Effect of Omega-3 Fatty Acid Supplementation Physical Fitness Clinical Trial
Official title:
Effects of 12 Weeks of Omega-3 Fatty Acid Supplementation on Metabolic and Physical Health Parameters in Older Adults
The biological membranes that surround a cell and its organelles are important to the
overall function of the cell. Fatty acids are the main structural components of a membrane,
and the presence of certain fatty acids can alter a membrane's characteristics, which
subsequently alters its function. Two fatty acids that are of particular interest to
researchers are eicosapentanoic acid (EPA) and docosahexanoic acid (DHA). These omega-3
fatty acids have unique unsaturated structures, and their incorporation into biological
membranes appears to elicit potent physiological effects. The body is unable to
intrinsically synthesize these important fatty acids, so they must be obtained from the diet
or through supplementation.
EPA and DHA supplementation has been reported to provide numerous positive health benefits,
including decreased blood pressure and an improved blood lipid profile. Recent research in
our laboratory has demonstrated in young men that resting metabolic rate was increased
following a 12 week period of omega fatty acid supplementation of 3 g/day. Fat utilization
was also increased and carbohydrate use was decreased both at rest and during a 1 hr
moderate exercise challenge. These findings have positive implications for people who are
interested in losing weight, but it not known whether these effects occur in older adults.
With age, body composition changes (increase in fat mass and decrease in lean mass) occur
which may negatively affect general health, particularly normal physical functioning and
quality of living of the older adult. The potential role of omega 3 fatty acids to increase
fat oxidation and increase resting metabolic rate may be a therapy for decreasing fat mass
in the older adult. Research has suggested that omega 3 fatty acids may elicit an additional
therapeutic role by reducing joint pain.
Another aspect of aging is a loss in lean body mass, which is associated with an attenuation
of skeletal muscle protein synthesis in response to nutritional stimuli (amino acids and
insulin). The weakened anabolic response is considered to be partly due to defects in the
anabolic signaling cascade in the muscle. Research in older adults has reported an increase
in muscle protein signaling with EPA and DHA supplementation in response to a nutritional
challenge. However it is unknown whether the increase in protein signaling results in an
eventual increase in lean body mass. The physical functioning of older adults is not only
influenced by body composition changes, but also age-related neuronal changes that affect
the velocity of axonal conduction and influence the ability of the muscle to generate torque
and the rate at which the torque is developed. Muscular strength and functional capacity
increases have been reported with chronic resistance exercise in a cohort of older women
supplemented with EPA and DHA. However, the effect of EPA and DHA intake on physical
strength in older adults with previously low EPA and DHA consumption, independent of
exercise, is currently unknown.
Therefore, the purpose of this study is to determine the effects of 12 weeks of omega-3
supplementation at 3 g/day on metabolic and physical health parameters in community-dwelling
older adults. We hypothesize that EPA and DHA supplementation will result in 1) a decrease
in resting heart rate and blood pressure; 2) a more healthy blood profile; 3) an increase in
resting metabolic rate; 4) a greater reliance on fat oxidation for energy both at rest and
during exercise; and 5) a decrease in fat mass; and 6) an increase in lean mass, strength
and physical function.
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Allocation: Non-Randomized, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Basic Science