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LE Magazine February 2003
Another
reason to skip the fries?
After hearing of
the dangers of eating charred meat from the grill, now comes a
new warning about another dietary carcinogen. Unpublished
findings from Stockholm University, Sweden, show that
acrylamide, found in high levels in fried and baked starchy
foods (i.e. potatoes, cereal grains), is a cancer-causing
agent. Acrylamide is used industrially in water processing
plants and plastics manufacturing [J Agric Food Chem 2002 Aug
14;50(17):4998-5006]. Apparently, high cooking temperatures
combines with certain types of food to form gene mutating
acrylamide.
Swedish
scientists set up a red flag after discovering up to 1000
mg/kg of acrylamide in various kinds of potato chips, 500
mg/kg in french fries and high levels in some breakfast
cereals and crispbread. The World Health Organization (WHO)
recommends one microgram (one-millionth of a gram) of
acrylamide per liter of drinking water as the maximum exposure
permitted in humans. The amount of acrylamide in a large order
of fast-food french fries is at least 300 times more than
that.
Earlier research
had found that rats fed fried animal feed for one or two
months showed a higher level of acrylamide than controls [Chem
Res Toxicol 2000 Jun;13(6):517-522]. Acrylamide is a known
carcinogen and neurotoxin in rodents, but the jury is still
out about human health effects. The U.S. Environmental
Protection Agency (EPA) has documented that human short-term
exposure to acrylamide can cause nerve damage; long-term
exposure, as yet unconfirmed by research data, may cause nerve
damage, paralysis and cancer
[http://www.epa.gov/safewater/dwh/c-voc/acrylami.html].
Convinced that
this is a serious issue, an international panel of 23
scientists convened for three days (June 25-27, 2002),
following the findings, to discuss future action. WHO called
for further urgent research to be conducted into the health
risks of acrylamide [The Lancet 2002 Jul 6;360(9326):64].
Prudence would suggest staying away from suspected foods in
the meantime. The identification of yet another dangerous
carcinogen in our diet emphasizes the importance of protecting
our genes against mutation by ingesting plant extracts such as
indole-3-carbinol, lycopene and chlorophyllin. By protecting
against gene mutation, we lower our risk of contracting
cancer.
-Angela
Pirisi
Studies:
green tea provides
powerful antioxidant protection
A large and
increasing body of evidence is revealing the powerful health
benefits that drinking tea provides, particularly green
tea.
The experts
revealed their findings at a meeting sponsored by the American
Cancer Society, the U.S. Department of Agriculture, the Tea
Council and other groups. They say tea may someday be added to
the list of fruits and vegetables that Americans should
include in their daily diet.
The secret is
green tea's so-called "phytochemicals"-a group of specialized
molecules which act as antioxidants, protecting DNA from
inherent damage caused by free radicals in the body [J Am Coll
Nutr 2002 Feb;21(1):1-13]. DNA damage is a typical precursor
to cancer and is linked to heart disease [Proc Natl Acad Sci
1993 Sep 1;90(17):7915-22].
One
USDA-sponsored study reported at the conference tested the
effects of green tea on blood lipids in eight men and women
over a three-week period. The researchers discovered that
drinking five cups of green tea in that time lowered lipid
levels of low-density lipoprotein. Total cholesterol, the
experts reported, dropped 6% in the subjects who drank green
tea. There was no effect on high density lipoprotein.
Yet another study
investigated the effects of a substance typically found in
urine that causes cellular oxidative damage (8-OHdG).
University of Arizona scientists recruited 140 smokers and
asked them to maintain their typical diets, but add green tea,
black tea or water to the menu for four months.
At the end of the
period investigators conducted urinalyses and found no changes
in levels of 8-OHdG in participants who consumed black tea or
water, but a 25% decrease among green tea drinkers.
-John Martin
Light,
healthy diet may
help starve cancer cells
Science has
certainly made a case for the diet-cancer connection,
suggesting that diet may contribute to one third of all
preventable cancers in the Western world, making it as risky
as smoking [Nat Rev Cancer 2002 Sep;2(9):694-704]. More
specifically, the danger is that a high-calorie, high-fat diet
leads to excess weight, which can result in a number of
cancer-promoting events. A recent review study by UK
researchers summed up that obesity increases the risk of
cancers of the esophagus, colorectum, breast, endometrium and
kidney [Lancet 2002 Sept 14;360(9336): 861-68].
One theory
suggests that obesity breeds insulin resistance and that
cancer cells feed off the extra sugar and insulin. So the
lower or more controlled your blood glucose, the less fuel
cancer cells gets. Israeli researchers at Ben Gurion
University have similarly suggested that cancer cells use more
calories than healthy cells to survive and multiply [J Theor
Biol 2001 Jun 7;210(3):319-25]. Obesity is also said to
adversely affect sex hormones, which may spur on
hormone-fueled cancer development, as in breast cancer where
fat tissue increases serum levels of free oestradiol [Lancet
Oncol 2001 Mar;2(3):133-140].
Meanwhile,
research at the Fred Hutchinson Cancer Research Center in
Seattle has found that higher calorie consumption can double
men's risk of prostate cancer [Cancer Epidemiol Biomarkers
Prev. 2002 Aug;11(8):719-25]. A number of studies have also
set forth the idea that high-fat foods may contribute to
oxidative damage, which predisposes cells to cancer
development. Simply put, evidence points to a preventive diet
that is high in fruits and vegetables and low in fat, which
translates into foods that are high in antioxidants, low in
oxidants and that have lower glycemic values. New approaches
for reducing excess serum insulin and body fat will be
appearing in future issues of Life Extension magazine.
-AP
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