| Is fish really a wonder food — or can its healthful benefits come from a pill? | |
| By Kevin Davis | |
Pity the health-conscious carnivore. In recent years, frequent beef consumption has been associated in some studies with an increased risk of heart disease, obesity and some cancers. Fowl has been implicated in well-publicized cases of Salmonella and other types of food poisoning.
Yet through it all, the reputation of fish as a delicious and nutritious food source has stayed swimmingly well. In fact, some might consider fish to be the real treasure from Davy Jones' locker - with numerous studies finding that eating fish can reduce the risk of heart disease and recommending it replace other animal food sources as part of a heart-smart eating plan.
But the reported health benefits don't end there: Other studies have suggested that the omega-3 fatty acids found in all fish - but in highest concentrations in salmon, mackerel and other cold-water varieties - may help relieve rheumatoid arthritis, lower blood pressure and even protect against some cancers. Just a few months ago, Australian researchers reported that eating fish can help you lose weight, and another 1999 study suggested that fish oil can be effective in treating depression.
Granted, fish is a great replacement for a diet rich in beef, pork and other higher-fat animal sources. Most types of fish are rich in protein, lower in saturated fat or cholesterol and are more likely to contain "heart-healthy" fats - including the much-ballyhooed omega-3 fatty acids, which are believed to hinder the formation of blood clots that can cause heart attacks and stroke and reduce triglyceride levels, another risk factor of coronary disease.
But the question remains: Is it the fish itself, or the omega-3 fatty acids - commonly known as "fish oil" and available in over-the-counter supplements available at supermarkets, pharmacies, health food stores and elsewhere where vitamins are sold? And exactly how much is needed to lower your disease risk?
For instance, a recent and well-publicized study of 11,000 heart attack survivors found that those who took a daily 1,000-milligram fish oil supplement each day - the amount found in a 3 1/3-ounce serving of broiled salmon - had approximately half the risk of dying of heart disease in the next three years compared with those who didn't consume the fish oil.
Still, experts are reluctant to recommend taking fish oil capsules instead of eating fish. "There may be another component of fish (other than omega-3 fatty acids) that is giving these benefits," says Martha Daviglus, M.D., assistant professor of preventive medicine at Northwestern University School of Medicine, who has studied the health properties of fish and omega-3 fatty acids. "No study has examined the long-term effects of fish oil capsules."
In her own study, Dr. Daviglus and colleagues found that men who ate about two 3-ounce servings of omega-3-rich fish per week had a lower risk of dying of a heart attack than men who did not eat fish. Her study, like most others, didn't compare the benefits of eating fish versus taking fish oil capsules.
"The evidence is inconsistent to some extent," says Alberto Ascherio, M.D., an associate professor of nutrition and epidemiology at Harvard University. "The bottom line is that there is fairly good evidence that a small amount of fish - one or two servings per week - is likely to lower the risk of fatal coronary heart disease. Whether or not consumption of larger amounts of fish or fish oil supplements will provide further benefits remains uncertain."
Omega-3 fatty acids, whatever their source, seem to offer benefits beyond reducing heart disease risk. Among some recent findings:
