Dietary supplementation and immunocompetence in housebound elderly subjects.

Immune function, particularly cell-mediated immunity (CMI), declines with age and it has been suggested that this may be secondary to the impaired nutritional status often found in the elderly. In the present study a balanced nutritional supplement consisting of several macro- and micro-nutrients was administered daily to 27 housebound elderly (aged 70-85 years) for 12 weeks. Thirty-one matched subjects served as a control group. Delayed cutaneous hypersensitivity (DCH) to seven recall antigens was measured using the Mérieux Multitest CMI device and total numbers of lymphocytes, B-cells, T-cells and T-cell sub-populations were determined using monoclonal antibodies. These tests and several indices of nutritional status were measured before and at the end of the 12-week study. Before supplementation 19% of the entire group of subjects were anergic and another 19% hypoergic, values greater than expected for healthy elderly subjects. A weak association (P = 0.056) was shown between plasma zinc concentration and the number of positive skin test responses. Supplementation had minimal effect on DCH, resulting in a significant (P < 0.05) increase only in the sum of positive indurations. Pre-study numbers of total lymphocytes and lymphocyte sub-populations were as expected for healthy elderly subjects, but a correlation was found between plasma selenium concentrations (mean 1.07, range 0.64-1.66 mumol/l) and the numbers of CD4 lymphocytes (P < 0.01). Supplementation did not result in a significant change in any of the lymphocyte populations.(ABSTRACT TRUNCATED AT 250 WORDS)

Thiamine status of healthy and institutionalized elderly subjects: analysis of dietary intake and biochemical indices.

Thiamine status was assessed in healthy young and elderly subjects and institutionalized elderly patients by measuring dietary intake, erythrocyte levels of thiamine and the activity of the thiamine-dependent enzyme, erythrocyte transketolase, with and without the addition of excess thiamine pyrophosphate (the TPP effect). Healthy elderly subjects had a reduced intake of thiamine compared with the younger subjects but erythrocyte levels of thiamine and the TPP effect were comparable, suggesting adequate thiamine status. The institutionalized elderly patients had a low intake of thiamine compared with the healthy elderly as well as abnormal biochemical indices suggestive of suboptimal thiamine status. Thiamine deficiency does not appear to be a problem in healthy elderly people but those in institutions are at risk of deficiency which might adversely affect their clinical state.

Research review: studies in the nutrition of elderly people with particular reference to essential trace elements.

Duplicate diet analysis, metabolic balance studies and the measurement of biochemical and haematological indices were used to assess the trace element and overall nutritional status of 24 apparently healthy and 20 housebound elderly subjects. The housebound subjects had suboptimal status (as compared with the healthy subjects) for nitrogen, zinc, copper, iron, selenium, calcium and phosphorus.

Calcium, magnesium and phosphorus status of elderly inpatients: dietary intake, metabolic balance studies and biochemical status.

The calcium, magnesium and phosphorus status of a group of elderly inpatients was studied by use of duplicate meal analysis over a 5 d period and biochemical indices in twenty-one patients, and metabolic balance (5 d) in six of these. Mean daily Ca intake was lower than that of apparently healthy elderly subjects in metabolic equilibrium, although commensurate with present UK recommendations. Metabolic balance was negative for Ca. Mean daily Mg intake was approximately half the US recommendation, and half the intake at which metabolic balance has been observed in healthy elderly people. The five patients studied were in metabolic balance for Mg. Mean daily P intake was close to the UK recommendation, but negative metabolic balance was observed. The disparity between official recommendations for Ca-intake, factors contributing to suboptimal Ca status, and measures that may improve Ca status in this group are discussed.

Selenium and vitamin E status of healthy and institutionalized elderly subjects: analysis of plasma, erythrocytes and platelets.

Levels of selenium in whole blood, plasma, erythrocytes and platelets, glutathione peroxidase (EC 1.11.1.9; GSH-Px) activity in erythrocytes and platelets and vitamin E, low-density-lipoprotein (LDL)-cholesterol and vitamin E: LDL cholesterol in plasma were measured in seventy-five healthy subjects aged less than 65 years and twenty-eight healthy and twenty-three institutionalized elderly people aged greater than 65 years. Healthy elderly subjects had significantly lower levels of Se in whole blood and plasma when compared with younger subjects. Other measurements of Se status were not significantly different. In the healthy subjects plasma levels of vitamin E and LDL-cholesterol increased with age to 60 years and decreased above 80 years. Vitamin E: LDL cholesterol values were not affected by age. Measurements of Se and vitamin E status in the institutionalized elderly compared with the healthy elderly were all reduced with the exception of platelet Se levels and erythrocyte GSH-Px activity. Ageing per se had minimal effect on Se and vitamin E status but intercurrent illness and decreased food intake can lead to reduced levels in the elderly.

