Vitamin C intake and apolipoproteins in a healthy elderly Japanese population

BACKGROUND: Adequate vitamin C (AsA) intake may lower the risk of arteriosclerotic cardiovascular disease, but little is known about its influence on the progression of atherogenic disease in the elderly. METHODS: We examined whether AsA intake was associated with serum lipids, apolipoprotein A-1 (ApoA1) and apolipoprotein B (ApoB), in 680 Japanese elderly persons. RESULTS: There were no significant gender differences among mean serum lipids and apolipoprotein concentrations and intakes of macronutrients. AsA intake had a significant positive association with serum concentrations of high-density cholesterol and ApoA1, but an inverse association with serum concentrations of low-density cholesterol and ApoB, after adjusting for age, body mass index, total energy, and macronutrients. AsA intake was strongly inversely related to ApoA1/ApoB. CONCLUSION: Increased AsA intake could play an important role in lipid composition and could be of potential importance in the genesis and prevention of atherogenic disease in the elderly.     

Positive correlation between dietary intake of sodium and balances of calcium and magnesium in young Japanese adults--low sodium intake is a risk factor for loss of calcium and magnesium--

The content of calcium (Ca) and magnesium (Mg) in sweat during exercise is considerably higher during a relatively low intake of sodium (Na) of 100 mmol/d than with an intake of 170 mmol/d. For this reason and also because Ca and Mg have a negative balance with a Na intake of 100 mmol/d, we analyzed the relationship between Na intake and balances of Ca and Mg in data from 11 balance studies. From 1986 to 2000, 109 volunteers (23 males, 86 females) with an age range of 18 to 28 y took part in mineral balance studies. The balance periods ranged from 5 to 12 d. In a given experiment, the diet of each subject contained the same quantity of food, although this varied between experiments, and was supplied during the balance period without consideration of body weight. In the data of all the studies (n= 109), the balances of Ca and Mg did not correlate positively with Na intake. However, when the data of the highest Na study were excluded, the balances of Ca and Mg correlated positively with Na intake. The mean value for the regression equation between Na intake and Ca and Mg balances when the respective balance was equal to zero were, 63.308 mg Na/kg BW/d (Ca: n=96, r2=0.134) and 60.977 mg Na/kg BW/d (Mg: n=96, r2=0.268), respectively. These values are considerably higher than Na requirements estimated by inevitable Na loss. Low dietary Na may therefore be a risk factor for maintaining positive balances of Ca and Mg.     

Higher urinary sodium, a proxy for intake, is associated with increased calcium excretion and lower hip bone density in healthy young women with lower calcium intakes

We assessed 24-h urinary sodium (Na) and its relationship with urinary calcium (Ca) and areal bone mineral density (aBMD) at the whole body, lumbar spine and total hip in a cross-sectional study. 102 healthy non-obese women completed timed 24-h urine collections which were analyzed for Na and Ca. Dietary intakes were estimated using a validated food frequency questionnaire. Participants were grouped as those with lower vs. higher calcium intake by median split (506 mg/1000 kcal). Dietary Na intake correlated with 24-h urinary loss. Urinary Na correlated positively with urinary Ca for all participants (r = 0.29, p < 0.01) and among those with lower (r = 0.37, p < 0.01) but not higher calcium intakes (r = 0.19, p = 0.19). Urinary Na was inversely associated with hip aBMD for all participants (r = -0.21, p = 0.04) and among women with lower (r = -0.36, p < 0.01) but not higher (r = -0.05, p = 0.71) calcium intakes. Urinary Na also entered a regression equation for hip aBMD in women with lower Ca intakes, contributing 5.9% to explained variance. In conclusion, 24-h urinary Na (a proxy for intake) is associated with higher urinary Ca loss in young women and may affect aBMD, particularly in those with lower calcium intakes.     

