Vitamin A and E intakes and plasma concentrations of retinol, beta-carotene, and alpha-tocopherol in men and women of the Baltimore Longitudinal Study of Aging.

Antioxidants have been linked to protection against degenerative diseases associated with aging. Plasma concentrations were determined for and 7-d diet records collected from 200 women and 231 men aged 20-95 y who took part in the Baltimore Longitudinal Study of Aging. Men consumed more vitamin A from animal and less from vegetable sources than did women. These sex differences are reflected in plasma concentrations of retinol and beta-carotene. About 20% of subjects had vitamin A intakes less than recommended dietary allowances; however, no men and only two women had marginal plasma retinol (< 0.35 mumol/L) concentrations. Older people had higher plasma alpha-tocopherol, which correlated with total intake. Forty-two men and 35 women had plasma alpha-tocopherol concentrations that were considered marginal. Sex differences in sources of dietary and plasma vitamin A may have consequences in relation to aging and longevity. Apparent marginal intakes and plasma concentrations of vitamin E need to be further examined to determine effects on health status.

Diets containing soluble oat extracts improve glucose and insulin responses of moderately hypercholesterolemic men and women.

The high amount of soluble beta-glucans in oats may be responsible for beneficial effects on glucose tolerance and blood lipids. We studied 16 women and 7 men (aged 38-61y) with moderately high cholesterol concentrations who consumed normal diets to which oat extracts with either 1% or 10% soluble beta-glucans were added. Oat extracts comprised 10% of energy and were consumed in a 5-wk crossover design after a 1-wk equilibration period. At the end of the equilibration period and each 5-wk period, a carbohydrate tolerance test was conducted and responses to glucose, glucose plus oat extract containing 1% glucan, or glucose plus oat extract containing 10% glucan were determined. Glucose responses were reduced by both extracts in both men and women; however, in women, responses to the 10% extract were lowest. Insulin responses did not differ between men and women, but were lower after oat extracts. Glucagon responses were higher initially in men and were lowered after oat extracts in men but not in women. Modest amounts of oat extracts can be incorporated into normal diets with beneficial effects on glucose tolerance factors.

Insulin and glucose responses in rats fed sucrose or starch.

Rats fed 54% sucrose for 11 to 13 weeks ad libitum or 5 weeks ad libitum followed by 6 to 8 weeks of meal feeding had significantly higher serum insulin, glucose, and triglyceride levels than rats fed comparable amounts of starch after 12 to 14 hr without food. The serum insulin response measured before, 1/2, and 4 hr after a meal showed insulin levels of sucrose-fed rats to be higher than comparable levels of rats fed starch at all three times. An intraperitoneal glucose tolerance test measuring serum glucose before, 1/2, 2, and 2 hr after a glucose injection revealed glucose levels of rats fed sucrose to be higher than levels of rats fed starch. When insulin was added to the injection medium, serum glucose of rats fed sucrose remained higher than comparable levels of rats fed starch indicating insulin insensitivity. Meal feeding generally resulted in higher insulin and triglyceride levels than in rats fed ad libitum but had little effect on glucose levels. These results are clear evidence that sucrose feeding has undesirable effects on glucose tolerance.

Blood lipid distribution of hyperinsulinemic men consuming three levels of fructose.

Twelve carbohydrate-sensitive men selected due to their abnormally high insulin responses to a sucrose load and 12 men with normal insulin responses were fed diets containing 0, 7.5, and 15% fructose for 5 wk each in a cross-over design. The diets contained 43% total carbohydrate, 42% fat, and 15% protein. Initial fasting total cholesterol and low-density lipoprotein cholesterol were higher in the hyperinsulinemic men than in the controls. Diastolic blood pressure was not affected by diet, but systolic blood pressure was slightly higher after the men consumed the 0% fructose diet. Free fatty acids were not different. Total plasma cholesterol and low-density lipoprotein cholesterol were higher after the men consumed 7.5 and 15% fructose than when they consumed the 0% fructose diet. Plasma triglyceride increased significantly as fructose in the diets of the hyperinsulinemics increased, but was not affected in the controls. These changes in blood lipids are associated with heart disease.

