Food aversion learning: a risk factor for nutritional problems in the elderly?

Food aversions that are acquired as a result of unpleasant experiences with foods represent a potent defense mechanism against poisoning. However, this powerful and durable form of conditioning can also contribute to avoidance of foods that are not poisonous, and are, in fact, quite nutritious. This is because such foods may be coincidentally associated with unpleasant gastrointestinal symptoms, sometimes due to transient, unrelated illness, or unpleasant drug side effects. Most of the studies of naturally occurring learned food aversions in humans have been focused on subjects of college age, so we have limited information about the extent to which such food aversions occur in the elderly. Additionally, most studies have employed questionnaire or interview methods that may have some significant limitations in the accurate assessment of the incidence of food aversions. Thus, although food aversion learning has been thoroughly documented in the animal laboratory, its role in everyday food selection in humans, including the elderly, remains relatively unclear.