Your Health, Part I: Comparing No-, Low-, and High-Meat Diets
The first of four parts; for the best scientific backing for natural, plat-based diet, see the new bestseller The Whole Foods Diet by Mackey, Pulde and Lederman
It will probably surprise many readers to know that the same reason a meatless diet is good for the planet and for alleviating world hunger—eating low on the food chain—is one reason vegetarians, on average, are much healthier than meat eaters. Because it takes 3-16 pounds of plants to create a pound of meat, any toxins in those plants become concentrated, aside from other aspects of meat that may be unhealthy.
But before we get into the details about that connection, let’s talk about the hard evidence that lower meat consumption actually improves overall health. One doesn’t need to compare pure vegetarians with heavy meat-eaters to understand the implications of the most important studies. The best way to do this isn’t the usual small clinical studies, but massive, long-term, real-world examples. Ideally, you want to find people who have somewhat similar lifestyles and live in the same area, but who have significant contrasts in their diets, so that there are not a lot of variables that create uncertainty about the true causes of their health differences.
T. Colin Campbell grew up on a dairy farm and earned his Ph.D. in animal nutrition at Cornell University on learning how to “grow cows more efficiently.” Continuing his research at MIT, he was in the group that discovered dioxin, the most toxic chemical known, which was in the feed that was killing millions of chickens each year.
He then spent 10 years on the faculty at Virginia Tech, where he says he worked “to promote better health by eating more meat, milk, and eggs. I was happy to believe that the American diet was the best in the world.” While overseeing a project in the Philippines to improve childhood malnutrition, he was startled to learn that the children who were eating the most protein had very high rates of liver cancer, usually an adult disease. Looking through the research of others, he uncovered “the dark secret”: a double-blind study proved that a low-protein diet could prevent carcinogenic chemicals from instigating cancer, while a high-protein diet would provide no protection. His own further experiments concluded that animal proteins in particular were linked to cancer, while plant proteins like those found in wheat and soy were healthful. It was the opposite of what he learned and taught.
He returned to Cornell to teach in 1975 and to look deeper into the protein and disease connection. In 1983, he surveyed 6,500 people in rural China on 367 aspects of their diet and lifestyle habits, then in 1989-1990 he investigated another 10,200 on 1,000 items and crunched the numbers on the causes of death for 100 million. The result—the China-Oxford-Cornell Diet and Health Project—was what The New York Times called “the Grand Prix of epidemiology and the most comprehensive large study ever undertaken of the relationship between diet and the risk of developing disease” (epidemiology is the study of the health of a group of people). The China Study, co-written with his son, Thomas M. Campbell II, became a bestseller.
They found that Chinese peasants ate very small amounts of animal protein simply because it was expensive. If their economic situation improved or they were otherwise able to add meat, dairy, or eggs, the negative impact on their health was measurable. “People who ate the most animal based foods got the most chronic disease. People who at the most plant-based foods were the healthiest and tended to avoid chronic disease. Even relatively small amounts of animal-based food were associated with adverse effects.”
Since then, he has continued to research the connection and the book documents that:
…heart disease, diabetes, and obesity can be reversed by a healthy diet. Other research shows that various cancers, autoimmune disease, bone health, kidney health, vision and brain disorders in old age (like cognitive dysfunction and Alzheimer’s) are convincingly influenced by diet. Most importantly, the diet that has time and again been shown to reverse and/or prevent these diseases is the same whole foods, plant-based diet that I had found to promote optimal health in my laboratory research and in the China Study. The findings are consistent.[1]
Dr. Campbell now teaches an upper-level course entitled Vegetarian Nutrition. “After a long career in research and policy-making, I have decided to step ‘out of the system.’ I have decided to disclose why Americans are so confused about diet and health.” He says the distinctions have been blurred between government, industry, science and medicine, as have conflicts between making a profit and promoting health. “The result is massive amounts of misinformation.”
