuming animal products — in combination with starchy refined carbs and sugar –– is switching their inflammatory response to the ON position. For a person with a chronic disease, in effect, the inflammation switch is stuck “ON.” Harsh and unruly!
Remembering COVID-19
Recall those souls with a “pre-existing condition” during COVID-19? Their immune response was already working overtime—battling some metabolic problem, probably linked to crappy food, excess calories, and worry—then they contracted the SARS COV-2 virus. The immune response itself was part of why most didn’t make it.
Health-science uses several names for the body’s internal inflammation: chronic systemic inflammation, or metabolic inflammation (meta-inflammation). It doesn’t let up until you stop the damage. Being in a chronically inflamed state is life-shortening. That’s among the reasons the SAD is dangerous. We can measure the body’s inflammatory condition with an easy blood test (Creatine Reactive Protein—CRP).
When diet and lifestyle lower internal inflammation, the body is a stronger better disease-fighting machine, and you get healthier (and may lose weight). This single sentence covers a ton and begs the question. How do you lower internal inflammation? What’s the magic pill?
We INCREASE metabolic-inflammation with:
Everyday refined carbohydrates, (sugar, muffins, pizza, white bread, deli-delights),
Excessive intake of omega-6 vegetable oil
Low intake of whole plant foods
High levels of saturated fat
Excessive calories
Chronic stress
We LOWER meta-inflammation by:
Increasing intake of fibrous and nutrient/antioxidant-rich whole plant foods
Shifting protein to include plant sources (that come without the baggage of saturated fat and cholesterol)
Reducing chronic stressors and improving our social connections (hopefully around a plate of healthy food).
Getting regular exercise that moves the body and works the muscles.
Metabolic inflammation elevates ALL disease risk-factor: heart disease, stroke, diabetes, obesity, kidney disease, auto-immune disorders, etc.
Lower Fat, Lower Inflammation
The current consensus within the major U.S. health-science institutions, and within the health agencies of many nations: you reduce your relative risk of chronic disease by keeping saturated fat intake low. The current U.S. average consumption of total fat is 36-percent of calories and the current saturated fat intake (12-percent of calories) is 100% higher than the recommendation. Of course, animal products are also high in cholesterol. As we will discuss, health improves when we are selectively in consuming meat, eggs, and dairy and favor whole plant foods for the majority of calories.
Crossing into Inflammatory Terrain
I call the grocery store Hazardous Terrain. If one is careless, it can be Inflammatory Terrain. When you cross the threshold, I suggest keeping your eyes down and walking deliberatively to the produce section. Grab something yummy and ask yourself, will this do it? Is this enough? Vegetables and fruit are ANTI-inflammatory and mostly very low in fat.
An avocado is an exception — about 75-percent of calories from fat — but it comes with benefits: whole fiber, vitamins, minerals, and gobs of disease-fighting antioxidants. For many, every crossing into this terrain means a bag or shopping cart full of inflammatory bullshit and metabolic danger. In a nutshell, the processed stuff engineered to be super-yummy is dangerous when consumed habitually.
Is your EV olive oil a sacred cow? Yes, choose heathy oil. Eating food fried in oil — deep or shallow — is going backwards, even olive oil. Using steam to cook most foods is far healthier–even a burger (one of my specialties). I discuss the bio-chemistry of why in my YouTube program Engines of Aging. Lower calories, lower glycation, fewer free-radicals.
Indeed, human-kind ate lean, whole, free-range meat and wild fish. That is FAR from deep/pan-frying in oil. Keeping overall fat intake on the low side yields greater health, greater longevity, and is the basis of diets that reverse disease.
Read This Before You Go “Carnivore”
Our long, long, ago ancestors never passed up good meat, be it fish, a gazelle, or a swarm of cicadas, but our closest living cousins, bonobos, chimps, and gorillas—in fact—don’t eat flesh as a daily habit. Yes, chimps hunt other monkeys and cannibalism does occur, as it did with humans, but that’s not day-to-day. Please look in the mirror and smile. Humanity possesses the jaws, teeth, hands, and metabolic machinery to eat fibrous plants very well, thank you.
Among the reasons Homo sapiens are so successful is that our physiology and our amazing intellect allow us many options. We take what we can get and make it work, at least for a while. Below, I’ve outlined two contrasting examples from our food history to clarify the point:
Traditional Greenland Inuit and Alaska’s Inupiaq (northern Eskimo) seasonally ate a diet very low in plants and fiber–almost marine-derived protein and fat (very high in anti-inflammatory omega-3 polyunsaturated fat). To our knowledge, heart disease was rare. The lives of northern Inuit people were extremely rigorous, but seasonally fairly sedentary.
