You can teach an old dog new tricks: olfaction and responses to novel foods by the elderly.

It can be difficult to document effects of age-related olfactory loss on eating behavior. However, we have reported that elders, especially those with poor olfaction, were more willing to accept novel foods than were younger adults. It was also found that elderly subjects were more willing to accept foods with unpleasant odors than were young subjects. Because there is often confounding between a food's odor pleasantness and its familiarity, the purpose of this study was to separate the effects of familiarity and odor pleasantness on food acceptance by the elderly. There was no evidence for effects of age or olfactory sensitivity on food neophobia. However, elderly subjects with poor olfaction showed less reluctance to try the unpleasantly smelling foods than did other subjects. These results suggest that increased willingness to try novel foods among elderly subjects with poor olfaction in earlier work was due to decreased rejection of foods with unpleasant odors and not due to decreased food neophobia per se.

Dietary monotony and food cravings in young and elderly adults.

Many hypothesized mechanisms for food cravings focus on nutritional deprivation. However, outside of the laboratory, nutritional inadequacy is often confounded with dietary monotony. Therefore, one aim was to examine the effects of a nutritionally adequate, liquid, sweet, monotonous diet on food cravings in young and elderly adults. In addition, previous retrospective questionnaire work has indicated that elderly individuals report fewer food cravings than do young adults. Because there are possible age differences in cognitive capacity, another goal of this work was to develop a prospective method (i.e.. a method that depends less on memory) of studying cravings that permits comparison of adults of different ages. Young adults reported significantly more cravings per day during the monotony manipulation than during the baseline period. Therefore, nutritional deprivation is not a necessary condition for food cravings. There were no gender differences. The increase was due primarily to a greater number of cravings for entrees (i.e., foods that differed in sensory quality from the monotonous diet). Cravings for sweets did not change. In contrast to predictions that liking for the monotonous diet would decline as a result of "repetition revulsion," there was no significant change in liking for the diet over the study period. In contrast to the young adults, elderly subjects were not responsive to the monotony manipulation. Elderly men reported almost no cravings at any time during the study. Elderly women reported as many cravings as did young adults during the baseline period, but did not show an increase in cravings during the monotony period. This lack of response to dietary monotony by the elderly could result in nutritionally inadequate diets.

"Try it; it's good and it's good for you": effects of taste and nutrition information on willingness to try novel foods.

In an attempt to understand the effects of information on willingness to taste foods, we presented college students with a variety of familiar and novel foods of animal and vegetable origin. Participants received one of four types of information about the foods: none, they tasted good, they were high in vitamins, or they were high in vitamins and might soon be available in the college cafeteria. The information manipulation had no effect on willingness to taste familiar foods. Willingness to taste novel non-animal foods was increased by both taste and vitamin-plus-availability information, while willingness to taste animal foods was not affected by information. Willingness to taste novel foods was also predicted by a measure of trait neophobia. The results suggest that (a) emotional reactions to animal foods may block information effects, and (b) nutrition information is more effective in a context where the food is believed to be available.

Food cravings in young and elderly adults.

Fifty young-adult and 48 elderly Ss participated in a structured interview study on food cravings (defined as an intense desire or longing to eat a particular food). Elderly Ss were less likely than young Ss to report cravings and reported craving a smaller number of different foods. In contrast to a number of other researchers, we found a relationship between dietary restrictions and cravings. Types of food craved differed by gender and age. Women reported significantly more cravings for chocolate and for sweets than did men. However, craving for sweets declined with age among women. Cravings were not evenly distributed throughout the day, but tended to occur in the late afternoon and early evening.

"Try it. You'll like it." Effects of information on willingness to try novel foods.

Three experiments are reported on the effects of "taste" or nutrition information on willingness to try novel foods. "Taste" information improved responses to four out of the five foods examined. There was a consistent, but not statistically significant, trend for nutritional information to be effective. In experiment I, conducted with 3- to 8-year-old children in a laboratory setting, and in experiment II, conducted with 10- to 20-year-olds in a cafeteria, there were strong age effects. Older subjects responded more positively to novel foods than did younger subjects. There were no significant interactions between information and age and there were no sex differences. It is commonly assumed that novel foods are rejected because they are thought to be dangerous. However, the fact that dangerous foods are good tasting should be irrelevant to willingness to taste them. Our results are consistent with the idea that, in settings like laboratories and cafeterias, culture has already defined foods as being safe. Perhaps rejection in such settings is based on fear of a negative sensory experience.

The effects of aging on the human sense of smell and its relationship to food choice.

