Combination of Resistance Training and Fish Oil Administration Improves Muscle Strength and Reduces Cardiovascular Disease Risk Factors in Postmenopausal Women

by | Dec 12, 2023 | 2023, Cardiovascular Health, Fish Oil Supplements, Menopause, Metabolic Syndrome, Omega - 3, Women's Health

Written by Taylor Woosley, Science Writer. An 8-week intervention of twice/week resistance training and three times daily fish oil supplementation significantly improved physical function parameters and decreased TNF-α (-24.6%, p < 0.001) and IL-6 (-10.9%, p = 0.011) levels. 

Menopause is defined as the absence of menstruation over a period of 12 months and typically occurs between the ages of 49 and 52 years1. The reduced secretion of progesterone and estrogen hormones may result in weight gain, lower total energy expenditure, reduced glucose tolerance, and adverse changes in lipoprotein patterns2. Research following postmenopausal women has shown that these unfavorable alterations can increase the risk of cardiovascular disease (CVD) development and metabolic syndrome3.

Resistance training is an efficient strategy to increase muscle mass, increase the resting metabolic rate, and 24-hour energy expenditure4. Furthermore, polyunsaturated fatty acids (PUFAs) provide anti-inflammatory and cardioprotective qualities, with research showing that postmenopausal women with increased serum omega-3 levels were associated with a lower incidence of coronary heart disease5. Omega-3 fatty acids are reported to significantly decrease BMI, blood pressure, serum triglycerides (TG), interleukin (IL)-6, and insulin resistance in postmenopausal women6.

Lee et al. conducted a randomized longitudinal study to investigate the efficacy of omega-3 PUFA supplementation in combination with 8-weeks of programmed resistance training on physical function, blood pressure (BP), fat metabolism, and oxidative stress and systemic inflammatory biomarkers in postmenopausal women. Subject inclusion consisted of healthy postmenopausal women without any physical or mental disorders, who were nonsmokers and did not consume excessive alcohol (more than five drinks a week). Furthermore, subjects were included if they had not consumed omega-3 PUFA and antioxidant supplements, had not taken anti-inflammatory drugs, and did not partake in resistance exercise training 12 months prior to the study.

Subjects had pre-intervention assessments, including grip strength evaluation, physical function, BP, TG, along with providing blood samples to analyze blood biomarkers for systemic inflammation and oxidative stress. 20 participants were randomly assigned to either the resistance exercise training combined with fish oil (FO) supplementation (RET-FO, n = 10) or the resistance exercise training and placebo supplementation group (RET-PL, n = 10) for 8 weeks. The FO supplement contained a blend of eicosapentaenoic acid (EPA; 0.7g) and docosahexaenoic acid (DHA; 0.24g). Participants were instructed to ingest 3 FO capsules daily for a total of 2.1 EPA and 0.72 The placebo group consumed a capsule containing safflower oil three times daily.

Subjects were informed to maintain their habitual diet, daily activity levels, and regular sleep schedule. At the end of the intervention all participants were reevaluated based on assessments performed pre-intervention. The scheduled RET was completed twice per week by participants and included 3 sets of 12 repetitions or until failure for 5 major muscle groups in the upper and lower body. All sessions were supervised for safety and the training load was gradually increased throughout the intervention to promote an adaptive hypertrophic response. Physical function was assessed via handgrip strength measurements, five times sit-to-stand (5X-STS), timed up and go (TUG), 6 m walk (6MW), and a 30 second sit-to-stand (30S-STS).

No significant differences were noted between participants regarding age and anthropometric characteristics prior to the intervention. Significant findings of the study are as follows:

  • The REF-FO group experienced a significant increase in handgrip strength compared to baseline (+5.7%, p < 0.001). A significant decrease in the time to complete the 5X-STS was noted in both the RET-PL (-8.1%, p < 0.001) and the RET-FO (-9.6%, p < 0.001) groups. Additionally, TUG test times were significantly reduced in the RET-PL (-7.9%, p < 0.001) and RET-FO (-11.3%, p < 0.001) groups.
  • A substantial decrease in systolic blood pressure (-4.4%, p = 0.041) and diastolic blood pressure (-4.4%, p = 0.001) was noted in the RET-FO group post-intervention. TG levels significantly decreased solely in the RET-FO group (-13.2%, p <0.001).
  • The RET-FO group had significantly decreased TNF-α (-24.6%, p < 0.001) and IL-6 (-10.9%, p = 0.011) levels. Furthermore, the RET-FO group had a significant reduction in MDA (-12.8%, p = 0.013) and 8-OHdG (-23.6%, p < 0.001).

Results of the 8-week intervention of resistance training and fish oil supplementation significantly improved muscle function and significantly decreased inflammatory and oxidative stress biomarkers in postmenopausal women. Further research should continue to explore the cardioprotective benefits of combined exercise and omega-3 consumption. Study limitations include the potential interaction of the placebo on lipid metabolism and the lack of testing the blood omega-3 levels and body composition of subjects.

Source: Lee, Sang-Rok, and Dean Directo. “Fish Oil Supplementation with Resistance Exercise Training Enhances Physical Function and Cardiometabolic Health in Postmenopausal Women.” Nutrients 15, no. 21 (2023): 4516.

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

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Posted December 12, 2023.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

References:

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