Traditional cultures in Okinawa, Papua New Guinea and China clearly thrived on the exact opposite diet—whole-plant starchy foods in the range of 75-85-percent of calories, along with various other vegetables and small amounts of animal fat and protein. Traditional Okinawans are among the longest-lived people, bar-none.
The second example has a proven association with great longevity.[I] We can assume, therefore, it is much closer to being optimal. It makes sense to consider “optimal” health within the context of longevity. No one dies of “old age,” we succumb to specific diseases. A “pre-existing condition,” meaning a chronic disease, means sub-optimal health. We’ve never been more able to make optimal a deliberate outcome; meaning, the body is ready and equipped to routinely fight-off the random disease-producing agents it encounters every day.
Fad diets thrive in food-confusion. “Carnivore,” or some other scheme to acquire a high percentage of calories from animal products, or drink multiple tall glasses of cow’s milk daily through the life-span, are not optimal for health. Modern health-science now tells us that diets very high in animal products are not associated with optimal disease fighting and longevity.
Metabolic Acidosis
Diets chronically high in animal-derived protein can shift the body towards excess hydrogen — meaning acidity. Your kidneys and urinary system pay the bill. We measure the body’s ability to buffer acid with the Serum-Bicarbonate test, part of a routine blood panel. Your serum bicarbonate is synonymous with carbon-dioxide dissolved in your blood. The number should never dip below 22mmol/L.
Our kidneys are tasked with maintaining the body’s acid balance — its pH. To do so, the kidneys re-generate bicarbonate (from dissolved carbon dioxide) and we pee-out acidic ions. When a body is in metabolic acidosis (high acid), it will be achieving this balancing of pH (high acidity) by mobilizing your body’s own mineral store-house: potassium, sodium, carbonate, magnesium, phosphorus, calcium, and others.
Metabolic acidosis is an emergency for the body. A bicarbonate number below “22” may mean the body is pulling essential mineral from bone and muscle–increasing frailty and muscle wasting. Another common side effect is higher insulin resistance.
The kidney produces more ammonia and the urine becomes more acidic–as we piss out excessive nitrogen (dissolved protein) and minerals. The change means a higher likelihood of kidney stones — formed from your very bones. The rate of kidney disfunction (or outright disease) among adults 65-up is now 38%.
Fortunately, we can easily avoid most kidney failure and the painful stones scenario. Diets rich in plants and low in animals will restore alkalinity, the opposite of acid. The human body is not designed for “Carnivore.”
[i] New Horizons: Dietary protein, ageing, and the Okinawan ratio. D. G Le Couteur, S Solon-Biet, D. Wahl, et al. Age and Ageing, 2016, Vol. 45: 443-447
Animal Products and Insulin Resistance
Insulin is The Queen of energy balance and the manager of glucose, the body’s primary fuel. Because of its importance, insulin is discussed here and on the page Insulin and Metabolic Disease. Glucose can satisfy the energy-needs of every cell in the body. That begs an important observation: the carbohydrate glucose is a very natural daily fuel. The disruption of the body’s sensitivity of insulin is absolutely central to the U.S. chronic disease crisis.
When the body acquires an insensitivity to insulin, health-science calls the condition insulin resistance. The description that cells “resist” insulin does not explain the disfunction, but glucose can’t get into cells and the pancreas must make more insulin to get the job done; and blood sugar (glucose) is poorly controlled. For the vast majority of people whose cells are resistant to insulin, the body adds pounds and blood sugar and Hb-A1c are a problem, meaning type-2 diabetes is a possibility
If we think about insulin at all, it’s about a metabolic health concern. The focus might be cutting the sugar and refined carbs, a great start. Insulin resistance is also associated with a diet high in animal products—meaning high in the other two macronutrients: protein and fat. That will come as a shock to someone trying to control blood-sugar, triglycerides, and the A1c number, and being successful by a) cutting refined carbs and b) eating more animal products.
There is plenty of evidence to support the “carbs are the problem” perspective. Refined carbs like sugar and white flour are a huge health problem. There was probably ZERO white flour in most of your ancestor’s diets before about 1870. And between 1710 and 2000, North America increased its intake of refined sugar at least 35-fold[i].
The various caveman diet strategies—“carnivore,” “keto,” and “paleo,” meaty or fatty—all restrict refined carbs. Combined with overall calorie reduction, these strategies do indeed lower the crazy glucose spikes and serum insulin.As a result, weight-loss becomes possible (provided that calories are restricted) and meat and fat are very satisfying. These approaches, both used for a very long time, have two very basic functional limitations as a best-practice treatment for optimal health.
Sourcing high levels of calories from animal protein and saturated fat (and cholesterol) is not a health-optimal, longevity diet.
