Heart Health

20 June 2018

How often should you eat fish to ward off heart disease?

Health experts are urging people to eat fish twice a week to help reduce the risk of heart disease.

There is more reason than ever for people to make fish a bigger part of their diets, according to the American Heart Association.

The heart group has long recommended that people eat fish, preferably fatty varieties, once or twice a week. Now it is reaffirming that advice based on additional evidence that fish helps ward off heart disease

According to the Heart and Stroke Foundation, foods that are high in omega 3 fats are incredibly good for your heart and can even help to improve cholesterol levels, especially naturally oily fish such as sardines, pilchards, mackerel and salmon, which should be eaten at least twice a week.

Specifically, adults should strive for two 3.5-ounce (100g) servings of fish each week, the American Heart Association (AHA) said. 

Preparation important

Whatever you choose, just don't fry it, the group warned. That's because studies have found that fried-fish lovers have increased rates of heart failure.

The main omega-3 fatty acids in fish are EPA and DHA, said Sonya Angelone, a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. EPA has anti-inflammatory effects that might help counter the hardening and narrowing of arteries that can lead to a heart attack, Angelone said.

Beyond that, she said, omega-3 fats may also make the blood less prone to clotting, while high doses can help lower triglycerides, a type of blood fat. Oily fish is not the only source of omega-3, said Angelone, who was not involved in the AHA recommendations. "Chia seeds, flaxseeds and walnuts are good sources of alpha linolenic acid (ALA), which is a precursor to EPA, which is then converted to DHA," Angelone said.

Fish at least once a week

In contrast, the heart association noted, 4 ounces (113g) of salmon each week would provide adults with the recommended daily intake of omega-3, which is around 250 milligrams. The latest heart association advice does not differ from its previous recommendations, issued in 2002. But there is now much more evidence to back it up.

Eric Rimm, a professor at the Harvard School of Public Health, is the lead author of the AHA report, published in Circulation. "Scientific studies have further established the beneficial effects of eating seafood rich in omega-3 fatty acids, especially when it replaces less healthy foods, such as meats that are high in artery-clogging saturated fat," Rimm said in an AHA news release.

A number of large studies have found that people who eat fish at least once a week have moderately lower risks of heart attack, stroke, heart failure and sudden cardiac death, according to the new report. 

salmon and red meat

So it seems key to replace red or processed meat, or other less-than-healthy fare, with fish, the heart association advised.

Fish may even benefit people who've already suffered heart trouble, the heart association said. A study of heart attack survivors found that those who were told to eat fish twice a week were 27% less likely to die over the next two years, versus those given standard care only.

Seafood does contain mercury, the AHA pointed out. And pregnant women and young children should avoid certain large fish that are high in mercury, such as shark, swordfish and king mackerel. But for most adults, the benefits of eating fish outweigh any potential harms associated with mercury, Rimm's team said.

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