Effect of UV exposure and beta-carotene supplementation on delayed-type hypersensitivity response in healthy older men.

OBJECTIVES: The aims of this study were to determine if ultraviolet light (UV) is immunosuppressive in healthy older males, if beta-carotene (betaC) supplementation could prevent any observed UV-induced immunosuppression, and to compare these effects with those observed previously in younger men. METHODS: The study was a placebo-controlled, randomized trial that employed a 2 x 2 factorial design. Healthy older men (mean age 65.5 years) received 30 mg betaC or placebo daily throughout the 47-day trial, while on a low carotenoid diet. After 28 days, half of each group received 12 suberythemic exposures to UV over a 16-day period. Delayed-type hypersensitivity (DTH) tests and plasma carotenoid assays were performed at baseline, pre-UV and post-UV time points, with DTH testing performed on an area of skin protected from UV exposure. RESULTS: UV exposure resulted in significantly suppressed DTH response in the placebo group but not in the betaC-UV group. While there was no significant interaction between betaC supplementation and UV on DTH response, there was a significant inverse relationship between final plasma betaC concentration and extent of UV-induced suppression of DTH response. A similar correlation existed among subjects not exposed to UV. CONCLUSIONS: Suberythemic UV exposure was immunosuppressive, as measured by DTH response, in healthy older men as in younger men. Higher plasma betaC was significantly associated with maintenance of DTH response, although the extent of protective effect of betaC appeared less than previously observed in younger subjects. The attenuated effect of betaC in the older UV-exposed subjects may have resulted in part from muted plasma betaC responses to betaC supplementation and/or higher plasma vitamin E levels than those of younger men. The finding that stronger DTH responses were associated with higher plasma betaC concentrations in both UV and non-UV subjects further supports a role for this nutrient in immunomodulation.

Evidence of a role for fat-free body mass in modulation of plasma carotenoid concentrations in older men: studies with hydrodensitometry.

We examined the relationship between body composition and changes in plasma carotenoid concentration in response to dietary carotenoid restriction or beta-carotene (betaC) supplementation in healthy older men. Subjects (mean age 65 y) were assigned randomly to supplement (30 mg betaC/d) or placebo groups, and all subjects consumed a standard low carotenoid basal diet plus 1.5 mg betaC/d as carrots. Body composition was measured at baseline by hydrodensitometry, and plasma carotenoids were measured at baseline and after 28 d of treatment by HPLC. Baseline plasma total carotenoid concentration was significantly and negatively correlated with body mass index (BMI) and fat-free mass (FFM) but not with fat mass, whereas baseline betaC concentration was negatively associated with all three variables. The increase in plasma betaC concentration in response to betaC supplementation was significantly and inversely correlated with BMI and FFM but not with fat mass. Likewise, the decline in plasma total carotenoid concentration in the placebo group was also significantly and inversely related to BMI and FFM but not to fat mass. Thus, FFM seems to be an important determinant of plasma carotenoid concentrations and to explain a substantial portion of the often-observed relationship between BMI and blood carotenoid levels. Fat-free mass seems to represent a dynamic reservoir that dampens short-term changes in plasma carotenoid concentrations during fluctuation in carotenoid intake.

A new placental enzyme in the metabolism of cocaine: an in vitro animal model.

OBJECTIVE: The aim of this study was to analyze placental metabolism in a genetically controlled in vitro animal model. STUDY DESIGN: Placentas from Sprague-Dawley rats were centrifuged, and microsomes were isolated. Four treatment groups were incubated with cocaine over four time periods: placental microsomes + cocaine, placental microsomes + diisopropyl fluorophosphate (an anticholinesterase) + cocaine, placental microsomes + cocaine + butyrylcholinesterase, and a blank (cocaine only). Gas chromatography was used to quantify cocaine (Limit of quantitation = 19 ng/ml) and metabolites. Gas chromatography/mass spectrometry was used to verify the identity of the metabolites. RESULTS: Butyrylcholinesterase enhanced cocaine metabolism to ecgonine methyl ester. More than 40% of cocaine was metabolized to norcocaine by rat placental when diisopropyl fluorophosphate suppressed cocaine. Norcocaine is produced by hepatic N-demethylase action on methyl-bearing nitrogen in cocaine, suggesting that placenta and liver have this capacity. Gas chromatography/mass spectrometry was essential to the identification of norcocaine, because norcocaine is frequently not identified. CONCLUSIONS: This biotransformation of cocaine to norcocaine may be a primary metabolic pathway induced in the cholinesterase-deficient placenta. This has clinical implications because norcocaine is ninefold more active physiologically than cocaine or ecgononine methylesterase.

Drug-nutrient interactions in three long-term-care facilities.

