The August, 2011 issue of the Journal of Internal Medicine published the findings of American researchers of a reduction in the incidence of high blood pressure in men and women who consumed higher amounts of long-chain omega-3 polyunsaturated fatty acids from fish. While the cardiovascular benefits of long-chain omega-3 fatty acids (which include EPA and DHA) are well known, the current research sought to determine potential interactions with the body’s levels of selenium and mercury, elements that also occur in fish.
The current study involved 4,508 men and women enrolled in 1985 in the ongoing Coronary Artery Risk Development in Young Adults (CARDIA) Study. Dr Ka He of the University of North Carolina in Chapel Hill and colleagues utilized responses to dietary questionnaires conducted upon enrollment and at the seven and twenty year follow-up examinations to determine average omega-3 fatty acid intake. Blood pressure was measured at all six follow-up visits, and incidences of high blood pressure or initiation of antihypertensive medication were noted. Selenium and mercury levels were determined by measuring the amounts contained in toenail clippings collected in 1987.
Dr He’s team found a 35 percent lower adjusted risk of developing hypertension among men and women whose EPA and DHA levels were among the top 25 percent in comparison with those whose intake was among the lowest fourth. When the fatty acids were separately evaluated, DHA was associated with the greatest protective effect. The benefit for omega-3 fatty acids appeared to be greater among those with higher selenium and lower mercury levels.
“To the best of our knowledge, no study has investigated three-way interactions of selenium, mercury and long-chain omega-3 polyunsaturated fatty acids in relation to incidence of hypertension,” the authors write. “The possible mechanisms explaining the modification of selenium and mercury on the antihypertensive effect of long-chain omega-3 polyunsaturated fatty acids may lie in that both selenium and mercury are somehow involved in the process of oxidative stress and cardiac function through the same pathway by which long-chain omega-3 polyunsaturated fatty acids regulate blood pressure.”
“Additional studies are warranted to elucidate the complex interactions amongst selenium, mercury and long-chain omega-3 polyunsaturated fatty acids, three important components in fish, in terms of hypertension prevention,” they conclude.
Salmon is one of the best crouches of omega-3 fatty acid, but not all salmon is equal. You want to only consume wild caught salmon. Most of what you find in stores and restaurants is farm raised. The difference is that salmon obtain the omega-3 oil from their main food source, krill. Krill also give the wild salmon their characteristic pin/orange color. Farm raised salmon on the other hand are raised in pens in near the short or in bays. The are fed corn, soy, and things you don’t want to know about. Farm raised salmon is white, so they add dye to the fish to make them look like real salmon. In farm raised salmon, often called Atlantic Salmon, the omega-3 oil levels are much lower.
Another options is fish oil capsules. Caution is necessary here as well. Most fish oil comes from large fish and usually from the organs and liver. These large fish are older and higher up the food chain, so they accumulate the mercury, PCB, and other toxins. Some very popular commercial brands of fish oil were fined in California because they contained dangerous levels of PCB and didn’t have California’s Prop-65 warning on them. A friend is a ER doctor and she had a young woman come into the ER with what turned out to be mercury poisoning. After investigation it turned out that she was taking several fish oil capsules she’d purchased at a big box store. They had so much mercury that with here taking a higher dosage, it gave her mercury poisoning.
The fish oil I take and recommend comes from small young fish such as anchovies, sardines, etc. The raw oil has less than 1/100th the amount of mercury allowed by the FDA. Then it goes through a double molecular distillation and the final product is 99.99999999% mercury free. You can’t get a purer fish oil. They also add lemon oil so you don’t have a fishy after taste, intact we give it to kids by just having them crew up the gel cap, and they love the lemon taste. Then they just spit out the gel cap.
Contact me if you ‘d like more information on the one I recommend.