Blood selenium concentrations and glutathione peroxidase activity.

Selenium concentrations in children and teenagers without a metabolic disorder eating normal diets (group 1), and young patients with classical phenylketonuria and milder forms of hyperphenylalaninaemia being treated with a diet low in natural protein (group 2) were investigated. There was a strong correlation between blood selenium concentration and age in children in group 1 up to 10 years of age. Blood selenium concentrations and glutathione peroxidase activities were significantly lower in the patients who were receiving diets containing reduced amounts of natural protein, and the differences were more than would be expected for age. When the concentrations of selenium in blood from groups 1 and 2 were compared with glutathione peroxidase activity, a strong association was found when blood selenium concentrations were below 1.26 mumol/l. Reduction in glutathione peroxidase activity may be harmful in the long term, and the addition of selenium to therapeutic diets is recommended.

Iron status of hospitalized and housebound elderly people: dietary intake, metabolic balances, haematological and biochemical indices.

The iron status of housebound and hospitalized elderly people was studied by duplicate diet analysis, metabolic balance, biochemical and haematological investigations. Evidence of biochemical iron deficiency in the hospital group was accompanied by low dietary intake and negative metabolic balance. Metabolic equilibrium in the housebound group was seen with intakes similar to those found in healthy elderly though biochemical measures suggested a borderline iron deficient state.

The effect on atopic dermatitis of supplementation with selenium and vitamin E.

Reduced concentrations of selenium in whole blood, plasma and white cells and reduced activity of selenium-dependent glutathione peroxidase in red cells have been found in atopic dermatitis. To determine the effect of selenium supplementation on this disease, the normal daily diet of 60 adults with atopic dermatitis was supplemented with selenium-enriched yeast for 12 weeks in a randomised double-blind study. Group 1 took 600 micrograms of selenium alone, Group 2 600 micrograms of selenium plus 600 IU of vitamin E and Group 3 a placebo. After 12 weeks, there was a significant increase in the concentration of selenium in whole blood and the activity of selenium dependent glutathione peroxidase in platelets in Groups 1 and 2 and the concentration of vitamin E in plasma in Group 2. There was no significant difference between the three Groups in the severity of the eczema or the concentration of selenium either before or after the 12 weeks of supplementation. The results suggest that although selenium-enriched yeast supplement was absorbed and bioavailable it does not enter the skin or produces a worthwhile improvement in atopic dermatitis.

The effect of supplementation with selenium and vitamin E in psoriasis.

Since reduced concentrations of selenium in whole blood, plasma and white cells had previously been observed in psoriasis, 69 patients were supplemented daily with either 600 micrograms of selenium-enriched yeast, 600 micrograms of selenium-enriched yeast plus 600 IU of vitamin E or a placebo for 12 weeks. Before supplementation, the patients' mean concentrations of selenium in whole blood and plasma were reduced compared with those of matched healthy controls but their red cell glutathione peroxidase (GSH-Px) activity was normal. After 12 weeks supplementation the patients' mean whole blood, plasma and platelet selenium concentrations, platelet GSH-Px activity and plasma vitamin E concentration had risen significantly from the baseline values but their mean skin selenium concentration and red cell GSH-Px activity remained unchanged. The mean white cell selenium concentration rose only in the group receiving selenium alone. Neither supplementation regimen reduced the severity of psoriasis or produced side-effects. The increase in platelet GSH-Px activity suggests that the supplements were bioavailable and that the patients' selenium status may have been reduced prior to supplementation. The failure of the selenium content of the skin to increase may explain why the patients' psoriasis remained unchanged during supplementation.

The relationship between blood lead, blood pressure, stroke, and heart attacks in middle-aged British men.