The effect of dietary caffeine on urinary excretion of calcium,magnesium, sodium and potassium in healthy young females

Twelve female college students drank decaffeinated coffee or tea to which 0, 150 or 300 mg caffeine had been added. Each subject had fasted at least ten hours before drinking each of the three test beverages. Urine samples were collected at one, two and three hours after caffeine consumption. Total urinary three hour excretion of calcium, magnesium and sodium, but not potassium, increased significantly after caffeine intake. The increased output of calcium and sodium was mainly due to significantly increased urinary calcium and sodium concentrations, while the increased output of magnesium appeared to be due to the combination of both a slightly increased urinary magnesium concentration and volume. Total urine volume correlated significantly with dose of caffeine per body weight when 300 mg of caffeine was consumed. The effects of caffeine on mineral excretion were primarily due to changes in mineral concentration and increased urinary volume at one and two hours.     

Alcohol intake in a healthy elderly population.

The relationship between amount of alcohol consumption and social, psychological, and cognitive status was examined in 270 healthy, independently living men and women over age 65. Forty-eight per cent of the sample recorded some alcohol intake during a three-day diet record, with 8 per cent drinking 30 or more grams of alcohol daily. Alcohol intake was positively associated with male gender, income, and amount of education and negatively associated with age. Alcohol intake was not associated with any changes in social or psychological status, but was positively associated with several measurements of cognitive status. These correlations were weak, however, and tended to disappear after controlling for income, education, gender, and age. Past alcohol intake was not associated with any indicators of present social, psychological, or cognitive functioning.     

Reduction in sodium chloride intake: effects on urinary Na, K and aldosterone output in healthy free-living adults

Eleven healthy free-living adults (six women, five men) weighed and recorded all food and drink consumed and collected all urine for two non-consecutive 7-day periods whilst eating their usual diet (Period 1) and attempting to reduce salt intake (Period 2). Bread (including pitta bread) provided on average a quarter of total Na intake of subjects in Period 1 so that wholemeal bread made without added salt was made available in Period 2. All subjects achieved substantial reductions (mean 65%) in Na intake in Period 2 with no change in K intake so that the Na:K molar ratio fell from 1.3 to 0.5. Urinary Na output closely followed intakes and there was a large increase (mean 11.2 μg/d) in aldosterone excretion with a non-significant increase in K output. Simple linear relationships which allow prediction of Na and K intake from the more easily measured urinary output were derived.     

Spinal bone density and calcium intake in healthy postmenopausal women

Dietary calcium intake and bone mineral density (BMD) of the lumbar spine (L2-L4) were determined in 131 healthy free-living postmenopausal women (aged 64.7 +/- 7.6 y, means +/- SD). The calcium consumption for the total population was 606 +/- 302 mg/d. Subjects consuming less than the population mean of dietary calcium had significantly lower BMDs than did subjects with intakes above the mean (P less than 0.009); these two groups did not differ in basic demographic characteristics. Additional analyses using a stepwise univariate regression model demonstrated that BMD was significantly associated with body weight (P less than 0.001) and dietary calcium intake (P less than 0.02). These data support the hypothesis that dietary calcium intake is a determinant of skeletal health in postmenopausal women.     

Associations between dietary intake and urinary excretion of sodium, potassium, phosphorus, magnesium, and calcium

