The effects of zinc supplementation on serum zinc concentration and protein catabolic rate in hemodialysis patients.

OBJECTIVE: To examine the effect of zinc sulfate supplementation on serum zinc concentrations and protein catabolic rate (PCR) in hemodialysis (HD) patients. DESIGN: Randomized, double-blind, before-after trial. SETTING: Outpatient dialysis center in a large metropolitan city. PATIENTS: Twenty-eight maintenance HD patients were selected. Twenty (15 women, 5 men) subjects completed the study. Subjects were identified for inclusion in the study by the following criteria: a history of low PCR (<0.09 g/kg body weight), HD treatment for a minimum of 6 months, no signs of gastrointestinal disorders, and no record of hospitalizations for reasons other than access complication within the last 3 months. INTERVENTIONS: Patients consumed 7.7 pmol zinc sulfate (2,200 microg) or a cornstarch placebo capsule daily for 90 days. In addition, patients completed a 2-day food record representative of 1 dialysis day and 1 nondialysis day. MAIN OUTCOME MEASURE: Fasting, predialysis serum samples were collected on days 0, 40, and 90 to determine serum zinc concentration and PCR. Dietary parameters including intake of zinc, protein, and energy were analyzed on Days 0 and 90. RESULTS: Initial analysis at Day 0 of serum zinc concentration indicated subjects were below the normal range for serum zinc standards (12.2 micromol/L [80 microg/dL]). After supplementation, subjects in the zinc-supplemented group showed significant increases in serum zinc concentrations from 12.2 micromol/L (80 microg/dL) at Day 0 to 15.3 pmol/L (100 microg/dL) at Day 90. A significant positive correlation (r = +0.61) was shown between PCR and serum zinc concentrations at the end of the study. Reported dietary protein intake did not change with zinc supplementation. CONCLUSION: Low serum zinc concentrations are reversible with zinc supplementation. Improvement in serum zinc concentration increases the PCR of HD patients.     

Soy isoflavones lower serum total and LDL cholesterol in humans: a meta-analysis of 11 randomized controlled trials

BACKGROUND: Clinical trials have reported the cholesterol-lowering effects of soy protein intake, but the components responsible are not known. OBJECTIVE: This meta-analysis was primarily conducted to evaluate the precise effects of soy isoflavones on lipid profiles. The effects of soy protein that contains enriched and depleted isoflavones were also examined. DESIGN: PUBMED was searched for English-language reports of randomized controlled trials published from 1990 to 2006 that described the effects of soy protein intake in humans. Eleven studies were selected for the meta-analysis. RESULTS: Soy isoflavones significantly decreased serum total cholesterol by 0.10 mmol/L (3.9 mg/dL or 1.77%; P = 0.02) and LDL cholesterol by 0.13 mmol/L (5.0 mg/dL or 3.58%; P < 0.0001); no significant changes in HDL cholesterol and triacylglycerol were found. Isoflavone-depleted soy protein significantly decreased LDL cholesterol by 0.10 mmol/L (3.9 mg/dL or 2.77%; P = 0.03). Soy protein that contained enriched isoflavones significantly decreased LDL cholesterol by 0.18 mmol/L (7.0 mg/dL or 4.98%; P < 0.0001) and significantly increased HDL cholesterol by 0.04 mmol/L (1.6 mg/dL or 3.00%; P = 0.05). The reductions in LDL cholesterol were larger in the hypercholesterolemic subcategory than in the normocholesterolemic subcategory, but no significant linear correlations were observed between reductions and the starting values. No significant linear correlations were found between reductions in LDL cholesterol and soy protein ingestion or isoflavone intakes. CONCLUSIONS: Soy isoflavones significantly reduced serum total and LDL cholesterol but did not change HDL cholesterol and triacylglycerol. Soy protein that contained enriched or depleted isoflavones also significantly improved lipid profiles. Reductions in LDL cholesterol were larger in hypercholesterolemic than in normocholesterolemic subjects.     

Effects on blood lipids of a blood pressure-lowering diet: the Dietary Approaches to Stop Hypertension (DASH) Trial.

