Multiple Servings of Fish Each Week Associated With Lower Risk of Stroke
Fish and fish oils have been associated with a variety of heart healthy benefits. It is believed that the omega 3 fatty acids in fish may help reduce inflammation and triglycerides. Both of these factors may help to make sure blood can flow easily through the blood vessels to deliver oxygen to the organs like heart or brain. The majority of studies have focused on prevention of heart disease but healthy blood vessels also play an important role in brain health. Clogged or impaired blood vessels can cause strokes and other injuries to the brain. Since certain heart diseases and certain brain injuries are caused by injuries of the blood vessels it is reasonable to assume that factors that lower heart disease risk may also decrease risk of brain injuries.
Researchers from England reviewed previous studies on the benefits of fish oil for preventing strokes and transient ischemic attacks (TIAs or mini-strokes). The review, published in British Medical Journal, found that higher consumption of fish may be associated with lower rates of these brain injuries.
About the Study
The systematic review included 26 cohort studies with 794,000 participants. The studies asked participants about their average weekly fish intake. The participants were then followed for any incidence of strokes or TIAs. By the end of the studies about 4% of participants had a stroke or TIA. Compared to participants that ate 1 or fewer servings of fish per week:
- Participants that ate 2-4 servings of fish per week had a 6% lower risk of stroke or other vascular-related event
- Participants that ate more than 5 servings of fish per week had a 12% lower risk of stroke or other vascular-related event
The review also included 12 randomized trials with 62,040 participants. These trials compared the risk of stroke or vascular events in the brain with participants that took fish oil supplements. These trials did not find a link between the use of supplements and the risk of stroke or other vascular-related events.
How Does This Affect You?
A systematic review can improve the reliability of an outcome by pooling together several smaller studies. The higher the number of participants the more likely the outcomes are true. However, the quality of trials included in the review can also effect the results. The results related to servings of fish were based on observational studies. These types of trials can not establish cause and effect, they can only demonstrate a possible link. Overall the outcomes suggest that there may be a connection between fish intake and blood vessel health in the brain.
Fish is a good, low-calorie source of protein. It is high in good fats like omega-3 fatty acids. Consider adding a few servings of fish to your weekly diet plan. Fish oil supplements have had unclear results. Most trial seem to lean toward whole foods showing greater benefits than supplements but very few Americans seem to reach ideal diet goals. Start by making small changes in your current dietary habits. Add some fruits and vegetables and consider fish options in place of less healthy protein sources. Experiment with different types of fish or cooking methods. A varied balance diet can help you get the nutrient you need.
American Heart Association
National Stroke Association
Chowdhury R, Stevens S, Gorman D, et al.
Association between fish consumption, long chain omega 3 fatty acids, and risk of cerebrovascular disease: systematic review and meta-analysis.
BMJ. 2012 Oct 30;345.