Other Population Comparisons
The International Agency for Research on Cancer studied 521,000 people in Europe starting from 1993 to 1999 and has done follow-ups since then. Known as the EPIC Project, it found a strong correlation between the amount of red and processed meats (such as cured ham, bacon, salami, and corned beef) eaten and colorectal cancer. It determined that the risk of colorectal cancer was reduced by 40 percent for those who had high-fiber diets. The optimum amount of fiber to be consumed per day is 30-40 grams, but meat eaters on average take in half that, while vegetarians get an adequate amount.[2] EPIC also discovered a link between gastric cancer and red and processed meats.
The Harvard Nurses’ Study of 88,000 women, published in 1990, found that those who ate beef, lamb, and pork daily were two-and-a-half times more likely to contract colorectal cancer than those who ate these meats less than once a month. Controlling for other factors, those who consumed a “prudent diet” (whole grains, legumes, vegetables, fruit, fish) had one-third as many strokes as those who ate a “Western diet” (red and processed meats, refined grains, sweets, and desserts).[3]
The National Cancer Institute conducted the AARP Diet and Health Study of over 500,000 people between 50 and 71, starting in 1995 and recently concluded. It compared the highest and lowest quintile (one-fifth) groups for red meat consumption: the median in the highest group of men was 5.4 oz. a day, while for women it was 4.3 oz.; the median for the lowest group of men was .85 oz. and the women .68 oz. The conclusions: “For overall mortality, 11 percent of deaths in men and 16 percent of deaths in women could be prevented if people decreased their red meat consumption to the level of intake in the first quintile.” The authors noted that cancer-causing compounds are formed during high-temperature cooking of meat, which is also a major source of saturated fat, something that has been linked to cancer, cardiovascular disease, and high blood pressure.[4]
The American Institute for Cancer Research and the Britain-based World Cancer Research Fund jointly examined 4,500 research reports and in 1997 published their conclusion that one-third of all cancers could be prevented by improved nutrition. They found evidence linking diet to cancers not only of the colon, but stomach, mouth, pharynx, larynx, esophagus, lung, pancreas, and prostate. Recently it reevaluated the evidence and stated: “To reduce your cancer risk, eat no more than 18 oz. (cooked weight) per week of red meats, like beef, pork, and lamb and avoid processed meat. The evidence is much stronger than it was in the mid-1990s.”[5]
John Robbins pointed to the dramatic differences between the breast cancer death rate in the U.S. (22.4 per 100,000) and the rates in Japan (6.3) and China (4.6), noting that people in Japan and China eat a lot less meat and a lot more fruits and vegetables (they also weigh less, drink less alcohol, and exercise more).[6] But more strikingly, he found that women in Japan who eat meat daily have 8.5 times the breast cancer as poor women who eat little meat. In Italy, women who eat a lot of animal products have three times the breast cancer rate of those who eat little; while in Uruguay the difference is 4.2 times.
The Seventh-day Adventists stress the importance of good diet, including abstaining from meat and eating whole foods, however, there is quite a bit of variation in actual practice (21 percent in one survey said they ate beef more than twice a week). They make a good population to study for lifestyle and dietary comparisons within the group and 23,000 church members participated in the first Adventist Mortality Study at Loma Linda University starting in 1958. In a follow-up called the Adventist Health Study that included 34,000, it concluded that “the strongest risk factor for colon cancer among the food variables was total meat intake.” Those who ate either red or white meat over four times per week had double or triple the colon cancer risk compared with those who did not.[7] In another part of the AHS study, men who ate beef up to three times a week had twice the risk of fatal coronary heart disease as the vegetarians.[8]
Research has shown American vegetarians have 14 percent lower cholesterol than meat-eaters, while vegans have 35 percent lower.[9] The cardiovascular superiority of low-meat diets have also been supported by medical doctors with a great deal of clinical success with patients following vegan diets (no animal products), such as Dr. Dean Ornish (Program for Reversing Heart Disease) and Dr. Caldwell Esselstyn (Prevent and Reverse Heart Disease).[10]
Obesity (having a Body Mass Index of 30 or greater) has been linked to higher risk for a range of potentially fatal disorders, including hypertension and type II (adult-onset) diabetes, according to the American Dietetic Association.[11] The Centers for Disease Control says that after a quarter century of rising obesity, the percentage of adults stabilized at 34 percent in 2004.[12] After analyzing studies of obesity and interviewing physicians, Robbins reported that the obesity rate for all vegetarians was only about 6 percent and 2 percent for vegans.[13] The National Weight Control Registry of individuals who have kept off weight over a long period shows that most do so on a low-fat, low-calorie diet, rather than the recently popular low-carbohydrate, high-protein diet.[14]
Other studies of relatively healthy populations around the world have supported this research. One in the 1990s examined two segments of the same ethnic group in Albania, as recounted in Pamela Rice’s 101 Reasons Why I’m Vegetarian.[15] The portion that lived in the mountains ate a lot of meat, while those living along the coast ate a diet mostly of fruits, vegetables, some fish, and olive oil. The former had a much higher death rate, while the latter suffered from very little cardiovascular disease. She also cites the case of Denmark, which was blockaded by the Allies during World War II and had to prohibit the feeding of grain to livestock. Its three million citizens had a one-third drop in their mortality rate.
