Comparison of salty taste acuity and salty taste preference with sodium intake and blood pressure based on zinc nutritional status in two rural populations in Korea

This study examined salty taste acuity and salty taste preference and sodium intake in relation to zinc nutritional status in 2 rural populations in Korea. And we also examined the main food contributors of their sodium intakes. We enrolled 218 adults (66 men and 152 women) from the Kangneung and Samcheok regions in Korea's Kangwon province in our study conducted from December 2011 to February 2012. Participants from each region were divided into 3 groups based on their serum zinc level (T1: lowest, T2: intermediate, T3: highest). We compared the salty taste acuity and preference, Na index (Dish Frequency Questionnaire for estimation of habitual sodium intake), blood pressure, and intakes of nutrients including sodium by 3 groups of serum zinc level. The results were as follows: a higher serum zinc level indicated a lower sodium intake and Na index (P < 0.05). The salty taste acuity was considerably higher for participants from the Kangneung region than those from the Samcheok region (P < 0.05). And the serum zinc level was significantly higher in participants from the Kangneung region than those from the Samcheok region (P < 0.05). We further divided the participants into 2 groups: those who consumed more zinc than the recommended intake (RI) and the others. We compared salty taste acuity and salty taste preference in the 2 groups. The salty taste threshold and palatable salty taste concentrations were lower for the group with a zinc intake above RI than for the group with zinc intake below the RI. However, the difference was not significant. This study confirms that taste function differs depending on zinc nutritional status. In future, it is required to a large-scale, long-term, prospective study on the correlation between zinc intake, serum zinc levels, and taste perception function and blood pressure.