Baked, Boiled Fish Better for Heart

ORLANDO, Fla.Baked or boiled fish is better for the heart than fried, salted or dried, according to research presented at the American Heart Associations Scientific Sessions 2009.  And, researchers said, adding low-sodium soy sauce or tofu will enhance the benefits.

It appears that boiling or baking fish with low-sodium soy sauce (shoyu) and tofu is beneficial, while eating fried, salted or dried fish is not, said Lixin Meng, M.S., lead researcher of the study and Ph.D. candidate at the University of Hawaii at Manoa. In fact, these methods of preparation may contribute to your risk. We did not directly compare boiled or baked fish versus fried fish, but one can tell from the (risk) ratios, boiled or baked fish is in the protective direction but not fried fish.

In this study, researchers examined the source, type, amount and frequency of dietary omega-3 ingestion among gender and ethnic groups. Participants were part of the Multiethnic Cohort living in Hawaii and Los Angeles County when they were recruited between 1993 and 1996. The group consisted of 82,243 men and 103,884 women of African-American, Caucasian, Japanese, Native Hawaiian and Latino descent ages 45 to 75 years old with no history of heart disease.  

Researchers divided their intake of canned tuna, other canned fish, fish excluding shell fish, or soy products that contain plant omega-3s (soy, tofu and shoyu) into quintiles, quartiles, or tertiles when applicable. They also surveyed the preparation methods: raw, baked, boiled; fried; salted or dried. The initial study did not consider grilled fish. Those in the highest quintile consumed a median 3.3 grams of omega-3 fatty acids a day. The lowest quintile consumed a median of 0.8 grams a day.  During the average 11.9 years of follow-up, 4,516 heart-related deaths occurred in the group, according to state and national death records, which were cross-referenced through the end of 2005.

Overall, men who ate about 3.3 grams per day of omega-3 fatty acids had a 23 percent lower risk of cardiac death compared to those who ate 0.8 grams daily.  Omega-3 intake was inversely associated with overall risk of death due to heart disease in men a trend mainly observed in Caucasians, Japanese Americans and Latinos. However, there werent many blacks or Hawaiians in the study, so the results should be interpreted cautiously, Meng said.

For women, the omega-3 effect was cardioprotective at each level of consumption but not consistently significant, Meng said. Salted and dried fish was a risk factor in women.

In contrast, adding less than 1.1 gram/day shoyu and teriyaki sauce at the dinner table was protective for men, but not for greater than 1.1 gram/day. For women, shoyu use showed a clear inverse relationship to death from heart disease. Meng noted shoyu that is high in sodium can raise blood pressure, so she stressed low-sodium products. Eating tofu also had a cardioprotective effect in all ethnic groups.  My guess is that, for women, eating omega-3s from shoyu and tofu that contain other active ingredients such as phytoestrogens, might have a stronger cardioprotective effect than eating just omega-3s, said Meng, noting that further studies are needed to confirm the hypothesis.