What You Need to Know About Vegetarian or Vegan Diets
All types of diets—vegetarian or non-vegetarian--have potential health risks as well as associated benefits. My patients frequently ask me questions about the most nutritious foods, and positive aspects and the dangers of different types of diets, particularly vegetarian and vegan.
Is a vegetarian or vegan diet the healthiest diet for my family?
What are the drawbacks of a vegetarian diet?
What are the drawbacks of an omnivorous diet?
Is a vegetarian or vegan diet safe for children?
Is an omnivorous diet safe for children?
As a start, we can define the various types of diets in these ways:
||Consists totally of plant foods, with no dairy, eggs, or other foods of animal origin.
||Avoids eating animals, but may or may not include some dairy, eggs or other products of animal origin.
||Utilizes both animal products and plant foods
||Contains no meat, fowl, or fish, but allows eggs and dairy products
IS VEGETARIAN OR VEGAN THE HEALTHIEST DIET?
When looking for the healthiest diet, people often consider vegetarian diets. But are vegetarian diets the healthiest diets? There are two things we all know with certainty. First of all, more nutritious food, such as vegetables, beans, fruits, raw nuts, and seeds in the diet have dramatic effects at reducing the risk of both heart disease and most cancers. The other thing we know is that as animal products increase in a population's diet, the risk of both heart disease and cancer increase. It has been observed in multiple scientific studies that vegetarians have fewer heart attacks and less incidence of cancer than those on omnivorous diets.
The chief feature that makes a vegetarian diet beneficial compared to more conventional ways of eating is that a person following a vegetarian diet is likelier to be consuming more high nutrient produce that contains protective fibers and antioxidant nutrients. This diet will naturally be lower in saturated fat, which is an accepted risk factor for both heart disease and cancer.
Not surprisingly, fruits and vegetables are the two nutritious foods with the highest correlation with longevity in humans. Not whole wheat bread, not bran, not even a vegetarian diet shows as powerful a correlation with decreased mortality as does a high level of fresh fruit and raw green salad consumption 1 . The National Cancer Institute recently reported on 337 different studies, with all showing the same basic information: 2
- Vegetables and fruit protect against all types of cancers if consumed in large enough quantities. Thousands of scientific studies document this. The most prevalent cancers in our country are primarily a plant-food deficiency disease.
- Raw vegetables have the most powerful anti-cancer properties of all foods.
- Beans, in general, and not just soy, have additional anti-cancer benefits against reproductive cancers, like breast and prostate cancer.
Clearly, the chief health reason to choose a vegetarian diet is to consume high levels of fruit, green vegetables, and beans. A diet primarily comprised of nutritious foods, not processed food or animal products is the key both to better health, and healthy weight loss.
People often ask me whether it is absolutely necessary to follow a vegetarian diet. Let me stress this: Following a strict vegetarian diet is not as important as eating a diet rich in fruits and vegetables.
A vegetarian whose diet is mainly refined grains, cold breakfast cereals, processed health food store products, vegetarian fast foods, white rice, and pasta will be worse off than a person who eats a little turkey, chicken, fish, or eggs but consumes large volumes of fruits, vegetables, and beans. That combination of little or no animal products with a higher consumption of fresh produce is the crucial factor that makes a vegetarian diet healthful.
Research has confirmed this. Multiple studies have shown that vegetarians live longer than non-vegetarians do 3 . The research shows those who avoid meat and dairy have lower rates of heart disease, cancer, high blood pressure, diabetes, and obesity, which are the leading causes of death in America 4 .
But when we take a close look at the data, it appears that those who weren't as strict with their diets as the vegetarians had longevity statistics that were equally impressive -- as long as they consumed high volumes of a variety of unrefined plant foods.
So the question is: can the total protection offered by increasing the nutritious foods - the high phytochemical/antioxidant (protective plant foods)-- to make ones diet produce-predominant be achieved, even if the diet is not totally vegetarian and includes some animal products? I think the answer is yes. In other words, you can achieve the benefits of a vegetarian diet, without being a vegetarian or a vegan, and the science available seems to support this.
So let's not debate whether it is all right to eat a little bit of animal food or not. The main focus here that cannot be contradicted or disagreed with is: Whether you eat a vegan or vegetarian diet or you include a small amount of animal foods you must get the majority of calories from unrefined plant food for optimal health. A large quantity of unrefined plant food grants the greatest protection against developing serious disease.
A strict vegetarian diet, then, may be the healthiest diet, but it also may not be. One can choose to be on a healthy vegetarian diet, with careful planning; and one can choose to be on a healthy omnivorous diet, with careful planning too. Both ways of eating still require knowledge about the most nutritious food to eat to assure excellent health and disease protection.