OBJECTIVES AND METHODS: The associations between dietary intake and urinary excretion of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), and phosphorus (P), and the major dietary sources derived from the urinary minerals were studied in a nutritional survey of 219 Japanese females aged 27-84 years, who completed anthropometric measurements, a one-day dietary record, and a 24 hr urine collection. RESULTS: The minerals excreted in the urine were significantly and positively correlated with each other, in which Na excretion was correlated with K and Ca excretion (r = 0.490 and r = 0.482, respectively, p < 0.01) and Ca excretion was correlated with Mg excretion (r = 0.526, p < 0.01). The ratios of urinary exertion to dietary intake of Na, K, Ca, Mg, and P were 81.5%, 62.7%, 24.5%, 21.7%, and 56.1%, respectively. The dietary intake and the urinary excretion of the minerals expressed per body weight (kg) were significantly and positively correlated (Na, r = 0.267; K, r = 0.460; Ca, r = 0.181; Mg, r = 0.245; P, r = 0.351, p < 0.01). Further examinations using chief component analysis for food intake showed several significant positive correlations, including between Na intake and the intake of vegetables, noodles, and seasonings (r = 0.332-0.381, p < 0.01); between K, Mg and P intake and the intake of vegetables, fruits, and potatoes (r = 0.332-0.533, p < 0.01); and between Ca intake and the intake of bread and dairy foods (r = 0.428, p < 0.01). In addition, significant positive associations were found between Na excretion and the intake of confectionaries, nuts, and seeds (r = 0.223, p < 0.01). Weak correlations were also found between K excretion and the intake of vegetables (r = 0.296, p < 0.01); between Ca and P excretion and the intake of meat, oil, and fats (r = 0.135, P < 0.05; r = 0.193, P < 0.01, respectively), and between Mg excretion and the intake of bread and dairy foods (r = 0.137, P < 0.05). CONCLUSIONS: Findings from this study indicate that, while urinary excretion of Ca and Mg is unlikely to be a reliable biochemical marker of dietary intake, the levels of urinary excretion of Na, K, and P can be reflective of the intake of salt, vegetables, and meats, respectively. The urinary excretion of the minerals, particularly Na, K, and Ca, may be highly linked to salt intake in Japanese females.     

Ascorbic acid intake and plasma levels in healthy elderly people

Plasma ascorbic acid concentrations were determined in eight men and nine women over age 65 on controlled intakes of vitamin C. Plasma ascorbic acid levels were significantly lower in elderly men compared with women for vitamin C intakes ranging from 30 to 280 mg/d. A maximum steady-state level of 1.0 mg/dL (56.78 mumol/L) ascorbic acid was observed in male subjects at an intake of approximately 150 mg/d; female subjects approached a plasma ascorbate level of 1.0 mg/dL (56.78 mumol/L) with an intake of approximately 80 mg/d. At a total vitamin C intake of 60 mg/d, plasma ascorbate levels in men were estimated to be 0.4 mg/dL (22.71 mumol/L) or less. The amount of dehydroascorbic acid in plasma did not vary with intake of vitamin C.     

Dietary calcium intake among patients with urinary calculi

Diet plays an important role in the formation and growth of kidney stones, and calcium intake below recommended dietary allowances may expose patients to a higher risk of recurrence. This study evaluated calcium intake and the dietary profile of 37 outpatients with renal lithiasis and 45 control subjects were age and sex matched. Dietary calcium, assessed by four-day dietary records, was significantly lower for patients with urinary calculi. When records for weekdays and Sunday were analyzed separately, a significantly lower calcium intake was again observed for patients with lithiasis both on weekdays and on Sundays. Adjustments to body mass index (BMI), income, age, and sex revealed a lower calcium intake for patients with lithiasis in all dietary records (P < 0.02), which may be explained by the fact that physicians and nutritionists still recommend these patients reduce calcium intake. As this may be one more risk factor for recurrence, recommendations made by health professionals should be reviewed.     

Soy intake and urinary sex hormone levels in preschool Japanese children

The authors investigated whether soy intake is associated with sex steroid levels in Japanese children. This cross-sectional study was conducted in autumn 2006. Subjects were substantially healthy preschoolers, 230 boys and 198 girls, aged 3-6 years. Dietary data, including soy intake, were assessed using 3-day dietary records. Each child's dietary intake was controlled for total energy intake using the Willett method (Nutritional Epidemiology. Oxford, United Kingdom: Oxford University Press; 1990:245-271). Urinary estrone, estradiol, testosterone, and 5-androstene-3β,17α diol levels measured using liquid chromatography-electrospray ionization tandem mass spectrometry, and urinary dehydroepiandrosterone level measured with a radioimmunoassay, were adjusted for urinary creatinine levels. In the analysis of covariance for sex steroids after adjustments for age and body mass index, soy intake was significantly negatively related to estrone and estradiol in boys and positively related to testosterone and 5-androstene-3β,17α diol in girls. Isoflavone had a significant tendency to be negatively associated with estradiol in boys and to be positively associated with testosterone in girls. Total energy intake was not associated with any sex steroids in boys or girls. These results suggest that soy intake might affect the secretion or metabolism of sex steroids in childhood and that the effects might differ by sex.     

