What's a Vegetarian?
“Vegetarian” is a blanket term for a variety of diets that exclude meat, poultry, and fish. The most healthful, the pure vegetarian (or "vegan") diet, only includes foods of plant origin, such as nuts, seeds, vegetables, fruits, grains, and legumes. A "lacto-vegetarian" includes these plant foods and also dairy products. A "lacto-ovo-vegetarian" consumes both dairy and eggs.
Is Veg Healthier?
There is abundant evidence that vegetarian diets are more healthful than the average American diet, especially for preventing, treating or reversing heart disease and reducing the risk of cancer.1 Research has shown a low-fat vegetarian diet is the single most effective way to stop progression of coronary artery disease or prevent it altogether. Several other health conditions, such as diabetes,2 obesity,3 gallstones,4 and kidney stones,5 are much less common in vegetarians. The health benefits of a vegetarian diet may be linked to the fact that vegetarians tend to eat less animal fat, protein and cholesterol and more fiber and antioxidants.6 Simply put, the fewer animal foods and the more varied, whole plantfoods consumed, the healthier the individual will be compared to the general population.
Plant foods have been shown to have "chemopreventive" properties. Risk of lung cancer in heavy smokers has been shown to be reduced in populations eating generous amounts of plant foods, and risk of breast, prostate and other cancers is substantially lower in populations which consume vegetarian or largely vegetarian diets. Researchers have identified eight food groups, each of which has unique cancer-preventing qualities. All eight of the food groups come from the plant kingdom. Conversely, animal product consumption is implicated in a host of degenerative diseases including cancer and heart disease, and animal-source foods in general provide little or no protection against most health conditions other than starvation.
Animal Protein and Cancer: Milk Causes Cancer in Rats
In our opinion, animal studies are problematic in many ways, and largely if not completely useless. However, there are people to whom such studies are very important, and those are the individuals and organizations which set health policies in the US and elsewhere. These people look at animal studies, rat studies, primate studies, etc., and extrapolate with great confidence what these studies tell us about human health. They make decisions that affect us all based on such studies, setting health policies and issuing advice and warnings.
The most fascinating -- and telling -- thing about all this is that there are powerful animal studies showing that the primary protein in milk -- casein -- promotes cancer. Yes, according to multiple animal studies, milk promotes tumor growth.
For example, in rats exposed to a known liver carcinogen and then fed levels of casein representing excess protein intake (20% of calories from animal-source protein), precancerous levels increased dramatically. Rats fed low animal-protein diets (5% of calories from animal-source protein) experienced a reduction in precancerous growths by over 90%. Similar studies with rats consuming excess vegetable protein (20% of calories from plant-source protein) also showed a dramatic reduction in precancerous growths -- the opposite of excess animal-source protein intake. When the "missing" amino acide, lysene, was added to the plant-source protein, making it a "complete" protein like animal protein, it had the same impact as feeding animal protein -- increasing cancer growth. 7 The take home message from these studies was that eating more than a very minimal amount of protein from animal sources promoted cancer growth while consuming excess protein levels from plant sources did not, but in fact reduced precancerous growth.
Why are these studies not only ignored -- but buried -- by the people who set our nutrition and health policy? The reason can only be that when such animal studies do not fit what is convenient to them, they disregard them. (Notable is that 6 of the 11 members of the USDA Dietary Guidelines Committee, which is responsible for making nutrition recommendations, receive or have received money from the meat, dairy, or egg industries. Even the Undersecretary of Agriculture, who participates in the Committee meetings, has a business relationship with a dairy-product manufacturer -- the Dannon Institute.)
With the USDA reporting that the average American diet consists of over 40% dairy products (by weight) as well as significant amounts of meat, chicken and fish, there would appear to be little mystery why certain cancers are rampant in the US.
Need to Combine Plant Foods to get "Complete Proteins?"