Plant-based diets with plant-sourced protein allow much lower fat intake and have been proven to be better at reversing insulin resistance, diabetes, vascular diseases, and can get people off pills permanently.
[i] Good Calories Bad Calories (2007), Gary Taubes. Alfred A. Knopf Pub.
As we consider the myths, choices, and science around animal-based eating, please keep in mind the predominant U.S. dietary program currently yields:
42-percent obese,
40-percent pre-diabetic or diabetic, and
38-percent of adults 65-up are dealing with kidney problems
Approaching 700,000 U.S. adults will die from heart disease this year. (C.D.C. Website, Dec. 2024)
With all the new failing kidneys, obesity, diabetes, vascular disease, dementia, etc.—and new construction for “specialized services” and treatments to manage the growing debility we’ve normalized—Disease-Care, Inc. is in great financial shape. Over $4-trillions in new disease-care cash will come online in 2025.
Insulin Resistance and Intramuscular Fat
To reverse metabolic disease and reclaim health, among the big challenges is burning inter-muscular fat, like the “marbled” fat in that juicy porterhouse steak. Only this stuff is embedded within a diabetic person’s thigh muscle[i]. The person must burn up these peripheral fat stores with exercise and at the same time be fully engaged in intense dietary control. Tough sledding!
QUOTED AT RIGHT: Researchers conducting weight loss trials with postmenopausal women showed the failure of meaty, high-protein/low-carb trials to improve muscle insulin sensitivity. The higher-animal protein diet trial generated higher circulating insulin. The “Disease Reversal” link on the page Fats, Oils, and Health describes how low-fat/high-carbohydrate plant-based diets are used to reverse diabetes, obesity and other chronic diseases.
“…it reflects a failure to improve a major pathophysiological mechanism involved in the development of T2D [type 2 diabetes]…and indicates more insulin is required in the HP [higher protein diet] group to dispose of a given amount of glucose”[i].
[i] High-protein intake during weight loss therapy eliminates the weight loss-induced improvement in insulin action in obese postmenopausal women. Gordon I. Smith, Jun Yoshino, Shannon C. Kelly, et al. Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis. In Cell Report, 2016
The Animal Protein “Difference”–
Branched Chain Amino Acids and Methionine
At the beginning of this page on animal products, I debunked a tragic—still pervasive—myth about plant protein being “incomplete,” but stated there are important differences between plant and animal protein that influence health outcomes. Compared to plant-based protein, animal protein has a much higher proportion of the branched-chain amino acids (BCAA). When excessive they can exacerbate disease.
The BCAA comprise about 35% of the nine essential amino acids (those derived only from food) in the human body. We increase our body-load of BCAA by consuming animal products, but a type-2 diabetes “treatment” diet is often higher in meat and, therefore, higher in BCAA. This strategy may not be optimal for lowering insulin resistance.
“Elevated plasma levels of BCAA have consistently been linked to insulin resistance in type 2 diabetes….emerging evidence suggests that the accumulation of their downstream metabolites…could play a crucial role in exacerbating insulin resistance[i].
In studies on different species, including humans, when we lower animal protein intake, key indicators of metabolic health improve.
“Our results highlight a critical role for dietary quality at the level of amino acids in the maintenance of metabolic health and suggest that diets specifically reduced in BCAAs…may offer a translatable way to achieve many of the metabolic benefits of a PR (protein restricted) diet.”[ii]
What’s this!? The health-science researcher described “metabolic benefits” of restricting the BCAA—meaning animal products. We were told that ample protein is good and a little more is better — and because fatty meals require less insulin, animal products in the diet are a health benefit. This is an important, present-day component of the American Diabetes Association’s “diabetes diet.”
The current, U.S.D.A. recommendation for protein intake (regardless of source) is between 10-percent and 35-percent of total daily calories, but SOURCES MATTER. Getting 35-percent of calories from animal protein is NOT optimal for health. Below are some weight-loss and diabetes treatment diets and their protein intake.
For today’s weight-loss “Paleo Diet” program, daily calories are about 25-percent protein.
The American Diabetes Association “Diabetes Diet” for people with type-2 diabetes, is about 20-percent protein[i].
In a review of studies of diet and diabetes indicators, all of which included randomized control trials, higher plant protein consumption correlated with “significant modest improvement” in fasting insulin, fasting glucose, and hemoglobin-A1c. The review study concluded that plant protein improved serum-glucose in type 2 diabetics when compared to animal protein[ii].
The same outcome can be inferred for weight loss, because excessive body fat is frequently caused by the same problem, elevated serum insulin and uncontrolled blood-sugar.
