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By Dean Ornish
March 23, 2015
MANY people have been making the case that Americans have grown fat because
they eat too much starch and sugar, and not enough meat, fat and eggs. Recently,
the Dietary Guidelines Advisory Committee lifted recommendations that
consumption of dietary
cholesterol should be restricted, citing research that dietary cholesterol
does not have a major effect on blood cholesterol levels. The predictable
headlines followed: "Back to Eggs and Bacon?"
But, alas, bacon and egg yolks are not
Although people have been told for decades to eat less meat and fat, Americans
actually consumed 67 percent more added fat, 39 percent more sugar, and 41
percent more meat in 2000 than they had in 1950 and 24.5 percent more calories
than they had in 1970, according to the
Department. Not surprisingly, we are fatter and unhealthier.
The debate is not as simple as low-fat versus low-carb. Research shows that
animal protein may significantly increase the risk of
premature mortality from all causes, among them
cancer and Type 2
diabetes. Heavy consumption of
saturated fat and trans fats may
double the risk of developing
A study published last March found a
75 percent increase in
premature deaths from all causes, and a 400 percent increase in deaths from
cancer and Type 2 diabetes, among heavy consumers of animal protein under the
age of 65 — those who got 20 percent or more of their calories from animal
Low-carb, high-animal-protein diets promote heart disease
other than just their effects on cholesterol levels. Arterial blockages may
be caused by animal-protein-induced elevations in free fatty acids and insulin
levels and decreased production of endothelial progenitor cells (which help keep
arteries clean). Egg yolks
red meat appear to significantly increase the risk of
coronary heart disease
and cancer due to increased production of trimethylamine N-oxide, or TMAO, a
metabolite of meat and egg yolks linked to the clogging of arteries. (Egg whites
have neither cholesterol nor TMAO.)
Animal protein increases
IGF-1, an insulin-like
growth hormone, and chronic inflammation, an underlying factor in many
chronic diseases. Also, red meat is high in
tumor-forming sugar that is linked to chronic inflammation and an increased risk
of cancer. A plant-based diet may prolong life by blocking the mTOR protein,
which is linked to aging. When
calories were carefully controlled, patients lost 67 percent more body fat
carbohydrates were controlled. An optimal diet for preventing disease is a
whole-foods, plant-based diet that is naturally low in animal protein, harmful
fats and refined carbohydrates. What that means in practice is little or no red
meat; mostly vegetables, fruits, whole grains, legumes and soy products in their
natural forms; very few simple and refined carbohydrates such as sugar and white
flour; and sufficient "good fats" such as fish oil or flax oil, seeds and nuts.
A healthful diet should be low in "bad fats," meaning trans fats, saturated fats
and hydrogenated fats. Finally, we need more quality and less quantity.
My colleagues and I at the nonprofit Preventive
Medicine Research Institute and the University of California, San Francisco,
have conducted clinical research proving the many benefits of a whole-foods,
plant-based diet on reversing chronic diseases, not just on reducing risk
factors such as cholesterol. Our interventions also included
management techniques, moderate exercise like walking and social support.
We showed in randomized,
controlled trials that these diet and lifestyle changes can
reverse the progression
of even severe coronary heart disease. Episodes of
chest pain decreased by 91 percent after only a few weeks. After five years
there were 2.5 times
fewer cardiac events. Blood flow to the heart
improved by over 300 percent.
Other physicians, including
Dr. Kim A.
Williams, the president of the American College of Cardiology, are also
finding that these diet and lifestyle changes can reduce the need for a lifetime
of medications and transform people's lives. These changes may also slow, stop
or even reverse the
progression of early-stage prostate cancer, judging from results in a
randomized controlled trial.
These changes may also
genes, turning on genes that keep you healthy, and turning off genes that
promote disease. They may even
the ends of our chromosomes that control aging.
The more people adhered to these recommendations (including reducing the amount
of fat and cholesterol they consumed), the more improvement we measured — at any
age. But for reversing disease, a whole-foods, plant-based diet seems to be
In addition, what's good for you is good for our planet. Livestock production
causes more disruption of the climate than all forms of transportation combined.
And because it takes as much as 10 times more grain to produce the same amount
of calories through livestock as through direct grain consumption, eating a
plant-based diet could free up resources for the hungry.
What you gain is so much more than what you give up.
Dean Ornish is a clinical professor of medicine at the University of California,
San Francisco and the founder of the Preventive Medicine Research Institute.