Moderate diet control in children: the effects on metabolic indicators that predict obesity-related degenerative diseases.

Nine prepubertal obese boys ages 9 1/2 to 12 yr followed moderately restricted diets and moderate exercise routine for 31 wk. Foods were selected from the family's basic diet and the physical activities were tailored to the home environment. This dietary (approximate decrease of 600 kcal/day) and activity (approximate increase of 300 kcal/day) intervention program was sufficient to stop weight gain and normalize key metabolic indices for prediction of atherosclerosis, hypertension, and diabetes. Throughout the treatment period serum lipid responses included significantly lower (p less than 0.05) total cholesterol, low-density lipoprotein-cholesterol and triglycerides. High-density lipoprotein-cholesterol was constant throughout the period. Responses in carbohydrate metabolism included significantly lower (p less than 0.05) fasting insulin and glucose. Insulin and glucose levels were positively correlated with total caloric consumption and insulin was also positively correlated with sucrose consumption (p less than 0.05). Fasting insulin/glucose ratios and glycosylated Hb decreased throughout the treatment period, but serum glucagon levels remained constant. In response to a glucose load, insulin and glucose decreased significantly by wk 31 of treatment. A practical approach for normalizing metabolism in obese male children is presented.

High plasma vitamin C associated with high plasma HDL- and HDL2 cholesterol.

High plasma vitamin C may lower risk of cardiovascular disease as indicated by direct association with plasma high-density-lipoprotein (HDL) cholesterol and HDL2 cholesterol. Plasma lipids and vitamin C were determined in 316 women and 511 men (aged 19-95 y). After adjustment for age, sex, obesity, and smoking, plasma vitamin C was directly associated with HDL- (P = 0.01) and HDL2 cholesterol (P = 0.0002). When men and women with diseases that might affect lipids were excluded, associations between plasma vitamin C and HDL- and HDL2 cholesterol persisted, though the relationships were strongest in older men. Comparisons of diets in a subset (n = 485) who completed 7-d diet records were made. Total fat, saturated fatty acids, energy from fat, and cholesterol intakes were not associated with plasma vitamin C. Mean intakes of vitamin C were well above recommended dietary allowances. These findings suggest that high plasma concentrations of vitamin C may lower atherogenic risk.

Isocaloric exchange of dietary starch and sucrose in humans. I. Effects on levels of fasting blood lipids.

For 6 weeks, 10 men and nine women aged 35 to 55 consumed each of two diets in a cross-over design. The diets were comprised of identical natural foods with 30% of the calories as either sucrose or cooked wheat starch. Carbohydrate, fat and protein supplied 43, 42, and 15% of the calories, respectively. Of the calories 10% were eaten at breakfast (7:00 to 8:30 AM) and 90% at dinner (4:30 to 6:30 PM). Initial body weights were essentially maintained. Total serum lipids, triglycerides, and total cholesterol levels were significantly higher when the subjects consumed the sucrose diet than when they consumed the starch diet. Increases associated with the sucrose diet were greatest for triglycerides (33.0%). In a subgroup of nine subjects with triglyceride levels above the normal range, sucrose feeding increased triglyceride levels 45.2%. Triglycerides and pre-beta lipoproteins were significantly higher in males than in females. Pre-beta lipoproteins were 32% higher when the subjects consumed sucrose than when they consumed starch. For alpha and beta lipoproteins, small, nonsignificant increases were associated with sucrose feeding. Serum free fatty acids were not affected by diet. These results indicate that the consumption of sucrose can increase blood lipids that are considered to be risk factors in heart disease and that males and carbohydrate-sensitive individuals may be more susceptible than others to the effects of sucrose.

Effects of sugars on indices of glucose tolerance in humans.