Regarding the epidemic of persistently excessive insulin (insulin resistance) here is a key concept the public is not being told and I hope readers will grasp. To do so, below I’ll use the cheeky all caps:
ALL the dietary macronutrients are involved in insulin resistance, NOT SOLELY REFINED CARBOHYDRATES AND SUGAR.
For the type-2 diabetic person blood glucose and insulin are definitely problems. What’s causing the problem is that insulin receptors embedded in cell membranes are jammed-up with fat (triglycerides) and the damaged cells can’t replace the dysfunctional ones. This subject is covered in more detail on the page Insulin and Metabolic Disease.
[i] The Effect of the Paleolithic Diet vs. Healthy Diets on Glucose and Insulin Homeostasis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Malgorzata Jamka, Bartosz Kulczynski, Agata Jurac, et al. J Clinical Medicine 2020. Jan 21;9(2):296.
[ii] Effect of Replacing Animal Protein with Plant Protein on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. E. Viguiliouk, S.E. Stewart, V. H. Jayalath, et al. Nutrients, December 2015.
[i] The role of branched-chain amino acids and their downstream metabolites in mediating insulin resistance. A.M. Abdualkader, Q. G. Karwi, G.D. Lopaschuk and R. A. Batran. Journal of Pharmacy and Pharmaceutical Sciences, 2024, Vol. 27.
[ii] Decreased Consumption of Branched-Chain Amino Acids Improves Metabolic Health. Luigi Fontana, Nicole E. Cummings, Sebastian I. Arriola Apelo, et al. Cell Reports, Jul 12; 2016(2):520-530.
About Those Troublemakers
About 500 amino acids have been identified in nature. Our body and brain use twenty-two, nine of which we must get with food. With these, we construct all our protein arranged in countless ways: muscle tissue, collagen, enzymes, cholesterol, hemoglobin, neurotransmitters, hormones and so forth.
The four “troublemakers,” as I call them, are unavoidable: methionine, isoleucine, leucine, and valine. The last three listed differ from the other 19, having a branched structure, hence the name branched-chain amino acids—BCAAs. The table on the right shows the percentage by which these four “troublemakers” are reduced when we lower animal-source of protein. We can reduce the BCAA, not avoid.
Adapted from: Defeating Diabetes (2003), authors Brenda Davis, RDN and Tom Barnard, MD.
As we considered above, diets high in animal protein elevate “the troublemakers” in circulation and this requires more insulin than if the protein was plant-based. In his summary, Dr. Abdualkader, a diabetes researcher with the Montreal Diabetes Research Center, writes:
Branched-chain amino acids “…appear to have unique effects in obesity-induced insulin resistance, and they are considered a major contributor to the pathology of type 2 diabetes and coronary artery disease.”[i]
The essential amino acid methionine is not “branched.” It’s the amino acid about twice as concentrated in animal protein compared to protein from plants (table above). Moreover, methionine is the dietary amino acid “most vulnerable” to free-radical damage. Mammalian studies show that increasing methionine intake correlates to a shorter life. Conversely, lab diets low in methionine extend animal lifespan “by as much as 44-percent.”[ii]
Plant-sourcing our protein allows a body to lower dietary methionine by about half! Elevating plant-sourced protein significantly reduce free-radical damage to DNA and the mitochondria, the power plants in all cells. Methionine’s breakdown-products have been shown to activate the enzyme mTOR (mechanistic target of rapamycin)—described variously as “childhood’s engine of growth” and “a speeding car without brakes”[iii]—not what adult bodies need lots of.
[i] Ibid– The role of branched-chain amino acids…. A.M. Abdualkader, Q. G. Karwi, G.D. Lopaschuk and R. A. Batran, 2024
[iii] How Not to Age (2023). Michael Greger, M.D. Flatiron Books—Pg 101.
Dairy Foods and the BCAAs
I fully appreciate that dairy intake is somewhat sacred in America. I certainly drank lots as a kid and my English and German ancestors were undoubtedly big milk-drinkers. I discuss milk and health in several sections, here and under Protein Sources and Hazard Ratios, the last section of this page.
A cow’s milk has three-times more of the BCAA leucine than does mother’s milk. Leucine is a potent activator of mTOR, the special enzyme absolutely critical for infant mammals. Extra leucine is great for super-fast growing rat-pups or the newborn calf that will achieve 400 pounds or more in five or six months. Not so optimal for humans.
Human infant growth is comparatively slow. Optimal human growth in both height and weight is manifest through the human mother’s milk, growth factors, enzymes, proportional fats, and protein. Plugging the toddlers, teens and post-reproductive adults into cow’s milk — our societal pattern of high levels of dairy intake — is especially problematic when we least expect it, decades later. Researchers have now associated higher intake of dairy products with higher incidence of bone fractures and diseases, including heart disease and cancer.
