This says: "Pump up the Fish Oil!
sday, July 31, 2008
ERA JUMP: Omega-3 fatty acids and plaque
By Dr Davis
The results of the uniquely-constructed ERA JUMP Study were just released, a fascinating study of the relationship of omega-3 fatty acids to coronary and carotid plaque.
The study adds insight into why the Japanese experience only one third of the heart attacks of Americans, and why Japan occupies the bottom of the list for least heart attacks among all developed countries.
The Electron-Beam Tomography, Risk Factor Assessment Among Japanese and U.S. Men in the Post-World War II Birth Cohort Study (ERA JUMP), a collaborative U.S.-Japanese effort, compared three groups of men:
-- 281 Japanese men living in Japan
-- 306 non-Japanese men living in the U.S. (Pittsburgh, Pennsylvania)
-- 303 Japanese Americans (having both parents Japanese without “ethnic admixture”) living in Hawaii.
The last group represents a group that is genetically similar to the group in Japan, but exposed to an American diet and lifestyle.
Three main measures were compared:
-- Blood levels of omega-3 fatty acids, EPA and DHA)
-- Carotid intimal-medial thickness (CIMT, the thickness of the carotid artery lining that can serve as an index of body-wide atherosclerosis)
-- Coronary calcium (heart scan) scores.
Interestingly, at the start of the study, the Japanese men possessed an overall cardiovascular risk profile worse than the Americans: Though more slender (BMI 23.6), Japanese men were more likely to be smokers, alcohol drinkers, had more high blood pressure, and were less likely to take cholesterol medications. The Americans, conversely, although heavier (BMI 27.9), were less likely to be smokers and drinkers, and had a four-fold greater use of cholesterol medications.
The Japanese Americans were the most likely to be hypertensive, diabetic, with a similar proportion of overweight as the non-Japanese Americans.
Despite the overall greater heart disease risk for profile for Japanese men, compared to non-Japanese Americans they had 10% less CIMT. In addition, only 9.3% of Japanese men had abnormal coronary calcium scores vs. 26.1% of non-Japanese Americans. Japanese-Americans were the worst, however, with nearly 10% more CIMT than non-Japanese Americans and 31.4% with abnormal calcium scores.
The most intriguing finding of all was the fact that, of all the various groups and degrees of atherosclerosis, whether gauged via CIMT or coronary calcium scores, the blood level of omega-3 fatty acids was inversely related, i.e., the greater the omega-3 blood level, the less plaque by either measure was detected.
Japanese men had the highest omega-3 blood levels: twice that of the non-Japanese Americans. The Japanese-Americans had levels only slightly greater than non-Japanese Americans.
While other studies, like the GISSI Prevenzione study, have persuasively demonstrated that omega-3 fatty acids substantially reduce heart attack, a weak link in the omega-3 argument has been a study that links greater omega-3 intake with less atherosclerosis. The unique construction of the ERA JUMP Study, employing two groups with sharply different omega-3 intakes, very powerfully argues for the plaque-inhibiting effects of this fraction of fats.
How much omega-3 fatty acids do Japanese people eat? Estimates vary, depending on part of the country, coastal vs. inland, age, etc., but Japanese tend to ingest anywhere from 5 to 15-times more omega-3 fatty acids than Americans. The actual intake of omega-3 fatty acids (EPA +DHA) in Japanese ranges from 850 to 3100 mg per day. |
