October 31, 2012
Preventing Stroke: Fish Oil Not As Effective As Eating Fish
Brett Smith for redOrbit.com — Your Universe Online
Fish oil supplements have been shown to have many health benefits, but a new study shows taking pills containing the fatty acids can´t completely replace the benefits of eating the fish itself.
According to the new report published by the British Medical Journal, a team of international scientists has found eating oily fish twice per week can reduce the odds of stroke, while that same benefit was not seen in people who had only taken fish oil supplements.
Led by Dr. Rajiv Chowdhury at Cambridge University, the research team scoured data from 38 individual studies that included 800,000 individuals across 15 countries to find an association between fish consumption and the risk of stroke or mini-stroke, collectively known as cerebrovascular disease.
Study participants´ fish and long chain omega-3 fatty acid consumption was determined by several different means including dietary questionnaires, identifying markers of omega-3 fats in blood samples, and documented use of fish oil supplements. Across all of the studies in the literature reviewed, almost 35,000 cerebrovascular events were recorded.
After adjusting for several risk factors and auditing each study for bias, participants who ate two to four servings of oily fish per week showed a 6 percent lower risk of cerebrovascular disease compared with those who ate one or fewer servings of fish a week. Those participants who ate five or more servings a week showed a 12 percent decreased risk.
The latest study also showed that any fish consumption was associated with some benefit. Those that ate just two servings per week of any fish had a 4 percent reduced risk of some type of stroke. The data also indicated that fish oil supplements were not significantly associated with risk reduction.
The researchers speculated that several reasons could be behind the perceived benefit of regular fish consumption. Those benefits may be the result of interactions among a wide range of nutrients, including some vitamins and amino acids that are commonly found in fish.
They also speculated including more fish in the diet left less room for more foods like red meat, which are considered detrimental to vascular health. The way the fish is prepared, whether fried or grilled, could also play a role.
Finally, the research team said a high-fish diet may simply be a sign of a healthier diet in general or possibly a higher socioeconomic status, which are both associated with better vascular health.
While the study won´t likely be seen as a ringing endorsement of fish oil supplements, the study´s authors said the results "reinforce a potentially modest beneficial role of fish intake in the cause of cerebrovascular disease."
The researchers also emphasized their results are in line with most dietary recommendations and physicians who advise at-risk patients to increase their fish oil consumption.
In an editorial that accompanied the study in the British journal, scientists from the Division of Human Nutrition at Wageningen University suggest that although it is "reasonable" to advise patients that eating one or two portions of fish per week could reduce the risk of cardiovascular disease, the benefit of doing so is small compared to other steps that patients could be taking to improve their overall health.