At 6-foot 5-inches, and now in my mid-60’s, I can say with some personal experience (that began in my teens) that increasing upward growth velocity does not mean “healthy.” More bone fractures from drinking milk? Isn’t that exactly what the U.S.D.A. believed more milk would prevent? Yes.
Strong bones and teeth, right? Taller people break more hips and have more skeletal problems, not fewer. Again, some additional discussion about milk intake is below in the section titled Protein Sources and Hazard-Ratios.
In our teaching and regulation, plant protein has gotten the short end of the stick. Key Concept: plant-sourcing more of your daily protein, avoids a bunch of unhealthy baggage: excessive branched chain amino-acids, mTOR, saturated fat and cholesterol.
Vascular Disease and Safety Talk
A few years ago in early July, I was the Wednesday morning volunteer DJ at the Haines public radio station, KHNS-FM. The Safety Talk, a top-notch community safety program sponsored by the Haines Volunteer Fire/EMS Department, was supposed to begin in a few minutes.
Right on que, two savvy volunteers pile into the control room, rap-sheets in hand. With a minute to spare, Al and Lyle were settled in. I adjusted the microphone-levels and cued the theme music to The Good, Bad, and Ugly.
At 8:45am, Fireman Al and Lyle launch into a no-nonsense, scripted safety conversation. This particular program focused on how to respond when there is a medical emergency. Over the years, unquestionably, “Safety Talk” has saved lives in Klukwan, Haines and Skagway, Alaska and many millions of dollars in property damage.
Wasn’t vascular sickness more complex? And didn’t you guys just raise money with a classic, July 4thBrisket Barbecue with all the fixins’? Well, after some very careful research, I can say that Lyle’s analogy is not wrong……however, acquiring vascular disease is complex; more so that just eating too many eggs or too much bacon and brisket.
Atherosclerosis is the scientific name for vascular disease and it does look a bit like chicken fat. Down the line, the blood vessel sickness with a hard-to-spell name, can mean hypertension, heart disease, stroke, vascular dementia, peripheral arterial disease, diabetes, amputations, blindness, on and on. Lyle’s entirely fair analogy just doesn’t capture a host of related factors.
Other Factors Associated with Blood Vessel Sickness:
Insufficient dietary fiber
Diets lacking in plant-sourced antioxidants
Excessive fat, white flour and sugar that elevate serum triglycerides
Elevates blood-sugar and insulin receptors jammed-up with fat (insulin resistance)
Elevate free-radical production (oxidative stress) that oxidizes LDL-cholesterol
Chronic stress and hacked eating hormones
Emotional eating and the lack of social connections
Health-science has correlated all of the above with vascular disease. These same complex factors were in play back in the 1950’s when the “diet-heart hypothesis” first vilified saturated fat, but scientists didn’t have the tools to discover those associations.
Unfortunately, it gets worse.
Atherosclerosis, TMAO and Red Meat
Choline is an important nutrient found in many whole foods. It is lower (but adequate) in vegetable sources. It is highest in red meat and eggs—peaking in the organ meat often used in processed meat products, like bologna and hotdogs. The “adequate intake” level for choline is about 500mg/day.
Your gut bacteria break down choline and produce a byproduct called tri-methyl-amine, which your liver then converts into TMAO—tri-methyl-amine-N-oxide and some other equally nasty byproducts. Excessive serum TMAO, derived from an everyday high meat diet, has an incontrovertible association with the oxidation of LDL-cholesterol. Bad news.
Today, I am personally not a vegetarian, but I sure get it! I do limit my animal-product intake and I certainly appreciate the arguments dealing with animal cruelty and environmental impacts. Eating less animal-based food is healthier. Eating lots of animal products–whether from wild game or an Omaha feedlot–means more TMAO and its kin and higher risk of vascular disease, especially where whole plant foods are very low or absent—as in the (very dangerous) Standard American Diet.
A 2022 study of disease risk and red meat intake, involving 3931 adults followed over a 12-year period, indicates that eating 1.1 servings of red meat daily increased the risk of atherosclerotic coronary vascular disease by 22-percent[i]. Whether you lay off the meat, or not, for Pete’s sake, increase your intake of high-fiber vegetables—salads first and big.
Only 10% of the U.S. is achieving our daily fruits and vegetable recommendation. These are the only foods that get you to the daily fiber intake recommendation of 25-grams for women and 38-grams for men, as recommended by the U.S. Centers for Disease Control.
Animal products contain no fiber and no antioxidants.
