|
This would suggest 3 conclusions. 1) Again, the whole lifestyle
package is important. Eating lots of fruit and vegetable while being
overweight and eating red meat and too many calories cuts into the
expected benefits. 2) Even Americans who meet the recommended guidelines
of eating 5 or more fruit and vegetable per day (accounting for
about a third of these subjects) may not be getting the benefits
seen in other countries with higher fruit and vegetable consumption
and much lower colon cancer risk. 3) A healthy diet may not be uniformly
healthy for every disease. These results suggest that the level
of fruit and vegetable that have previously been shown to prevent
other diseases like heart disease and diabetes may not help prevent
colon cancer.
At a recent gathering on vegetarian diets, Walter Willet, the principal
investigator of the Nurses Health Study, commented on the health
benefits that are measurable among vegetarians. He asked what part
of the vegetarian lifestyle, including less meat, more fruit and
vegetable, or more exercise, was the most beneficial part. His answer
was, all of the above. In reports on meat and colon cancer from
these same research groups, it was clear that red meat consumption
promoted colon cancer. Their group and others have concluded that
sustained physical exercise is also protective against colon cancer.
So while the fruit and vegetable part of a healthy lifestyle may
not be active against this specific disease (and this point is still
in debate) other parts of the lifestyle are measurably protective.
In fact, a report from the Health Professionals’ Follow-up Study
earlier this year calculates the proportion of colon cancer that
could be prevented by changing various practices to healthier choices.
They considered 6 practices that they had previously shown to cause
colon cancer: obesity, physical inactivity, alcohol consumption,
early adulthood cigarette smoking, red meat consumption, and low
intake of folic acid supplements. While we might not agree with
this exact list, they concluded that if the study subjects had improved
their lifestyle in all of these practices to that of the healthiest
8% of the population, then about half of the colon cancer could
have been avoided. This seemingly elite group of 8% is not that
hard to get into. The reason this healthy group is so small is that
they meet not just one of two of the healthy goals but they reach
all six of the rather modest goals.
We should continue to eat a great variety of fruit and vegetable
every day at the same time as we do everything else that is part
of a healthy lifestyle, eschew meat, exercise regularly, maintain
a healthy weight, quit smoking, and minimize drinking. The pattern
of a healthy lifestyle will give a pattern of healthy outcomes.
We will enjoy ourselves at both ends of the bargain and not have
to worry about side effects.
Discuss
this aritcle on the VegScience
board.
Marty Root has a PhD in Nutrition from Cornell University,
and works as a Senior Research Scientist at BioSignia,
Inc. in Chapel Hill, NC. His work involves making statistical
models that predict the onset of chronic diseases such as heart
disease and the cancers, and he is a frequent contributor to VegSource.
|
