For nearly two decades, we’ve been bombarded with sensationalist headlines claiming that “red meat causes cancer.” Terrified by the news, many people have significantly limited or completely given up their consumption of beef and other red meats, opting instead for chicken or fish. Some have decided to give up meat altogether, adopting vegetarian or vegan lifestyles they believe are better for their bodies and the planet. As you will see below, however, not only does red meat not cause cancer, it is in fact an extremely healthful, nutrient dense food that can help you avoid the very degenerative diseases it’s been claimed to cause.
The Flawed Science Behind the Headlines
While many news stories and study abstracts seem to paint a clear, causative connection between red meat consumption and cancer, an honest review of the science behind these grand claims reveals a number of problems:
- Correlation is NOT Causation. Most of the studies claiming to show a link between red meat and cancer were observational, not clinical. By definition, observational studies can only tease out correlation, not causation.
- The Healthy User Bias. When it comes to red meat consumption, studies will always suffer from confounding variables caused by the “healthy user bias”. Red meat has been aggressively maligned in the media for so long that most people who actively avoid it do so because they think it is the healthy thing to do. Such people are also more likely to exercise regularly and less likely to indulge in other unhealthy behaviors such as drinking alcohol, smoking cigarettes, and eating sugar, refined carbohydrates, trans-fats, fast food, processed foods, and so on. Just take a look at the rate of alcohol abstinence among vegans, vegetarians, and omnivores: 75% of vegans completely abstain from alcohol, 25% of vegetarians, and only 8% of omnivores. A similar pattern can be seen for smoking: 94% of vegans abstain from tobacco, 74% of vegetarians, and 67% of omnivores. ((Source: Maria Gacek, “Selected Lifestyle and Health Condition Indices of Adults With Varied Models of Eating.”))
- Food Frequency Questionnaires Are Unreliable. Observational studies usually rely on self-reported “Food Frequency Questionnaires” which are notoriously faulty since 1) they rely on feeble memories (quick, tell me exactly what you ate for dinner a week ago today!), and 2) people often have an overly optimistic perception of what they tend to eat.
Food Quality Matters
A big problem with well publicized studies claiming to link red meat and cancer is that they don’t control for differences in food quality or confounding variables like 1) what the animal ate (grass vs corn), 2) whether the meat is processed, 3) if/how the meat is cooked, and 4) what the meat is consumed with (e.g. french fries). When you say “red meat”, are you referring to:
- A) Processed hot dogs charred to death on a BBQ, or B) Unprocessed steak cooked at low heat?
- A) Beef from corn-fed, antibiotic-laden feelot cows, or B) Beef from healthy cows eating only grass as they are evolved to do?
- A) A hamburger patty served on a white bun (refined grains that spike insulin levels and irritate the gut) with a side of Coca Cola ® (refined sugar) and french fries (more carbohydrates, all fried in pro-inflammatory omega-6 vegetable oils), or B) Properly-sourced ground beef served on a bed of organic lettuce?
You Are What You Eat Eats
We’ve all heard the phrase, “You are what you eat.” And this is certainly true. But what’s equally important is that we are what we eat eats! All animals have evolved to eat certain things, including cows and humans. Humans are lucky (or perhaps cursed) in that we can survive and even thrive on a variety of foods, but cows are designed to eat only thing: grass.
When cows are fed the wrong foods (corn, grain, and artificial nutrients), bad things happen to the cows, and to the humans who eat them. Illness and nutrient deficiencies are the rule, not the exception, in CAFOs (concentrated animal feeding operations). Sick cows then require antibiotics, which damage the proper gut flora balance of cows, and later in the humans who eat them. Proper gut flora is essential for cow and human health, helping keep dangerous strains of bacteria in check, helping us better digest foods, and even creating important nutrients as byproducts:
- Short-chain fatty acids (which feed the cells of the colon in humans and provide cows most of their energy).
- Vitamin K2 (works hand in hand with other vitamins and minerals to help maintain a healthy heart and bones).
- Vitamin B1 (essential for cardiovascular health).
- Vitamin B2 (which helps break down proteins, fats, and carbohydrates, and is involved in energy production).
- Vitamin B12 (helps maintain the health of nerve and blood cells, and is involved in the production of healthy DNA).
Conversely, cows raised exclusively on grass have:
- More Omega-3s. Though exact amounts vary based on the breed of cow and bio-individual differences, grass-fed beef generally contains 2 to 5 times more Omega-3 fatty acids than cows raised on grain.
- More Conjugated Linoleic Acid (CLA). This amazing PUFA (polyunsaturated fatty acid) acts as a powerful antioxidant and research suggests that it can help prevent a number of chronic degenerative diseases, including heart disease, diabetes, and cancer. The flesh and milk of cows is one of the best sources of the substance, but grain-fed beef products have 2 to 3 times less than their grass-fed brethren.