Vegetable sources of protein (such as beans, peas, and grains) were once thought to be deficient in one or more essential amino acids. However, Western vegetarians rarely show protein deficiency or even deficiencies in any of the essential amino acids, thus the outdated belief that vegetarians need to be concerned about combining certain foods to obtain a balanced profile of amino acids has now been disproved by research and is universally rejected by scientists. Part of the reason that vegetarians do not need to “balance” amino acids is that the body’s requirement for essential amino acids now appears to be much less important than researchers once believed, especially in adults. In fact, it is now accepted that protein deficiencies rarely occur in people who simply eat enough calories.
Can I get My RDA's from a Veg Diet?
A lacto-vegetarian or lacto-ovo-vegetarian diet can easily meet the Recommended Dietary Allowances (RDAs) for all vitamins, minerals, protein, and other nutrients. A varied vegan diet will also ensure adequate amounts of all nutrients except, perhaps, Vitamin B12, which is an area where there is some controversy and question. Vitamin B12 was once abundant in plant foods until the advent of modern farming and food processing techniques. While Vitamin B12 deficiency is quite rare in vegans, medical literature has reported isolated cases of B12 deficiency in some vegans, usually nursing mothers and very small children. For this reason, and until more is known about the production and absorption of B12 in the human body, vegans are advised to find a supplemental source of B12. Vitamin B12 supplements or B12-fortified soy or rice milks are ideal sources of B12, Vitamin D, and added calcium. (Certain algae and some fermented soybean products, such as tempeh and miso, are plant sources of Vitamin B12, but they contain varying, unreliable amounts, and not all such forms of B12 can be absorbed by the body.)
What About Calcium?
Some researchers question the wisdom of current government calcium recommendations. They note that the Standard American Diet is so fundamentally flawed that trying to protect our bones by taking in loads of calcium is like trying to fill a tub with no stopper by turning up the faucets. In general, world dietary patterns show that countries where people consume large amounts of calcium are also countries where people eat enormous amounts of animal protein, such as in the United States and northern Europe. These countries also suffer among the world's highest rate of fractures due to osteoporosis, the disease characterized by weak, porous bones. "The correlation between animal protein consumption and fracture rates in different societies is as strong as that between lung cancer and smoking," says T. Colin Campbell, professor of nutritional biochemistry at Cornell University.
Eating animal protein, which is high in sulfur-containing amino acids, requires the body to find a way to buffer the effects of those amino acids. It does so by releasing calcium from the bones, literally peeing them away. Robert Heaney, professor of medicine at the Creighton University School of Medicine and a proponent of high dairy consumption, nevertheless admits that his research shows the "single most important determinate" of the rate of bone gain in young women is not how much calcium they consume, but how much calcium they consume in relation to animal protein. The more protein eaten, the more calcium must be consumed to offset the calcium drain. Unfortunately, most people in the US and Northern Europe eat well more than double the recommended amount of protein and more than four or five times the amount of protein actually needed -- with 70 percent of it coming from animal sources. Hello, osteoporosis.
Ovo-lacto-vegetarians can get the Recommended Daily Allowance of calcium by consuming dairy products, but this is not recommended. Although many people think of calcium in the diet as good protection for their bones, this is not at all the whole story. In fact, in a 12-year Harvard study of 78,000 women, those who got the most calcium from dairy products actually broke more bones than women who rarely drank milk.8 Similarly, a 1994 study of elderly men and women in Sydney, Australia, showed that higher dairy product consumption was associated with increased fracture risk. Those with the highest dairy product consumption had approximately double the risk of hip fracture compared to those with the lowest consumption. 9 A study following adolescent girls from age 12 through 18 found that the amount of calcium they ingested made zero difference in development of bone mineral density during the years when women develop between 40 to 60% of their bone mass. (read story)
The bottom line on osteoporosis is that the scientific literature contains a lot of conflicting conclusions about calcium that have yet to be reconciled. There are studies showing that vegans or near-vegans have lower bone mineral density (BMD) than omnivores or ovo-lacto-vegetarians. T. Colin Campbell, Ph.D. has co-authored a study showing that Chinese women living in counties with low dairy consumption have lower BMD than women in counties with higher dairy intake. 10 However, it has not been shown that these women were more susceptible to osteoporosis.