BACKGROUND: Effects of diet on blood lipids are best known in white men, and effects of type of carbohydrate on triacylglycerol concentrations are not well defined. OBJECTIVE: Our goal was to determine the effects of diet on plasma lipids, focusing on subgroups by sex, race, and baseline lipid concentrations. DESIGN: This was a randomized controlled outpatient feeding trial conducted in 4 field centers. The subjects were 436 participants of the Dietary Approaches to Stop Hypertension (DASH) Trial [mean age: 44.6 y; 60% African American; baseline total cholesterol: < or = 6.7 mmol/L (< or = 260 mg/dL)]. The intervention consisted of 8 wk of a control diet, a diet increased in fruit and vegetables, or a diet increased in fruit, vegetables, and low-fat dairy products and reduced in saturated fat, total fat, and cholesterol (DASH diet), during which time subjects remained weight stable. The main outcome measures were fasting total cholesterol, LDL cholesterol, HDL cholesterol, and triacylglycerol. RESULTS: Relative to the control diet, the DASH diet resulted in lower total (-0.35 mmol/L, or -13.7 mg/dL), LDL- (-0.28 mmol/L, or -10.7 mg/dL), and HDL- (-0.09 mmol/L, or -3.7 mg/dL) cholesterol concentrations (all P < 0.0001), without significant effects on triacylglycerol. The net reductions in total and LDL cholesterol in men were greater than those in women by 0.27 mmol/L, or 10.3 mg/dL (P = 0.052), and by 0.29 mmol/L, or 11.2 mg/dL (P < 0.02), respectively. Changes in lipids did not differ significantly by race or baseline lipid concentrations, except for HDL, which decreased more in participants with higher baseline HDL-cholesterol concentrations than in those with lower baseline HDL-cholesterol concentrations. The fruit and vegetable diet produced few significant lipid changes. CONCLUSIONS: The DASH diet is likely to reduce coronary heart disease risk. The possible opposing effect on coronary heart disease risk of HDL reduction needs further study.     

The prevalence of low serum zinc and copper levels and dietary habits associated with serum zinc and copper in 12- to 36-month-old children from low-income families at risk for iron deficiency

OBJECTIVE: Iron and zinc share common food sources, and children at risk of iron deficiency may also develop zinc deficiency. We determined the prevalence of zinc and copper deficiency and examined factors associated with serum zinc and copper in young children from low-income families at risk of iron deficiency. DESIGN: A cross-sectional study design was used to assess serum zinc and copper, along with an interview-assisted survey to assess factors associated with serum zinc and copper in a convenience sample. SUBJECTS/SETTING: Participants were 435 children aged 12 to 36 months recruited from select clinics of the Special Supplemental Nutrition Program for Women, Infants, and Children in Contra Costa and Tulare Counties, California. STATISTICAL ANALYSES PERFORMED: Frequencies were used to report prevalence. Multiple linear regressions were conducted to examine factors associated with serum zinc and copper, controlling for age, sex, and ethnicity. RESULTS: The prevalence of low serum zinc level (<70 microg/dL [<10.7 micromol/L]) was 42.8%, and low serum copper level (<90 microg/dL [<14.2 micromol/L]) was <1%. Mean+/-standard deviation of serum copper was 150+/-22 microg/dL (23.6+/-3.5 micromol/L) and 140+/-24 microg/dL (22.1+/-3.8 micromol/L) for anemic and non-anemic children, respectively (t test, P=0.026). In multiple linear regression consumption of sweetened beverages was negatively associated with serum zinc level, and consumption of >15 g/day meat was positively associated with serum zinc level, whereas current consumption of breast milk and >15 g/day beans were positively associated with serum copper level. CONCLUSIONS: The prevalence of low serum zinc concentration in the sample was high, and warrants further investigation amongst vulnerable populations.     

Effects of walnut consumption on plasma fatty acids and lipoproteins in combined hyperlipidemia.

