HealthNotes

• By Kimberly Beauchamp, ND

Love Your Heart? Eat More Fish

Reports of heart-healthy effects have helped fish oil gain in popularity in recent years. But how much fish do you need to eat to get the protective effect? That is a question that US and Canadian researchers tried to answer in a review published in the British Journal of Nutrition.

These fish have the best combination of high amounts of omega-3 fatty acids and the lowest amounts of mercury: wild salmon, mackerel, herring, trout, and sardines

Gathering the evidence

EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are both long-chain omega-3 fatty acids found in fish that have beneficial effects on brain, nervous system, and heart health.

The report combined the results from 214,426 people who participated in eight different studies that looked at omega-3 fatty acid consumption from fish and the risk of heart disease. The average daily intake of omega-3 fatty acids was estimated using dietary recall information, and the risks of sudden cardiac death, total fatal coronary events (including sudden cardiac death and fatal heart attacks), and nonfatal heart attacks were assessed.

Risk of sudden cardiac death was reduced by 35% and the risk of total fatal coronary events was reduced by 17% in people consuming more than 250 mg of omega-3 fatty acids per day, compared with people who consumed less than 250 mg per day. The risk of nonfatal heart attacks did not seem to be affected by omega-3 fatty acid intake. Based on Japanese studies, the authors suggested that omega-3 fatty acid intakes upwards of 1,000 mg per day may protect against nonfatal heart attacks.

“The present evidence suggests that 250 mg per day of long chain omega-3 fatty acids should be considered a minimum target and not an absolute target,” said Kathy Musa-Veloso, the study’s lead author.

Catch of the day

The most abundant sources of DHA and EPA are from cold water fish. Walnuts and flaxseeds contain alpha-linolenic acid (ALA) which the body can convert in very small amounts to DHA and EPA, but these sources may not provide optimal amounts of these important nutrients in the diet. The American Heart Association recommends eating 3.5 ounces of partially fatty fish two or more times per week to help prevent heart disease. Depending on the fish you’re eating, this amount will provide about 400 mg of omega-3s per day. While fish is a great source of heart healthy omega-3 fats, it can also contain contaminants, such as mercury. These fish have the best combination of high amounts of omega-3 fatty acids and the lowest amounts of mercury:

• Wild salmon
• Mackerel
• Herring
• Trout
• Sardines

Fish oil supplements are another option for increasing your omega-3 intake. Look for a brand that is “third-party certified” to be free of contaminants, including mercury and PCBs.

(Brit J Nutr 2011;106:1129–41)