Olfaction plays a significant role in the perception of foods. For the most part, taste is limited to sweet, sour, bitter, and salty. The sensory experiences during consumption of complex foods and drinks cannot be constructed from these units. Indeed, much of the taste of a meal derives from olfactory stimulation. Hence, factors that influence olfactory perception should affect treatment of food-related odors. This article initially reviews previously published observations on the effects of age on olfaction and food preferences and then presents the results of original analyses of data derived from a substantial database formed as a result of the National Geographic Smell Survey. Included in the Survey form were topics relevant to the present article. They include the following question: Would you eat something that smelled like this? Two of the odors in the Survey were food related and two were fragrance related. Hence, in addition, we assessed responses to the following question: Would you apply something that smelled like this to your body? Answers were affected in part by the age and gender of the respondent and by the perceived pleasantness and intensity of the odor.

A possible genetic association between PROP-tasting and alcoholism.

Fifty-five young adult subjects and their parents were classified as alcoholic or nonalcoholic based on a standardized questionnaire (the MAST) filled out by the subjects. Subjects' thresholds for detection of 6-n-propylthiouracil (PROP; a PTC-like compound) were determined with the experimenter blind to MAST responses. There was a significantly higher proportion of nontasters of PROP among children of alcoholics than among children of nonalcoholics. There was no relationship between the child's alcoholism status and ability to taste PROP. These results are inconsistent with the view that excessive use of alcohol causes the association between nontasting and alcoholism and are consistent with the view that there is a genetic association between PROP/PTC-tasting and alcoholism.

Neophobia in humans and the special status of foods of animal origin.

Research from the anthropological, psychological, and animal behavior literatures suggests that foods of animal origin have a special status. In two studies we explored the question of whether individuals are more neophobic with respect to animal foods than non-animal foods. In the first study male and female subjects, after reading descriptions, rated their willingness to taste ten "novel" foods, which were actually fictitious. Foods in meat/fish/poultry and dairy/egg categories received lower ratings than those in fruit, vegetable, and grain categories. In the second study subjects were exposed to real foods, some of which were named and described accurately and were, therefore, familiar and some of which were named and described fictitiously and were, therefore, novel. There were no food category differences in subjects' willingness to taste familiar foods, but subjects were less willing to eat novel flesh foods than foods in the other categories. The results are discussed in terms of Rozin & Fallon's (1980) taxonomy of motivations for rejecting foods.

Sapid savvy in sucklings: the effect of quinine hydrochloride on intraoral negative pressure and intake by 11-13-day-old rat pups.

Three experiments describe the consummatory behavior of 11-13-day-old rat pups during and following experience with a model aversive taste, quinine hydrochloride. Pups were observed while away from the dam and while suckling. Results show that pups actively reject quinine adulterated solutions in both situations. They do so by spitting the solution from the mouth when away from the nipple and by leaving the nipple and/or decreasing their sucking effort when with the dam.

Similarities in food preferences between children and their siblings and parents.

Fifty-five Canadian women completed questionnaires about the food likes and dislikes of members of their families. Each family consisted of a mother, a father, a "target" child (24-83 months old) and the child's nearest-age sibling. The likes and dislikes of the target children were cross-tabulated with those of their mothers, fathers, and siblings, and phi-statistics were computed for the child-mother, child-father and child-sibling pairs as measures of similarity in food preferences. The results revealed that the target children resembled all three members of their families in their food preferences and that this resemblance was especially pronounced in the case of siblings.

Quality of acquired responses to tastes by Rattus norvegicus depends on type of associated discomfort.

Rats were trained to avoid a sugar solution through pairing with LiCl toxicosis (upper gastrointestinal tract discomfort), shock (peripheral pain), or high levels of lactose (lower gastrointestinal tract discomfort). Among animals matched for strength of avoidance of the sugar solution, only the LiCl group showed orofacial responses (e.g., gaping) indicative of distaste; the other groups continued to show positive orofacial responses to the sugar solution. These results, in conjunction with recent results on humans, are interpreted to represent a distinction between food rejection based primarily on unpalatability (distaste) and food rejection based primarily on anticipated negative consequences of ingestion (danger). The results also support the hypothesis that upper gastrointestinal distress (most probably nausea) plays a special role in negative palatability shifts (acquired distastes). These results have implications for the understanding of predispositions in learning and suggest important differences in the quality (readout) of different types of associations. Prior research, by relying on intake measures alone, was insensitive to the differences revealed here by monitoring a wider range of responses.