From: altar@beaufort.sfu.ca (Ted Wayn Altar)
Subject: Health Advantages of Vegetarianism
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Mon, 9 Nov 1992 15:52:43 GMT


I guess here on this conference we all know that vegetarianism
incurs some pretty significant health advantages.  But how much
of an advantage might there be?  An estimate of the effect size
is useful so as to compare, say, the relative advantages of other
possible dietary regimes.  To date, the evidence would indicate
that no omnivorous diet incurs the same advantages as does a
vegetarian diet.  To me, this would suggest that the less meat
you eat, the better and that none is probably best.  The same,
however, would seem to also apply to diary/egg consumption.  For
instance, comparing just the non-smoking Seventh Day Adventists
men we Phillips et al. (1978) found that:

=============================================================
|   OBSERVED-TO-EXPECTED CORONARY HEART DISEASE MORTALITY   |
|                     ADVENTIST MEN                         |
|                                                           |
|  Total Vegetarians                14%                     |
|  Lacto-Ovo-Vegetarians            39%                     |
|  Meat Users                       56%                     |
|                                                           |
=============================================================
Note that even the SDA meat users have a lower than expected
mortality which can be accounted for in large part by the fact
that even meat eating SDA's eat less meat then North Americans
in general.

To take another example, consider the RELATIVE risk of breast
cancer among Japanese woman (from a paper by Hirayama cited in
John Scharffenberg's "Problems with Meat", 1989)

=================================================================
|                 RELATIVE RISK OF BREAST CANCER                |
|                                                               |
|                              Meat       Eggs    Butter/cheese |
|  less than once per week      1.0        1.0        1.0       |
|  2-4 times per week           2.55       1.91       3.23      |
|  almost daily                 3.83       2.86       2.10      |
=================================================================

Such results again affirm the general rule that less is better
and none is likely best.

To return to our Seventh Day Adventists again, consider the
following from Phillips R. et al. "Environmental Aspects of
Cancer: The Role of Macro and Micro Components of Foods" 1983.

=================================================================
|           Meat Use and Ovary Cancer Death Rates:              |
|                                                               |
|  Lacto-ovo-vegetarian Adventists                15.9/100,000  |
|  Adventists using meat 1-3 times per week       18.0/100,000  |
|  General population                             24.0/100,000  |
|                                                               |
=================================================================

These are just three examples of the many studies that converge
to the same general conclusion that the LESS meat, eggs and whole
dairy you eat, the better.  Evidence to date supports the
reasonable extrapolation that not only is less better, but none
is best.  Of course, one simply doesn't omit these products but
when one becomes a vegetarian one also eats more grains, egumes,
vegetables and fruits to take the place of meat, eggs and whole
dairy.  Hence, it is not simply the omission of meat per se that
accounts for these results but we should also consider the
effects of the "better" diet (i.e., more fruits, vegetables, &
fiber) that is part and parcel of the vegetarian life style.  The
relative contribution of omitting meat, eggs and whole dairy
versus eating more vegetables and fruits on reducing such things
as one's risk for cancer, has yet to be worked out.  So far, both
these factors are implicated with respect to cancer.  At a
practical level, the easiest thing to do is simply give up meat
products.  With  respect to atherosclerosis and heart disease,
the ommision of meat, eggs and dairy is more clearly the
predominant factor accounting for why vegans have the lowest risk
of all populations.

To help make this point, permit me to re-post some more tables
I've already posted here some months earlier:

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+     RELATIVE PERCENTAGE OF LIFE STYLE FACTORS CONTRIBUTING    +
+ TO A DECREASED LIFE EXPECTANCY FROM ATHEROSCLEROSIS & CANCER  +
+                                                               +
+           Tobacco                                 25%         +
+                                                               +
+           Meat                                    25%         +
+                                                               +
+           diary Products                          15%         +
+           eggs, high fat                                      +
+           foods                                               +
+                                                               +
+           Obesity                                 10%         +
+                                                               +
+           Lack of Exercise                        10%         +
+                                                               +
+           Stress, refined sugars,                 15%         +
+           other factors                                       +
+                                                               +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

 The above chart is useful in providing one estimate of the
relative contribution of life style factors for an increased risk
for atherosclerosis and cancer.  This result was first presented
at an annual meeting of the American Association for the
Advancement of Science by John Scharffenberg (M.D., M.P.H.) who
is Adjunct Professor of Nutrition at Loma Linda University and is
the Vice President of the Pacific Health Education Center (also
published in Scharffenberg's "Problems with Meat", 1989). These
estimates of the relative contribution of life style factors are
based upon epidemological data.

In particular, Scharffenberg employed epidemiological data educed
from some vegetarian populations (e.g., Seventh Day Adventists).
It turns out from Scharffenberg's data that the best diet for
human beings in terms of health and longevity is vegetarian.  In
general, vegetarians live about 6 years longer than their meat
eating counterparts (i.e., meat-eating Seventh Day Adventists).
If we select as our comparison group only those Seventh Day
Adventists who still eat meat AND who do not smoke, it turns out
that their total vegetarian counterparts still out live them by 3
years.  Hence, even when we use a somewhat CONSERVATIVE
comparison group (remember, even though not all SDA's are
vegetarian but on the whole they would still eat less meat then
the average North American) and thereby control for known life
style hazards like smoking, VEGETARIANS STILL LIVE LONGER (ABOUT
3 YEARS) THAN EVEN MODERATE MEAT EATERS, and here we are talking
a compable comparison group of meat eaters who otherwise share
essentially the same life style.  This is still a substantial
difference and it would appear that the hazards of meat eating
are on the same level as that of smoking (which as we have seen
shortens this comparison group's lifespan by about 3 years).

