Omega-3s and Healthy Muscle Function as You Age

By John Neustadt, ND

Most people think about muscle only when they are trying to get stronger or change how their body looks. But your muscles work for you all day. They help you get out of bed, stand up from a chair, climb stairs, carry groceries, maintain posture, and react quickly when you lose your balance. Muscle is also metabolically active tissue that uses amino acids, glucose, and fatty acids. Maintaining healthy muscle function is therefore an important part of staying active as you get older.¹

Muscle size matters, but it is only part of the story. Strength decreases before muscle mass does and is an early warning sign that your health is headed in the wrong direction. In the Health, Aging and Body Composition Study, researchers followed 1,880 adults ages 70 to 79 at enrollment. Over three years, the investigators measured knee-extension strength and lean muscle mass. Men lost 3.4-4.1% of their leg strength annually, while women lost 2.6-3.0% per year; however, lean mass decreased by only approximately 1% per year.¹

Muscle Mass, Strength, Power and Quality

Fortunately, muscle remains responsive to nutrition and exercise throughout life. Progressive resistance exercise supplies the strongest signal for muscle to adapt. Dietary protein provides the building blocks used to create new muscle proteins. Researchers have also investigated whether the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can make muscle more responsive to those signals. The findings are encouraging and provide more evidence of the health benefits of essential fatty acids.

Like with bones and other tissues in your body, old muscle proteins are constantly being broken down and rebuilt. In muscle, this remodeling process allows the tissue to maintain itself and adapt to activity. After you eat protein or perform resistance exercise, muscle protein synthesis normally rises. As people get older, that response may become less robust. Researchers call this anabolic resistance. This means that older people need more protein to get the same response they did when they were younger.

Omega-3 fatty acids are incorporated into the membranes surrounding muscle cells. Those membranes are not passive wrappers. They help regulate how cells communicate and respond to hormones, nutrients, and exercise. This led researchers to ask whether increasing EPA and DHA in muscle-cell membranes could make the muscle-building machinery more responsive. 

In a randomized clinical trial, 16 healthy older adults took either omega-3 fatty acids or corn oil for eight weeks. The omega-3 supplement provided 1.86 grams of EPA and 1.50 grams of DHA per day. When people were fasting, muscle protein synthesis did not increase. However, after amino acids and insulin were provided to simulate a meal, muscle protein synthesis was about three times higher than it had been before. The study also found stronger activation of an intracellular signaling pathway involved in building muscle protein.²

That distinction is important. The study did not show that taking fish oil by itself continuously builds muscle. It suggested that EPA+DHA helps muscle respond more effectively when the body receives an anabolic signal, such as protein. That is one reason omega-3s make the most sense as part of a complete program that includes adequate nutrition and resistance exercise.

A Six-Month Trial Without an Exercise Program

The same research group later tested whether the laboratory finding translated into measurable changes in muscle size and strength. They randomized 60 healthy men and women, 60 to 85 years old, to six months of corn oil or the same omega-3 dose used in the earlier trial. The participants were asked to maintain their usual diet and activity. The researchers used MRI to measure thigh-muscle volume, a hand dynamometer to measure grip strength, and one-repetition maximum testing for leg press, chest press, knee extension and knee flexion. Compared with corn oil, omega-3 supplementation increased thigh-muscle volume by 3.6%. Handgrip strength increased by an additional 2.3 kilograms, and a composite of upper- and lower-body one-repetition maximum strength increased by 4.0%.³

The findings are notable because the volunteers were not participating in a structured training program. However, the trial was small, and approximately one-quarter of the participants in both groups did not complete it. The results were based on the 44 completers rather than all 60 randomized volunteers. There was also substantial individual variability. Therefore, the trial supports the possibility that a relatively high dose of EPA and DHA can support muscle size and strength in some healthy older adults, but it does not establish that everyone will experience the same response.³

Omega-3s Combined with Resistance Exercise

Resistance exercise remains the most direct way to stimulate strength gains, so several trials have tested whether EPA and DHA can enhance the response to training. These studies are particularly useful because they compare fish oil plus exercise with exercise alone or exercise plus placebo. They also show why the exact training program, participant population, and outcome measure matter.

Study 1: Progressive Training

One trial enrolled 45 women with a mean age of 64 years and assigned 15 women to each of three groups. The first group completed strength training without fish oil. The second group took two grams of fish oil per day during 90 days of training. The two-gram fish-oil dose provided approximately 400 milligrams of EPA and 300 milligrams of DHA per day. Participants were asked to maintain their usual diet and physical activity.⁴

Both groups improved peak torque and the rate of torque development in the knee flexors, knee extensors, ankle plantar flexors and ankle dorsiflexors. However, post-training peak torque was significantly higher in fish-oil groups for all muscles tested. Muscle activation and electromechanical delay also changed only in the fish-oil groups, suggesting that part of the effect may have involved neuromuscular function rather than simply larger muscles.

Chair-rise performance improved with training and improved even more in the group that took fish oil during the 90-day training period. The results suggest fish oil can enhance strength and neuromuscular adaptations.⁴

Study 2: Women vs Men

A later double-blind, placebo-controlled trial enrolled 50 adults older than 65 years (27 men and 23 women with a mean age of about 70.5 years). Twenty-three participants received three grams of fish oil per day, providing 2.1 grams of EPA and 600 milligrams of DHA. Twenty-seven received three grams of safflower oil as a control group. Everyone completed supervised lower-body resistance training twice weekly for 18 weeks. 

Each session included four sets of nine repetitions of the leg press, leg extension, leg curl and calf press at approximately 70% of the participant’s one-repetition maximum. The investigators measured muscle cross-sectional area, maximal isometric knee-extension torque, isokinetic torque at three movement speeds, four-meter walking time, five-chair-rise time, and muscle quality, defined as isometric strength relative to muscle cross-sectional area.⁵

Among women, maximal knee-extension torque increased 34.3% with fish oil compared with less than half of that (15.8%) with safflower oil. Muscle quality in women increased 27.0% with fish oil compared with 8.8% with placebo.⁵

How Much EPA and DHA?

When comparing products, look at the Supplement Facts panel for the actual milligrams of EPA and DHA, not merely the total amount of fish oil. A product with “2,000 mg fish oil” may contain only a fraction of that amount as EPA and DHA. Quality also matters. The label should clearly identify EPA and DHA amounts, and the oil should be protected against oxidation and tested for contaminants, like Best Catch Omegas.

What This Means for You

EPA+DHA can support muscle strength, muscle quality, and the normal muscle response to amino acids or resistance exercise, and may be an important addition to someone’s wellness plan. 

Progressive resistance exercise and ensuring adequate protein remain the foundation. The goal is to challenge the major muscle groups with enough resistance that the final repetitions are difficult while maintaining good form. Adequate dietary protein provides the amino acids needed for remodeling. Sleep, recovery, total calorie intake, and consistency also influence the response. Omega-3s are best considered one layer on top of that foundation.

Best Catch Omegas^®

Take Best Catch Omegas and track outcomes that matter. Over several months, you might monitor the weight you can lift with good technique, the number of controlled chair rises you can perform, your walking pace, or how easily you carry out normal activities. A visible change in muscle size is not the only meaningful result.

Best Catch Omegas provides at least 1,500 milligrams of EPA+DHA per two-softgel serving, including at least 1,000 milligrams of EPA and 500 milligrams of DHA in a 2:1 ratio. The oil comes from sustainably sourced, wild-caught anchovies and sardines and is molecularly distilled. EPA and DHA are provided in triglyceride form. Vitamin E and rosemary extract help protect freshness and potency, and the softgels are enteric-coated to help eliminate the fishy aftertaste.

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