Plasmagen is a subclass of phospholipids widely distributed in animal tissues and ingested as food. However, the absorptive characteristics of plasmalogen have not been clarified. Also, vinyl-ether linkage in the sn-1 position of plasmalogen is very sensitive to oxygen radicals and has antioxidative properties in the lipid bilayer or lipoproteins; this lipid is a component of lipoproteins and reported to suppress cholesterol oxidation, which suggests that plasmalogen is an essential lipoprotein lipid to prevent atherosclerosis. Over many years, we have been researching this strange phospholipid. In this article, we would like to introduce the absorptive characteristics of plasmalogen and the availability of serum/plasma plasmalogen as the biomarker for atherosclerosis.

Well-regulated eating habits are said to be important for health. A major breakthrough was the discovery of the negative regulatory feedback for transcription via the binding of Clock/Bmal1 to E-box, which forms the basis of biological clocks. Well-regulated eating habits normalize the liver clock gene, the rhythm of CYP7A1 gene, and blood cholesterol levels through insulin secretion. Moreover, well-regulated eating habits actively contribute to better lipid metabolism such as obesity.

Increasing number of patients with diabetes has become a worldwide healthcare problem, and it is expected to reach approximately 600 million patients in 2035. In Asia-Pacific region, the prevalence of type 2 diabetes has increased dramatically in recent decades as the result of modern lifestyle changes, e.g., Western dietary pattern and reduced physical activity, on their genetic basis of lower insulin secretion capacity. In particular, nutritional surveys in East Asian countries consistently reported nearly three-fold increase in dietary fat intake in this half of century; dietary fat appears to be the major culprit of type 2 diabetes pandemic in East Asia. However, epidemiological cohort studies have not yet provided convincing evidence whether high-fat diet causes type 2 diabetes. Here, we summarize epidemiological studies on the relationship of dietary fat to type 2 diabetes and animal studies on high-fat diet-induced diabetes including our recent works on novel mouse lines selectively bred for different susceptibilities to high-fat diet-induced diabetes. These epidemiological and experimental findings would provide further insight into the etiology of type 2 diabetes under the modern nutritional environment.