Omega-3 Fatty Acid Supplementation for 12 Weeks Increases Resting and Exercise Metabolic Rate in Healthy Community-Dwelling Older Females

Abstract

Critical among the changes that occur with aging are decreases in muscle mass and metabolic rate and an increase in fat mass. These changes may predispose older adults to chronic disease and functional impairment; ultimately resulting in a decrease in the quality of life. Research has suggested that long chain omega-3 fatty acids, found predominantly in fatty fish, may assist in reducing these changes. The objective of this study was to evaluate the effect of fish oil (FO) supplementation in a cohort of healthy, community-dwelling older females on 1) metabolic rate and substrate oxidation at rest and during exercise; 2) resting blood pressure and resting and exercise heart rates; 3) body composition; 4) strength and physical function, and; 5) blood measures of insulin, glucose, c-reactive protein, and triglycerides. Twenty-four females (66 ± 1 yr) were recruited and randomly assigned to receive either 3g/d of EPA and DHA or a placebo (PL, olive oil) for 12 wk. Exercise measurements were taken before and after 12 wk of supplementation and resting metabolic measures were made before and at 6 and 12 wk of supplementation. The results demonstrated that FO supplementation significantly increased resting metabolic rate by 14%, energy expenditure during exercise by 10%, and the rate of fat oxidation during rest by 19% and during exercise by 27%. In addition, FO consumption lowered triglyceride levels by 29% and increased lean mass by 4% and functional capacity by 7%, while no changes occurred in the PL group. In conclusion, FO may be a strategy to improve age-related physical and metabolic changes in healthy older females. Trial Registration: ClinicalTrials.gov NCT01734538.

The Effects of Dietary Omega-3s on Muscle Composition and Quality in Older Adults

“…Greater improvements in lower limb isometric peak torque and chair raising performance following exercise training in older adults have also been observed in subjects supplementing with omega-3 fatty acids compared with exercise training alone [85]. Whether the omega-3 fatty acid-induced improvements in muscle strength and function observed by our group and others [76, 78, 85] are solely related to gains in muscle mass or are instead influenced by improvements in muscle quality is unclear. However, results from our recent study, where increases in strength following omega-3 fatty acid supplementation were ~2-fold greater than the gain in muscle volume [78], provide at least some circumstantial evidence for an omega-3 fatty acid-induced improvement in muscle quality.…”

“…There is, however, little consensus on the effect of omega-3 fatty acid supplementation on lean body or fat-free mass in the weight stable state in relatively healthy adults. For example, 4 studies to date have reported lean body or fat-free mass to be unchanged following omega-3 fatty acid supplementation [72–74, 62] with 2 additional studies reporting 1–4% increases in lean body mass [75, 76]. Although the discrepant findings may simply be due to the short duration of all of these studies (i.e., 3 to 12 weeks) there is circumstantial evidence that a minimum dose of omega-3 fatty acids (>2 g EPA and DHA per day) may be required before an anabolic response is observed.…”

“…Although the discrepant findings may simply be due to the short duration of all of these studies (i.e., 3 to 12 weeks) there is circumstantial evidence that a minimum dose of omega-3 fatty acids (>2 g EPA and DHA per day) may be required before an anabolic response is observed. In support of this notion, when 0.51 to 1.8 g EPA and DHA per day was provided non-significant results were presented [72–74, 62] with increases in lean body mass confined to those studies giving 2.4 to 3.0 g EPA and DHA per day [75, 76]. One important limitation of these studies, and by extension the minimum effective dose hypothesis, is that without exception whole-body lean mass was examined (by dual-energy X-ray absorptiometry, air displacement plethysmography or bioelectrical impedance analysis) with muscle only contributing ~50% to total body lean mass [77].…”

Differential Effects of Omega-3 Fatty Acid, Docosahexaenoic Acid (DHA), In Animals and Humans

“…In contrast to its effects on young adults, DHA supplementation increased the resting metabolic rate in older females by 14% [30]. In healthy older males, DHA supplementation was found to modulate age-related cardiovascular responses (mean and diastolic arterial blood pressure) in response to exercises utilizing autonomic nerve activity [26].…”

“…In healthy older males, DHA supplementation was found to modulate age-related cardiovascular responses (mean and diastolic arterial blood pressure) in response to exercises utilizing autonomic nerve activity [26]. DHA supplementation lowered the triglyceride levels in both older women [30]and men [27]. In elderly patients with established Alzheimer's disease, DHA intervention is controversial [29,31,32].…”