The truth is that nobody knows what the adequate level of calcium intake is for vegans. Given how little is really known, if you are vegan it may not hurt to try to get something close to the RDA for calcium. Good vegan calcium sources include collard greens, broccoli, kale, turnip greens, tofu prepared with calcium, and fortified beverages including orange juice, soy or rice milk (check the labels).
Osteoporosis runs rampant through Western civilization with our elderly fracturing their spines and hips at an unprecedented rate. Conventional wisdom teaches us that we are not getting enough calcium and exercise, that we are smoking too much or drinking too much coffee or, in the case of women, that we lack estrogen. A closer examination of the evidence would agree that these are contributing factors, but the primary culprit lies elsewhere.
The women of Bantu who are over 60 years of age do not have osteoporosis. They have a huge calcium drain, having an average of 10 children and nursing each child for 14 months. Their diet includes 440 mg of calcium per day, half of our recommended daily allowance.11-12 They are protected because they eat only 50 gm of protein daily. When they move to civilization and their protein intake increases and they develop osteoporosis.13 The mechanism of this is further clarified by viewing the Eskimo diet.14 The Eskimo consumes a diet that is high in protein (250 to 400 gm per day) and a diet high in calcium (2000 mg per day); yet, despite much physical activity, they have one of the highest rates of osteoporosis.15 These two contrasting cultures of the Bantu and the Eskimo illustrate the osteoporotic effect of a high protein diet. Ammonia and urea (the breakdown products of protein) initiate a calcium diuresis, the mechanism of which is still not clearly understood.16
During the past 25 years this observation has been increasingly scientifically documented, but poorly publicized. A long-term study noted a negative calcium balance in persons daily ingesting 75 gm of protein despite a daily intake of 1400 mg of calcium. 17 The conclusion of Allen et al.: "Our data indicate that high protein diets cause a negative calcium balance to occur even in the presence of more than ad equate dietary calcium. Osteoporosis would seem to be an inevitable outcome of continued consumption of a high protein diet."
Millions of Americans have osteoporosis, accounting for 190,000 hip fractures annually. 18 Fifteen thousand women die each year as a result of hip fractures. Despite such data, osteoporosis is unknown in many countries around the world except in Western civilization, which consumes two to three times more protein than required. It would appear that osteoporosis is a disease of chronic dietary protein excess. 19
The dairy industry has spent millions of dollars attempting to promote the idea that dietary calcium intake is the key to preventing osteoporosis. However, this is little more than a self-serving advertising campaign.
One scientifically proven way to prevent osteoporosis and increase Bone Mineral Density (BMD), whether you're vegetarian, vegan or omnivore is called weight-bearing exercise. Studies of people working out with weights have shown dramatic increases in BMD, even in individuals in their 70s and older. (Consult with Joyce Vedral, Ph.D., an exercise specialist who developed a program using small hand weights and who, at age 56, has 200% greater BMD of the average woman her age, and 130% higher BMD than a young woman. Along with diet, regular exercise is key to maintaining good health over a lifetime.)
As mentioned, other factors with significant impact in promoting calcium loss include sodium, caffeine, and tobacco intake.
In conclusion, vegans often consume products supplemented with vitamin B-12 and calcium, just as non-vegetarians consume foods supplemented with vitamins, calcium and other nutrients. (Milk, for example, has Vitamin D added during the treatment process it must go through in attempting to make it suitable for human consumption.)
1. Key TJA, Thorogood M, Appleby PN, et al. Dietary
habits and mortality in 11,000 vegetarians and health conscious
people: results of a 17 year follow up. BMJ 1996;313:775–79.