Move over HDL and LDL. There is another fat to consider--triglycerides. In fact, triglycerides are hardly rare: they are the major storage form of fat in the body and account for most of the fat from food we eat. Saturated, polyunsaturated or monounsaturated fats are all trigylcerides and after eating a meal, blood trigylceride levels will normally go up. When triglyceride levels remain elevated, they are an important risk factor for heart disease. Consequently, scientists are working on ways to maintain levels within normal limits. The results of one such study, published in a recent issue of the American Journal of Clinical Nutrition, reports that fish oil supplements may lower a postmenopausal woman's triglyceride level and subsequently decrease her risk of heart disease.

In this latest study, Canadian researchers gave capsules containing either fish oil or vegetable oil to 35 postmenopausal women. After 28 days, they measured triglycerides and the ratio of tryglycerides to HDL cholesterol, both strong indicators of heart disease risk. Results showed a significant 26% decrease in triglyceride levels and 28% decrease in the triglyceride to HDL ratio in the women who had been taking the fish oil supplements. Further calculations determined that these decreases could lower the risk of heart disease by 27%.

The researchers also looked at whether hormone replacement therapy influenced the effect of fish oil supplements on participants' trigylceride levels. Previous studies have found that hormone replacement therapy can increase trigylceride levels, and that higher levels are more likely to respond to the lowering effects of fish oil. That was not a consistent finding in this study, however. The changes in triglyceride levels were similar whether or not the women were receiving hormone therapy, but changes in the triglyceride to HDL ratio were greater for those who were not on hormone therapy. Clearly, more study is necessary to clarify the interactions among triglycerides, hormone therapy, and fish oils.

The fish oil capsules used in this study contained two omega-three (n-3) fatty acids that are believed to benefit heart health: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Certain types of fish can provide these fatty acids as well. However, the levels of DHA and EPA used in this study would be difficult to meet without using supplements. It would require eating as much as 11 ounces of salmon or 15 ounces of tuna daily. That would be neither practical nor advisable, and besides, there are several ways to control triglyceride levels.
Triglyceride levels are routinely measured along with cholesterol, but until recently have not received much attention. Women should ask their health care provider whether their levels are within normal limits. If they are, fine. If not, losing excess weight, avoiding alcohol, and limiting intake of sugar-laden foods such as soft drinks, candy, and cookies can all contribute to lowering triglyceride levels. Available evidence to support regular consumption of these oils in capsule form is insufficient. On the other hand, it is important to consider including fish that provide omega-three fatty acids in the diet on a regular basis.

Some countries including Canada and the United Kingdom have made official dietary recommendations regarding optimal levels of omega-3 fatty acids. The US does not have formal guidelines. It may sound like eating a heart healthy diet keeps getting harder. But the same sound nutrition principles prevail: eat a diet with fruits, vegetables, whole grain foods, and moderate protein and fat. Fish, which provides protein, generous amounts of vitamins and minerals, - and omega-3 fatty acids, fits well into a healthy eating