抄録
Basic principles of Japanese dietary reference intakes (DRIs) published in 2005 for lipid were briefly described.
Among several criteria used for DRIs, adequate intake (AI) and tentative dietary goal (DG) was adopted for the determination of fat intake DRIs. Since n-6 and n-3 fatty acids are essential fatty acids and their deficiency leads to dermatitis and growth retardation, their minimal requirement (=lower limit) should be established. However, since only a few case reports of n-6 and n-3 fatty acids deficiency have been published, it is difficult to establish their minimal requirement and thus the concept of AI that represents the median intake of the Japanese people was adopted.
For DG, since a lower intake of saturated fat increased an incidence of apoplexy (=brain bleeding) and a higher intake increased an incidence of obesity, DG of saturated fat was set as 4.5-7% of total energy intakes. Less than 10% of total energy intakes was set for n-6 fatty acids, since safety of a large amount n-6 fatty acids intakes were not known. Reports published to date demonstrate that sufficient intake of n-3 fatty acids can prevent ischemic heart diseases. The median intake of n-3 fatty acids of the Japanese people is much larger than that in the highest intake group of n-3 fatty acids among the Americans. Thus, for those more than 18 years of age, the median intake of n-3 fatty acids of the Japanese people was set as a lower limit of the tentative dietary goal (DG) for preventing life-style related diseases; the lower limit of DG of those more than 18 years of age becomes 2.0-2.9 g/day. Since a higher intake of cholesterol in Japanese populations increased cancer incidence in women and ischemic heart disease in men, DG of cholesterol was set less than 750 mg/day in man and 600 mg/day in women.
