Utilization of Processed Foods Rich in Docosahexaenoic Acid: Clinical Trials Using Foods for Specific Health Purposes

Abstract

Recently, numerous studies have shown a hypolipidemic effect of docosahexaenoic acid (DHA, C22:6n-3) and eicosapentaenoic acid (EPA, C20:5n-3), which are commonly described as omega-3 fatty acids; however, in most cases, DHA and EPA are ingested as capsules, pills, or health supplements with little chance of being prepared in tasty foods eaten on a daily basis. We planned to develop fish sausage, which is recognized as a healthy food that is high in protein and low in lipids, supplemented with DHA and EPA to allow the claim of lowering serum triglycerides for the prevention of lifestyle related diseases. Based on clinical data, the fish sausage (containing 850 mg DHA and 200 mg EPA) was validated as a food for a specific health use in 2005 by the Ministry of Health, Labour and Welfare, following further validation of 9 sausage series. The impact of this permission to label the DHA sausage had an influence not only in food markets but also in the medical industry. In postmenopausal women, hyperlipidemia conditions are generally partially managed, but rarely return to normal levels, even with hypolipidemic drugs. In a sample of postmenopausal women, dietary DHA and EPA supplementation was administered once a day for 1 month with continuing administration of statins. Lipid levels returned to normal levels, including lowering of remnant-like particle (RLP)-cholesterol as well as normalization of triglyceride levels.Concerning the effects in the central nervous system, DHA was studied mechanically in the enhancement of long-term potentiation (LTP) in vitro and was investigated in a rat model of Alzheimer's disease, but there have been few clinical trials to examine the effects of DHA in mild dementia in Japanese. A 2-year randomized, double-blind, placebo-controlled trial aimed at examining the effects of daily dietary DHA and EPA supplementation on cognitive function in healthy elderly Japanese. The Mini Mental State Examination (MMSE) sub item "Language: copying" and Frontal Assessment Battery (FAB) sub item "Conflicting instructions" scores were significantly greater in the treatment group. Long-term daily dietary DHA and EPA supplementation seems to have beneficial effects for age-related cognitive decline in otherwise healthy elderly Japanese with very mild dementia. We would like to develop a line of processed foods rich in DHA, which are effective for the maintenance of human health, particularly relating to the central nervous system and cardiovascular stability.