A recent study of women in their 60’s suggests that taking fish oil when strength-training leads to greater improvements in strength than training alone. Women who took fish oil were not only stronger but had a greater functional capacity, such as being able to rise faster from a chair.
A small study in Brazil looked at the potential benefit of fish oil on strength training in older individuals, based on the fact that omega-3’s play a role in the plasma membrane and cell function of muscles (Rodacki, Am J Clin Nutr 2012). Forty-five mostly sedentary women in their mid-60s were given two doses a day of a gram of fish oil containing 180 mg of EPA and 120 mg of DHA. After twelve weeks of supervised lower-body resistance-training (3 times per week), the strength of those taking the fish oil had improved more than those who did not supplement. Functional capacity (e.g., the speed of rising from a chair) also increased more among those who took fish oil. There was no improvement in the strength of women who took fish oil without strength training, and taking fish oil for two months before training started did not confer added benefit.
ConsumerLabs.com is an independent testing organization who tests all types of supplements for quality, potency, contamination, etc. Below is what they had to say about fish oil quality:
Quality Concerns and What CL Tested for:
Because omega-3 fatty acids are obtained from natural sources, levels in supplements can vary, depending on the source and method of processing.
Contamination has also been an issue, because fish can accumulate toxins such as mercury, dioxins, and polychlorinated biphenyls (PCBs). Mercury can damage the nervous system — particularly in a fetus. Dioxins and PCBs may be carcinogenic at low levels of exposure over time and may have other deleterious effects.
The freshness of the oil is also an important consideration because rancid fish oils can have an extremely unpleasant odor and taste. While you can sometimes determine this yourself if you take fish oil directly as a liquid, it can be masked by added flavors and not readily detected if you use a softgel and other encapsulated product. There may be safety considerations with rancid fish oils due to a variety of compounds produced, some of which are odorless, such as peroxides. A study commissioned by the government of Norway (where fish oil supplement use is extremely high) concluded there would be some health concern related to the regular consumption of oxidized (rancid) fish/marine oils, particularly in regards to the gastrointestinal tract, but there is not enough data to determine the risk (The Norwegian Scientific Committee for Food Safety, 2011). The study explained that the amount of spoilage and contamination in a supplement depends on the raw materials and processes of extraction, refining, concentration, encapsulation, storage and transportation. However, it saw no significant risk of contamination by microorganisms, proteins, lysophospholipids, cholesterol, and trans-fats.
Additionally, some capsules are enteric-coated and are expected to release the oil after the stomach to theoretically reduce fishy aftertaste or burp. If they release too soon they lose that potential benefit. If they release too late, the oil may not get absorbed.
Neither the FDA nor any other federal or state agency routinely tests fish or marine oil supplements for quality prior to sale. ConsumerLab.com, as part of its mission to independently evaluate products that affect health, wellness, and nutrition, purchased many dietary supplements sold in the U.S. claiming to contain EPA and/or DHA and tested them for their levels of omega-3 fatty acids (EPA, DHA and, if listed, ALA), mercury, lead, PCBs, and signs of decomposition. Enteric-coated capsules were tested to see if they properly released their ingredients. One product was additionally tested for dioxins at the request of its manufacturer. Among the products purchased and tested, the majority was for use by people and a few were for use by pets. Most of the supplements were softgel capsules or liquids.
What CL Found:
Among the 24 products that ConsumerLab.com selected for review, only 17 passed quality testing, meeting requirements for freshness and purity, and containing their claimed amounts omega-3 fatty acids. Seven (7) products failed to pass testing due to having less omega-3 than listed, spoilage, contamination, or problems with the enteric coating.
To insure you’re taking a quality fish oil product make sure it is manufactured to pharmaceutical good manufacturing practices (GMP) standards by a company which has been NSF certified as complying with pharmaceutical GMPs. Some companies claim their products are “Pharmaceutical Grade”, but this is only marketing as there is no definition of pharmaceutical grade for fish oil.