Correction: An earlier version of this story gave the incorrect average seafood consumption in the United States. Americans eat about 3 1 /2 ounces of seafood per week. This version has been corrected.


Fish-oil capsules. (bigstockphoto)

Question: I’ve avoided taking fish-oil pills because they made me feel weird and I didn’t like the taste in my mouth hours later. Now I’ve been reading that research is showing that fish-oil pills don’t actually live up to their promise of preventing heart disease. Can I skip them?

Answer: Thanks for this timely question. The answer, as for many nutrition topics, has evolved as research has revealed fresh findings. “Nothing in nutrition is set in stone. We just don’t yet know the details of everything various nutrients do, let alone exactly how much people need and how to account for individual differences,” says Catherine Price, author of “Vitamania: Our Obsessive Quest for Nutritional Perfection.”

To fit current guidance about fish-oil supplements into the evolving recommendations for how much and what types of fats to eat or supplement, let’s look at fats in general and polyunsaturated fats (the more healthful fats) in particular. Keep in mind that research and recommendations in this area are aimed squarely at reducing cardiovascular disease, particularly heart disease and strokes, which, according to the Centers for Disease Control and Prevention, are among the top five leading causes of death in the United States.

Zoom out: Fats

Fish, red meat, peanut butter, avocados and other foods contain different types of fats, including saturated fat and the two main categories of unsaturated fats, polyunsaturated and monounsaturated. Even the highly esteemed olive oil contains a small amount of saturated fat.

We all need to eat some fat. Fats provide vitamins A, D, E, and K and, among other functions, help maintain healthy skin.

But the message to cut as many calories from fat as you can is from a bygone era. Today the focus is on quality. In a nutshell, this translates to: Don’t eat too few (less than 20 percent) or too many (no more than 35 percent) calories from fat and make the fats you eat more healthful ones. Reducing artery-clogging saturated fats continues to be priority No. 1 to reduce cardiovascular disease, according to the 2013 American Heart Association and American College of Cardiology Guideline on Lifestyle Management to Reduce Cardiovascular Risk and the soon-to-be released 2015 Dietary Guidelines Advisory Committee report.

The AHA/ACC guidelines focus on decreasing LDL-cholesterol (the unhealthful cholesterol in the blood) and blood pressure to reduce cardiovascular disease. “Research shows that preferentially replacing polyunsaturated fats for saturated fats provides the greatest impact on reducing cardiovascular disease,” says Penny Kris-Etherton, registered dietitian, Penn State University nutrition professor and spokeswoman for the American Heart Association. Monounsaturated fats come in second place and healthful sources of carbohydrates come in third.

Zoom in: Polyunsaturated fats

Omega-6 and omega-3 fats are the two main types of polyunsaturated fats. Liquid vegetable oils, such as corn, soybean and sunflower oils, contain mainly omega-6 fats. Omega-3 fats are found in plant-based foods such as canola and soybean oil, flax oil and seeds, and walnuts or walnut oil, and, as you know, fish.

Your reading of the research that now questions the early promise of fish oils and supplements in preventing heart disease is correct. In the 1970s, researchers observed Eskimos’ low prevalence of cardiovascular disease and high intake of fish oils. Early studies in this area showed remarkable benefits of fish-oil supplements in preventing repeat heart attacks and strokes and sudden death from heart disease. But more recent research has not duplicated these dramatic benefits (though it has shown some).

Kris-Etherton details three potential reasons why: First, the later studies looked at fewer participants over a shorter time span, and lower doses of the fish-oil supplement were used. Second, many people were already taking statin (LDL-cholesterol-lowering) medication. Third, the care for people who experience heart disease has greatly improved in the ensuing years. So you might say participants in the later research started with a leg up on the Eskimos.

Consuming sufficient amounts of omega-3s from fatty fish remains an important goal for heart health, along with attention to eating more plant-based omega-3s. “People don’t eat sufficient amounts of either,” Kris-Etherton says. According to the 2010 Dietary Guidelines for Americans, we eat about 31/2 ounces of seafood per week — much less than the eight ounces the guidelines recommend .

Suzanne Steinbaum, director of the Women and Heart Disease Center at Lenox Hill Hospital in New York and co-founder of the Global Nutrition & Health Alliance, recommends fatty fish such as salmon, mackerel, herring, trout, sardines and tuna.

Why the focus on eating fish rather than swallowing fish-oil supplements? “Fish provides a good source of protein along with vitamin D, B vitamins, potassium and other nutrients,” Kris-Etherton says.

Supplements

The answer to your question about whether you can skip fish-oil supplements depends greatly on your willingness to eat a sufficient amount of fish each week, along with your health status and disease risk.

Kris-Etherton and Steinbaum encourage people to get as much of their omega-3 fats as possible from foods, but they also don’t shy away from recommending fish-oil supplements to meet your needs, because most people don’t eat enough. Kris-Etherton recommends one gram per day of a fish-oil supplement for healthy individuals who don’t eat fatty fish. Steinbaum recommends one gram per day for people at risk of or with heart disease, and more for those with elevated triglyceride levels. (Check with your doctor.) And, as always, it’s a good idea to discuss your individual health status and disease risks with your health-care provider before starting a supplement.

When you scan the shelves for a high-quality fish-oil supplement in the right dose for you, zero in on the Supplement Facts label. Look at the serving size, total amount of omega-3 fats and the amount and ratio of EPA and DHA. Make sure the supplement contains both EPA and DHA, the two types of omega-3s in fatty fish. For help choosing a fish-oil supplement, Price likes Consumer Lab, a subscription service. “They pull products off the shelves randomly and test them to make sure they contain what they claim to on their labels and Supplement Facts,” she says. Another trusted resource on supplements is the National Institutes of Health Office of Dietary Supplements.

“‘Change and replace’ is today’s general message on fats. Minimize saturated fat and get sufficient amounts of all types of polyunsaturated fats,” Kris-Etherton says. If you’re concerned about your calorie tally from fats, even the healthful ones, slash calories from other areas of your diet, particularly sugar-sweetened beverages, refined grain-based foods and desserts. This move will accomplish several important health goals.

Warshaw, a registered dietitian and certified diabetes educator, is the author of numerous books published by American Diabetes Association and the blog EatHealthyLiveWell found on her Web site, www.hopewarshaw.com.