Ten men and nine women were studied to determine whether replacement of utilizable complex carbohydrate by sugars (mono- and disaccharides) in a high-fiber, low-saturated fat diet would affect indices of glucose tolerance. Diets differed in that the 50% of calories derived from carbohydrate was either 35% complex and 15% sugars (low-sugar) on 15% complex and 35% sugars (high-sugar). Summation of glucose responses 30-180 min following an oral glucose tolerance test was significantly higher in men, but not women, after they consumed the high-sugar diet. Corresponding insulin responses were significantly higher in men consuming the high-sugar compared to the low-sugar diet. Insulin binding was significantly lower during the base line period and after the high-sugar diet compared to the low-sugar diet. Results indicate that sugars adversely affect indices of glucose tolerance when they replace complex carbohydrates even in a high-fiber, low-saturated fat diet.

Serum insulin and glucose in hyperinsulinemic subjects fed three different levels of sucrose.

Twenty-four adult men and women, classified as carbohydrate-sensitive on the basis of an exaggerated insulin response to a sucrose load, consumed diets containing 5, 18, and 33% of calories as sucrose for 6 wk each in a cross-over design. The diets contained identical natural and processed foods except for a patty containing 2, 15, or 30% of the calories as sucrose at the expense of wheat starch. Carbohydrate, fat, and protein provided 44, 42, and 14% of the calories, respectively. Of total calories, 25% were consumed at breakfast and 75% at dinner. Initial body weights of the subjects were essentially maintained. Fasting serum insulin levels increased with the sucrose content of the diet and were significantly higher in men than in women. Mean fasting glucose was significantly higher on either 18 or 33% sucrose than on 5% sucrose. The sucrose content of the diet did not affect fasting serum glucagon. When compared to the insulin response to a sucrose load (2 g/kg body weight) after consuming the 5% sucrose diet, serum insulin was significantly higher at 1 h after the 18% sucrose diet and at 0.5, 1, 2, and 3 h after the 33% sucrose diet. Except after 2 h, the glucose response was significantly greater after the 18 and 33% sucrose diets than after the 5% sucrose diet. These results indicate that sucrose intake by carbohydrate-sensitive individuals, even at levels approximating the average United States intake, can produce undesirable changes in several parameters associated with glucose tolerance.

Seasonal variation in plasma glucose and hormone levels in adult men and women.

Twenty-nine men and women collected diet records for 1 yr. Fasting blood samples were collected four times during the year so that each season of the year was represented. An oral glucose tolerance test was given in the spring and in the fall. Regardless of season men consumed significantly more kilocalories, carbohydrate, sugar, and starch than did the women. Men consumed more simple sugars in the fall than in the spring. No seasonal effect was observed for calories, total carbohydrate, or starch intake. Fasting glucose and insulin were higher in the fall than in the spring. Summed insulin levels after the oral glucose tolerance were significantly different by age and season. Summed insulin levels were significantly higher in older than younger subjects; men and older subjects had higher levels in the spring than in the fall. Fasting levels of thyroxine, free thyroxine, triiodothyronine, and glucagon varied significantly with the season. A significant sex by season interaction was observed in the thyroid hormones. It appears that seasonal variation as well as diurnal variation should be considered in evaluating hormone levels.

What are people really eating? The relation between energy intake derived from estimated diet records and intake determined to maintain body weight.

Two hundred sixty-six free-living human volunteers, 21-64 y old, were trained by dietitians to record daily their food intake for at least 7 d. Subsequently, they were fed diets of conventional foods adjusted in amounts to maintain their body weight for greater than or equal to 45 d. Comparing their estimated energy intake with the intake determined to maintain weight yielded mean differences of 2365 and 1792 kJ (565 and 428 kcal) in men and women, respectively, representing an underreporting of 18%. Twenty-two individuals (8%) overestimated and 29 (11%) were accurate to within 419 kJ (100 kcal) of their maintenance requirement. The remaining 215 individuals (81%) reported their habitual intake at 2930 +/- 1586 kJ (700 +/- 379 kcal) below that subsequently determined as their maintenance requirement. These findings suggest caution in the interpretation of food-consumption data.

Isocaloric exchange of dietary starch and sucrose in humans. II. Effect on fasting blood insulin, glucose, and glucagon and on insulin and glucose response to a sucrose load.