OBJECTIVE: To assess the risk of drug-nutrient interactions (DNIs) in three long-term-care facilities. DESIGN: Retrospective audit of charts. SETTING: Three long-term-care facilities in central New York State. SUBJECTS: Fifty-three patients selected randomly from each facility. MEASUREMENT: Data were collected from the medical record of each patient for a period of 6 months. A computerized algorithm was used to assess the risk for DNIs. Mean drug use, most frequently consumed drugs, incidence of potential DNIs, and the most commonly observed potential DNIs are reported. RESULTS: In facilities A, B, and C, respectively, patients consumed a mean of 4.86, 4.04, and 5.27 drugs per patient per month and were at risk for a mean of 1.43, 2.69, and 1.43 potential DNIs per patient per month. The most commonly observed potential DNIs were gastrointestinal interactions affecting drug bioavailability and interactions affecting electrolyte status. CONCLUSIONS: Patients in long-term-care facilities, who are primarily elderly and chronically ill and who consume multiple medications, are at notable risk for certain DNIs. Efforts need to be made to ensure appropriate pharmacologic and nutrition therapies as well as adequate and timely monitoring of patients in these facilities. Dietitians can play an important role in training other health professionals and in designing policies to prevent DNIs.

Prolonged breastfeeding without the introduction of supplementary feeding.

A study on the determinants of nutritional marasmus (NM) and kwashiorkor (K) was conducted using Sudanese children aged 6-36 months. The hypotheses tested were related to the specific circumstances leading to the development of NM and K. Subjects consisted of 55 children with NM and 55 with K, admitted to the Children's Emergency Hospital in Khartoum. This paper presents the results of the association between NM and prolonged breastfeeding without introduction of supplementary feeding between the ages of 6 and 24 months. Mothers were interviewed in hospital, and information on duration of breastfeeding, age at introduction of supplementary foods, and weaning foods was obtained. Observations were made in 20 per cent of homes of study children. The results suggest a positive association between prolonged breastfeeding without introduction of supplementary feeding between the ages of 6 and 24 months, and NM. Using multivariate analysis the data show that late introduction of supplementary foods produces an increase of 1.4-fold the odds of developing nutritional marasmus, rather than kwashiorkor. In contrast the odds ratio is 1.9 for the two conditions in terms of age of cessation of breastfeeding, the kwashiorkor children breastfeeding for fewer months. Results suggest strategies to reduce the prevalence of NM and K, plus mild and moderate PEM.

Medications and nutrition in the elderly.

Single drug and drug combinations taken by elderly individuals may impose nutritional risk. Nutritional risk induced by drug intake include anorexia, excessive increase in appetite, drug-induced nutritional deficiencies, and toxic reactions. Drug side effects, such as postural hypotension, may interfere with food shopping or cooking ability. Prescribed diets may also impose a risk of drug-induced side effects or diminished drug efficacy. Unwanted outcomes of drug-food and drug-nutrient interactions can be minimized by instructing elderly men and women and their caregivers to avoid timing errors in drug-taking behavior and toxic reactions due to food incompatibility. In addition, drug-induced nutritional deficiencies can be avoided by advising drug-taking elderly on the appropriate levels of nutrient intake.

Development and current status of home-delivered meals programs in the United States: are the right elderly served?

Federal home-delivered meals programs for the frail elderly began in the United States in the 1970s, and during the 1980s the provision of meals to the homebound elderly has been expanded through development of state-funded meals programs. The time has now come to pose two questions relative to coverage and program impacts. These questions are whether the program serves those who are currently most needy and whether the meals programs reduce the need for higher levels of care. Information available suggests that the elderly most served are those with socioeconomic problems that reduce their ability to obtain regular meals. Medical disability as a criterion for program eligibility or priority is less often used. The new finding that provision of home-delivered meals reduces hospitalization rates has to be re-examined, to ask the key question of whether the medically needy are actually kept out of the hospital by being provided with home-delivered meals.

The difference in food and nutrient intake between smokers and non-smokers in an elderly Chinese population in Beijing, China.

This study examined variations in dietary intake, which were associated with differences in education, lifestyle and health behaviours of elderly men and women (n=305) in Beijing Twenty-four-hour dietary recalls were obtained through in-home interview. Nutrient analyses of the reported diets were carried out using the Chinese nutrient database. It was found that more men than women smoked and that alcohol consumption was associated with smoking. Smokers had a lower intake of vitamin C (P<0.01), carotenoids (P<0.05) and calcium (P<0.05) than non-smokers in both genders. Female smokers also showed a lower intake of fruits, vegetables and milk compared with female non-smokers.

Home-delivered meals programs for the elderly: distribution of services in New York State.

