Do chemosensory changes influence food intake in the elderly?

Food intake declines with age, and elderly individuals frequently report a decrease in appetite. Changes in chemosensory systems may partially explain this low intake. However, few data have directly linked changes in gustatory or olfactory function to food choice or intake. In two studies, taste perception and preference were unrelated to sodium chloride or sugar intakes. Olfaction may be more affected by age than taste. Olfactory dysfunction is associated with decreased enjoyment of food, and adding odors to foods can increase intake in some elderly individuals. The consumption of a varied diet depends in part on sensory-specific satiety (a decrease in the pleasantness of a food as it is consumed). Sensory-specific satiety diminishes with age, and this could be part of the explanation of why some elderly individuals have little variety in their diets. However, the impact of chemosensory deficits on nutritional status depends on a number of social and environmental factors. For example, despite their age, financially secure, free-living healthy older men and women consumed more varied diets than young adults. Changes in mechanisms regulating food intake can make it difficult for some elderly individuals to maintain energy balance. When chemosensory impairments are combined with changes in food intake regulatory mechanisms, the risk for nutritional deficiencies may be high. If we are to optimize food intake and nutritional status in the elderly, additional basic studies on how changes in chemosensory systems associated with aging affect food selection and intake are required.