BACKGROUND: Epidemiologic studies show an inverse relation between nut consumption and coronary heart disease. OBJECTIVE: We determined the effects of walnut intake on plasma fatty acids, lipoproteins, and lipoprotein subclasses in patients with combined hyperlipidemia. DESIGN: Participants sequentially adhered to the following diets: 1) a habitual diet (HD), 2) a habitual diet plus walnuts (HD+W), 3) a low-fat diet (LFD), and 4) a low-fat diet plus walnuts (LFD+W). RESULTS: In 13 postmenopausal women and 5 men ( +/- SD age 60 +/- 8 y), walnut supplementation did not increase body weight despite increased energy intake and the LFD caused weight loss (1.3 +/- 0.5 kg; P < 0.01). When comparing the HD with the HD+W, linoleic acid concentrations increased from 29.94 +/- 1.14% to 36.85 +/- 1.13% and alpha-linolenic acid concentrations increased from 0.78 +/- 0.04% to 1.56 +/- 0.11%. During the LFD+W, plasma total cholesterol concentrations decreased by 0.58 +/- 0.16 mmol/L when compared with the HD and by 0.46 +/- 0.14 mmol/L when compared with the LFD. LDL-cholesterol concentrations decreased by 0.46 +/- 0.15 mmol/L when compared with the LFD. Measurements of lipoprotein subclasses and particle size suggested that walnut supplementation lowered cholesterol preferentially in small LDL (46.1 +/- 1.9% compared with 33.4 +/- 4.3%, HD compared with HD+W, respectively; P < 0.01). HDL-cholesterol concentrations decreased from 1.27 +/- 0.07 mmol/L during the HD to 1.14 +/- 0.07 mmol/L during the HD+W and to 1.11 +/- 0.08 mmol/L during the LFD. The decrease was seen primarily in the large HDL particles. CONCLUSIONS: Walnut supplementation may beneficially alter lipid distribution among various lipoprotein subclasses even when total plasma lipids do not change. This may be an additional mechanism underlying the antiatherogenic properties of nut intake.     

Elevated plasma homocysteine and low vitamin B-6 status in nonsupplementing older women with rheumatoid arthritis

OBJECTIVE: The purpose of this study was to determine if nonsupplementing older women (aged >or=55 years) with rheumatoid arthritis had higher plasma homocysteine and lower B-vitamin status compared to healthy controls. Elevated plasma homocysteine, a risk factor for cardiovascular disease, may help explain why individuals with rheumatoid arthritis have an increased risk of cardiovascular disease. METHODS: Older, free-living women were classified as rheumatoid arthritis (n=18) or healthy control (n=33). Participants were not using B-vitamin supplements. Fasting blood samples were measured for pyridoxal 5'phosphate (PLP) (the metabolically active coenzyme form of vitamin B-6), folate, red blood cell folate, vitamin B-12, transcobalamin II, homocysteine, C-reactive protein, and lipid concentrations. Participants completed 7-day weighed food records, the Stanford Health Assessment Questionnaire (HAQ), and a visual analog pain scale. RESULTS: PLP concentrations were lower in the rheumatoid arthritis vs healthy control participants (4.93+/-3.85 vs 11.35+/-7.11 ng/mL [20+/-16 vs 46+/-29 nmol/L]; P<0.01) whereas plasma homocysteine was higher in the rheumatoid arthritis group (1.63+/-0.74 vs 1.15+/-0.38 mg/L [12.1+/-5.5 vs 8.5+/-2.8 micromol/L]; P=0.02). Red blood cell folate concentrations were lower in the rheumatoid arthritis vs healthy control participants [414+/-141 vs 525+/-172 ng/mL [938+/-320 vs 1,190+/-390 nmol/L]; P=0.02). No significant differences were found for plasma folate, vitamin B-12, and transcobalamin II. An inverse correlation was found between PLP concentrations and the HAQ disability index (r=-0.37; P<0.01). A positive correlation was found between homocysteine concentrations and the HAQ disability index (r=0.36; P=0.01). Total cholesterol and low-density lipoprotein cholesterol levels were lower in the rheumatoid arthritis group (cholesterol 191+/-43 vs 218+/-33 mg/dL [4.95+/-1.11 vs 5.65+/-0.85 mmol/L]; P=0.02; low-density lipoprotein cholesterol 110+/-36 vs 137+/-29 mg/dL [2.85+/-0.93 vs 3.55+/-0.75 mmol/L]; P<0.01). No significant differences were seen between groups for protein (g/day), fat (g/day), cholesterol (mg/day), folate (microg/day), vitamin B-12 (microg/day), and vitamin B-6 (mg/day) dietary intakes. CONCLUSIONS: Poor vitamin B-6 status and elevated plasma homocysteine concentrations were seen in older women with rheumatoid arthritis compared to healthy controls and may contribute to their increased risk of cardiovascular disease.     