This study examined the ability of six countywide home-delivered meals programs in upstate New York to meet the challenge of serving the elderly in geographically isolated and impoverished regions. The six counties were divided geographically into county subdivisions. For each subdivision, program client levels were analyzed in relation to two subdivision-level census statistics: poverty rates and population densities for community-residing individuals aged 65 years and older. Client levels were positively correlated with population densities but not with poverty rates. These findings suggest that service delivery was concentrated in densely populated regions. In contrast, impoverished and sparsely populated regions received minimal services.

Influence of fruit and vegetable juices on the endogenous formation of N-nitrosoproline and N-nitrosothiazolidine-4-carboxylic acid in humans on controlled diets.

Water, green pepper, pineapple, tomato, strawberry, carrot, and celery juices were made 46 mg/100 ml in ascorbic acid by the addition of distilled water or ascorbate. The ability of each juice to inhibit endogenous formation of N-nitrosoamino acids (NAA) in humans was determined in controlled experiments. Sixteen men consumed a standard diet low in nitrate and ascorbic acid for 18 consecutive days. Nitrate (5.24 mmol) and L-proline (4.35 mmol) were given orally on days 3, 5, 7, 9, 11, 13, 15, 17 and 18. On days 3 and 18, L-proline was immediately followed by 100 ml distilled water (positive control). On days 5, 7, 9, 11, 13, 15 and 17, L-proline was immediately followed by 100 ml juice or 46 mg ascorbate in 100 ml distilled water (treatment). Only diet was given in between dosing days to ensure baseline levels of NAA excretion. Urine was collected for 24 h following treatments and analyzed for NAA. Green pepper, pineapple, tomato, strawberry and carrot treatments significantly inhibited N-nitrosoproline (NPRO) formation relative to the positive control. Also, green pepper, pineapple and tomato juices significantly inhibited NPRO formation relative to ascorbic acid alone. Green pepper significantly inhibited N-nitrosothiazolidine-carboxylic acid formation relative to ascorbic acid alone. These data demonstrate that green pepper, tomato, pineapple, strawberry and carrot juice have greater ability to inhibit endogenous nitrosation than would be expected based solely on their ascorbate content.

Effect of beta-carotene supplementation on photosuppression of delayed-type hypersensitivity in normal young men.

The aim of this study was to examine whether beta-carotene protects against the immunosuppression seen with long-wave ultraviolet-light (UV-A) exposure. Free-living, healthy men, aged 19-39 y received 30 mg beta-carotene/d or a placebo while on a single-menu, low-carotenoid diet. After 28 d all subjects received 12 exposures to a UV-A/B light source over a 16-d period. The total UV-A dose received ranged from 15.9 to 19.3 J/cm2. The total shorter-wave ultraviolet-light (UV-B) dose varied from 1.59 to 1.96 J/cm2. Follow-up continued for 21 d. Carotenoid assays and delayed-type hypersensitivity (DTH) tests were performed at baseline, pre-UV, post-UV, and after follow-up. The DTH-test responses were significantly suppressed in the placebo group after UV treatments. The suppression was inversely related to plasma beta-carotene concentrations in this group. There was no significant suppression of DTH test responses in the beta-carotene group. It is concluded that beta-carotene protects against photosuppression of immune function.

Riboflavin requirements and exercise adaptation in older women.

The effects of exercise training on riboflavin requirements and of riboflavin intake on endurance were examined in 14 women, 50-67 y of age, who participated in a 10-wk, two-period crossover exercise study at two riboflavin intakes, 0.15 micrograms/kJ (0.6 micrograms/kcal) and 0.22 micrograms/kJ (0.9 micrograms/kcal). Subjects exercised 20-25 min/d, 6 d/wk, for 4-wk periods on a cycle ergometer at 75-85% of their maximal heart rate. Riboflavin status was assessed by measuring the erythrocyte glutathione reductase activity coefficient (EGRAC) and urinary riboflavin excretion. Physical performance was evaluated by using a walking treadmill test to determine maximal oxygen capacity (VO2max) and anaerobic threshold by gas exchange (ATGE). Exercise significantly affected riboflavin status as EGRAC increased (P less than 0.001) and riboflavin excretion decreased (P less than 0.01) in both groups. VO2max increased significantly with exercise (P less than 0.01). However, changes in VO2max (L/min) and ATGE with exercise training were not different in the two groups. Riboflavin requirements of older women increased with exercise training, but increased riboflavin intake did not enhance improvements in endurance.

Characteristics related to elderly persons' not eating for 1 or more days: implications for meal programs.

We examined how social, economic, location, health, and food need characteristics are related to elderly persons' not eating for 1 or more days. The following variables were positively related to not eating: ethnicity, location, receipt of Medicaid, living alone, health problems, mobility, age less than 80 years, cancer, nausea, difficulty swallowing, diarrhea, loss of appetite, and receipt of food from a food pantry. These results have implications for allocating meal program funds, screening clients, and monitoring whether clients eat regularly.