Eat To Grow: Right Fat, More Muscle

Food supplements reputed to provide anticatabolic effects in muscle are clearly in vogue these days. An anticatabolic supplement is supposed to help prevent excessive muscle protein breakdown, which in turn tips the metabolic balance toward anabolic processes, such as muscle protein synthesis, that lead to muscular growth.

Various supplements have been suggested as having potential anticatabolic effects, including phosphatidylserine (PS), HMB, leucine and vitamin C, among others. A lesser known category of potential anticatabolic nutrients involves certain forms of dietary fats.

In fact, combinations of dietary fats, known as structured lipids, are used in tube feeding of hospital patients under severe catabolic conditions; for example, severe burn cases, where controling body-protein losses determines the patient’s ultimate fate’life or death. Giving structured lipid emulsions to catabolic patients appears to promote increased nitrogen retention while providing a needed hedge against excessive protein loss. Most structured lipids are combinations of long-chain fatty acids, such as omega-6 fatty acids, which are commonly found in vegetable oils, and medium-chain triglycerides, which offer the advantage of easily absorbed calories; however, scientists have recently noticed that other fatty acids, such as those in the omega-3 category, may offer even greater anticatabolic effects.

The point is illustrated by a study involving rats that were given an endotoxin (toxins released from bacteria) and provided with structured lipids containing predominantly omega-6 or omega-3 fatty acids.1 Giving rats an endotoxin leads to a significant catabolic effect characterized by extensive protein breakdown. In the study the rats that got the omega-3 lipid showed far less nitrogen excretion and muscle loss than those that got the omega-6. The mechanism for the superiority of the omega-3 lipid was linked to a more favorable pattern of fat-based substances involved in catabolic processes in the body, such as various prostaglandins and interleukins, as well as tumor necrosis factor.

Omega-3 fatty acids, which are two primary fatty acids with the acronyms of EPA and DHA, are found in fatty fish, such as salmon, halibut and mackerel. Alpha-linoleic acid is also considered an omega-3 fat, since it is partially converted (about 15 percent) to EPA and DHA in the body. Alpha-linoleic acid occurs naturally in nuts, vegetables and flaxseed oil. Suggested doses of preformed omega-3 fatty acids (such as are found in fish) are three to five grams daily.

The omega-3 fatty acids also have potent anti-inflammatory effects and have shown preventive effects against cardiovascular disease and cancer. In contrast omega-6 fatty acids have been linked to cancer, especially if consumed without additional dietary antioxidants, which would stabilize them. IM

1 Druschky, K., et al. (2000). Different effects of chemically defined structured lipids containing omega-3 or omega-6 fatty acids on nitrogen retention and protein metabolism in endotoxemic rats. Nutrition Research. 20:1183-1192.