Ten men and nine women ages 35 to 55 consumed two diets for 6 weeks each in a cross-over design. The diets were composed of identical natural foods and 30% of the calories as either sucrose or wheat starch. Carbohydrate, fat, and protein supplied 43, 42, and 15% of the calories, respectively. Of the calories 10% was eaten at breakfast (7:00 to 8:30 AM) and 90% at dinner (4:30 to 6:30 PM). Inital body weights were essentially maintained. Fasting serum insulin and glucose levels were significantly higher with the sucrose than with the starch diet. The insulin response and the insulin:glucose ratios after a sucrose load (2 g/kg body weight) were greater after the subjects consumed the sucrose diet. Sucrose feeding produced increases in fasting serum insulin, the insulin:glucose ratio and the insulin response to a sucrose load that were of greater magnitude in a subgroup of nine subjects classified as potentially carbohydrate-sensitive than in normal subjects. Glucose response to a sucrose load and fasting serum glucagon did not differ significantly with diet. Fasting insulin and glucose showed significant increases as a function of time on diet. These results indicate that sucrose feeding produces undersirable changes in several of the parameters associated with glucose tolerance.

Modification of the United States' diet to effect changes in blood lipids and lipoprotein distribution.

Twenty men, 19 premenopausal and 14 postmenopausal women consumed a diet for 13 weeks that supplied 35% of the calories from fat, 50% from carbohydrate, and 15% from protein. The diet was low in cholesterol, saturated fat, and salt, and high in complex carbohydrate and fiber. The 7-day menu was composed of common well-accepted foods prepared in a simple attractive manner. Plasma total cholesterol, LDL cholesterol, and VLDL cholesterol were reduced, but triglyceride levels were not different than after self-selected diets. When 20% of the complex carbohydrate was replaced by simple carbohydrate and other diet components remained optimal, triglyceride and VLDL cholesterol levels increased in men and premenopausal women and total cholesterol increased in premenopausal women. These results suggest that beneficial effects on the blood lipids and lipoprotein distribution of men and women may be obtained by minimal modification of a typical U.S. diet.

Does diet provide adequate amounts of calcium, iron, magnesium, and zinc in a well-educated adult population?

Standard advice from dietitians, nutritionists, and physicians is that if one eats a well-balanced diet containing a variety of foods, supplements are not necessary. Little information is available, especially in those over 75, to determine whether actual diets do provide adequate amounts of these minerals. The participants of the Baltimore Longitudinal Study of Aging provide seven-day records which include vitamin and mineral supplement intakes. Median daily dietary intakes from diet in all 564 subjects and from diet plus supplements in those who use them were analyzed by age group and gender. More women than men took supplements. Median intakes of calcium from diet were below the recommended dietary allowance (RDA) for unsupplemented women and for supplemented women over 60. Approximately 25% of women under 50 and 10% of women over 50 consumed less than two thirds of the RDA for iron from diet. For both men and women, all groups had median diet intakes below the RDA for magnesium. Forty percent of men and about half of women consumed less than two thirds of the RDA. These results indicate that many people in this well-educated, presumably well-nourished population did not consume adequate amounts of calcium, iron, magnesium, and zinc from diet. More women than men are at risk. Even those taking supplements did not consume adequate levels of some minerals.

The importance of dietary protein in healing pressure ulcers.

