All functionality claims for foods in Japan have been decided by the government so far. In contrast, new functionality claiming system will be enforced from April, 2015, in which a company will be able to decide the claims based on scientific evidence. The functionality claiming system of dietary supplement in the US, namely structure/function claim based on the Dietary Supplement, Health and Education Act (DSHEA) was referred for making the new system. Most foods including perishable foods are covered by the new system and the prior notification to the Consumer Affairs Agency was decided to be introduced. Substantiation of scientific evidence for the claims, providing accurate and understandable information to consumers, securing safety and quality of the foods and the government's role are the main subjects but the most important thing is that the securing of safety and quality is the major premise for the system. The framework of the new system is introduced in this paper with a consideration of the future challenges especially in securing safety and quality that arose by the comparison with DSHEA.
Eicosapentaenoic acid ethyl ester (EPA-E) with a high degree of purity is marketed as a medical supply. In vivo pharmacokinetics of EPA-E is examined in detail via animal experiments. Orally administered eicosapentaenoic acid (EPA) is found in triglyceride (TG) in the rat intestine, and is absorbed via the lymphatic system. Moreover, EPA is gradually detected in cholesterol ester and phospholipid (PL) in blood. Whereas EPA is found in low density fractionation of lipoprotein such as chylomicron in the lymph fluid, it gradually transitions to high density fractionation in systemic circulation. EPA is distributed to several tissues such as fat, liver, heart, brain and aorta. Whereas EPA and its metabolized fatty acids are found in TG in fat, they are predominantly found in PL in the brain, liver and heart. EPA transforms systemically into docosahexaenoic acid (DHA) by chain elongation and subsequent desaturation after intestinal absorption. Interestingly, DHA is found in the brain earlier than in blood and the liver, suggesting the synthesis of DHA occurs in not only the liver but also the brain. This hypothesis is also supported by a recent clinical trial.
Gut microbiota affects not only host immune system but also host nutrient acquisition and energy regulation, and thereby influencing the development of obesity and diabetes. Short-chain fatty acids (SCFAs), produced by the gut microbial fermentation of dietary fiber, are essential host energy sources and signal molecules via G-protein coupled receptor GPR41 and GPR43. We report that these SCFAs receptors are involved in host energy homeostasis, GPR41 regulates sympathetic activity, and GPR43 regulates adipose-insulin signaling by sensing SCFAs. These results indicate that gut microbial metabolites regulate host homeostasis via novel molecular signal mechanism.
Cyclic phosphatidic acid (cPA), one of the natural simplest phospholipids, is found in organisms from slime molds to humans. cPA and its derivative 2-carba-cPA (2ccPA) exhibit various biological functions such as suppression of cancer cell invasion/metastasis and attenuation of ischemia-induced neuronal cell death. We showed that cPA/2ccPA inhibited chronic and acute inflammations, attenuated neuropathic pain, and increased hyaluronic acid synthesis. In this review, we focused on newly identified effects of cPA/2ccPA on osteoarthritis (OA) and multiple sclerosis (MS). OA is a degenerative disease frequently associated with symptoms such as inflammation and joint pain. We examined the effects of 2ccPA on OA in vivo and in vitro. Using rabbit meniscectomy model of OA, we revealed that intra-articular injection of 2ccPA significantly reduced pain and articular swelling. Using human OA synoviocytes and chondrosarcoma SW1353 cells, we found that 2ccPA increased hyaluronic acid synthesis and suppressed MMP-1, -3, and -13 productions in synoviocytes and chondrocytes.
In mammals, the circadian clock system regulates many physiological functions such as feeding, sleep-wake behavior, hormones and metabolism. Regular feeding pattern can entrain peripheral circadian clock system, whereas circadian clock can control absorption/ metabolism of food and nutrition. Thus, the interaction between food/nutrition and circadian clock is so-called as “chrono-nutrition”. For example, a bigger meal for breakfast is effective for protection from obesity, and also for entrainment of peripheral circadian clock. Intake of high fat diet disturbed the circadian clock and this clock disturbance potentiates the obesity. Circadian clock system exists in the white adipose tissue, and clock gene such as Bmal1 controls the differentiation of adipose cells and accumulation of fat in the cells. We demonstrated that fish oil, especially tuna oil, containing rich DHA/EPA increased insulin secretion and entrained peripheral circadian clock. Talking about nutrition including lipids, the idea of “chrono-nutrition” may become important and provide new aspects of the form of nutrition action.
The metabolic syndrome is a condition characterized by an array of factors including abdominal obesity, dyslipidemia, hypertension and impaired glucose metabolism. Since individuals with metabolic syndrome have a higher risk of morbidity and mortality of cardiovascular disease (CVD), compared with those without metabolic syndromes. Recently our studies provide evidence that dietary factors may improve metabolic syndrome. The current review will discuss the physiological functions and molecular actions of dietary bioactive lipids such as n-3 high unsaturated fatty acids (n-3HUFAs), phospholipids and conjugated fatty acids. The role of bioactive lipids on the prevention of metabolic syndrome and associated metabolic impairments, such as non-alcoholic fatty liver disease (NAFLD) and inflammation were also discussed. Dietary bioactive lipids suppress an accumulation of lipids in the liver, muscle and abdominal adipose tissues through the alteration of transcriptional factors involved in lipid and glucose metabolism and alleviate hypertension and insulin resistance via adiponectin induction.
Consumer interest in foods and food safety has been increasing recently, and food-related information is easily available on demand. While nutrition and ingredient labeling of food should, in the first place, be easily intelligible to any consumer, current nutrition labeling in Japan is voluntary and does not necessarily present information helpful for consumers. Thus, providing accurate information to allow adequate and safe ingestion of lipids via ingredient labeling is one of our first priorities. We have, accordingly, decided to approach the national government with a proposal to improve the current labeling standards. The following article, “Improvements we seek in lipid nutrition and ingredient labeling and the reasons for our proposal - including problems in current lipid nutrition ingredient labeling and an explanation of the need for change -” is to be attached to the proposal. The purpose of this article is to provide adequate grounds for proposing changes in labeling, and we would invite suggestions and comments on this article from subscribers concerned with lipid nutrition and ingredient labeling of food, for our consideration.