by Mark Hyman
To learn more about how gut flora is connected to your weight and the risk of heart disease, diabetes, and cancer (and how to get good bacteria and cultivate a healthy inner garden), see my free e-book Beyond Food: Other Causes of Obesity and Damaged Metabolism and follow the section on “How to Tend Your Inner Garden.” You can download it at www.eatfatgetthin.com.
DOES RED MEAT CAUSE TYPE 2 DIABETES AND WEIGHT GAIN?
There have been some studies linking meat intake to type 2 diabetes.19 The Health Professionals’ and Nurses’ Health Study of more than 400,000 people followed for decades was based on food questionnaires. Researchers found that a 50-gram serving of processed red meat, like hot dogs and deli meats, increased the risk of type 2 diabetes by 51 percent, and the same serving of fresh red meat increased the risk by about 20 percent. But these numbers show relative risk, not absolute risk. In other words, if you reduce the risk from 3 percent to 2 percent, that’s a 30 percent “relative” risk reduction, but it is only a 1 percent reduction in actual risk. So in the Nurses’ Health Study the actual risk (or absolute risk) increase for fresh red meat was from 7 percent to 8.4 percent. But again, the meat eaters in the study were also not so healthy overall. They exercised less than the non–meat eaters; smoked more; drank soda, sugar-sweetened beverages, and more alcohol; ate more sugar, processed food, fried foods, and trans fats; and ate fewer vegetables but more potatoes. So was it the meat or the soda? I vote for the soda!
The researchers were very clear to warn readers that this study could not prove cause and effect, yet they went on to say, paradoxically, that we should reduce red meat and processed meat to reduce type 2 diabetes. What they really should have been saying is that if you eat red meat and have an otherwise crappy diet, don’t exercise, smoke and drink too much, and eat lots of sugar, your risk of diabetes goes up 1.4 percent. Not too convincing, in my opinion.
Other studies using a higher intake of meat without the accompanying sugar or starch, like grains or beans (a caveman-like diet), found that blood sugar was even better controlled than in the Mediterranean diet, which is well known to help improve blood sugar levels.20 Another study found that the Paleolithic diet far outperformed a traditional diabetes diet in controlling blood sugar and cardiovascular risk factors.21 And in a two-year study on obese postmenopausal women, the women following the Paleolithic diet lost twice as much weight after two years and reduced their belly fat by twice as much as the women following recommendations for weight loss according to the Nordic Nutrition Recommendations.22 These recommendations are what the Nordic scientists and countries deem a healthy dietary pattern and include plenty of vegetables, fruits and berries, beans, regular intake of fish, vegetable oils, whole grains, low-fat versions of dairy and meat, and limited intake of red and processed meat, sugar, salt, and alcohol.
DOES RED MEAT CAUSE CANCER?
This is a big, scary question, I know… so let’s tackle it.
Most of the data we have is about colon cancer. In a review of more than thirty-five prospective studies on colon cancer and meat consumption, there was little risk found.23 In fact, in some studies, those with the highest meat intake had lower risk than those with the lowest intake. What they did find, of course, was that meat eating was also associated with other dietary and lifestyle habits that promote cancer, including high intake of refined sugar and alcohol and low intake of fruits, vegetables, and fiber. The meat eaters also generally didn’t exercise, smoked more than non–meat eaters, and were more overweight, all of which are associated with an increased risk of cancer.
As I’ve mentioned, some studies do link processed red meat, such as hot dogs, bacon, and luncheon meats, to cancer.24 A 2015 World Health Organization (WHO) report on meat and cancer found that processed meats did increase cancer risk. The effects of red meat were not conclusive. Let me translate what that increased risk actually means. The WHO found that processed meat increased cancer risk by about 20 percent; that is what we call relative risk. It is quite different than the absolute risk, or the true change in risk. If your absolute risk goes from 1 to 2 percent, the relative risk increase is 100 percent. Sounds impressive. But the absolute risk increase was only 1 percent. Not too impressive. So in the WHO study, the absolute risk of getting cancer would be an increase from a 2.6 percent to a 3.2 percent chance of getting cancer—or about a 0.6 absolute increase in risk. In other words, about three extra appearances of colon cancer in every 100,000 people, for the bacon eaters. This is not too impressive. Cancer is also linked to compounds that form when you cook meat;25 we’ve all heard the dire warnings about charred meat being carcinogenic. What’s the real story?