OBJECTIVE: To determine the effect of dietary protein on healing of pressure ulcers in malnourished patients. DESIGN: Nutritional intervention trial with the non-randomized assignment of patients by pressure ulcer stage and bed type. SETTING: Long-term care facility. PATIENTS: Twenty-eight malnourished patients (age = 72 +/- 18 years, mean +/- SD) with a total of 33 truncal pressure ulcers. Nine patients had stage II ulcers, eight had stage III ulcers, and 16 had stage IV ulcers. METHODS: Patients received liquid nutritional formulas as tubefeedings or meal supplements containing either 24% protein (61 g protein/L; n = 15) or 14% protein (37 g protein/L; n = 13) for 8 weeks. RESULTS: There was a significant decrease in total truncal pressure ulcer surface area of the 15 patients in the 24% protein group (-4.2 +/- 7.1 cm2, P < 0.02), but not in the 13 patients in the 14% protein group (-2.1 +/- 11.5 cm2, P = NS). The change in total ulcer area correlated with both dietary protein intake per kg body weight (rs = -0.50, P < 0.01) and caloric intake per kg body weight (rs = -0.41, P < 0.03). The decrease in stage IV ulcer area in eight patients in the 24% protein group (-7.6 +/- 5.8 cm2, P < 0.02) was significantly greater (P < 0.05) than in eight patients in the 14% protein group (-3.2 +/- 16.4, P = NS). In these 16 patients, the decrease in ulcer size also correlated with dietary protein intake per kg body weight (rs = -0.63, P < 0.01). CONCLUSION: High protein diets may improve the healing of pressure ulcers in malnourished nursing home patients.

Are antioxidants or supplements protective for age-related macular degeneration?

OBJECTIVES: The relationships between fasting plasma levels of retinol, ascorbic acid, alpha-tochopherol, and beta-carotene and age-related macular degeneration (AMD) were studied in a population enrolled in the Baltimore Longitudinal Study of Aging (BLSA), in which most of the data were collected 2 or more years before assessment of macular status. DESIGN: A total of 976 participants in the study were scheduled for a biennial examination from January 1988 through January 1, 1990, which included taking lens and macular photographs. A total of 827 (85%) of the participants had fundus photographs taken, and most plasma data were available for 82% of those subjects with fundus photographs. Age-related macular degeneration was defined as neovascular changes, geographic and nongeographic atrophy, large or confluent drusen, or hyperpigmentation. A total of 226 cases of AMD were available for analysis. RESULTS: Logistic regression analyses suggested that alpha-tocopherol was associated with a protective effect for AMD, adjusted for age, sex, and nuclear opacity. An antioxidant index, including ascorbic acid, alpha-tocopherol, and beta-carotene, was also protective for AMD. Our conclusions must be tempered with the knowledge that the population under study was basically well nourished, and few individuals had any clinically deficient status. The study cannot exclude the possibility that quite low levels of micronutrients, lower than those observed in this study, might be risk factors for AMD. CONCLUSIONS: The data suggest a protective effect for AMD of high plasma values of alpha-tocopherol. An antioxidant index, composed of plasma ascorbic acid, alpha-tocopherol, and beta-carotene, was also protective. The use of vitamin supplements to prevent AMD is not supported by these data, which showed no protective effect of vitamin use.

Bone-related mineral content of water samples collected on the Navajo reservation.

Although dairy food intake is low among the Navajo people, hip fracture rates are lower than in Caucasians. Genetic differences in bone density have been cited as the reasons for low fracture rates among Native Americans and other segments of the population. However, more detailed examination of mineral intakes suggests that environmental factors may provide part of the explanation for the lower fracture rates. Cultural practices such as the addition of ash to traditional foods and the high mineral content of water may provide much higher intakes of bone-related minerals than food intake surveys have previously reported. As part of a larger study to assess overall intake of minerals related to bone health and other conditions, water samples were collected from the Navajo reservation. Duplicates were collected at least one week apart from 53 sites including wells, springs, taps, and storage barrels and analyzed by atomic absorption and inductively coupled plasma spectrometry for a number of minerals. For average intakes of 2 l/day, water could provide up to 212 mg of calcium, 150 mg of magnesium and 8 mg of zinc. The combined contribution of mineral intakes provided by the addition of juniper ash to traditional foods, not genetic differences, may partially explain the lower fracture rates of the Navajo people. Further research in this area is required to confirm this hypothesis.

Acceptability of a 7-day higher-carbohydrate, lower-fat menu: the Beltsville Diet study.