Accuracy and precision of HDL cholesterol measurements using an office chemistry analyzer

BACKGROUND. A physician can obtain a patient's complete lipoprotein profile at the time of the office visit including assays of the total serum cholesterol, high-density lipoprotein cholesterol (HDL-C), and fasting triglyceride concentrations, and then calculate the low-density lipoprotein cholesterol (LDL-C). Until recently, this was not possible. Instruments are currently available that provide reliable rapid total serum cholesterol and fasting triglyceride measurements. METHODS. This study evaluated the accuracy and precision of a recently developed analytical method for the rapid measurement of HDL-C (Seralyzer Cholesterol System) as compared with a reference clinical laboratory method (Kodak Ektachem 700 XR). Blood specimens were taken from 90 participants and were analyzed in duplicate for HDL-C concentrations and total cholesterol using the Seralyzer and a standard Ektachem 700 XR. RESULTS. Nearly all (98.9%) of the initial Seralyzer HDL-C measures were within +/- 0.08 mmol/L (+/- 3 mg/dL) of the duplicate Seralyzer values. Most (98.3%) of the Seralyzer HDL-C results were within +/- 0.16 mmol/L (+/- 6 mg/dL) of the Kodak HDL-C values. CONCLUSIONS. The Seralyzer HDL-C test provides a reliable and accurate measure of the HDL-C concentration.     

A Softgel Dietary Supplement Containing Esterified Plant Sterols and Stanols Improves the Blood Lipid Profile of Adults with Primary Hypercholesterolemia: A Randomized,Double-Blind,Placebo-Controlled Replication Study

A well-controlled clinical trial previously demonstrated the efficacy of a novel softgel dietary supplement providing 1.8 g/day esterified plant sterols and stanols, as part of the National Cholesterol Education Program Therapeutic Lifestyle Changes diet, to improve the fasting lipid profile of men and women with primary hypercholesterolemia (fasting low-density lipoprotein [LDL] cholesterol ≥130 and <220 mg/dL [≥3.37 and <5.70 mmol/L]). The purpose of this randomized, double blind, placebo-controlled crossover study (conducted July 2011 to January 2012) was to support these previous findings in a similar, but independent, sample with a different lead investigator and research site. Repeated measures analysis of covariance was used to compare outcomes for sterol/stanol and placebo treatment conditions using the baseline value as a covariate. Forty-nine subjects were screened and 30 (8 men and 22 women) were randomized to treatment (all completed the trial). Baseline (mean±standard error of the mean) plasma lipid concentrations were: total cholesterol 236.6±4.2 mg/dL (6.11±0.11 mmol/L), high-density lipoprotein (HDL) cholesterol 56.8±3.0 mg/dL (1.47±0.08 mmol/L), LDL cholesterol 151.6±3.3 mg/dL (3.92±0.09 mmol/L), non-HDL cholesterol 179.7±4.6 mg/dL (4.64±0.12 mmol/L), and triglycerides 144.5±14.3 mg/dL (1.63±0.16 mmol/L). Mean placebo-adjusted reductions in plasma lipid levels were significant (P<0.01) for LDL cholesterol (–4.3%), non-HDL cholesterol (–4.1%), and total cholesterol (–3.5%), but not for triglycerides or HDL cholesterol. These results support the efficacy of 1.8 g/day esterified plant sterols/stanols in softgel capsules, administered as an adjunct to the National Cholesterol Education Program Therapeutic Lifestyle Changes diet, to augment reductions in atherogenic lipid levels in individuals with hypercholesterolemia.     

Effectiveness of individualized long-term therapy with niacin and probucol in reduction of serum cholesterol

A retrospective analysis was made of the results of the individualized office management of hypercholesterolemia in 37 patients (25 male, 12 female) with severe atherosclerosis (n = 35) or a predisposition to it (n = 2). The effects of diet instruction, diet and a niacin supplement, and diet plus the niacin supplement and probucol were assessed. Diet alone (n = 37) was prescribed for an average of 4.8 years; diet plus niacin (n = 37) for an average of 2.0 years; and diet plus niacin and probucol (n = 19) for an average of 2.9 years. Each patient served as his or her own control. The maximum serum cholesterol at the beginning of the diet period was 8.69 +/- 2.15 mmol/L (336 +/- 83 mg/dL) (mean plus or minus standard deviation; n = 37). The goal cholesterol was less than 5.20 mmol/L (200 mg/dL). On diet alone the cholesterol level fell to 7.21 +/- 1.27 mmol/L (279 +/- 49 mg/dL) (P less than .001); and goal cholesterol was reached by 12 of 37 patients (32.4 percent), but was maintained in none. On adding niacin, the mean cholesterol fell to 6.21 +/- 1.16 mmol/L (240 +/- 45 mg/dL) (P less than .001). The goal cholesterol was reached in 22 of 37 patients (59.4 percent), but was maintained in only 7 of 37 (18.9 percent). Nineteen of 37 patients on diet plus niacin also received probucol. Goal cholesterol was reached in 14 of 19 patients (73.6 percent), and was maintained in 11 of 19 (57.9 percent).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of zinc status on salivary zinc concentrations in the rat.

