Dietary fat is important in determining cardiovascular health and risk of heart disease development. "There actually are fats that protect against heart disease," says LSU AgCenter nutritionist Dr. Heli Roy.
For some time, high dietary intake of saturated fat has been determined to be a risk factor for heart disease and hardened arteries. Recently, trans-fatty acids have been implicated in increasing the risk for heart disease. On the other hand, long-chain unsaturated fatty acids or omega-3 fatty acids from seafood protect against heart disease.
"Several different mechanisms account for the protection offered by these omega-3 fats," Roy says. A diet high in omega-3 fatty acids reduces high triglyceride levels, which are considered a separate risk factor for heart disease. Omega-3 fatty acids also improve cardiovascular function by improving cell wall functions in arteries.
In addition, omega-3 fats reduce molecules that make several different components in the blood adhere together. When these adhesive molecules are reduced, particles moving in the blood stream are smaller and less likely to clog the arteries.
Another protection offered by omega-3 fatty acids is improved heart rhythm function. Recently, omega-3 fatty acids (also known as fish oils) were found to help protect those who have heart disease from having further fatal events.
In July 2003 issue of the "American Journal of Clinical Nutrition," researchers followed more than 400 individuals who had coronary heart disease for five years. Dietary intake was collected for total energy, saturated, monounsaturated, polyunsaturated fats, cholesterol, protein, carbohydrate, fiber and alcohol.
Intake of fish was divided into three groups: those who consumed no seafood, those who had less than 57 grams per day and those who consumed more than 57 grams per day.
At the end of the study, 36 had died. Those who died had higher levels of LDL cholesterol and total cholesterol than those who survived. A risk of death for all causes was higher with higher intake of saturated fats. A higher intake of cholesterol was associated with high risk of death.
Those who had fewer events and survived had higher intake of fish in their diets. Higher intake of long-chain omega-3 fatty acids resulted in fewer deaths from cardiovascular disease, heart attack or stroke. The risk of dying was reduced by more than half by those who consumed the most fish.
Roy says this research study is one of several over the years that have looked at intake of seafood and its effect on heart disease. "In all of the studies, what is clear is that seafood protects against heart disease," the LSU AgCenter nutritionist emphasizes.
"Consistent consumption of seafood and fish increases the ‘good fats’ in our cells and arteries," Roy says, but cautions, "To get the full benefit of the omega-3 fatty acids, avoid eating seafood and fish that have been deep-fat fried." She explains that when fish and seafood are fried, the frying oil changes the balance of fatty acids.
On the other hand, consuming broiled, baked and sautéed seafood preserves the proportion of fatty acids high in omega-3 that offer the protective effect. Seafood fits in the meat, fish and poultry area of the MyPyramid. Three ounces of fish is considered one serving.
Roy also suggests contacting an extension agent in your parish LSU AgCenter office to learn more about omega-3 fatty acids.