M I Griep’s research while affiliated with Vrije Universiteit Brussel and other places

The combined influence of age-associated factors such as general health, degree of dependency, diminished odor perception, and poor oral health on the risk for malnutrition was explored. A total of 81 persons living in retirement homes took part in the study (mean age 83.4 years, SD = 6.6, range 61-98). The Mini-Nutritional Assessment (MNA) was used to evaluate the risk of malnutrition. Odor perception was measured by the detection threshold for isoamylacetate. The number of drugs taken by each person was counted. General health status was determined by the Medical Outcome Study (MOS) scores. Oral examinations were carried out to count the number of natural teeth and type of dentures. On average, women had slightly, but significantly, lower MNA scores than men (respectively, 23.4, SD = 2.8; and 24.6, SD = 2.6; p = .048). The correlations between age and MNA score and between odor perception and MNA score were not significant. Significant correlations were found between age and number of natural teeth (r = -.26, p = .001) and between MNA score and number of natural teeth (r = .27, p = .001). The mean MNA score of complete denture wearers (22.8, SD = 2.9) was significantly lower than that of partial denture wearers (25.8, SD = 2.9; p = .0005). The total MOS and MNA scores were not correlated, but a significant correlation was found with the subscales mental functioning (r = .29, p = .003), social functioning (r = . 19, p = .045), and perceived health (r = .19, p = .047). No relation was found between the activities of daily living (ADL) and MNA scores. A significant negative correlation was observed between number of drugs taken and the MNA score (r = -.34, p = .001). When participants without risk of malnutrition (MNA > or = 24) were compared with those at risk (MNA = 17-23.5), again, the number of drugs taken was significantly different (on average, respectively, 4.5, SD = 2.9; and 7.0, SD = 2.6; p < .0005). Using multiple regression to test the separate effects of the different independent variables, the number of drugs taken showed a significant negative regression coefficient (beta = -.31, p = .008), as did the mental health score (beta = .27, p =.02), giving a total R2 = .32. The other parameters did not contribute significantly. Among the elderly in retirement homes, the health state (as measured by the MOS subscale mental health and by the medication use) appears to be the most clinically relevant parameter to explain the risk for malnutrition. Loss of natural teeth and perceived health are less independently contributing, whereas no contribution derives from decline of odor perception, degree of dependency, and age itself.

Since the food habits of many elderly people are inadequate, the first experiment of the present study tested whether flavour amplification induces changes in preferences for and consumption of food and thus might result in a nutritional benefit. Two panels, one of 260 and one of 120 subjects, aged 19-98 years, took part in the study in which preferences for flavour-amplified yoghurt and Quorn were measured. For both products, only a few of the young subjects (20%) preferred the high flavour level; the percentage of subjects preferring the high flavour levels increased with age. These changes were highly significant. In a second experiment, participants received, under ad libitum conditions over 2 d in random order, a dish of yoghurt with either a high or a low flavour level. When adjusted for total consumption quantity, consumption of the highly flavoured yoghurt was not significantly correlated with age (r -0.03, P = 0.35). In a third experiment, odour perception was measured by determining the detection threshold for isoamylacetate. BMI values were obtained and the relationships between BMI and odour perception, age, preference and consumption were assessed in the age group 40-65 years. A significant correlation was observed between age and BMI (r 0.51, P < 0.0005). No significant correlation was observed between BMI and relative consumption of highly flavoured yoghurt (r -0.14, P = 0.14). A significant correlation was observed between BMI and preference for flavour-amplified yoghurt (r 0.35, P < 0.001). However, no significant correlation was observed between BMI and odour perception (r 0.07, P = 0.32). With increasing age, a combined influence of age, sex, BMI and odour perception on food preference is to be expected. According to our multiple regression analysis, BMI showed a significant partial regression coefficient (standardized beta 0.36, P = 0.03). In conclusion, flavour amplification of food for older adults deserves attention, but specific approaches, which are tailored to the candidate food systems and older adult target groups, are needed.