The relationship between blood lead concentration and blood pressure is examined in a survey of 7371 men aged 40 to 59 from 24 British towns. After allowance for relevant confounding variables, including town of residence and alcohol consumption, there exists a very weak but statistically significant positive association between blood lead and both systolic and diastolic blood pressure. These cross-sectional data indicate that an estimated mean increase of 1.45 mm Hg in systolic blood pressure occurs for every doubling of blood lead concentration with a 95% confidence interval of 0.47 to 2.43 mm Hg. After 6 years of follow-up, 316 of these men had major ischemic heart disease, and 66 had a stroke. After allowance for the confounding effects of cigarette smoking and town of residence there is no evidence that blood lead is a risk factor for these cardiovascular events. However, as the blood lead-blood pressure association is so weak, it is unlikely that any consequent association between lead and cardiovascular disease could be demonstrated from prospective epidemiological studies. An overview of data from this and other large epidemiological surveys provides reasonably consistent evidence on lead and blood pressure. While NHANES II data on 2254 U.S. men indicate a slightly stronger association between blood lead and systolic blood pressure, data from two Welsh studies on over 2000 men did not show a statistically significant association. However, the overlapping confidence limits for all these studies suggest that there may be a weak positive statistical association whereby systolic blood pressure is increased by about 1 mm Hg for every doubling of blood lead concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood cadmium concentrations in the general population of British middle-aged men.

Blood cadmium concentrations were determined for 6919 men aged 40-59 randomly selected from general practice registers in 24 British towns. The mean and median blood cadmium were 1.9 and 1.4 micrograms/1 respectively and the distribution was highly skewed. The mean levels in non-smokers was 1.0 micrograms/l and current smokers showed a marked gradient with the daily amount smoked, with a mean of 3.9 micrograms/l in men smoking 40 or more cigarettes per day. Whereas 95% of men who never smoked had blood cadmium less than 2.0 micrograms/l, 80% of men smoking 20 or more cigarettes a day exceeded this figure. 1% of the men had blood cadmium concentrations greater than or equal to 7 micrograms/l virtually all of whom currently smoked cigarettes. Blood cadmium levels in ex-smokers were much lower than in current smokers even for those who had stopped within the past year. However, the mean levels in ex-smokers remained higher than the 'never smoked' for several years after stopping. There was little evidence that age, social class, or alcohol consumption were associated with blood cadmium levels after allowance for cigarette smoking. There is substantial geographic variation in mean blood cadmium for middle-aged men which could not be completely accounted for by smoking differences. Towns in the south and east of England all had mean levels under 2.0 micrograms/l whereas the majority of towns in other parts of Britain had mean levels greater than 2.0 micrograms/l. Possible reasons for this geographic pattern (e.g. geochemistry, industrial exposure, dietary differences) need further exploration.

Selenium balance studies in apparently healthy and housebound elderly people eating self-selected diets.

1. Metabolic balance studies (5 d) for Se were conducted in twenty-four apparently healthy elderly people (age 69.6-85.4 years), and twenty housebound subjects (age 69.9-85.1 years) with chronic disease. During the study the subjects lived in their own homes, ate self-selected diets and continued their normal daily activities. 2. Geometric mean daily dietary intakes of the two groups were significantly different (P less than 0.01), being 819 (range 310-1631) nmol for the healthy and 475 (range 233-1136) nmol for the housebound elderly. 3. Daily intake of Se significantly correlated with balance in both groups. Solution of the regression equations gave theoretical daily requirements of 447 nmol for the healthy and 419 nmol for the housebound subjects. The healthy elderly were in positive balance of 148 nmol/d for Se and the housebound were in equilibrium with an overall mean retention of 43 nmol/d. 4. Mean levels of Se in blood fractions for the healthy and housebound subjects were significantly different, being 1.65 and 1.40 mumol/l whole blood, 1.45 and 1.21 mumol/l plasma and 5.72 and 5.30 nmol/g haemoglobin in erythrocytes respectively. There was no difference in the whole-blood glutathione peroxidase (EC 1.11.1.9) activities between the two groups. 5. There were clear differences in Se status between the two groups of elderly people. The cause of the positive balance in the healthy subjects remains unexplained.

Energy, protein, zinc and copper status of twenty-one elderly inpatients: analysed dietary intake and biochemical indices.

