Does eating fish help prevent heart disease?it depends

For years we have been told to eat fish, especially oily fish, twice a week to prevent heart disease. Omega 3 fatty acids in fish have been shown to reduce inflammation, reduce blood triglycerides (fats), and prevent blood from coagulating.

Now, a new research question will give you that advice.

Eating two servings of fish each week did not provide protection from heart disease in healthy people, according to a study published in JAMA Internal Medicine on March 8. However, among individuals with pre-existing heart disease or diabetes, eating fish on a regular basis provided modest cardiovascular benefits.

About research

Researchers at McMaster University in Hamilton analyzed data from 191,558 participants enrolled in a prospective urban and rural epidemiology (PURE) study.

Participants with an average age of 54 did not suffer from cardiovascular disease and provided complete information on their normal diet. They have been tracked for 9 years.

Eating at least 12 ounces a week compared to eating little or no fish (less than 2 ounces a month) is a major cardiovascular event (eg, heart attack, stroke, sudden cardiac death, congestive heart failure). ) Was not associated with the risk. Or total mortality.

The researchers also pooled data from three previous randomized controlled trials conducted in 40 countries on 43,413 participants with cardiovascular disease or diabetes.

The risk of major cardiovascular events and death was lowest among those who ate 6-12 ounces of fish per week compared to those who consumed little or no fish. Eating more than 12 ounces of fish per week was not associated with any further heart benefits.

Fish as high in omega 3 fatty acids were more strongly associated with protection.

In both analyzes, the researchers described other cardiovascular risk factors such as age, gender, smoking status, physical activity, alcohol intake, and fruit and vegetable intake.

Limitations

These new discoveries support the heart health benefits of eating two servings of fish per week for people with cardiovascular disease or diabetes.

However, the fact that researchers have found no benefit to healthy people should not prevent you from following the current dietary advice of consuming fish twice a week. This analysis has limitations.

The type of fish eaten and the method of cooking the fish have not been evaluated in the PURE study. For example, it is unclear whether high intakes of low-fat and fried fish may explain the lack of protective effects.

Similarly, the dietary information in the PURE study is self-reported, which can be error-prone.

CONCLUSIONS: This one study does not alter the large amount of existing evidence that supports the cardiac benefits of fish intake in healthy populations.

Advice on fish intake

The Heart and Stroke Foundation recommends eating at least 2 servings of fish each week. Serving is usually 3 ounces of cooked fish.

The protective effect of fish is mainly due to its two omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Good sources include salmon, herring, mackerel, sardines, trout, sardines, anchovy, and albacore tuna.

To minimize mercury exposure, women of childbearing age, especially pregnant and lactating women, and children under the age of 11 should have high mercury fish such as swordfish, sharks, marlin, orange roughy, king mackerel, and escolar. You need to avoid eating.

Albacore tuna may also contain a large amount of mercury depending on the place of origin. Mercury is low when caught in the Pacific Northwest. When buying canned albacore tuna, look for “Canadian products” on the label.

Canned light tuna containing bonito, yellowfin and tongol seeds is relatively low in mercury.

Enjoy grilled, pouched, steamed and grilled fish recipes that minimize the loss of omega 3 fatty acids. Fried fish and frying pans at high temperatures can destroy these beneficial fats.

Fish also supply other nutrients. B vitamins, vitamin D, selenium, iodine, potassium, and certain proteins found in seafood can also provide health benefits.

If you don’t eat fish, consider taking fish oil capsules. Although not conclusive, evidence from the VITAL trial published in 2018 suggests that doing so may reduce the risk of heart attack.

DHA supplements made from algae are available for people who follow a vegan diet.

Lesliebeck, a Toronto-based private dietitian, is the director of food and nutrition at Medcan. Follow her on Twitter @LeslieBeckRD

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