Considering the possible role of age-related phenomena such as general health, dental health and nutrition in odour perception, their joint effect on variability in odour perception was evaluated in the present study. A total of 171 apparently healthy adults with a mean age of 66.0 years (S.D. 7.3), ranging between 53 and 86 years, living in the community took part in this study. The SENIEUR protocol was used to assess the general health status and anthropometric measures were obtained to assess the nutritional status of the persons. The sensory detection threshold for isoamyl acetate was determined to measure odour perception. Oral examinations were used to assess dental status. Those in poor general health had lower mean values for odour perception than those in good or reasonably general health. Complete denture wearers and those with partial dentures had significantly lower values for odour perception than those with only natural teeth. Odour perception correlated significantly with measures of body fat and muscle mass, indicating that a poor sense of smell is associated with low body fat and muscle area. Our results indicate that general health and dental state are important age-associated factors in odour perception. Since odour perception is an important determinant of food consumption, early detection of diminished odour perception might be an indication of physical deterioration.

The sense of smell plays an important role in the quality of life. Many studies have shown a declining odour perception in the elderly, as well as in subjects in poor health or nutritional state. Considering the high prevalence of poor nutritional state in renal disease and the importance of odour perception in nutrition and health, the relationship between renal function, nutritional state, and odour perception is explored in this study. A total of 101 patients with chronic renal failure participated in the study. Thirty-eight haemodialysis patients (mean age = 64.3 years) were evaluated both before and after dialysis. Sixteen patients on peritoneal dialysis treatment (mean age = 64.0 years), 28 transplanted patients (mean age = 53.5 years, mean creatinine clearance = 64.0 ml/min) and 19 patients with varying degrees of renal insufficiency were also included (mean age = 63.7 years, mean creatinine clearance = 29.5 ml/min). Patients with cognitive deficits or upper respiratory airway diseases were excluded. A validated objective procedure was used to measure odour perception, by determining the detection threshold for isoamyl acetate (banana odour) as the lowest detectable odour concentration. Healthy control persons had significantly lower odour thresholds compared to patients on peritoneal (P = 0.001) and haemodialysis (P = 0.002). No significant difference was observed in odour perception between patients on peritoneal and haemodialysis (P = 0.779) and for patients on haemodialysis before and after a dialysis session. Transplanted patients had significantly better odour perception compared to matched patients on dialysis (P < 0.001). Odour perception of transplanted patients and matched healthy control persons was similar (P = 0.81). In patients with varying degrees of renal insufficiency, including healthy controls and transplanted patients, a significant positive correlation was found between odour perception and creatinine clearance (P = 0.02). A significant negative correlation was found between odour perception and serum concentration of urea (P < 0.001), serum phosphorus (P = 0.022) and protein catabolic rate (P < 0.05). Other parameters measuring nutritional status (albumin, BMI) were not correlated with odour perception. Our results show that the ability to smell is severely impaired in patients with chronic renal failure and is related to the degree of renal impairment and the degree of accumulation of uraemic toxins. After renal transplantation, patients have a normal odour perception, indicating the capacity of the olfactory system to recover once the concentration of uraemic toxins remains below a critical threshold. Acute removal of uraemic toxins by dialysis does not correct olfactory disturbances, suggesting a long lasting effect of uraemia on olfactory function.