Also, keep in mind that the observed-to-expected coronary heart
disease mortality among total vegetarians is only 14%.
Vegetarians, of course, do have heart attacks but they occur
approximately 20 years later in life than for meat eaters.  Thus,
not only is longevity increased but so is the quality of health
for the life span that one does live out.  This is important,
especially if we hope to live a robust and vital life and not end
up being a valetudinarian or invalid during our "golden" years,
which indeed should be golden.

Many other studies have consistently demonstrated that
vegetarians have a far lower risk for certain major cancers (see
the National Cancer Institute's 1982 report) and some other major
diseases.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Here are some upper estimates by how much you can        +
+ reduce your risk of heart attack if you reduce your      +
+ consumptionof meat, dairy  products and eggs by a given  +
+ amount:                                                  +
+                                                          +
+ 10% reduction of consumption = 9% reduction in risk      +
+ 50%   "       "       "      = 45%  "        "  "        +
+ 100%  "       "       "      = 90%  "        "  "        +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

With respect to cancer, in 1982 a committee of scientists
(epidemiologists, oncologists, nutritionists, etc.) were
commissioned by the American National Cancer Institute (a very
conservative organization indeed). Their findings were as
follows:

   +++++++++++++++++++++++++++++++++++++++++++++++++++++++
   +            THE LARGEST CANCER FACTORS               +
   +            ARE THE ONES WE CAN CONTROL              +
   +                                                     +
   +   diet                                         35%  +
   +   tobacco                                      30   +
   +   viruses                                      5%   +
   +   occupation                                   4%   +
   +   alcohol                                      3%   +
   +   excess sun exposure                          3%   +
   +   environmental pollution                      2%   +
   +   medicine and medical procedures              1%   +
   +   food additives                               1%   +
   +                                                     +
   +++++++++++++++++++++++++++++++++++++++++++++++++++++++

The cruel probability of developing cancer sometime during one's
life is now approaching 1 in 3.  Of those who do get cancer, 1 in
5 will die from it.  Even by these conservative estimates, the
food we eat we consume is the greatest single cause of cancer.
In particular, it is meat and diary products in our diet that
puts us at risk.

Given the above estimates to be correct, it is indeed curious
that so much attention and public funding has gone into educating
the public about the need to quite smoking, lose weight and
exercise while comparative very little attention has been given
to the problem that the eating of meat by itself may be as
hazardous as smoking!

The health benefits of vegetarianism is really beyond dispute.
The effect size of this advantage, as we can see, is quite
substantial and no omnivorous diet has yet been devised and shown
to achieve the same degree of advantage.  Even a judiciously
planned "lean meat" diet still does not incur the same advantages
of even a fatty lacot-ovovegetarian diet, as evidence by the well
design experiment study by Kestin et al. (1989).  One can only
wonder what might be the sociological and psychological
conditions behind people's irrational persistence in denying the
objective evidence that has been around for decades.  Of course,
many people are even still denying the hazards incurred by
smoking.

To end, permit me to note in passing that better health is only
ONE reason favouring a vegetarian diet.  More persuasive, I would
hope, would be the ethical and the ecological arguments.
Expanding the circle of concern and caring for things beyond our
own skins or propinquity is not only one of our better human
possibilities, but it is a necessity for a sad planet so
endangered by human over-population, human exploitation,
unbridled greed and callow disregard.

                                           ted


References:

 John Scharffenberg   PROBLEMS WITH MEAT, 1989
 Keatin, M., et al.  Cardiovascular disease risk factors ...
      AMERICAN  JOURNAL OF CLINICAL NUTRITION, 50(2):280, '89.
 Kestin, M. et al.  Cardiovascular disease risk factors in
     free-living men: Comparsion of two prudent diets, one
     based on lactoovovegetarianism and the other allowing
     lean meat.  AMERICAN JOURNAL OF CLINICAL NUTRITION,
     1989, 50:280-7.
 Arehart-Treichel, J.  Eating your way out of high blood
      pressure.  SCIENCE  NEWS 123:232 (April 9), '83.
 Brody, J.  New research on the vegetarian diet.  THE NEW
      YORK TIMES  Oct.  12, '83.
 Hardinge, M.  Nutritional studies of vegetarians: IV.
      dietary fatty acids and serum cholesterol levels.
      AMERICAN JOURNAL OF CLINICAL NUTRITION 10:522, '62.
 Phillips, R., Coronary heart disease mortality among seventh
      day Adventists with differing dietary habits.  ABSTRACT
      AMER.  PUBLIC HEALTH ASSOC.  MEETING Nov.  16-20, '75
 Ruys, J., Serum cholesterol .  .  .  in Australian Adolescent
       vegetarians. BRITISH MEDICAL JOURNAL 6027:87, '76.
 Sacks, F.  Plasma lipids and lipoproteins in vegetarians
       and controls.  NEW ENGLAND JOURNAL OF MEDICINE
       292:1148, '75.
 Sacks, f., Blood ...  in vegetarians.  AMERICAN JOURNAL OF
        EPIDEMIOLOGY  100:390, '74.
 Armstrong, B.  Blood...  American Journal of Epidemiology
        104:444, '78. Sirtori, C.  Soybean protein diet....
        LANCET 8006:275, '77.
 Barrow, J., Studies in atherosclerosis...  ANNALS OF INTERNAL
         MEDICINE   52:372, '60.
 Phillips, R., Coronary heart disease.differing dietary habits: a
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         NUTRITION 31:181, '78


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