Three experiments were done to determine whether salivary zinc concentration is a more sensitive indicator of zinc status than plasma zinc. Weanling male rats fed a low zinc (less than 1 ppm) diet for 5 weeks with or without zinc (100 ppm) in the drinking water had salivary zinc concentration of 0.19, 0.16, and 0.20 microgram/ml for the zinc-deficient, zinc-supplemented restricted-intake, and zinc-supplemented ad libitum-fed groups, respectively. Combined values for male and female rats after 4 weeks of the same treatments in experiment 2 were 0.60, 1.2 and 0.44 microgram/ml. Saliva collected on day 22 of pregnancy contained 0.30 and 0.24 microgram/ml from zinc-supplemented and zinc-deficient rats, respectively. Salivary zinc concentrations in the deficient rats did not differ from those of the zinc-supplemented ad libitum-fed controls in any of the experiments. Salivary zinc concentration in the zinc-supplemented restricted-intake group in experiment 2 was significantly higher than that in the other two groups. Decreases in serum, bone, and fetal zinc concentrations indicated that the rats were definitely zinc-deficient. Since zinc concentration of mixed saliva in the rat was not decreased by even a severe zinc deficiency, salivary zinc does not appear to be as good an indicator of zinc status as plasma zinc.     

Cholesterol precursors and plant sterols in children with food allergy

BACKGROUND: The data on lipid metabolism in allergic children is limited. OBJECTIVE: We investigated lipid and sterol metabolism in young children whose diets were restricted because of food allergy. DESIGN: Children in group A [n = 21; mean (+/- SD) age: 1.78 +/- 0.73 y] were allergic to fish, eggs, and either cow milk or cereals; those in group B (n = 31, aged 1.45 +/- 0.58 y) were allergic to fish, eggs, and both cow milk and cereals. Cholesterol precursor and plant sterol to cholesterol ratios (10(2) x micro mol/mmol cholesterol) and apolipoprotein E phenotype distributions were analyzed in 36 subjects. The control group for cholesterol precursor and plant sterol measurements consisted of 18 healthy age-matched children. RESULTS: The mean serum cholesterol concentration was 3.6 +/- 0.6 mmol/L, and HDL cholesterol was 1.03 +/- 0.3 mmol/L in group A. Corresponding values in group B were 3.4 +/- 0.7 and 1.09 +/- 0.2 mmol/L. The daily cholesterol intake was low: 61.3 +/- 36.0 mg in group A and 50.7 +/- 48.5 mg in group B. Cholesterol precursor plant sterol concentrations were significantly higher in allergic subjects than in control subjects. CONCLUSIONS: Allergic children with restricted diets have a low intake of cholesterol and relatively low serum cholesterol concentrations. Dietary intake of plant sterols was obviously increased because of supplementation with rapeseed oil, which is rich in plant sterols, leading to elevated plant sterol concentrations. Plant sterols may have inhibited cholesterol absorption, which in turn stimulated cholesterol synthesis in compensation, also explaining the increased precursor sterol ratios in serum in our subjects.     

Serum lipids and lipoproteins in advanced age. Intraindividual changes.

