Less meat, More life

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Vegetarians outlive non-vegetarians by several years.  The result may be largely (or entirely) due to lower weight, and higher consumption of fresh vegetables and fruits, rather than to an adverse effect of meat per se.   Vegans have an even greater advantage than vegetarians who eat dairy and eggs, and again vegan weight trends even lower than other vegetarians.  It goes without saying that in this context a longer life goes hand-in-hand with a healthier life. Rates of diabetes, heart disease, and selected cancers are much lower in vegetarians, and yet lower in vegans.  

I have been a vegetarian since 1973, motivated (now) by years of habit and (then) by a hypnotic suggestion from my first yoga teacher.  One evening, about five months into my discovery of yoga, I was lying on the floor in savasana (deep relaxation) when the revered and beloved voice of my teacher suggested to the class that perhaps we might find our practice leading us to eat less meat.  I was startled awake, and sat bolt upright.  In previous weeks, she had suggested cutting back coffee and alcohol and TV and marijuana (this was Berkeley!) and cigarettes—it all went down smoothly because I had never been attracted to any of those things.  But what could she be thinking, classing meat with intoxicants and mind-altering drugs?  I had never questioned that a diet that was ultra-high in protein would keep me strong and healthy.  The phrase “new age hocum” hadn’t been invented yet, but those are just the words for which my mind was searching.

Six weeks later, I was a vegetarian.  My teacher’s hypnotic suggestion awakened my discomfort with surrogate killing of animals.  It had nothing to do with science.  Now there is evidence linking low meat consumption with longevity, but much less was known 40 years ago, and even that was unknown to me.  I became aware that I was uncomfortable eating animals, and I have never looked back.

Years later, I raised my two daughters to eat whatever they wanted to eat, and was secretly delighted when, as pre-teens, they each decided that (though they enjoyed the taste of meat), it was too unsettling for them to think of the animal who died to become their meal.  Both daughters have maintained their vegetarianism into adulthood, though everything else about them has changed.

As a public health advocate, I have been very cautious about suggesting vegetarianism to anyone.  I am still wary that my own habits and emotions may be affecting my judgment.  But more studies than ever support the role of vegetarianism in a life extension plan, and prompted by a recent ScienceDaily article, I’ll look at vegetarian diets in this week’s column.

 

Seventh Day Adventist Study

Studying the long-term consequences of a vegetarian diet is complicated by the fact that vegetarians are far from a random sample.  There are a lot more women than men, more liberals than conservatives, more environmental awareness, more health-consciousness, more propensity to exercise among vegetarians [2012 Gallup poll].  More surprisingly, vegetarianism is associated with fewer years of education, and there are a lot more Baby Boomer vegetarians than among younger generations.

41% of Seventh Day Adventists call themselves vegetarians, compared to 5% of Americans generally.  This makes SDA an ideal population to a study the effects of a vegetarian diet holding other factors fairly constant.  Vegetarianism among SDA cuts across racial and socio-economic divisions.

Consistent with past studies, the SDA study gave vegetarians 3 extra years of life.  Note that SDA men already live 7 years longer than other Americans (4½ years for women).  So the vegetarian advantage in SDA studies is on top of a large head start.  7 years is big! comparable to the difference between Japan (world’s highest life expectancy) and Mexico (representative of the worldwide average, outside Africa which is shockingly low) [Wikipedia list]

Benefits were reported for for heart disease (especially) and selective cancers, cancers of the digestive tract in particular.  Past studies have found that cardiovascular mortality is 24% lower among vegetarians.

Gary Fraser, an MD-PhD cardiologist at SDA-affiliated Loma Linda University, has written a great deal on the health benefits of vegetarian diets.  Here is a chart from his 2009 reviewof SDA and other data:

 

Diet group BMI rel incidence
of Diabetes
rel incidence
of Hypertension
Nonvegetarian 28.26 1.00 1.00
Semivegetarian 27.00 0.72 0.77
Pescovegetarian 25.73 0.49 0.62
Lactoovo-vegetarian 25.48 0.39 0.45
Vegan 23.13 0.22 0.25

Look at the diabetes rates for vegans compared to non-vegarians – only 1 / 5th as high!  Diabetes contributes to all the diseases of old age.

But look at the first column, BMI.  Non-vegetarians in the study had BMI of more than 28, compared to 25 – 26 for vegetarians and 23 for vegans.  Differences of this order could easily account for the entire 3 year life expectancy advantage [Oxford study, 2009].  There are theoretical reasons why vegetable protein might be helpful in modulating the metabolism in ways that keep weight down and insulin sensitivity up.

The vegetarian advantage appears in a much reduced incidence of early death, most apparent between ages 50 and 60.  (For younger decades, the death rate for both vegetarians and meat eaters is too low to make much difference, and at older ages, the advantage of vegetarianism is gradually overtaken by genetic and other factors affecting longevity.)

Findings about the advantage of fruit and (especially) green vegetable consumption should come as no surprise.  More interesting is a paper from the SDA study devoted just to nuts.  Eating a lot of nuts contributed to a lower risk of obesity and, to a lesser extent, metabolic syndrome.  Peanuts were not as helpful as other nuts.  Personally, I find that nuts are a convenient and tasty component of a low-carb vegetarian diet.

 

The Bottom Line

If you are inclined to a vegetarian diet for poliitcal or environmental or philosophic or religious reasons, then by all means enjoy the satisfaction of knowing that you are doing your body a favor, and your diet is conducive to health and longevity.  If your diet includes meat, keep in mind that the most important things you can do are to keep your weight down and expand on vegetables, nuts and fruits, with leafy greans at the top of the list.  If you are contemplating a change, I suggest that you try a vegetarian eating style for a week or even for a day at a time as a way to expand your culinary horizons and explore how it feels to you.

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This post previously appeared in Josh’s blog here: