To Top

Does Fish Oil Interfere With Muscle Growth?

Fish oil is one of the most important supplements anyone can take because of its content of omega-3 fatty acids—docosahexaenoic acid and eicosapentaenoic acid—which are essential to human health. Interestingly, no actual nutritional requirement for those fatty acids has been established. Alpha linoleic acid, which is found naturally in many foods, including walnuts and flaxseed oil, is listed as the required omega-3. While it’s easier to obtain ALA than docosahexaenoic acid or eicosapentaenoic acid in food, ALA has poorer conversion than they do. In men only about 2 percent of ALA is converted into EPA, and even less can be converted into DHA. Even so, DHA and EPA are the active omega-3 fatty acids. That isn’t to say that ALA does nothing—it helps prevent cardiovascular disease—but it pales in comparison to DHA and EPA in relation to health protection.

The problem with EPA and DHA—and the reason they still aren’t listed as “essential fatty acids”—is that there is only one reliable food source for them, namely fatty fish—like mackerel, halibut, sardines and salmon. The lowfat fish favored by many bodybuilders, such as tuna, tilapia and orange roughy, are relatively poor sources of EPA and DHA. Unless you eat fatty fish at least two to three times a week, the odds are good that you’re deficient in omega-3 preformed fatty acids. There’s an easy solution: fish oil supplements, which contain concentrated DHA and EPA and come in liquid or capsule form.

Fish oil supplementation is particularly important today, since people get an abundance of omega-6 fats in their diets, while omega-3s are often in short supply. Although one of the omega-6 fatty acids, linoleic acid, is essential, it’s also easy to get from vegetables and vegetable oils. The problem is, an excess of omega-6 fats leads to the synthesis of another fatty acid, arachidonic acid. While arachadonic acid does some important things in the body, it’s also the primary precursor of several inflammatory substances, collectively known as eicosanoids. Because excess inflammation is now known to be the cornerstone of every degenerative disease from cardiovascular disease to cancer, it’s not hard to understand how an overabundance of omega-6 fats in the diet can fan the flames of out-of-control inflammation and herald pain and disease.

The good news is that omega-3 preformed fats from fish oil oppose the inflammatory activity of omega-6 fats. That has enormous health implications. Getting enough omega-3s can provide potent health-protective effects. In some respects it can also favorably affect bodybuilding progress. One example is that taking in a generous amount of omega-3s facilitates the behavior of enzymes and body processes that increase bodyfat oxidation. One example: It makes insulin more efficient by modifying cellular membranes. With more fluid in cell membranes insulin can more readily react with its cellular receptors, which makes it more efficient. When that happens, you secrete less insulin, meaning that your body synthesizes less bodyfat. It also opens the door to increased fat burning.

By increasing insulin efficiency, fish oil may also play a positive role in muscle growth. Insulin, particularly in the presence of a large amount of amino acids in the blood, turns on processes that boost muscle protein synthesis. Fish oil’s omega-3 fat content fosters the process. Its best feature, however—that is, its potent natural anti-inflammatory properties—may also hinder muscle growth. How is that possible?

It turns out that one of the inflammatory eicosanoids synthesized from arachidonic acid by way of omega-6 fats plays an important role in a process that initiates muscle hypertrophy. That particular eicosanoid, prostaglandin F2A, helps activate muscle-specific hormones, such as IGF-1, in triggering the work of satellite cells, which are muscle stem cells that are required for the repair and growth of muscle fibers.

Prostaglandin F2A acts like a chemical switch to turn on muscle hypertrophy. So the initial stage of muscle hypertrophy demands an acute dose of inflammation. Because omega-3 fats, as found in fish oil, oppose the activity of arachidonic acid, less prostaglandin F2A is produced when you take in large amounts of fish oil.

Several studies have found that taking anti-inflammatory drugs right after a workout significantly blunts muscle gains. Those drugs include many common over-the-counter painkillers, including ibuprofen and aspirin. More recent studies show that smaller doses of the drugs don’t have that adverse effect because they aren’t sufficient to blunt prostaglandin F2A production. Specifically, the safe dose for ibuprofen is 400 milligrams. Any more interferes with muscle recovery after training.

A recent study provided two groups of rats with identical diets except for the fat content.1 One group received corn oil, a rich source of omega-6 fats, while the other group got fish oil. The rats were first immobilized for 10 days, which resulted in muscle atrophy. Then they were allowed to move around while eating the previously described diets for three to 10 days. In the rats on the corn oil diet muscle size was restored after three days of activity. In the rats on fish oil it took 13 days for muscle size to return. An analysis showed that the corn oil rats had more muscle-protein-synthesis reactions than the fish oil rats at the three-day mark. More important, it took 13 days for the fish oil rats to show full activity of prostaglandin F2A. The researchers concluded that the fish oil had significantly blocked the conversion of arachidonic acid into prostaglandin F2A, explaining the blunted muscle recovery in the fish oil group.

One thing to consider about this study—and it applies to many other animal-based studies—is that the amount of fish oil fed to the rats was far higher than what most humans eat, even those who generously gulp down fish oil supplements. Just as anti-inflammatory drugs don’t begin to adversely affect muscle growth until a certain dosage is achieved, the same probably is true for fish oil.

While there’s no denying that fish oil has major anti-inflammatory effects in the body or that initial muscle growth processes require an inflammatory stage, the odds that you would take in enough fish oil to seriously interfere with the processes are slim. On the other hand, taking a high dose of fish oil with an anti-inflammatory drug directly after training may not be a good idea if you’re interested in building muscle size and strength. Meanwhile, some books and articles are advising people to take huge doses of fish oil to combat inflammation. That’s a good idea, but not right after a workout. Small doses shouldn’t hurt muscle gains, but avoid the megadose. In practical terms, that means don’t take more than two grams of fish oil in close proximity to a training session. After about two to three hours you can take as much as you want, but beware of fishy burps. You won’t make many human friends, but a few whales may be interested.

Editor’s note: Have you been ripped off by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Natural Anabolics, available at

1 You, J.S., et al. (2010). Dietary fish oil inhibits the early stage of recovery of atrophied soleus muscle in rats via Akt-p70s6k signaling and PGF2a. J Nutr Biochem. In press.

Instantized Creatine- Gains In Bulk

You must be logged in to post a comment Login

Leave a Reply

More in Latest