As Dr. Paavo Airola pointed out in the 1970s (at a time when the health food industry was idolizing ultra-high-protein advocates like Adelle Davis, Carlton Fredericks, and J.I. Rodale), the longest-living and healthiest people in the world were either vegetarian or had low meat diets. The Hunzans in the Himalayas, a tribe in Yemen, Maya Indians in Yucatan, Bulgarians, and the residents of the Caucasus mountains (of what was then the U.S.S.R.) were rarely sick and relatively frequently lived to age 100.[16] John Robbins’ recent book, Healthy at 100, takes an updated look at the Hunzans and Abkhasians in the Caucasus, as well as the Vilcabamban Indians in the Andes and Okinawans. The latter eat fish regularly, but otherwise little meat and lots of fruits and vegetables. They have the world’s highest documented proportion of centenarians and these generally retain vigorous mental functioning until death.[17]
[1] T. Colin Campbell and Thomas M. Campbell II (Dallas: Benbella Books, 2005). Most of the quotes here are on their web site www.thechinastudy.com.
[2] Neal Barnard, Food for Life (New York: Three Rivers Press, 1993), p. 96.
[3] Willett, Stamper, Colditz, Rosner, Speizer, “Relation of fat, fiber and meat intake to colon cancer risk in a prospective study among women,” New England Journal of Medicine 1990: 323: 1669-72.
[4] Sinha et all, “Meat intake and mortality: A prospective study of over half a million people,” Archives of Internal Medicine, 2009; 169 (6): 562.
[5] American Institute for Cancer Research www.aicr.org, Second Expert Report: Food, Nutrition, Physical Activity and the Prevention of Cancer: A Global Perspective.
[6] John Robbins, The Food Revolution (Boston: Conari Press, 2001), 44.
[7] P. Sinkh, G. Fraser, “Dietary risk factors for colon cancer in a low-risk population,” American Journal of Epidemiology, 1998; 148:761-774.
[8] www.llu.edu/llu/health/heart.html, “The Adventist Health Study: findings for fatal heart disease.”
[9] Resnicow, Barone, Engle, et al., “Diet and serum lipids in vegan vegetarians: A model for risk reduction,” Journal of the American Dietetic Association 91 (1991):447-53.
[10] Dean Ornish, Program for Reversing Heart Disease (New York: Ivy Books, 1995) and Dr. Caldwell Esselstyn Prevent and Reverse Heart Disease (Visa, CA: Avery Books, 2008).
[11] American Dietetic Association Position Paper “Vegetarian Diets,” June 2003 www.eatright.org.
[12] National Center for Health Statistics, “Obesity among adults in the United States,” Nov. 2007.
[13] Robbins, 58.
[14] National Weight Control Registry www.nwcr.ws.
[15] Pamela Rice, 101 Reasons Why I’m Vegetarian (New York: Lantern Books, 2005), 151-153.
[16] Paavo Airola, Are You Confused? (Phoenix: Health Plus, 1971) and How to Get Well (Phoenix: Health Plus, 1977).
[17] John Robbins, Healthy to 100 (New York: Ballantine, 2007).
18John Robbins, The Food Revolution, 86.
19www.atkinsexposed.org