For 13 weeks, 20 men (aged 23 to 56), 19 premenopausal (aged 21 to 48), and 14 postmenopausal women (aged 49 to 65) consumed a 7-day rotation menu conforming to dietary recommendations of several research and health organizations. The diets were designed to make minimal changes in the standard American diet by the use of well-accepted normal foods. The average daily composition of the diet was 50% carbohydrate (complex 35%, simple 15%), 35% fat (P:S 0.7), and 15% protein; it contained 100 mg cholesterol, 1 gm sodium, and 14.5 gm neutral detergent fiber per 1,000 kcal. The acceptability of the menus was examined through questionnaires administered after the experimental diet period. Subjects rated the menus and individual foods and made recommendations for improvement of the menus. Most subjects (33 of 41 responding) rated the menu better than or almost as good as their usual diet. Few (9) were ever hungry during the 13-week period. During the study, a number of biochemical parameters were measured; the measurements indicated beneficial results. Blood pressure, cholesterol levels, and glucose responses were all improved after consumption of the menu. The results indicate that with minimal changes in the normal U.S. diet, acceptable menus that have beneficial effects on risk factors for heart disease and diabetes can be developed.

Plasma glucose and insulin reduction after consumption of breads varying in amylose content.

OBJECTIVE: Consumption of a meal high in amylose starch (70%) decreases peak insulin and glucose levels and area under the curve (AUC). The objective was to determine the amount of amylose necessary in a meal for the beneficial decrease in glucose or insulin to occur. DESIGN: Twenty-five subjects, 13 men (averaging 88.1 kg, 41 y, and 27.9 body mass index) and 12 women (averaging 72.4 kg, 41 y and 27.1 body mass index) were given six tolerance tests in a Latin Square design: glucose alone (1 g glucose/kg body weight) and five breads (1 g carbohydrate/kg body weight) made with 70% amylose cornstarch, standard cornstarch (30% amylose), and blends of the two starches (40, 50 and 60% amylose starch). A standard menu was fed for 3 days. One subject withdrew from the study. RESULTS: Glucose, insulin and glucagon response to the carbohydrate loads was similar in men and women. Peak glucose response was lowest after the breads containing 50-70% amylose starch. AUC was significantly higher after the glucose load than after all bread loads. The lowest AUCs occurred after the 60 and 70% amylose starch breads. Insulin response and AUC were significantly lower after the 60 and 70% amylose starch breads than after the glucose or the other breads. CONCLUSION: Results indicate that the amylose content of the starch used in the acute meal needs to be greater than 50% to significantly reduce plasma glucose and insulin in men and women.

Malnutrition in tubefed nursing home patients with pressure sores.

This study compares the nutritional status and dietary intake of 14 tubefed nursing home patients with pressure sores (age: 70 +/- 5 years, mean +/- SEM) to 12 tubefed patient-controls without sores (age: 60 +/- 7 years). Patients tended to have higher calorie intake (32 +/- 3 kcal/kg) than patient-controls (26 +/- 2 kcal/kg, p = 0.11). Protein intake was significantly higher in patients (1.4 +/- 0.2 g/kg) than patient-controls (0.9 +/- 0.1 g of protein per kg, p less than 0.05). Despite increased calorie and protein intake, biochemical measures of nutritional status were worse in the patients. Serum albumin was lower in patients (33 +/- 1 g/L) than in patient-controls (37 +/- 1 g/L, p less than 0.05) as was level of hemoglobin (patients: 117 +/- 5; patient-controls: 132 +/- 5 g/L, p less than 0.05). Patients with stage IV (severe) sores had lower serum cholesterol levels (3.46 +/- 0.31 mmol/L, n = 5) than patients with stage II/III (milder) sores (4.58 +/- 0.23 mmol/L, n = 9, p less than 0.05). Plasma zinc was low in both patients (11.2 +/- 0.6 mumol/L) and patient-controls (11.5 +/- 0.7 mumol/L, p = NS). Pressure sore surface area was positively correlated with calorie intake per kilogram of body weight (r = +0.59, p less than 0.04) and negatively correlated with body mass index (r = -0.70, p less than 0.03), hemoglobin (r = -0.55, p less than 0.07) and serum cholesterol (r = -0.57, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)