DRAWBACKS OF A VEGETARIAN DIET?
A strict vegetarian or vegan diet is deficient in meeting the nutrient needs of most individuals for vitamin B12. If you choose to follow a complete vegetarian or vegan diet, it is essential you consume a multivitamin or consume a B12 source, such as fortified soymilk.
Vitamin D, often called the sunshine vitamin, is another common deficiency in those not drinking vitamin D fortified milk. Synthetic vitamin D is added to both cow's milk and most brands of soy milk today.
Most of us work indoors and avoid the sun or wear sunscreens, which lowers our vitamin D exposure. Some of us live in northern climates, are not outdoors as much, don't absorb it as well, or may just require more. It is important to assure your vitamin D requirements are met sufficiently.
It is a myth that a vegetarian diet, rich in green vegetables, beans, and whole grains would be likely to be low in calcium or protein. Plant food contains adequate levels of these nutrients. However, if a vegetarian diet is not carefully designed to include foods such as nuts, seeds, green vegetables, beans, and whole grains, then levels of calcium, iron, zinc, and protein could be low.
For example, iron deficiency anemia has been reported in some macrobiotic vegetarians who followed a very restrictive diet and consumed a diet with rice as their staple food. This would not have occurred if these individuals ate more green vegetables and beans which contain adequate iron.
Likewise, if vegetarians and vegans eat a variety of plant proteins, their intake of protein should be as good as that of a person who eats meat or other foods that contain animal protein. The mixture of proteins from grains, legumes, seeds, nuts, and vegetables provides a complement of amino acids so that deficits in one food are made up by another. Not all types of plant foods need to be eaten at the same meal, since the amino acids are combined in the body's protein pool. So there is no need to mix or match amino acids to form complete protein at each meal; your body can do that on its own from what you consume all day.
Keep in mind that it is not a vegetarian diet per say that is low in these mentioned nutrients; it is just that some who indiscriminately drop animal products from their diet may not substitute enough of the nutrient-rich plant foods to make the diet adequate. You can be a vegetarian, yet be a vegjunktarian with a poor diet.
Although a low-saturated-fat vegan diet may markedly reduce risk for coronary heart disease, diabetes, and many common cancers, the real Achilles heel of the low-fat vegan diet is the increased risk of hemorrhagic (vessel rupture leading to bleeding) stroke. Apparently the atherosclerotic (plaque building) process that creates a local vascular environment favorable to coronary thrombosis (clot) and intravascular embolism (traveling clot) may be protecting the fragile blood vessels in the brain from rupture under years of stress from high blood pressure. Admittedly, hemorrhagic stroke is a very small percentage of the deaths in modern countries. It still is worth noting that if strict vegetarians are to have the potential to maximize their lifespan, it is even more important they avoid a high salt intake because salt intake increases blood pressure. Almost all of the soy based meat analogues and many other health food store (vegan) products are exceptionally high in sodium.
A number of studies both in Japan (where the high salt diet had made stroke a leading cause of death) and the West have illustrated that less animal products and a low serum cholesterol was associated with an increased risk of hemorrhagic stroke 5 . The high salt->high blood pressure ->stroke causation chain may be more likely a late life event in a vegetarian successfully maintaining excellent heart health. So avoiding excess sodium may be even more important for a vegetarian than an omnivore. Of course, excess sodium increases both heart attack and stroke death in all diet-styles, but in a vegan, the high-salt diet is even more likely to rear its ugly head as a cause of late life morbidity and mortality. Especially since vegans often live longer and will not likely have a fatal heart attack at a relatively young age. Obviously, dying prematurely of a heart attack would preclude having a stroke at a later point in life, because you are dead already.
Keep in mind, stroke mortality is significantly higher in Japan and exceptionally high in certain areas of China where salt intake is high, in spite of low fat diets. It is also well established that populations in Third World countries which do not salt their food are virtually immune to hypertension, the age-related rise in blood pressure we see in 90 percent of Americans and the incidence of strokes.
And lastly, another concern is that many vegetarians may not have ideal levels of all essential fatty acids. Fish supply two non-essential fatty acids (EPA and DHA) that have been shown to have beneficial effects, offering protection against both heart disease and aging of the brain. To assure that vegetarians get sufficient levels of these omega-3 fats, people on vegetarian diets need to consume foods such as flax seeds, hemp seeds, and walnuts on a regular basis. The body can then manufacture the longer chain fats typically found in fish.
Some individuals may still not have optimal levels of long chain omega-3 fats, even with the consumption of a well designed vegetarian diet utilizing these seeds and nuts, therefore I recommend vegetarians and those not eating fish regularly consume a DHA supplement.