[i] Dietary meat, trimethylamine N-oxide-related metabolites, and incident cardiovascular disease among older adults: the Cardiovascular Health Study. Meng Wang, Zeneng Wang, Yulin Lee, et al. Arteriosclerosis, Thrombosis, and Vascular Biology, 2023, Vol. 42(9): 273-288
Body Fat and Cancer Risk
When a body adheres to the Standard American Diet (one-third animal-products and nearly 60-percent highly processed plant calories), it will also increase many well-known disease markers—chief among them body fat. Men and women with more body fat produce higher levels of estrogen and the more you have in circulation the higher is the level of your insulin-like growth factor-1 (IGF-1)—a messenger that helps cells connect to a blood supply. That’s not a happy event where cancer is concerned. With a blood supply, cancerous cells can thrive, multiple, and become a tumor.
In our bodies, some random cells have mutated DNA and are floating around amongst trillions of normal cells. Technically, they may be “cancerous”, but that may not mean you get “C.” Mixing in some extra IGF-1 increases the risk of those mutated cells a) tapping into a food supply (glucose), b) dividing, and with time c) creating a spreading cancer mass. Dr. Michael Greger comments:
“Animal protein seems to be the main culprit….men and women who avoid meat, eggs and dairy proteins have significantly lower IGF-1 levels, even when their diets exceed protein recommendations [due to higher plant protein intake].[i]”
We can see the excess weight with our eyes, but we cannot see, nor commonly measure, the parallel increases in estrogen and serum IGF-1. Breast cancer treatment expert, Dr. Kristi Funk reports “no controversy.” “Overweight women do have excessive estrogen in the blood and it does promote cancer.” Citing studies of breast cancer risk and weight gain, Funk notes that women who added weight after high school also increased their cancer risk:
Adding 8 – 14 pounds increases risk 25%
Adding 14 – 29 pounds increase risk 60%
Above 29 additional pounds increases risk 200%
Dr. Funk also reports that “all cancer treatments are less effective” in overweight and obese people[ii]. Here again, we see the benefit of swapping out animal protein for plant protein–lowering disease risk. Trading-out just five-percent of your animal protein with plant sources lowered dementia diagnoses by twenty-percent[iii]. Swapping animal protein for high-protein plant foods is exactly what Harvard’s School of Public Health is now saying we need to do to lower risks for all-cause mortality[iv].
[i] How Not to Age (2023), Michael Greger, M.D. Flatiron Books. pg 71
[ii] Kristi Funk, M.D., breast cancer treatment specialist. Presenter in Food Revolution Network Plant Based Coaching Certification program.
[iii] How Not to Age (2023), Michael Greger, M.D. Flatiron Books.
[iv] Association of Animal and Plant Protein Intake with All-Cause and Cause-Specific Mortality. Mingyang Song, MD, Teresa Fung, ScD, Frank Hu, MD, PhD, et al. Journal of the American Medical Association, Internal Medicine, 2016, Vol 176(10: 1453-1463
Cholesterol: the Good, Bad and Ugly
Total cholesterol is a clunky measurement. It’s comprised of three factors—one good, one bad and one ugly. Respectively, HDL, LDL, and triglycerides. The medical system has measured “serum cholesterol” (total cholesterol) since at least the 1940’s.
The current recommendations imply that serum cholesterol up to 200 mg/dL is OK. In fact, there are people who have familial (genetic) high cholesterol, irrespective of diet. For average folks, the C.D.C. advises try to keep it “less than 200.” The assumption would, therefore, be that “200” is pretty protective for stroke or heart disease, wouldn’t you think? I looked at data from the Framingham Heart Study and found something interesting.
Ongoing since 1948, the Framingham Heart Study began before we could reliably measure LDL and HDL. For the Framingham participants, ages 40 to 60 who had a heart attack, over one-quarter had total cholesterol at or below 200mg/dL.[i]
From research and lifestyle medicine, we know that vascular disease is about impossible when total cholesterol is at or below 150mg/dL[ii]. Thus, for several generations of Framingham study participants, one-quarter who had a heart attack between age 40 and 60, the total cholesterol number was between, say, 160mg/dL and 200mg/dL.
Here’s my point. It’s impossible for me to conclude that a total cholesterol reading approaching “200” will protect you from cardiovascular disease. For context, hundreds of thousands of Chinese tested in the early 1980’s averaged total cholesterol of 127mg/dL!! Meaning, around half had cholesterol well below this very, very low (to us) value![iii] At that time, before the “western” burgers, pizza, dairy, etc., China’s heart disease and cancer rates were extremely low. Keeping cholesterol low reduces your risks for more than heart disease.
