Posted on December 31, 2012 by RalphWeber by Lee Kurisko, MD
It is often assumed that vegetarianism and veganism are healthy practices, but this does not hold up to scrutiny. Not eating animal products produces an array of deficiencies of nutrients that are essential to health.
If you look at primitive man as a model of how humans are supposed to eat, meat consumption has been ubiquitous for the 2.6 million year history of human kind. No aboriginal culture on earth has ever voluntarily adopted a vegetarian diet. The human brain likely would never have evolved into its current form without the ingestion of meat. No primate (that includes us) has a purely vegetarian diet.
Cows are vegetarians. They have four stomachs and a long digestive tract designed to extract energy and nutrition from a plant based diet to a degree that is not possible for humans. They have the enzyme systems necessary to break down cellulose (fiber) and use it for energy. Humans cannot do this.
According to Mark Houston MD of Vanderbilt University, vegetarianism produces a deficiency of zinc in just one week! Zinc is essential to hormone production, reproductive health, and immunity.
Vitamin B12 is necessary for health. The fact that it is classified as a vitamin by definition means that it is “vital” or “essential” for survival. Vitamin B12 can only be obtained in sufficient amounts from animal sources. Low B12 levels can lead to pernicious anemia, dementia, and subacute combined degeneration of the spinal cord.
Homocysteine is likely a major factor in the development of cardiovascular disease, Parkinson’s disease, and Alzheimer’s disease. Vitamin B12 is instrumental in lowering homocysteine to healthy levels. Vegetarians have higher levels of homocysteine, potentially raising their risk for these diseases.
Although it is true that the careful combining of plant sources of protein can provide all essential amino acids (the building blocks of protein), the quantity of protein is likely marginal and not necessarily sufficient to thrive on a vegetarian diet.
Vegetarians have a hard time getting adequate omega-three fatty acids. Although ALA can be obtained from sources such as flax oil, it is difficult for the body to then synthesize them into the other necessary forms such as DHA and EPA.
One of the most serious problems with vegetarian diets is that they tend to be high carbohydrate and low fat diets. This raises blood sugar and drives up insulin, two key factors that are now accepted as accelerating the aging of the body.
The carb based, low fat nature of such diets will tend to make people fat further increasing the risk of heart disease. I remember being shocked years ago when I met a doctor that was an avowed vegetarian supposedly to protect himself from heart disease and he was fat! The high glycemic load from the grains and sugars he was eating to replace the fats and protein that he was missing was making him fat and likely diabetic, thereby raising his risk of heart disease.
“But don’t vegetarians live longer?” you may ask. No they don’t. When health conscious Seventh Day Adventist and Mormons are compared, the Mormons win in the longevity contest. Seventh Day Adventists are vegetarians. Mormons eat meat.
“What about the dangers of red meat?” you may object. Critiques of the evidence for cancer risk from red meat actually attributes that risk to processed meats like cold cuts, bacon, and hot dogs because of preservatives like nitrites. There is no evidence specifically against non-processed meats like sirloin steak.
The ethical/moral question about eating meat is not the