I also recommend that all individuals--vegetarian or not-- consume a daily multivitamin.
DRAWBACKS OF AN OMNIVOROUS DIET?
Despite the availability of nutritious foods, much of the modern developed world today eats a much less than optimal diet. In fact, the incidence of heart disease and cancer is higher in more developed countries and still kills about 80% of all adults, despite the fact that the nutritional causes of these illnesses have been explained by scientific studies.
Unfortunately, our society has developed to the point where half of all caloric intake today comes from refined or processed foods and about 40 percent from animal products. Both processed food and animal products lead to heart disease and cancer, according to scientific literature.
The most commercially successful diet books in our country appeal to America's love-affair with saturated, fat-rich animal products and still leave the public with a relatively dangerous solution to their growing waistlines. These books encourage a higher percentage of animal products in people's diets in spite of the preponderance of evidence showing the links to heart disease and cancer.
There are three main problems with diets that contain significant amounts of animal products:
- More than a thousand well-designed studies have led to all major health authorities around the world to conclude that saturated fat is a leading contributor to high cholesterol, heart disease, and many cancers. In spite of that, some still believe the earth is flat, and saturated fat is not harmful.
- Fat soluble petrochemicals such as PCB's and dioxin, as well as other toxic elements such as mercury are transferred to humans predominantly via the fatty portions of fish, dairy, meat, and poultry and in that order. Fatty fish that are rich sources of omega-3 fats are also typically heavily contaminated with harmful pollutants.
- Animal products contain no fiber, and almost no antioxidant vitamins such as vitamins C, K, E and folate. They also are lacking in all the anti-cancer phytochemicals, bioflavonoids, lignins, and carotenoids that are so essential to protect us against chronic illnesses, immune system disorders, and a premature death.
With animal products occupying a major caloric percentage of the diet, less remains for natural, unrefined plant produce, nutritious foods essential to our health. The inclusion of sugar, white flour, oil and other low-nutrient calories in an omnivorous diet virtually guarantees phytonutrient deficiency and the occurrence of late life cancer. So the low levels of certain essential nutrients are inevitable, unless an omnivorous diet is carefully designed to include substantial amounts of fresh fruits, vegetables, beans, raw nuts, and seeds to supply crucial food elements for optimal health.
The amount of produce necessary to afford a considerable degree of protection would automatically necessitate animal products be a significantly smaller percentage of ones dietary intake, rather than a main portion. After that, the type of animal products chosen is crucial to minimize their potential harmful effects. The animal products that are lowest in saturated fat are egg whites, low fat fish, skinless white meat turkey, and chicken. The highest saturated fat animal products are butter, cheeses, and red meat.
Because animal products do not contain significant omega-3 fat it is important for those omnivorous diet to consume walnuts, flax, hemp, and other plant sources of omega-3. The valuable omega-3 fats should not be derived exclusively from the regular consumption of fatty fish, which are such a polluted food. Instead, I recommend the lower fat (less polluted) fish such as flounder, sole, and tilapia and using the cleaner, plant sources of omega-3.
In addition, a multivitamin and a DHA supplement would still be a good idea, for the assurance that optimal levels of these nutrients are met.
VEGETARIAN OR VEGAN DIETS: SAFE FOR CHILDREN?
Parents often ask me whether their children should be eating a vegetarian or vegan diet. A diet optimally designed for the human species, would naturally be ideal for the children of that species too. There are no special needs children have that would make them require a different diet. Even at the time of rapid growth and brain development the optimal supply of energy and essential fats can be met by and appropriately planned vegetarian or vegan diet.
According to the American Dietetic Association and the Institute of Food Technologists vegan diets can provide adequate nutrition for children.
In May 1998, the seventh edition of Dr. Spock's Baby and Child Care was published. In it, Dr. Spock recommends a vegan diet for children. Dr. Spock was concerned that the diet we fed our children, rich in animal products and dairy fat set them up for adult disabilities and a premature death. He wasn't wrong. But this sparked a long overdue discussion about the scientific and practical issues of optimal diets for children.
Clearly children of all ages need an adequate supply of healthy fats to fuel their growth and energy needs and for brain development. Some people believe even a B12 supplemented vegan or vegetarian diet would not supply enough essential fats for comfort. This could be a concern if the diet is essentially carbohydrate-based, comprised of foods such as bread, potato, rice and fruit.