1. Duplicate diet analysis for energy, protein, zinc and copper with estimates of biochemical status for Zn and Cu were undertaken in twenty-one elderly long-stay inpatients (mean age 82 (range 63-89) years) consuming their customary hospital diet and in a stable medical condition. Fourteen patients had a long-standing and significant healing problem, either a leg ulcer or pressure sore. 2. Mean daily intakes of energy (5.2 MJ), protein (45 g), Zn (85 mumol) and Cu (14 mumol) were low in comparison with both official recommendations and levels of intake at which metabolic equilibrium was observed in healthy elderly people studied by the same methods (Bunker et al. 1984a). 3. Mean leucocyte Zn (9 pmol/10(6) cells) and Cu (7.5 pmol/10(6) cells) were low in comparison with results from healthy elderly people (Bunker et al. 1984a), implying suboptimal status for these elements. Those patients with healing problems tended to have the lower values within the range. 4. Recommendations are made with respect to improving nutritional status in this disadvantaged group of people.

Metabolic balance studies for zinc and copper in housebound elderly people and the relationship between zinc balance and leukocyte zinc concentrations.

Five-day metabolic balance studies for zinc and copper were carried out in 20 housebound elderly people with stable chronic diseases. Subjects were age 70.0-85.1 y, lived in their own homes, and ate self-selected diets. Mean daily intakes for Zn and Cu were 90 mumol and 13.4 mumol with mean negative balances of -16 and -1.1 mumol, respectively. Both balance values significantly differed from equilibrium (p less than 0.05). For Zn and Cu, respectively, mean concentrations were 11.3 and 22.1 mumol/L plasma, 103 and 19.4 mumol/L whole blood, and 98 and 8.7 pmol/10(6) leukocytes. The results for Zn and Cu balance and leukocyte concentrations were different from those obtained by us for healthy elderly people (Am J Clin Nutr 1984;40: 1096-120). A highly significant (r = 0.75, p less than 0.001) correlation was observed between zinc balance and leukocyte zinc concentrations.

Nitrogen balance studies in apparently healthy elderly people and those who are housebound.

Metabolic balance studies (5 d) for nitrogen were carried out in twenty-four apparently healthy elderly people (age 69.7-85.6 years) and a heterogeneous group of twenty housebound elderly people (age 69.9-85.1 years) with chronic diseases. During the study all subjects ate self-selected diets, lived in their own homes and continued their normal daily activities. Seven of the housebound received meals-on-wheels 5 d/week. Healthy men and women had mean metabolizable energy intakes of 8.7 and 6.6 MJ/d respectively compared with 6.3 and 4.8 MJ/d in the housebound. The average energy content of the meals-on-wheels as delivered was 2.4 MJ per meal, of which 2.1 MJ were consumed. The healthy men and women had average daily protein intakes of 69.4 and 59.7 g respectively compared with 46.3 and 39.1 g in the housebound. Meals-on-wheels as supplied provided 19.4 g protein per meal, of which 16.2 g were consumed. Healthy subjects were in equilibrium for N balance (0 mmol/d) with a daily intake of 733 mmol, which was equivalent to 11.04 mmol N (0.97 g mixed protein)/kg body-weight per d. Housebound individuals were in negative N balance (-95 mmol/d) with an intake of 475 mmol/d, corresponding to 7.59 mmol N (0.67 g mixed protein)/kg body-weight per d. We were unable to determine in the present study whether the negative N balance observed in the housebound people was due to the relatively low N intake or the underlying disease condition.

The trace element content of hospital meals and potential low intake by elderly patients.

The metabolizable energy, protein, calcium, phosphorus, magnesium, zinc, copper, iron and manganese contents of a typical day's menu offered to patients in a teaching hospital were analysed. Results obtained were compared with the appropriate UK Recommended Daily Amounts (RDA), or where no British standards were available, American Recommended Daily Dietary Allowances (RDDA) for magnesium, phosphorus and zinc and American Estimated Safe and Adequate Dietary Intakes (ESADI) for copper and manganese. Patients on an acute geriatric ward selected meals, which, even if consumed entirely, provided approximately half the daily recommended dietary allowances for zinc and copper, less than the recommended daily amounts for iron and magnesium, but more than adequate content of energy, protein, calcium, phosphorus and manganese.

The trace element and macronutrient content of meals-on-wheels.

The trace element and macronutrient contents of 35 different meals-on-wheels received by seven housebound elderly people have been analysed. The contribution these meals made to the existing Recommended Daily Allowance or the Safe and Adequate Dietary Intake as well as the overall daily nutrient intake was assessed. In general the meals provided adequate amounts of energy, protein, calcium, phosphorus, potassium and iron. Levels of magnesium, manganese, copper, chromium and zinc were low in comparison with some recommended intakes. In addition the meals appeared to contain a relatively high level of sodium. Recommendations for the nutrient content of meals-on-wheels have been made.