Eggs are a top-notch source of both cholesterol and TMAO (described above). Will eating a half-dozen eggs weekly elevate the risk for heart disease? The CDC recommends keeping daily cholesterol intake to under 300mg and there are about 210mg in one chicken egg. So, hell ya. A half-dozen a week is not a “heart-healthy” food habit, and vascular disease is what kills us most of the time. As noted elsewhere, most of the 40-percent of U.S. adults who are diabetic or pre-diabetic will actually die from a complication of vascular disease.
Statins
Got hypertension or elevated cholesterol? No problem. Disease Care, Inc. has numerous handy pills for that. There is no question that the use of a statin drug can be both a health benefit and an expedient. For many with a fresh prescription for a statin, the vital signs of vascular disease were “blinking red” for years, if not decades. In 2022, to lower hypertension or LDL-cholesterol, U.S. doctors prescribed statin drugs[1] 800-million times—to about one-quarter of the U.S. population (80-million individuals).[iv]
[1] Seven different medications are classed as “statins.”
[i] Wilson, P. 2013. Lipids and Vascular Disease: a Framingham Perspective.
[ii] Prevent and Reverse Heart Disease (2008). Caldwell Esselstyn, M.D.
[iii] The China Study (2006). T. Colin Campbell, Ph.D. and Thomas M. Campbell. Benbella Books
[iv] Source: https://clincalc.com/DrugStats/Top300Drugs.aspx
Protein Sources and Hazard Ratios
Dairy intake in Italy was studied. The 45,000 participants were surveyed over a 19-year period. Researchers discovered the beneficial correlation of drinking less than one-cup of milk daily—2oz to 5oz (50g – 160g/day)[i]. A similar result is seen in Japan where overall dairy intake is far lower than in the U.S.[ii]. Here we are, again considering dairy; this time comparing milk and other protein sources from the view-point of hazard for all-cause mortality.
Both studies computed a “hazard ratio” for all-cause mortality. Those who drank some milk regularly lived longer than those who did not.
The image at above-right shows the diversity of foods with ample protein. Below, I present U.S. data from research lead by scientists at the Harvard School of Public Health—a comparison of dairy to other, animal-based protein sources—in terms of the hazard ratio of each for all-cause mortality. The data-base for Harvard’s analysis was 131,342 U.S. men and women surveyed over a 32-year period[iii] As shown, all-cause mortality risk from sourcing protein from plants, poultry and fish is lower than is dairy (the black line). Red meat and eggs (on the right) have a higher association with all-cause mortality, processed meat being by far the worst.
I derived the graph (right) from a similar presentation in Milk and Health (2021). Lead author, Walter C. Willett, Ph.D., is the long-time professor at Harvard’s School of Public Health, Dept. of Nutrition and Epidemiology. Willett’s earlier work helped clarify the benefits of the traditional Mediterranean Diet. The same diet-style is shown at the top of this web-page as the “Healthy Eating Plate.” In the study’s conclusion, the authors recommend limiting the consumption of cow’s milk to zero to two-cups daily (or the equivalent of other dairy foods). Key take-home message: more is not better.
The researchers concluded that, if you already have good overall nutritional access, there may be no benefit in consuming any dairy foods. Less than one-cup daily—beneficial; zero to two—probably OK. Dr. Willett’s recommendation offers flexibility, a clear caveat, and is very different from the current U.S.D.A. recommendation of “three-cups daily.”
Then, Dr. Willett shatters two sacred cows of the dairy industry–Calcium and Vitamin D:
“For calcium, alternative dietary sources include kale, broccoli, tofu, nuts, beans, and fortified orange juice; for vitamin D, supplements can provide adequate intake at far lower cost than fortified milk.”[i]
On the far-left side of the above graph you find the most beneficial, lowest-risk-approach to sourcing protein—plants! Nuts, seeds, legumes, tofu, dark greens, yada, yada.
With or without some animal products, obtaining more protein and fats from whole-plant sources yields the greatest health, longevity, and disease fighting. Compared to years ago, agencies and health-science institutions—like the Harvard School of Public Health, Cleveland Clinic, UCLA, the C.D.C., the National Institutes of Health, and so forth—are recommending much lower, more selective levels of animal product consumption. Naturally, that means less animal protein and more from plant sources.
[i] Ibid–Milk and Health. Walter C. Willet, Ph.D, David S. Ludwig, M.D
Bibliography
Brenda Davis, RDN—presenter in Food Revolution Network Plant-Based Coaching Certification program
The Queen of Fats: why omega-3 fats were removed from the western diet and what we can do to replace them (2008). Susan Allport. University of California Press.
The Demise of Artificial Trans Fat: A History of a Public Health Achievement Amico, A., Wootan, M.G., et. al. Milbank Quarterly, 2021 Sep; 99(3): 746–770.