Conversely, raw nuts, seeds and avocados are rich in protein, fat, vitamins and minerals. Whole nuts, such as peanuts, should be avoided in young children as the shape makes them possible to get stuck in a toddler's windpipe, if not chewed. But nuts can be safely utilized in the diet after one year of age utilizing nut butters, dressing, sauces and desserts to meet these concerns of fat adequacy.
Nuts are rich in protein and also a clean source of nourishment as they grow on deep-rooted trees and do not contain chemical residue. Avocados are appropriate food for infants starting at six months and can be mashed with bananas and mixed with other foods to add a nutritious fat source. The addition of fortified soy milks and tofu, beans, and green vegetables assures complete nutrition for toddlers and children on vegetarian diets.
Of course, informed parents know that if children are to maximize their intellectual and health potential they must be breast fed. Breast feeding should be continued to at least the first and preferably the second birthday to maximize benefits at reducing cancer incidence for both the baby and the mother doing the nursing.
THE REAL QUESTION IS: CAN AN OMNIVOROUS DIET BE SAFE FOR CHILDREN?
Clearly the omnivorous diet that most children consume today is particularly dangerous to their future health.
The most recent scientific evidence is both overwhelming and shocking—apparently what our parents choose to feed or not feed their children during childhood has a greater effect on the cause of certain cancers than dietary intake over the next 50 years.
Today it is well recognized that our children eat less than 2% of their diet from natural plant foods such as fruits and vegetables. American children move into adulthood eating 90% of their caloric intake from dairy products, white flour, sugar, and oil. Then many develop autoimmune illnesses as young adults before heart disease and cancer strikes later. Diseases of nutritional ignorance flourish, but they have not been connected to their cause—childhood diets—until now. The diet rich in cheese, whole milk, white flour and sugar is implicated.
High dairy fat and animal food consumption in childhood assures unnaturally high levels of hormone promoters that raise our children's blood level of estrogen and testosterone, induce an earlier maturity, and initiate changes that promote adult cancers. It is well accepted that an earlier puberty significantly increase the adult risk of both prostate and breast cancer. Animal fats (especially dairy and fish) also contain contaminants that place children at increased risk.
One could make an omnivorous diet safer if dairy fat were removed, if one avoided the potential pollutants in fish, if processed food were significantly limited and if an abundance of produce were consumed. I would rather a young child added eggs to her diet than fish or dairy, because of the potential for transmission of chemicals mercury and PCB's in the fish and dairy.
Therefore I encourage consumption of a carefully planned vegetarian diet or one that includes a small amount of animal products, perhaps 10% of total calories or less, rather than 40 -60 % that children eat today. An animal-product-rich omnivorous diet cannot be considered nutritious food or called healthful.
If one is to utilize animal products in their family and children's diet they should only choose low-fat or nonfat varieties of dairy products, if they are included in the diet at all. I still recommend substituting nuts, seeds, and avocados as the major sources of fat in the diet.
Fruits, vegetables, avocados, nuts, seeds, beans/legumes, and whole grains are the optimal foods for children. Here are some of the long-term advantages of plant-based diets:
Here are some of the long-term advantages of plant-based, vegetarian diets:
- Vegetarian diets prevent and reduce high blood pressure 6
- Cholesterol levels are much lower in vegetarians 7
- Cancer rates are much lower in vegetarians 8
- Vegetarians are leaner and have less obesity in adulthood 9
- Plant-based vegetarian diets encourage a later menarche, which has been shown to be associated with reduced risk of prostate and breast cancer 10
Both vegetarian and omnivorous and diets can be made healthful or harmful; nutritious food choices, wise supplementation and nutritional sophistication will make the difference in the type of diet you choose. Inclusion of high nutrient produce, including nuts, seeds, fruits, vegetables and beans are an essential part of every healthy diet.
1 Key TJA, Thorogood M, Appleby PN Burr ML. Dietary habits and mortality in 11,000 vegetarians and health conscious people: results of a 17 year follow up. British Medical Journal 1996;313:775-779.
2 Nelson NJ. Is chemoprevention research overrated or underfunded? Primary Care & Cancer. 1996;16(8):29-30.
3 Chang-Claude J, Frentzel-Beyme R. Dietary and lifestyle determinants of mortality among German vegetarians. International Journal of Epidemiology. 1993;22(2):228-236.
Kahn HA, Phillips RI, Snowdon DA, Choi W. Association between reported diet and all cause mortality: Twenty-one year follow up on 27,530 adult Seventh-Day Adventists. Am J Epidemiol 1984;119:775-787.
Nestle M, Animal v. plant foods in human diets and health: is the historical record unequivocal? Proc Nutr Soc 1999;58(2):211-228.
4 Barnard ND, Nicholson A, Howard JL. The medical costs attributed to meat consumption. Preventive Medicine 1995;24:646-655.
