Effects and contents of nutrition education relating to sarcopenia and frailty for Japanese older adults: A systematic review.

This systematic review aimed to clarify whether nutrition education relating to sarcopenia and frailty for Japanese older adults has been effective and to identify the content of nutrition education that is provided to participants. We examined relevant studies published before January 2021. The inclusion criteria were as follows: (i) studies on nutrition education provided by experts; (ii) studies on Japanese participants aged 60 years or older; (iii) full papers published in English or Japanese; and (iv) studies with outcomes that include measurement items related to sarcopenia and frailty. A search strategy was designed using keywords such as "Japan" or "Japanese" and "nutrition education." In total, 798 titles and 179 abstracts were examined, and 63 full texts were selected for reading. Ten articles met all the inclusion criteria. Only two studies aimed to determine the effectiveness of nutrition education. We could not clarify whether nutrition education relating to sarcopenia and frailty for Japanese older adults was effective. However, we did identify various nutrition education contents on sarcopenia and frailty for Japanese older adults. Further studies are needed as follows: (i) studies designs that can determine whether nutrition education is effective; (ii) studies in which the content of the cooking training can be reproduced; (iii) studies in which the intervention group and the control group have the same educational content with different duration and frequency; (iv) studies that are written in English; and (v) studies that are conducted on men. Geriatr Gerontol Int 2021; 21: 1084-1092.

Identification and characterization of a dipeptidyl peptidase IV inhibitor from aronia juice.

Aronia berries have many potential effects on health, including an antioxidant effect, effect for antimutagenesis, hepatoprotection and cardioprotection, an antidiabetic effect and inhibition of cancer cell proliferation. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders. In this study, we found that aronia juice has an inhibitory effect against dipeptidyl peptidase IV (DPP IV) (EC 3.4.14.5). DPP IV is a peptidase that cleaves the N-terminal region of incretins such as glucagon-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Inactivation of incretins by DPP IV induces reduction of insulin secretion. Furthermore, we identified that cyanidin 3, 5-diglucoside as the DPP IV inhibitor in aronia juice. DPP IV was inhibited more strongly by cyanidin 3, 5-diglucoside than by cyanidin and cyanidin 3-glucoside. The results suggest that DPP IV is inhibited by cyanidin 3, 5-diglucoside present in aronia juice. The antidiabetic effect of aronia juice may be mediated through DPP IV inhibition by cyanidin 3, 5-diglucoside.