Benefits Outweigh Potential Risks of Eating Fish
The cardiovascular health benefits of fish consumption outweigh the potential risks from exposure to methylmercury or other environmental contaminants contained in some fish, according to two studies released on Tuesday, the Washington Post reports (Squires, Washington Post, 10/18).
For the first study, which was sponsored by NIH and published on Wednesday in the Journal of the American Medical Association, researchers at Harvard Medical School, the Harvard School of Public Health and Brigham and Women's Hospital analyzed data from more than 200 previous studies that examined the health benefits of fish consumption and the potential risks from exposure to methylmercury, dioxin and polychlorinated biphenyls contained in some fish.
For the second study, which was sponsored by the National Oceanic Atmospheric Association and FDA, Institute of Medicine researchers conducted qualitative analyses of hundreds of previous studies on the issue.
The JAMA study found that the health benefits of moderate fish consumption significantly outweighed the potential risks (Bernstein, Wall Street Journal, 10/18). The study found that adults who consumed two servings of fish weekly had a 36% lower mortality rate from heart disease and a 17% lower overall mortality rate than those who ate a small amount of fish or no fish (Washington Post, 10/18). According to the study, fish that contain high levels of omega-3 fatty acids provide the most health benefits.
The IOM study found that the scientific evidence on health benefits and potential risks of fish consumption in large part remains preliminary or inconclusive. Limited evidence exists about the environmental contaminants in fish and how the health benefits of fish consumption might offset the potential risks, according to the study.
The study found that fish consumption can reduce risk for heart disease but did not find adequate evidence that the practice can reduce risk for diabetes, cancer, Alzheimer's disease or other diseases. According to the study, whether the cardiovascular health benefits of fish result from the protective effects of omega-3 fatty acids or the substitution of fish for foods that contain more unhealthy fats, such as saturated fats, remains undetermined (Wall Street Journal, 10/18).
The study also founds that omega-3 fatty acids contained in fish can help with vision and cognitive development in infants and can help reduce the risk of preterm births when consumed by pregnant women (AP/Washington Times, 10/18).
According to the Post, the studies "are expected to help put to rest a hotly debated nutritional debate" that left many consumers "perplexed" about whether to consume fish (Washington Post, 10/18). The IOM study found that children ages 12 and younger and women who are breastfeeding, pregnant or might become pregnant can benefit from the consumption of two three-ounce servings of fish weekly and can safely consume as much as 12 ounces of fish weekly.
However, individuals in those groups should not consume shark, swordfish, tilefish or king mackerel, according to the study. Children ages 12 and younger can safely consume as much as six ounces of white, or albacore, tuna weekly, and women who are breastfeeding, pregnant or might become pregnant can safely consumer as much as 12 ounces weekly, the study found.
Adolescent men, adult men and women who cannot become pregnant can benefit from the consumption of two three-ounce servings of fish weekly, according to the study. Individuals in those groups who consume more than two servings of fish weekly should vary the fish that they consume to limit their exposure to a single source of contaminants, the study recommended (Wall Street Journal chart, 10/18).
The JAMA study included similar recommendations but recommended that women who are breastfeeding, pregnant or might become pregnant eat as much as 12 ounces of fish weekly (Wall Street Journal, 10/18).
Several broadcast programs reported on the studies:
- ABCNews' "World News Tonight": The segment includes comments from David Bellinger, a co-author of the IOM study; Mozaffarian; and Malden Neshim, provost emeritus of Cornell University (Stark, "World News Tonight," ABCNews, 10/17).
- CBS' "Evening News": The segment includes comments from Jean Halloran, director of food safety at Consumers Union; Susan Krebs-Smith, chief of the risk factor monitoring and methods branch of the applied research program at the National Cancer Institute; Leape; Jose Ordovas, a Tufts University researcher; and pregnant U.S. women (Alfonsi, "Evening News," CBS, 10/17). A transcript of the segment is available online. A related CBS video segment is available online in RealPlayer.
- NBC's "Nightly News": The segment includes comments from Julie Caswell, a physician at the University of Massachusetts; Mozaffarian; and U.S. residents who do and do not eat seafood (Bazell, "Nightly News," NBC, 10/17). The complete segment is available online in Windows Media.
- NPR's "All Things Considered": The segment includes comments from Mozaffarian; Neshim; and Jonathan Scher, professor of obstetrics and gynecology at the Mount Sinai School of Medicine (Aubrey, "All Things Considered," NPR, 10/17). The complete transcript of the segment is available online. The complete segment is available online in RealPlayer.
- NPR's "Day to Day": The segment includes comments from Allison Aubrey of NPR (Brand, "Day to Day," NPR, 10/17). The complete segment is available online in RealPlayer.