Effects of ginger koji intake on skin surface temperature for young women sensitive to cold temperatures.

This study investigated the effect of ginger koji powder on sensitivity to cold temperatures among young women. Ginger koji is an enzyme-rich food which is produced by solid-state fermentation with Aspergillus oryzae in ginger chips. Ginger koji powder (500mg/2cp), ginger powder (500mg/2cp), or a placebo (cellulose, 500mg/2cp) was adminite to 5 women (20.6±0.4 years old) with cold fingertips using a double-blind placebo-controlled crossover protocol. The combined effect with a milk protein drink was investigated. Twenty minutes after a single administration, the hand of each subject was exposed to cooling at 20°C for 1min, and then the skin surface temperature on the hand along with the width of blood vessels in their fingers were measured. In the case of a single administration of ginger koji, the recovery rates of hand temperature were significantly higher than those in the placebo group. In addition, after a single administration of a combination of a milk protein drink and ginger koji, hand temperature recovery time was shorter than in the placebo group. It can therefore be suggested that the administration of both a milk protein drink and ginger koji leads to an increase in diet-induced thermogenesis, and subsequently the recovery of skin surface temperature. Our findings suggested that ginger koji can be helpful for women sensitive to cold temperatures.