Nutrition: Good fats for your heart

Friend Indeed, A, Nov/Dec 2004 by Osher, Susan

Most women enjoy protection from heart disease until menopause. But after 50, the risk of heart and stroke increases significantly. Recent research, however, points to omega-3 fatty acids - found in cold-water fish such as salmon, trout and sardines as well as flaxseed, walnuts, soybeans and canola oil - as being heart protective.

Before menopause, women typically have pear-shaped bodies with body fat stored primarily in thighs and buttocks. When many women go through menopause, their excess fat storage shifts to the abdominal cavity surrounding organs, especially the heart. In addition to the change to a more apple-shaped physique, women's blood cholesterol levels tend to change. The so-called bad cholesterol (LDL) goes up by about 10 to 20 percent and good cholesterol (HDL) drops slightly. All of these changes in women's bodies increase the risk of cardiovascular disease.

Typically, when we think of protecting our hearts, we think of decreasing fat intake. One exception seems to be omega-3 fatty acids, one of the polyunsaturated fats. Among their other health benefits such as treating depression and inflammatory conditions, omega-3 fatty acids act like blood thinners, similar to Aspirin, which can cut the risk of heart attack and stroke.

Omega-6 and omega-3 fatty acids ate two polyunsaturated fats that work together to balance hormones. Their requirements are often referred to in terms of a ratio. The typical North American eats far more omega6 polyunsaturated fats than omega-3 (10:1). Omega-6 fatty acids, which are derived from vegetable oils, tend ] to lead to a hormone cascade that constricts blood vessels. In contrast, omega-3s increase the so-called relaxing hormones, making blood vessels more flexible. The ideal ratio of omega-6 to omega-3 is 4:1. What that means is that you don't need to decrease your use of vegetable fats; you just need to boost your omega-3 intake.

The best sources of omega-3s are fish oils. If you like fish, try to eat fattier fish three times a week. These include salmon, trout, sardines, herring, mackerel, swordfish and fresh tuna. Be aware, however, that recent studies revealed that the fat in farmed salmon is not only an extremely rich source of omega-3s, but also contains cancer-causing industrial chemicals (PCBs, dioxins and pesticides). These studies have left many feeling confused about whether it is safe to eat salmon. The U.S. Environmental Protection Agency recommends that we eat 6 oz. cooked (8 oz. raw) farmed salmon only once a month. (Health Canada has not issued any limits.) If you score the flesh, grill or broil the fish so that the juice drips off and remove the skin before eating, your allowance doubles. Even in light of this study, the Canadian Heart and Stroke Foundation still recommends that adults cat fish, particularly fatty fish, two to three times a week.

The bottom line is to try to cat a variety of seafood. If you can afford wild salmon, that's your best bet. (All canned salmon is wild and provides an affordable way of getting those omega-5s.) Another way of getting enough omega-3s is by taking a citrus-flavoured fish-oil supplement such as Nordic Naturals or Nutrasea, which like most other fish-oil supplements, are contaminant-free. The recommendations for women are 1.1 g of omega-3 fatty acids per day. If you're getting them from only vegetarian sources such as flaxseed, canola oil and soybeans, I suggest increasing your supplement intake to 2.2g to 4.4g of omega-3 per day.

Susan Osher is a registered dietitian who bos been practising in the Toronto area for more than seven years. In both hospital and private settings, Susan has worked extensively with women across the age spectrum, and specializes in women's issues including eating disorders, body image and menopause. susanosher@totalnutrition.ca