- A higher percentage of stearic acid. Though saturated fat in general is not the villain it has been made out to be in the mainstream media (read Is Saturated Fat Bad For You?), certain kinds of saturated fat (e.g. palmitic and myristic acid) can raise blood cholesterol levels more than others (e.g. stearic acid). Though grass-fed and grain-fed cows have the same percentage of total saturated fat, the percentage of saturated fat made up of stearic acid is higher in the grass-fed variety.
Red Meat is a Superfood
Red meats, especially organ meats, are one of the most nutrient dense foods on the planet, rich in:
- Vitamin A. Sufficient vitamin A is critical for growth, proper function of the immune system, the ability to reproduce, and good vision. But munching on a bag of carrots is not as a good strategy for getting vitamin A as eating animal products rich in the vitamin. Meat contains the bioavailable form of vitamin A known as “retinol”, while plants only contain “provitamin A carotenoids”, a form that must be converted in the body (a conversion that most people can’t do very well, or not at all, thanks to genetic mutations, liver diseases, food allergies, celiac disease, parasite infection, or deficiencies in minerals like iron or zinc).
- Vitamin B12. B12 is critical for healthy 1) nerves (especially myelin sheaths, the “electrical insulation” around brain cells required for proper function of the nervous system), 2) blood cells, and 3) DNA. This crucial nutrient is only found in animal products. You may have heard that it can be derived from seaweed, too, but it is important to note that plants can only create B12 analogues that the body cannot use as well as the more bioavailable form found in meat. Because of this, vegetarians and vegans are frequently deficient in the vitamin, leading to an increase in homocysteine levels, putting people at higher risk of heart disease.
- Vitamin D. Really a hormone, vitamin D plays a number of crucial roles in the body, including 1) the regulation of bone growth and strength, and 2) proper function of the immune system. Though we can (or rather should) get most of our vitamin D from sun exposure, red meat is a good boost during the winter months and for those who live in cloudy areas since it contains 25-hydroxycholecalciferol (a highly bioavailable form of vitamin D).
- Vitamin K2. As mentioned above, K2 can be created by some bacteria (found in your gut and in fermented foods like natto and sauerkraut). But if stinky, sticky soy beans are not your thing, not to worry: vitamin K2 is also rich in organ meats and dairy. It is important to note that vitamin K2 (menaquinone) and K1 (phylloquinone, found in leafy green vegetables) are not the same. Both are necessary for optimal health, but K1 alone will only help with blood clotting, while K2 is involved in the health of blood vessels, your bones, and more.
- Heme Iron. The human body can absorb and use the form of iron found in red meat, “heme iron”, much better than plant-based non-heme iron. While some people, especially men or those with hereditary hemochromatosis can suffer from iron overload (there is a simple blood test to check for this), many people are deficient. Women are especially at risk, and those who are pregnant or trying to conceive should be especially vigilant about getting sufficient bioavailable iron as it is required for the proper development of a baby’s brain.
- Zinc. Red meat is a great source of this vital mineral, which has numerous critical functions in the body, including 1) the production of sufficient stomach acid (which you need to break down proteins and extract minerals), 2) maintaining healthy male sexual function, 3) ensuring a strong immune system), 4) building the proper structure of various proteins and enzymes, and 5) regulating gene expression.
And even though some of the above nutrients can be obtained from plant sources, their animal based counterparts are far more bioavailable.
Grass-Fed Red Meat is Even Good for the Planet
Natural food chains (evolved over millions of years) are far healthier—not only for our bodies, but also for the planet and the economy—than the industrial food chains that have sprung up to replace them in the last century. By eating grass (nature’s solar cells), ruminant animals such as cows, sheep, bison, etc., convert sun energy (a clean, free, virtually endless fuel source) into nutrient-dense protein and fat. And while doing so, they help fertilize grasslands with their manure, create ideal seed germination pools when their hoofprints fill with water, and help grasslands remain grasslands; without ruminant animals grazing upon them, many grasslands would become deserts.
Some ecologists and vegetarians have argued, however, that it is more efficient calorically to raise crops instead of cattle since a significant amount of food energy is lost when one animal eats another (9 calories for every 1 we eat). There are three big problems with these arguments:
- Non-arable grass lands could not be used for row crops anyway.
- Even for land that can be used to grow crops, far more more nutrients are produced per acre when ruminants eat grass on well-managed pasture than in an acre of farmed grain.
- Since pasture doesn’t required fossil fuel based fertilizers, grassing over existing crop lands would reduce reliance on fossil fuels.
Even from an ethical point of view, eating large animals raised on grass is better than growing crops as Michael Pollan details well in The Omnivore’s Dilemma:
“Killing animals is probably unavoidable no matter what we choose to eat. If America was suddenly to adopt a strictly vegetarian diet, it isn’t at all clear that the total number of animals killed each year would necessarily decline, since to feed everyone animal pasture and rangeland would have to give way to more intensively cultivated row crops. If our goal is to kill as few animals as possible people should probably try to eat the largest possible animal that can live on the least cultivated land: grass-finished steaks for everyone.”