The effect of dietary sodium on urinary calcium and potassium excretion in normotensive men with different calcium intakes

On the basis of their usual calcium intake, 12 healthy normotensive male students were divided into a low and a high calcium group. Both groups were provided with complete diets containing the same calculated quantities, expressed per MJ, of protein, fat, carbohydrate, sodium, potassium, phosphorus, and calcium. After an initial period of two weeks during which all participants received an additional 100 mmol sodium daily, 6 participants received an additional 22 mmol sodium/day (low sodium), the other 6 participants 178 mmol sodium/day (high sodium). After two weeks the sodium regimes were crossed over for a subsequent two-week period. When the second week of the low sodium period is compared with the second week of the high sodium period, the increase in the calcium/creatinine ratio, expressed on molar basis, was 0.059 for the low and 0.053 for the high calcium group (p less than 0.05). The increase in the molar potassium/creatinine ratio was 0.65 for the low and 0.03 for the high calcium group (p less than 0.025). However, after correcting for the calcium intake the effect in the low calcium group was found to be greater (p less than 0.05). Sodium supplementation was found to have no effect on blood pressure, but mean systolic (p less than 0.10) and diastolic in the high calcium group were lower. This suggests that calcium may well play a role in the regulation of blood pressure.     

Daily salt intake of healthy Japanese infants of 3-5 years based on sodium excretion in 24-hour urine

We measured concentrations of sodium and creatinine in previously validated overnight urine and 24-h urine of 79 healthy infants of 3 to 5 y of age in two cities in Miyagi Prefecture, Japan. Thereafter, we estimated daily salt intake from daily urinary sodium excretion and daily urinary volume. Corrections for potential sweat loss of sodium chloride were conducted based on urinary volume and urinary creatinine concentration. We also measured urinary volume and urinary sodium concentration in infants who failed to provide complete urine samples. The estimated salt intake did not differ between boys and girls, but varied between the two cities. The estimated salt intake per unit of body weight differed neither between genders nor between cities. The grand means for estimated salt intake and that per unit of body weight were 5.5 g/d (SD 1.8) and 0.32 g/kg/d (SD 0.10), which supported previous results both in Japan and abroad. It was also possible to roughly estimate salt intake from sodium concentration in overnight urine or incomplete 24-h urine, and published urine volume.     

Relationship of urinary sodium/potassium excretion and calcium intake to blood pressure and prevalence of hypertension among older Chinese vegetarians

OBJECTIVE: To examine the associations of dietary sodium and potassium, as reflected by the urinary sodium/potassium excretion, and calcium intake with blood pressure and the prevalence of hypertension among older Chinese vegetarians in Hong Kong. DESIGN: Cross-sectional study. SETTING: Research clinic in a teaching hospital in Hong Kong. SUBJECTS: A total of 111 ambulatory vegetarians over the age of 55 were recruited from members of religious organizations or old age hostels. MAIN OUTCOME MEASURES: Hypertension was defined as supine blood pressure >140/90 mmHg or a history of hypertension. Dietary sodium, potassium and calcium intakes were assessed by 24 h recall method or fasting urinary sodium or potassium/creatinine ratios. RESULTS: Seventy-one subjects (64%) were found to have hypertension. Compared with normotensive subjects, hypertensive subjects had lower calcium intake (411+/-s.d. 324 vs 589+/-428 mg, P=0.04), but higher urinary sodium/creatinine ratio (32.6+/-19.3 vs 21.0+/-12.4, P=0.00) and sodium/potassium ratio (4.7+/-2.8 vs 3.4+/-2.3, P=0.02). Among 88 subjects not taking diuretics or antihypertensive drugs, systolic blood pressure was related to calcium intake (r=-0.40), urinary sodium/creatinine ratio (r=0.39), urinary sodium/potassium ratio (r=0.30) and age (r=0.23). Diastolic blood pressure was related to urinary sodium/creatinine (r=0.29). Twenty-three subjects with high urinary sodium/potassium and low calcium intake and 16 subjects with low urinary sodium/potassium ratio and high calcium intake differed markedly with respect to systolic blood pressure (159+/-26 vs 130+/-15 mmHg) and prevalence of hypertension (78% vs 25%). CONCLUSIONS: Older Chinese vegetarians are predisposed to hypertension because of their sodium-rich but calcium-deficient diets.     

