リノール酸摂取の問題点

昨年9月に脂質栄養学会で行われたシンポジウムを受けて

抄録

In 2005, Japan Society for Lipid Nutrition conducted a symposium on "the Approach of Dietary Reference Intakes for Japanese, 2005, (DRIJ) to Fatty Acids and Cholesterol". We appreciate that DRIJ drastically increased the upper limits (UL) of cholesterol intakes, and we do not further discuss this issue here. However, the UL of linoleic acid set by DRIJ was 10 energy %. This is calculated to be 22g for 2000kcal-taking people. If the whole linoleic acid is provided from cooking oils, 22g is equal to 50g of usual cooking oils found in Japan. This amount is not practical for Japanese, and almost identical to "no limits". Judging from the comments in the symposium of Dr Osamu Ezaki who chaired the lipid session in DRIJ, the lipid recommendation of DRIJ seems to be considerably influenced by the results of the Nurses' Health Study (NHS) performed in the United States. Its results read that the more linoleic acid, the better after adjustments for many confounding factors. However, Japanese are completely different from the cohort of NHS; Americans' intakes of fish oils have been essentially the lowest of the developed countries for these forty years. It is not appropriate to draw a conclusion about lipid nutrition from the results of cohorts whose marine n-3 fatty acid intakes are extremely low. We need well-planned epidemiological studies in Japan to understand the upper limits of linoleic acid. Until then, it is prudent to keep our linoleic acid intake low, considering the results of some epidemiological studies.