Relationship between essential amino acids and muscle mass, independent of habitual diets, in pre- and post-menopausal US women.

The purpose of this secondary analysis was to examine the relationship between protein and essential amino acids (EAAs) intake with the level of muscle mass (MM) independent of the diet. Twenty-one omnivores, 22 ovo-lacto-vegetarians and 20 vegans were recruited. MM (urinary creatinine), dietary intake (5-day dietary records) and biochemical analyses (urinary and plasma sex hormones) were obtained. We observed no significant difference between groups for MM, total EAA intake, leucine, isoleucine, age and body mass index. However, we observed a significant difference between groups for total dietary protein intake and total energy intake. Despite significant differences in total dietary protein, the EAA intake was not different, indicating that neither the amount nor the quality of protein in these diets was a limiting factor in determining the amount of MM. Thus, each of these diet patterns appears adequate to maintain MM.

Estimated net acid excretion inversely correlates with urine pH in vegans, lacto-ovo vegetarians, and omnivores.

OBJECTIVE: Diet affects urine pH and acid-base balance. Both excess acid/alkaline ash (EAA) and estimated net acid excretion (NAE) calculations have been used to estimate the effects of diet on urine pH. This study's goal was to determine if free-living vegans, lacto-ovo vegetarians, and omnivores have increasingly acidic urine, and to assess the ability of EAA and estimated NAE calculations to predict urine pH. DESIGN: This study used a cross-sectional design. SETTING AND PARTICIPANTS: This study assessed urine samples of 10 vegan, 16 lacto-ovo vegetarian, and 16 healthy omnivorous women in the Boston metropolitan area. Six 3-day food records from each dietary group were analyzed for EAA content and estimated NAE, and correlations with measured urine pH were calculated. RESULTS: The mean (+/- SD) urine pH was 6.15 +/- 0.40 for vegans, 5.90 +/- 0.36 for lacto-ovo vegetarians, and 5.74 +/- 0.21 for omnivores (analysis of variance, P = .013). Calculated EAA values were not significantly different among the three groups, whereas mean estimated NAE values were significantly different: 17.3 +/- 14.5 mEq/day for vegans, 31.3 +/- 8.5 mEq/day for lacto-ovo vegetarians, and 42.6 +/- 13.2 mEq/day for omnivores (analysis of variance, P = .01). The average deattenuated correlation between urine pH and EAA was 0.333; this value was -0.768 for estimated NAE and urine pH, with a regression equation of pH = 6.33 - 0.014 NAE (P = .02, r = -0.54). CONCLUSIONS: Habitual diet and estimated NAE calculations indicate the probable ranking of urine pH by dietary groups, and may be used to determine the likely acid-base status of an individual; EAA calculations were not predictive of urine pH.

Lipoprotein response to diets high in soy or animal protein with and without isoflavones in moderately hypercholesterolemic subjects.

OBJECTIVE: The objective of this study was to assess the independent effect of soy relative to common sources of animal protein and soy-derived isoflavones on blood lipids. METHODS AND RESULTS: Forty-two subjects with LDL cholesterol levels > or =3.36 mmol/L were fed each of four diets in randomized order for 6 weeks per phase. Diets contained a minimum of 25 g animal protein or isolated soy protein/4.2 MJ, with each containing trace amounts or 50 mg of isoflavones/4.2 MJ. Soy protein had a modest effect on total, LDL and HDL cholesterol, and triglyceride concentrations (-2%, P=0.017; -2%, P=0.042; +3%; P=0.034, -11%, P<0.001, respectively). Soy protein had no significant effect on plasma lipids in individuals with LDL cholesterol <4.14 mmol/L and significantly reduced total and LDL cholesterol and triglyceride concentrations in individuals with LDL cholesterol > or =4.14 mmol/L (-4%, P=0.001; -5%, P=0.003; -15%, P<0.001, respectively). No significant effect of isoflavones on plasma lipid levels was observed either constituent to the soy protein or supplemental to the animal protein. CONCLUSIONS: Although potentially helpful when used to displace products containing animal fat from the diet, the regular intake of relatively high levels of soy protein (>50 g/day) had only a modest effect on blood cholesterol levels and only in subjects with elevated LDL cholesterol levels (> or =4.14 mmol/L). Soy-derived isoflavones had no significant effect.

A diet high in saturated fat and cholesterol accelerates simian immunodeficiency virus disease progression.