Age-related changes in energy intake and weight in community-dwelling middle-aged and elderly Japanese

Objective

This study attempts to describe trends in energy intake and weight change over 12 years according to age at first participation in the study.

Design

Prospective cohort study.

Setting

The National Institute for Longevity Sciences - Longitudinal Study of Aging (NILS-LSA), a community-based study.

Participants

Participants included 922 men and 879 women who participated in the first study-wave (age 40–79 years) and also participated in at least one study-wave from the second to seventh study-wave. Each study-wave was conducted biennially. For individuals, the entire follow-up period was 12 years.

Measurements

Energy intake was calculated from 3-day dietary records with photographs. Weight and height were measured under a fasting state. To estimate linear changes in energy intake and weight over 12 years according to age at first study-wave, we used the mixed-effects model.

Results

Mean (SD) follow-up time and number of study-wave visits were 9.5 (3.7) years and 5.4 (1.8) times, respectively. The fixed effect of the interaction of age and time in energy intake and weight was statistically or marginally statistically significant both in men (p<0.01) and in women (p<0.06). In men, when energy intake was estimated according to age, the rate of decrease in energy intake increased from -6.8 to -33.8 kcal/year for ages 40-79 years. In women, the rate of decrease in energy intake slightly increased in older age groups (-9.1 to -16.7 kcal/year for ages 40-79 years). Weight increased in males in their 40s (0.07 kg/year from age 40) and started to decline by age 53. In women, weight started to decline around age 47 (-0.04 kg/year).

Conclusion

Twelve-year longitudinal data showed energy intake declined both in men and women in their 40s, and the rate of decrease increased in older males. Weight started to decline in men in their mid-50s and women in their late 40s. Further studies that focus on energy intake and weight reduction are needed to prevent weight loss or underweight in an increasingly aging society.

     

Effect of acetaldehyde on urinary salsolinol in healthy man after ethanol intake

The effect of acetaldehyde on urinary salsolinol (6, 7-dihydroxy-l-methyl-1,2,3,4-tetrahydroisoquinoline) after ethanol intake was investigated. Healthy Japanese male volunteers were divided into two groups, i.e., a normal aldehyde dehydrogenase (ALDH) group of 13 subjects with a low Km isozyme of ALDH and a deficient group of 12 subjects. The subjects were given 0.4 or 0.8 g/kg of ethanol. Blood ethanol and acetaldehyde levels, urinary excretions of salsolinol, norepinephrine, epinephrine and dopamine were determined. A significant elevation of salsolinol in urine was found after intake of 0.8 g/kg of ethanol in the two groups, but the increase in the deficient group was greater than that in the normal group, while 0.4 g/kg of ethanol did not affect the excretion of salsolinol in either group. Blood acetaldehyde was highly correlated with urinary salsolinol (r = 0.88, p less than 0.001) and the correlation coefficient was greater than that between blood ethanol and salsolinol.     