Indeed, some things happen when you cook meat that may be harmful. High-temperature cooking, grilling, frying, smoking, or charring meat, including fish and chicken, all lead to the production of compounds call polycyclic aromatic hydrocarbons (PAH) and heterocyclic amines (HCA).26 HCAs and PAHs have been shown to cause cancer in animal models, and it is a good idea to reduce your exposure to these toxic compounds.27 But meat is not the only source of PAHs. Surprisingly, other than meat charred over an open flame, the most common source is vegetables and grains.28 So much for grilled vegetables!
The take-home message is to focus on low-temperature cooking of meat (and veggies), including baking, roasting, poaching, and stewing. Think crockpots and a method of low-temperature poaching that is gaining popularity called sous vide, where food is cooked in water in airtight plastic bags. I don’t like to cook in plastic, but some may choose to do this. Just be sure to get BPA-free and heat-stable plastic so toxins don’t leach into the food.
Cooking meat can also produce compounds called AGEs, which result from protein interacting with sugars in food. These are what make things crispy—the crust that forms on a loaf of bread, crispy chicken skin, or the crunchy sugar top on crème brûlée. AGEs damage arteries and the brain, and they can cause cancer. Your best bet is to reduce high-heat cooking and grilling. Another tip to reduce AGEs, HCAs, and PAHs is to soak your meat in an acidic marinade with lemon juice or vinegar; this makes it taste better and cuts AGEs in half and HCAs by 90 percent.29
Most important to say here is that red meat contains compounds that prevent cancer, including omega-3 fats, CLA (conjugated linoleic acid), and nutrients such as selenium, vitamins B6 and B12, and vitamin D. Eating a healthy diet full of cancer-fighting plant foods, rich in phytochemicals and spices, and including lots of fiber to feed good gut bacteria can help you ward off cancer.
DOES MEAT CAUSE INFLAMMATION?
By now, you can probably answer this yourself! If you eat meat in the context of the average Western diet full of sugar and processed food and low in fruits and vegetables, nuts, and seeds, then yes. But if you eat a whole-foods, high-quality, grass-fed, organic, low-glycemic, high-fiber diet like the one laid out in Part III of Eat Fat, Get Thin, then the answer is no. In fact, in studies that replaced meat with carbohydrates, levels of inflammation went up.30
The omega-6 fat arachidonic acid is found in meat. It is in every one of your cell membranes and helps your body control inflammation, grow, and repair. Grass-fed meat actually increases levels of both omega-3s and the right omega-6s—it helps keep the fats in balance. In large population studies, those with the highest levels of both omega-3s and arachidonic acid had the lowest levels of inflammation31 and heart disease. Population studies, as I have said, are imperfect, but they are often the best we have.
IS EATING MEAT IMMORAL OR UNETHICAL?
The ethical concerns about eating meat inspire many vegetarians, including millions of Buddhists around the world. I spent two weeks in a Tibetan monastery with a Bon abbot. (Bon is the pre-Buddhist indigenous religion of Tibet.) His beliefs dictated that he not harm any living creature, because you never know which being (human, animal, or insect) was your mother in your last life, or who will be your mother in your next life. That surely engenders loving kindness to all beings. There was only one problem: Because he followed his traditional die
t, the abbot was overweight and a poorly controlled diabetic.
One morning in his private quarters, he and I shared a breakfast of tsampa, a traditional Tibetan roasted barley flour, dri cheese (from a female yak), and hot salted tea. I suggested that he might not want to eat flour for breakfast since he had type 2 diabetes. He protested, saying that was his traditional breakfast. I said yes, that may be so, but that diet would make sense only if he were herding yaks all day at an elevation of 17,000 feet, not sitting on a meditation cushion all day. We checked his blood sugar after eating it. It was over 300 mg/dl (normal is less than 90 mg/dl).
