http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10910295&dopt=Abstract
Dietary fats and immune status in athletes: clinical
implications.
Venkatraman JT, Leddy J,
Pendergast D.
Department of Physical
Therapy, Exercise and Nutrition Sciences,
Sports Medicine
Institute, University at Buffalo, NY 14214, USA.
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Athletes are
competitive, train at very high levels with inadequate
rest, consume too few
calories, avoid fats, and may be at increased
risk of infections. The
immune system is sensitive to both fat intake
and intense exercise,
suggesting that athletes may have suppressed
immune function. It has
been reported that many athletes consume about
25% fewer calories than
the estimated expenditure, leading to low
intakes of some
essential micronutrients and fats. Acute exercise has
been shown to increase
inflammatory and decrease antiinflammatory
immune factors and may
increase oxidant stress. Chronic exercise
appears to improve
immune competence. Lipids are powerful mediators of
the immune system, and
they may modulate the immunosuppressive effects
of strenuous exercise.
Studies have shown that a low-fat
high-carbohydrate diet
(15% fat, 65% CHO, 20% protein of total
calories), typically
eaten by athletes, increases inflammatory and
decreases
antiinflammatory immune factors, depresses antioxidants, and
negatively affects blood
lipoprotein ratios. Increasing total caloric
intake by 25% to match
energy expenditure and the dietary fat intake
to 32% in athletes
appears to reverse the negative effects on immune
function and lipoprotein
levels reported on a low-fat diet. Increasing
the dietary fat intake
of athletes to 42%, while maintaining caloric
intake equal to
expenditure, does not negatively affect immune
competency or blood
lipoproteins, whereas it improves endurance
exercise performance at
60-80% of VO2max in cyclists, soldiers, and
runners. There is no
evidence that higher fat intakes (up to 42% of
total calories), in
calorically balanced diets, increase the risk of
cancer, but studies are
needed to determine whether the beneficial
effects of higher fat
diets in athletes reduce their rate of
infections.
Publication Types:
Review
Review, Tutorial
PMID: 10910295 [PubMed -
indexed for MEDLINE]
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