Negative balance of calcium and magnesium under relatively low sodium intake in humans

The balance of minerals (sodium [Na], potassium [K], calcium [Ca], and magnesium [Mg]) was measured in six female students for 10 d while under a relatively low Na intake (100 mmol/d or 2.2 g/d) with receiving adequate Ca (20 mmol/d or 800 mg/d) and Mg (12 mmol/d or 280 mg/d). Both the plasma renin activity (PRA) and aldosterone level were above the reference ranges throughout the experiment, which implied that the subjects were Na deficient. However, the urine Na excretion was about the same as that ingested, while there was no substantial reduction of sweat Na concentration observed during moderate physical exercise (13.2+/-2.6 mmol/L) (mean+/-SD). On the other hand, the urine Ca and Mg levels were high, but the apparent absorption of Ca and Mg was moderate (21 +/- 5%, 34 +/- 4%, respectively), which resulted in a negative balance of these two elements. It seems that the stored Na in the bone is eluted so as to compensate for the low dietary Na intake, while any excess Ca and Mg also inevitably flows into the blood stream with Na, which inhibited the intestinal absorption of both Ca and Mg and accelerates their excretion in urine.     

The effect of dietary caffeine on urinary excretion of calcium,magnesium, phosphorus,sodium, potassium,chloride and zinc in healthy males

Fifteen males drank decaffeinated coffee to which 0, 150 or 300 mg caffeine had been added. Each subject had fasted at least ten hours before drinking each of the three test beverages. Urine samples were collected at one, two and three hours after caffeine consumption. Total urinary three hour excretion of calcium, magnesium, sodium and chloride increased significantly after caffeine intake, while zinc, phosphorus, potassium, creatinine and volume were unchanged. The increased outputs were due to increased urinary mineral concentrations.     

昆明某高校学生尿液钠钾水平与膳食摄入相关性分析

探讨昆明某高校在校生膳食钠钾摄入比值与随机尿钠钾排泄比值和24h尿钠钾排泄比值之间的相关性,为学生的膳食营养指导提供参考.方法 选取符合纳入标准的12名昆明某高校在校大学生(男、女各半)作为受试者,将其随机平均分入4 g/d、8 g/d、12 g/d等3个不同摄盐组(每组2男2女);为其统一提供4d膳食,称重计算其每日膳食钠、钾摄入总量,收集并测定研究对象3d内随机尿钠、尿钾含量和24 h尿钠、尿钾排泄总量.结果 对3个不同摄盐组的膳食钠钾比值作秩和检验,3组间差异有统计学意义(F=7.731,P=0.021).对3个不同摄盐组的24h尿钠钾比值做方差分析,3个组间差异有统计学意义(F=7.982,P=0.01),符合分组要求.膳食钠钾比值与3d上午随机尿钠钾比值之间有正相关关系(r值分别为0.625,0.635,0.608,P值均<0.05);膳食钠钾比值与24 h尿钠钾比值之间呈正相关(r=0.642,P=0.024).结论 通过测定在校大学生上午的随机尿钠钾排泄比值或者24 h尿钠钾排泄比值对判定膳食钠钾摄入比值有一定参考价值.     

Vitamin A intake and plasma retinol levels in healthy elderly men and women

We examined intakes of vitamin A (diet plus supplement) and plasma retinol levels in a select group of elderly men (n = 90) and women (n = 110) on three separate occasions over a 4-y period. Median dietary levels remained at approximately 1400 retinol equivalents (RE) in men and 1250 RE in women. There were no time trends or gender differences noted in plasma retinol concentrations. Approximately 44% of the elderly men and women consumed an average of 2000 RE of a vitamin A supplement daily. Those taking supplement had a greater mean plasma retinol concentration than those not taking a supplement. This effect was greater in men than in women. A review of previous studies revealed that plasma retinol increases from a mean of approximately 35 micrograms/dL (1.22 mumol/L) at preschool age to a plateau of approximately 60 micrograms/dL (2.09 mumol/L) by age 40 y in men and 60 y in women.