While I didn’t convince him to start eating meat, I did get him on a high-protein, high-fat, lower-sugar, and lower-carb diet of nuts, seeds, beans, and vegetables and had him walk around the monastery every day for an hour. He lost thirty-five pounds and reversed his diabetes. Now I have 1.5 million Bon people praying for me!
I honor those who want to be vegetarians for moral or religious reasons, and I do believe you can construct a healthy vegan or vegetarian diet if it follows the basic principles of good-quality fats and low-sugar, high-fiber, and unprocessed foods. It may be harder to eat that way, but with a good plan and discipline, it can work for many people. In full disclosure, I was a vegetarian for nine years and did pretty well, although my health is much better now, with less inflammation, baggy eyes, and allergies, fewer rashes and digestive problems, and more muscle mass, even though I am 25 years older.
Vegans quote studies of large populations who are vegetarian that show they live longer and are healthier. This is true, but the question is, Why? Is it the absence of meat, or is it their other lifestyle habits? Vegetarians on the whole are more health conscious and more likely to exercise and to avoid junk, sugar, processed foods, and smoking; they even floss their teeth more.32 Remember, this is called the healthy user effect. On the other hand, as we’ve discussed, meat eaters tend to have worse habits. So is it the meat or is it the bad habits that cause more deaths? Studies that compare health-conscious meat eaters with vegetarians show no difference in health outcomes.
One of the most eye-opening discussions of the ethical issues surrounding vegetarianism is The Vegetarian Myth by Lierre Keith. While you may not agree with all of her arguments, she points out that in the plowing of fields, clearing of forests, and growing of plants, there is wholesale destruction of natural ecosystems, including the death of birds, rodents, bugs, worms, and trillions of microbes in the soil. She says, “The truth is that agriculture is the most destructive thing humans have done to the planet, and more of the same won’t save us. The truth is that agriculture requires the wholesale destruction of entire ecosystems. The truth is also that life isn’t possible without death, that no matter what you eat, someone has to die to feed you.”
What most vegetarians don’t realize is that many organic agriculture practices require animal products to build up the soil. I recently visited the largest rooftop organic farm in America, the Brooklyn Grange, on top of an old navy shipyard. It was a marvel to behold, and as we toured the farm, I asked about the soil, and how they cared for it. It turns out it is fortified with bone meal and oyster shells. Who knew that your vegetables were carnivores!
It is well known that vegans are more likely to have nutritional deficiencies of B12, omega-3 fats, fat-soluble vitamins like A and D, iron, calcium, vitamin K2, and zinc.33 I have treated tens of thousands of patients and have seen serious nutritional deficiencies and health problems in vegans and vegetarians. It can be a healthful choice, but you need to make sure you are getting the right nutrients: focus on eating seaweed and DHA supplements from algae, and high-fat plant foods such as nuts and seeds, avocados, and coconut oil; and minimize starchy foods, sticking instead with high-fiber, low-glycemic grains like black rice and quinoa. Eat non-GMO soy foods such as tempeh or tofu, which have been consumed safely for thousands of years in Asian countries. Eat more mushrooms, which contain minerals and vitamin D. Avoid sugar and refined vegetable oils, except extra virgin olive oil.
I support my friends who choose to be vegetarian or vegan for moral, health, or environmental reasons. The key is making it a high-fat vegan diet. But as I’ve said, each of us is genetically and biochemically different and may do better on different diets. Find out what is best for you by monitoring yourself. How do you feel? What does the scale say? What are your numbers: your blood pressure, waist size, blood sugar, levels of inflammation, HDL, and triglycerides, and the size of your LDL particles? Monitor your levels of nutrients such as vitamin D, zinc, B12, and iron. Find out what’s optimal for you.
IS GRASS-FED MEAT BETTER?
From an environmental perspective, factory farming puts more pressure on the environment through degradation of the topsoil, depletion of our aquifers and global freshwater supplies (because 70 percent of the world’s freshwater is used to grow animals for human consumption), negative effects on climate change, use of fossil fuels for fertilizers and agricultural chemicals, overuse of antibiotics in animal feed, and the need for extensive food transportation because of centralized food production. Those considerations alone should move us all toward more sustainably raised, local animal products (and vegetables). From a moral perspective, the intensive, crowded, and harsh conditions for animals on factory farms should also inspire us to boycott those foods. If you haven’t seen the movie Food, Inc. yet, it might convince you.