Segasothy M, Phillips PA. Vegetarian diet: panacea for modern lifestyle disease? QJM 1999;92(9):531-544.
5 Gillman MW, Cuples LA, Millen BE, et al. Inverse association of dietary fat with development of ischeimic stroke in men. JAMA 1997;278:2145-2150. Iso HM, Stampfer MJ, Manson JE, et al. Prospective study of fat and protein intake and risk of intraparenchymal hemorrhage in women. Circulation 2001;103:856. Sasaki S, Zhang XH, Kestleloot H. Dietary sodium, potassium, saturated fat, alcohol and stroke mortality. Stroke 1995;26(5):783-789
6 Ophir O, Peer G, Gilad J, et al. Low blood pressure in vegetarians: the possible role of potassium. Am J Clin Nutr 1983;37:755-62. Melby CL, Hyner GC, Zoog B. Blood pressure in vegetarians and non-vegetarians: a cross-sectional analysis. Nutr Res 1985;5:1077-82. Melby CL, Goldflies DG, Hyner GC, Lyle RM. Relation between vegetarian/nonvegetarian diets and blood pressure in black and white adults. Am J Publ Health 1989;79:1283-8. Rouse IL, Armstrong BK, Beilin LJ, Vandongen R. Blood-pressure-lowering effect of a vegetarian diet: controlled trial in normotensive subjects. Lancet 1983;1:5-10. Rouse IL, Belin LJ, Mahoney DP, et al. Nutrient intake, blood pressure, serum and urinary prostaglandins and serum thromboxane B2 in a controlled trial with a lacto-ovo-vegetarian diet. J Hypertension 1986;4:241-50. Margetts BM, Beilin LJ, Armstrong BK, Vandongen R. A randomized controlled trial of a vegetarian diet in the treatment of mild hypertension. Clin Exp Pharmacol Physiol 1985:12:263-6. Margetts BM, Beilin LJ, Vandongen R, Armstrong BK. Vegetarian diet in mild hypertension: a randomised controlled trial. Br Med J 1986;293:1468-71. Lindahl O, Lindwall L, Spangberg A, et al. A vegan regimen with reduced medication in the treatment of hypertension. Br J Nutr 1984;52:11-20.
7 West RO, Hayes OB. Diet and serum cholesterol levels: a comparison between vegetarians and nonvegetarians in a Seventh-day Adventist group. Am J Clin Nutr 1968;21:853-62. Sacks FM, Ornish D, Rosner B, et al. Plasma lipoprotein levels in vegetarians: the effect of ingestion of fats from dairy products. JAMA 1985;254:1337-41. Fisher M, Levine PH, Weiner B, et al. The effect of vegetarian diets on plasma lipid and platelet levels. Arch Inter Med 1986;146:1193-7. Burslem J, Schonfeld G, Howald M, et al. Plasma apoprotein and lipoprotein lipid levels in vegetarians. Metabolism 978;27:711-9. Cooper RS, Goldberg RB, Trevisan M, et al. The selective lowering effect of vegetarianism on low density lipoproteins in a cross-over experiment. Atherosclerosis 1982:44:293-305.
8 Chang-Claude J, Frentzel-Beyme R, Eilber U. Mortality pattern of German vegetarians after 11 years of follow-up. Epidemiology 1992;3:395-401. Thorogood M, Mann J, Appleby P, McPherson K. Risk of death from cancer and ischaemic heart disease in meat and non-meat eaters. Brit Med J 1994;308:1667-70. Block G. Epidemiologic evidence regarding vitamin C and cancer. Am J Clin Nutr 1991;54:1310S-4S.
9 Pixley F, Wilson D, McPherson K, Mann J. Effect of vegetarianism on development of gallstones in women. Br Med J 1985;291:11-2. Frentzel-Beyme R, Claude J, Eilber U. Mortality among German vegetarians: first results after five years of follow-up. Nutr Cancer 1988;11:117-26. Burr ML, Batese J, Fehily AM, Leger AS. Plasma cholesterol and blood pressure in vegetarians. J Human Nutr 1981;35:437-41. Rouse IL, Armstrong BK, Beilin LJ, Vandongen R. Vegetarian diet, blood pressure and cardiovascular risk. Aust NZ J Med 1984;14:439-43.
10 de Ridder CM, Thijssen JHH, Vant Veer P, et al. Dietary habits, sexual maturation, and plasma hormones in pubertal girls: a longitudinal study. Am J Clin Nutr 1991;54:805-13. Beaton GH, Bengoa JM. WHO monograph. 1976;62:500-19.