Several lines of evidence suggest that dietary fat and cholesterol may play a role in the pathogenesis of human immunodeficiency virus (HIV) infection and disease progression. We examined the effect that an atherogenic diet (AD) high in saturated fatty acids and cholesterol has on disease progression and systemic inflammation in the simian immunodeficiency virus (SIV)-infected macaque model of acquired immunodeficiency syndrome. Macaques fed an AD had significantly more rapid disease progression, resulting in an increased risk of SIV-related death compared with that in control macaques (hazard ratio, 5.4 [95% confidence interval, 1.7-17.0]; P<.001). Peak viral load was higher in the AD group compared with control values, but further statistically significant differences were not detected at viral set point. The baseline plasma interleukin-18 level after 6 months of the AD was predictive of disease progression. Our findings may have important implications for HIV-infected individuals, because they suggest that dietary changes and manipulation of lipid metabolism could offer potential benefits by slowing disease progression.

Hormonal response to diets high in soy or animal protein without and with isoflavones in moderately hypercholesterolemic subjects.

Consumption of soy protein has been associated with altered risk of developing endocrine-regulated cancers. This study was designed to assess the independent effect of soy relative to animal protein and soy-derived isoflavones on circulating estrogen and androgen concentrations in postmenopausal women and older men. Forty-two subjects (> 50 yr) with low-density lipoprotein cholesterol levels of > or = 3.36 mmol/l were fed each of 4 diets in randomized order for 6 wk/phase. All food and drink were provided. Diets contained 25 g soy or common sources of animal protein/4.2 MJ containing trace or 50 mg isoflavones/4.2 MJ. At the end of each diet phase, concentrations of estrone sulfate, estrone, estradiol, testosterone, androstendione, dihydrotestosterone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate were measured. In postmenopausal women, concentrations of estrone were higher and its precursor, dehydroepiandrosterone, lower after consuming the soy compared with animal protein diets (P = 0.0396 and 0.0374, respectively). There was no significant effect of isoflavones on any of the hormones measured. In older men, dehydroepiandrosterone sulfate concentrations were lower after consuming the isoflavone (P = 0.0106) and higher after soy, compared with the animal protein diets (P = 0.0118). These data suggest that relatively large amounts of soy protein or soy-derived isoflavones had modest and limited sex-specific effects on circulating hormone levels.

The effect of micronutrient supplementation on disease progression and death in simian immunodeficiency virus-infected juvenile male rhesus macaques.

BACKGROUND: We investigated the impact that micronutrient supplementation has on the progression of simian acquired immunodeficiency syndrome (SAIDS). METHODS: Twenty-four simian immunodeficiency virus-infected juvenile male rhesus macaques were randomized into 2 groups. One group was given certified chow, and the other group was given chow and a supplement that contained 2-3 times the estimated nutritional requirement of micronutrients. Virological, immunological, and body composition measurements were taken every 4 weeks for 120 weeks. RESULTS: There was no difference between groups in weight gain, body mass index (BMI), crown-heel length, waist circumference, total tissue mass, lean mass, bone mineral content, or bone mineral density. The rhesus macaques on the supplemented diet had a higher death rate (hazard ratio, 2.39; P<.001) than those on the nonsupplemented diet; death in both groups was associated with a higher viral load set point during the early phase of infection. Additionally, higher body weight, BMI, crown-rump length, and lower viral load set point were protective from death in both groups. CONCLUSIONS: Micronutrient supplementation did not significantly alter the progression of SAIDS with respect to changes in body composition and immunological characteristics. A significantly higher rate of death was observed in rhesus macaques on the supplemented diet.

Copper modulates activities of genistein, nitric oxide, and curcumin in breast tumor cells.

Several papers have reported that low level of genistein (<8 microM), the major bioactive component of isoflavones, stimulates the growth of MCF-7 cells. In the present study, we found that genistein-induced growth stimulation of MCF-7 cells is inhibited in the presence of Cu(2+) (5 microM). Genistein induces the release of nitric oxide in MCF-7 cells in a concentration-dependent manner. The release of nitric oxide was inhibited by N(G)-nitro-L-arginine methyl ester, suggesting the possibility of the activation of nitric oxide synthase. The growth of MCF-7 cells also increases in the presence of low levels of sodium nitriprusside (<10 microM), a nitric oxide donor compound, while high levels (>25 microM) are toxic. The sodium nitroprusside-induced growth of MCF-7 cells is drastically suppressed in the presence of Cu(2+) (5 microM). This parallel behavior between Cu(2+)-genistein and Cu(2+)-sodium nitroprusside mixtures suggests that Cu(2+) and/or copper-protein complexes, that may be formed in the media, may be reacting with nitric oxide or nitric oxide-derived reactive species. The products of these reactions may be responsible for the toxic effects of these mixtures. In contrast, the effect of curcumin that inhibits the growth of both estrogen receptor-positive and -negative breast tumor cells appreciably decreased in the presence of Cu(2+). Since copper is known to overwhelmingly bind with proteins, present data suggest that an increase in copper-protein moieties or complexes formed in the serum containing media and their reactions with nitric oxide may be responsible for their toxic effects. Further studies are needed to characterize these reactions.