Grass-fed meat is better not just for the planet, but for our bodies as well. It would be hard for anyone to argue that the higher amounts of antibiotics, hormones, and pesticides in factory-farmed meat are good for you, and there is much evidence to show they are harmful. The main reason that grass-fed meat is better for you is that you are not what you eat—you are what your food eats! The difference in diets of grass-fed vs. grain-fed cows has a big impact on the health effects of the meat. Let me break this down.
Cows are ruminants that have special stomachs designed to eat grass. When they are fed grains, the levels of the inflammatory omega-6 fats in their bodies—and thus in the meat we eat—increase. Cows also have to be given antibiotics to prevent their stomachs from exploding from the bloat caused by their gut bacteria fermenting the corn feed (isn’t that a lovely image?). Grass-fed cows, on the other hand, don’t need antibiotics. We use about 24 million pounds of antibiotics per year in America; about 19 million of those are used in animal feed. This causes serious antibiotic resistance in animals and humans and has led to the growth of superbugs that don’t respond to antibiotics.
Grass-fed meat has a healthier fat profile than conventionally raised meat, with two to five times more omega-3 fats.34 It also has lower levels of omega-6 fats. The ratio of omega-6 to omega-3 fats in grass-fed beef is about 1.5 to 1. In grain-fed beef it is about 7.5 to 1. Grass-fed beef has more stearic acid, the saturated fat that has no impact on cholesterol. It also has two to three times as much conjugated linoleic acid (CLA) as grain-fed beef, a potent antioxidant that is protective against heart disease,35 diabetes,36 and cancer and even helps with weight loss and metabolism.37
In addition to having a better fat profile, grass-fed meat has more vitamin E, beta-carotene, vitamin A, zinc, iron, phosphorous, sodium, and potassium.38 It also has higher levels of antioxidants, including glutathione, catalase, and superoxide dismutase.39
Yes, it is more expensive to eat grass-fed meat. But I believe it is worth the price, given its health and environmental benefits. You can find cheaper sources online. You can even buy a cow or a lamb with friends and share it. Some call it “cowpooling.” Check out the website Mark’s Daily Apple (www.marksdailyapple.com) for sources of grass-fed meat and cowpooling, or the website US Wellness Meats (www.grasslandbeef.com) for more grass-fed beef options. Eating smaller amounts of good-quality animal products is better for you, your wallet, and the planet. Save on quantity, splurge on quality!
8
Controversial Foods—What’s Good, What’s Bad?
I know you’re reading this book because
you want to know the truth about what’s good for you and what isn’t, so let’s clear up any confusion you might have about the fat in some of your favorite foods.
EGGS: FRIEND OR FOE?
How many of us have begrudgingly eaten dry, tasteless egg-white omelets because we thought we were “supposed to”? Well, no more!
In a large analysis of sixteen major studies, each of which had anywhere from 1,600 to more than 90,000 participants, eggs were found not to be linked to heart disease.1 In one detailed case report in the New England Journal of Medicine, one man had been eating twenty-five eggs every day for more than 15 years, and it had no impact at all on his cholesterol or his heart.2 He might have been crazy, but he had no heart disease!
In the Physicians’ Health Study, no link could be found between eggs and heart disease.3 Other experimental studies have found protein- and fat-rich eggs aid weight loss by suppressing your appetite, speeding up your metabolism, and reducing your overall food intake during the day.4
Eggs have been eggsonerated!
In fact, eggs might be the cheapest and best new health food. But stick to pasture-raised or omega-3 eggs, which are much higher in nutrients and antioxidants. Avoid eggs with pale yellow yolks (the ones from commercial, industrial operations) and go for the ones with dark, deeply colored orange-yellow yolks. It turns out that the yolks are a treasure trove of nutrients (after all, they must supply the ingredients for creating new life). While the whites have vitamins B2 (riboflavin) and B3 (niacin), the yolks contain B6 and B12, folic acid (B9), pantothenic acid (B5), and thiamin (B1). The yolks are also rich sources of vitamins A, E, K, and D. In fact, egg yolks are one of the few foods that naturally contain vitamin D.