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Glycemic Load and colorectal
cancer
Researchers from Harvard Medical
School, Brigham and Women's Hospital and UCLA
recently published a study indicating that a diet
with a high glycemic load may increase the risk of
colorectal cancer. A group of nearly 40,000 women
were followed for an average of 7.9 years to examine
the association of dietary glycemic load, overall
dietary glycemic index, carbohydrate, fiber,
non-fiber carbohydrate, sucrose and fructose with
subsequent development of colorectal cancer. Dietary
glycemic load was significantly associated with an
increased risk of colorectal cancer. The researchers
speculate that a diet prominent in foods with high
glycemic indices, like white bread and white rice,
affect insulin factors or exacerbate inflammatory
responses and, thereby, increase the cancer risk.
Higginbotham S, Zhang ZF et al.
Dietary glycemic load and risk of colorectal cancer
in the Women's Health Study. J Natl Cancer Inst 2004
Feb 4;96(3):229-33.
Antioxidants and Alzheimer's
Disease
A new study in Archives of
Neurology looked at Alzheimer's disease in 4,740
people age 65 or older in Utah. Those who took
vitamins were compared to those who didn't. The
study found a combination of vitamin E and C
supplements reduced the incidence of Alzheimer's
disease by about 64 percent. There was no benefit
from the use of vitamin C alone, vitamin E alone, or
multivitamins alone.
In this study, vitamin E use was
categorized as more than 400 international units of
vitamin E. Vitamin C use was defined as at least 500
micrograms of ascorbic acid. These levels are higher
than are commonly found in most multivitamins.
Multivitamins typically contain the relatively
small, recommended daily allowance of vitamin E,
usually somewhere around 30 international units (IU).
Vitamin C in a multivitamin is normally 60 to 90
milligrams.
The findings suggest that vitamins
E and C may offer protection against Alzheimer's
when taken together in the higher doses available
from individual supplements. Individual supplements
of C and E contain much larger doses of up to 1,000
international units of vitamin E and up to 1,000
milligrams or more of vitamin C.
The theory is that vitamins E and
C may help protect against damage caused by free
radicals, the by-products of metabolism that can
damage cells. Some believe free radicals may
contribute to the development of Alzheimer's,
because cells in the brain are especially sensitive
to their damaging effects.
Further study is needed to confirm
the benefits before any official recommendations can
be made, but the researchers say the results are
extremely exciting.
The threat from Alzheimer's
disease is thought to be growing since the
population is living longer in general. Since
antioxidant vitamin supplements are relatively safe
and are thought to have other wide-ranging health
benefits, the hope is they could turn out to be an
ideal Alzheimer's prevention strategy for the aging
population.
Peter P. Zandi, PhD et al. Reduced
Risk of Alzheimer Disease in Users of Antioxidant
Vitamin Supplements. Arch Neurol. 2004;61:82-88.
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