Many studies have shown that odour perception declines with age. Considering the possible role of age-related phenomena such as general health, dental health and nutrition in such a decline, their joint effect on variability in odour perception was evaluated in the present study. 73 apparently healthy adults aged from 53 to 86 years (median age = 66), living in the community, took part in this study. The SENIEUR protocol was used to assess the general health status and anthropometric measures were obtained to assess the nutritional status. The sensory detection threshold for isoamylacetate (banana odour) was determined as the lowest detectable odour concentration. Dental status was assessed by a questionnaire on the presence of natural teeth and wearing of dentures. Those in poor general health had significantly higher mean odour thresholds (2.35, SD = 1.34), where threshold concentration was expressed as -log(mol/l), than those in good (3.47, SD = 1.46) or reasonably general health (3.75, SD = 1.02). Partial denture wearers had significantly higher odour thresholds (2.99, SD = 1.12) than those having only natural teeth (4.24, SD = 1.43). Significant correlations between age and anthropometrical values were found, indicating that with age, muscle mass particularly in women decreases (r = -0.50). Odour perception of women correlated significantly inversely with triceps skinfold thickness (r = -0.42), indicating that poor sense of small is associated with high body content of fat. Our results indicate that general health and dental state are important age-associated factors in odour perception. Since age does not show a significant independent effect, neither in an analysis of variance, nor in a multiple regression analysis, such factors tend to become more important than chronological age per se.

Flavour perception has been rated as the strongest determinant of food choice in the elderly. Old age is often associated with inadequate nutritional status and diminished odour perception. Adjusting flavour to compensate for diminished odour perception may improve the quality of life for the increasingly older population. In this study, we test whether flavour amplification can induce changes in the consumption of particular food. The majority of the younger subjects prefer the low flavour soup, Quorn® and yoghurt, while the elderly subjects prefer the high flavour level soup, Quorn® and yoghurt. Comparing the consumed quantities of high and low flavour meals shows that for the younger subjects, flavour amplification decreases consumption levels of soup and yoghurt. For the elderly subjects, amplification of yoghurt increases consumed quantities. In conclusion, flavour amplification of food for the elderly deserves attention. Regular consumption of the products would improve nutritional status. Manipulation of flavour and other factors that determine the food choice of consumers in real life situations is a subject that deserves further study.

Since the proportion of elderly people with an insufficient intake of nutrients is high and many of the elderly have poor odour perception or poor dental state, in this study, the relation between age, odour perception, dental state and nutrient intake is explored. Single centre cross sectional study. Independently living elderly were tested at their homes in 4 locations in Belgium, ranging in ages 60-90 y. 200 elderly participated in a 7 d food record study, resulting in 119 complete records. Food quantities were converted to nutrient intake levels. For all people, odour detection threshold was determined of isoamylacetate and dental status was noted. Path analysis was used and the separate effects of age, dental state, odour perception and gender were tested on macronutrient intake and micronutrient intake respectively. For all nutrients, no significant correlation was observed between nutrient intake and odour perception, except for energy, water, Fe and niacin (P < 0.05). A significant separate effect of odour perception was observed for water intake (CR = 2.09). Significant separate effects of dental state were observed for animal protein (CR = 2.29), niacine (CR = 2.04) and mono-unsaturated fats (CR = 2.32). Although odour perception and dental state can not fully explain variability in nutrient intake, our results show that people with poor odour perception have lower nutrient intake levels than people with good odour perception. Dental state may not be a direct cause of poor nutrition but a contribution factor in those elderly who have other risk factors.

The aim of this study was to investigate to what extent declining odour perception can be ascribed to dental status and oral hygiene habits, taking into account gender and age. Apparently healthy adults (n = 182), ranging from 53 to 93 years (mean age = 68.4) were tested. Information about oral hygiene habits (brushing teeth and cleaning dentures) and dental status was obtained by questionnaires. A validated objective procedure was used to measure sensory detection thresholds for isoamylacetate by an ascending method of limits. A significant negative correlation of odour perception with age was shown by the edentulous subjects which might reflect their wider age spread with many subjects over age 75. The evaluation of odour perception as a function of dental status shows no significant difference in odour perception between persons partial denture wearers, with natural teeth only or complete dentures. However, a tendency for lower odour perception was observed among male partial denture wearers, especially those reporting less frequent oral hygiene, which justifies further more detailed study.