Nutritional Approaches for Management of Metabolic Acidosis in Chronic Kidney Disease. A. Noce, Guilia Marrone, G. W. Jones, et al. Nutrients, July, 2021
Good Calories Bad Calories (2007), Gary Taubes. Alfred A. Knopf Pub.
Statistics from website of the U.S. Center for Disease Control, December 2024
Thigh adipose tissue distribution is associated with insulin resistance in obesity and in type-2 diabetes mellitus. Bret H. Goodpasture, F Leland Thaete, and David E. Kelley. Am. J Clinical Nutrition 2000 Apr;71(4):885-92.
High-protein intake during weight loss therapy eliminates the weight loss-induced improvement in insulin action in obese postmenopausal women. Gordon I. Smith, Jun Yoshino, Shannon C. Kelly, et al. Center for Human Nutrition and Atkins Center of Excellence in Obesity Medicine, Washington University School of Medicine, St. Louis. In Cell Report, 2016
The role of branched-chain amino acids and their downstream metabolites in mediating insulin resistance. A.M. Abdualkader, Q. G. Karwi, G.D. Lopaschuk and R. A. Batran. Journal of Pharmacy and Pharmaceutical Sciences, 2024, Vol. 27.
Decreased Consumption of Branched-Chain Amino Acids Improves Metabolic Health. Luigi Fontana, Nicole E. Cummings, Sebastian I. Arriola Apelo, et al. Cell Reports, Jul 12; 2016(2):520-530.
The Effect of the Paleolithic Diet vs. Healthy Diets on Glucose and Insulin Homeostasis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Malgorzata Jamka, Bartosz Kulczynski, Agata Jurac, et al. J Clinical Medicine 2020. Jan 21;9(2):296.
Effect of Replacing Animal Protein with Plant Protein on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. E. Viguiliouk, S.E. Stewart, V. H. Jayalath, et al. Nutrients, December 2015.
Ibid– The role of branched-chain amino acids…. A.M. Abdualkader, Q. G. Karwi, G.D. Lopaschuk and R. A. Batran, 2024
How Not to Age (2023). Michael Greger, M.D. Flatiron Books
How Not to Age (2023). Michael Greger, M.D. Flatiron Books—Pg 101.
Gut microbiota in atherosclerosis: focus on trimethylamine N-oxide. Yingqian Zhu, Qingqing Li Jiang. Journal of Pathology, Microbiology and Immunology, 2000 Vol 128(5): 353-366.
Dietary meat, trimethylamine N-oxide-related metabolites, and incident cardiovascular disease among older adults: the Cardiovascular Health Study. Meng Wang, Zeneng Wang, Yulin Lee, et al. Arteriosclerosis, Thrombosis, and Vascular Biology, 2023, Vol. 42(9): 273-288
How Not to Age (2023), Michael Greger, M.D. Flatiron Books. pg 71
Kristi Funk, M.D., breast cancer treatment specialist. Presenter in Food Revolution Network Plant Based Coaching Certification program.
How Not to Age (2023), Michael Greger, M.D. Flatiron Books.
Association of Animal and Plant Protein Intake with All-Cause and Cause-Specific Mortality. Mingyang Song, MD, Teresa Fung, ScD, Frank Hu, MD, PhD, et al. Journal of the American Medical Association, Internal Medicine, 2016, Vol 176(10: 1453-1463
Wilson, P. 2013. Lipids and Vascular Disease: a Framingham Perspective.
Prevent and Reverse Heart Disease (2008). Caldwell Esselstyn, M.D.
The China Study (2006). T. Colin Campbell, Ph.D. and Thomas M. Campbell. Benbella Books
Source: https://clincalc.com/DrugStats/Top300Drugs.aspx
New Horizons: Dietary protein, ageing, and the Okinawan ratio. D. G Le Couteur, S Solon-Biet, D. Wahl, et al. Age and Ageing, 2016, Vol. 45: 443-447
Associations of dairy product consumption with mortality in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy cohort. Valeria Pala, Sabina Sieri, Paulo Chiodini, et al. The American Journal of Clinical Nutrition, Vol 110, Issue 5, Nov. 2019, pages 1220-1230
Association between dairy intake and mortality due to all cause and cardiovascular disease: the Japan Public Health Center-based prospective study. Sanyu Ge, Ling Zha, and Tomotaka Sobue, et al. European Journal of Nutrition, 2023, Vol 62: 2087-2104
Ibid–Association of Animal and Plant Protein Intake with All-Cause and Cause-Specific Mortality..
Ibid–Milk and Health. Walter C. Willet, Ph.D, David S. Ludwig, M.D