WHAT YOU
DON'T KNOW CAN HURT YOU
by Franklin L. Murphy, MD
Fiber
There is
substantial evidence that lack of dietary fiber and nutrient
deficiency are responsible for many of the diseases which afflict
humans. Diseases such as diabetes, heart disease, cancer,
cataracts, and even aging itself can be ameliorated or prevented
by proper nutrition. It has been estimated that 35% of all
cancers are associated with the typical low fiber, high fat
American diet. Boston researchers reported in 1996 that
increasing dietary fiber intake from the average 12 grams per day
to 28 grams per day resulted in a dramatic 41% reduction in heart
attacks. The American Dietetic Association has advised all
Americans to consume 25-35 grams of fiber each day. Guidelines
have been developed for children by the American Academy of
Pediatrics recommending that a child consume the number of grams
of fiber equivalent to age plus 5-10 grams per day. Public health
agencies are advocating the "optimal diet", that is,
25% of calories as fat and 25 grams of fiber per day. Somewhere
between 25 and 35 grams of fiber per day people enter into a
"health envelope" where there appears a reduction in
the incidence of heart disease and certain cancers including
colorectal, prostate and breast.
Mechanism of Action
There are
many mechanisms responsible for the dramatic health benefits of
foods high in dietary fiber, but before discussing these one must
recognize that there are two kinds of fiber, soluble and
insoluble. Foods rich in soluble fiber include whole grain foods
(made from oats barley and oat bran), fruits, vegetables,
legumes, brown rice and seeds. Foods high in insoluble fiber
include whole grain foods (made from wheat, rice and corn) and
some fruits and vegetables. Insoluble fiber keeps foods moving
through the colon reducing the time that cancer causing
substances can remain in the digestive tract. Soluble fiber
delays emptying of foods from the stomach resulting in a more
uniform absorption of carbohydrates improving glucose control.
Soluble fiber also binds cholesterol for elimination. Once in the
colon, soluble fiber is fermented causing production of
substances known as short chain fatty acids which are absorbed
and cause further glucose and cholesterol control. Recently, a
study from Norway has demonstrated that a high fiber diet also
decreases the tendency of the blood to clot adding another
mechanism for heart attack reduction.
Nutrients
Foods high in dietary fiber also contain many
potent anti-aging and disease preventing nutrients, cofactors,
vitamins and antioxidants. The list is large. Antioxidants appear
to decrease the incidence of heart disease by preventing the
oxidation of cholesterol making it less likely to get stuck in
blood vessels. Antioxidants also are believed to protect against
a number of cancers and age-related chronic diseases such as
macular degeneration, cataracts and skin photo aging.
Phytochemicals, recently discovered compounds present in fruits
and vegetables, prevent cancer by helping to remove cancer
causing substances from the cell or preventing entry into cells.
Elements such as selenium appear to reduce the risk of colorectal
cancer. Coenzyme Q10 also known as ubiquinone may help to prevent
not only cancer but find use in the treatment of heart disease,
allergies and ulcers as well. Bioflavonoids are vitamin like
substances which enhance the absorption of vitamin C and work
synergistically with vitamin C to protect and preserve the
structure of blood vessels. The list goes on.
DASH Trial
A report recently published in the New England
Journal of Medicine on the DASH Trial (Dietary Approaches to Stop
Hypertension) compared the effects of three different diets on
blood pressure in patients with hypertension. The first group
followed the regular daily American low fiber, high fat diet (9
grams fiber, 37% fat). The second group followed a high fiber,
high fat diet (31 grams fiber, 37% fat). The third group followed
a high fiber, low fat diet (31 grams fiber, 27% fat) that was
supplemented with calcium (1240 mg) from low-fat dairy products.
Sodium intake and body weights were maintained at constant
levels. A significant reduction was seen in both high fiber
groups, however, the most profound reduction was seen in the high
fiber, low fat high calcium group. In that group the systolic and
diastolic blood pressures fell by 11.4 and 5.5 mm Hg,
respectively. In summery, a diet high in fiber, low in fat and
high in dietary calcium is an effective alternative approach to
the treatment of high blood pressure.
Suggested Dietary Guidelines
7-8 daily servings of grains and grain products
4-5 daily servings of vegetables
4-5 daily servings of fruit
2-3 daily servings of low-fat or non-fat dairy foods
1-2 daily servings of lean meat, poultry (no skin, breast
preferable) or fish
4-5 weekly serving of legumes, nuts and seeds
Total daily fat intake not to exceed 30%
Preventative Medicine and
National Health Policy
In conclusion, the staff in our organization are
firm believers in preventative health. This and similar articles
found in this publication will hopefully serve to enhance
nutritional awareness and in so doing inspire people to
incorporate this important aspect of preventative medicine into
their lifestyles. We will continue to encourage the development
of a National Health Policy further defining nutritional
guidelines in conjunction with educational implementation.
Without such a policy in place, untold lives will be lost with
associated costs projected to be in the billions of dollars.