The Bronx Aging Study is a longitudinal investigation of nondemented, nonterminally ill, community-residing, old old volunteer subjects, designed to assess risk factors for the development of dementia and coronary and cerebrovascular diseases. During the first five annual evaluations, total cholesterol, high-density (HDL) and low-density lipoprotein (LDL), and triglyceride levels were measured. Mean cholesterol values (+/- standard error of the mean) for subjects at baseline were significantly higher for women than for men. Respectively, the values for total cholesterol were 6.1 +/- .1 mm/L (234 +/- 3 mg/dL) and 5.3 +/- .1 mm/L (207 +/- 3 mg/dL); for LDL cholesterol, 4.1 +/- .1 mm/L (158 +/- 2 mg/dL) and 3.7 +/- .1 mm/L (141 +/- 3 mg/dl); and for HDL cholesterol, 1.2 +/- .1 mm/L (47 +/- 1 mg/dL) and 1.0 +/- .1 mm/L (38 +/- 1 mg/dL). Mean triglyceride levels were 1.5 +/- .1 mm/L (135 +/- 5 mg/dL) for women and 1.6 +/- .1 mm/L (138 +/- 5 mg/dL) for men. Further, mean values remained stable over time. However, there was considerable intraindividual change observed in a substantial proportion of subjects between initial and final determinations. Changes of at least 10% from baseline were observed in 41%, 63%, 52%, and 78% of the cohort for cholesterol, HDL, LDL, and triglycerides, respectively. Thus, single measurements appear inadequate for establishing a diagnosis of hyperlipidemia in the elderly.     

Comparison of effects of lauric acid and palmitic acid on plasma lipids and lipoproteins.

The effects of lauric acid (C12:0) on plasma lipids and lipoproteins were compared with the effects of palmitic acid (C16:0) and oleic acid (C18:1) in a metabolic-diet study of 14 men by using liquid-formula diets fed for 3 wk each in random order. Lauric acid was supplied in a synthetic high-lauric oil, palmitic acid was provided by palm oil and oleic acid in oleic-rich sunflower seed oil. The high-lauric oil resulted in higher concentrations of plasma total cholesterol (4.94 +/- 0.75 mmol/L [mean +/- SE]) and LDL cholesterol (3.70 +/- 0.57 mmol/L) when compared with high-oleic sunflower oil (4.44 +/- 0.54 and 3.31 +/- 0.44 mmol/L, respectively), but did not raise total and LDL cholesterol concentrations as much as did palm oil (5.17 +/- 0.65 and 3.93 +/- 0.51 mmol/L, respectively). No differences were noted in plasma triglycerides or HDL cholesterol. Lauric acid raises total and LDL cholesterol concentrations compared with oleic acid, but is not as potent for increasing cholesterol concentrations as is palmitic acid.     

慢性三氯化镧暴露对大鼠血糖和血脂水平的影响

目的探讨稀土元素镧的慢性暴露对大鼠血糖、血脂的影响。方法分别以0.1、2和40 mg/kg剂量的三氯化镧(LaC l3)给大鼠经口灌胃,每天1次,90 d后处死;取全血测定糖化血红蛋白(HbA1 c),分离血清测定血糖(G lu)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)水平。结果与对照组相比,3个LaC l3暴露剂量组大鼠HbA1C、血清G lu、TG和LDL-C水平无统计学意义;0.1和2 mg/kg剂量LaC l3暴露组大鼠血清TC水平分别为(1.38±0.14)mmol/L和(1.37±0.26)mmol/L,与对照组大鼠(1.57±0.14)mmol/L相比有明显降低;0.1 mg/kg剂量LaC l3暴露组大鼠血清HDL-C为(0.79±0.12)mmol/L,比对照组大鼠(0.93±0.10)mmol/L有明显降低。结论0.1~40 mg/kg LaC l3慢性暴露对大鼠血清G lu、TG和LDL-C水平无显著影响;低、中剂量LaC l3慢性暴露可使大鼠血清TC和HDL-C降低。     

Fasting increases serum total cholesterol, LDL cholesterol and apolipoprotein B in healthy, nonobese humans.

Voluntary fasting is practiced by many humans in an attempt to lose body weight. Conflicting results have been published on the effects of food deprivation on serum lipids. To study the effect of acute starvation on serum lipids, 10 nonobese (93-124% of ideal body weight), healthy adults (6 men, 4 women, 21-38 y old) fasted (no energy) for 7 d. Fasting increased total serum cholesterol from 4.90 +/- 0.23 to 6.73 +/- 0.41 mmol/L (37.3 +/- 5.0%; P < 0.0001) and LDL cholesterol from 2.95 +/- 0.21 to 4.90 +/- 0.36 mmol/L (66.1 +/- 6. 6%; P < 0.0001). Serum apolipoprotein B (apo B) increased from 0.84 +/- 0.06 to 1.37 +/- 0.11 g/L (65.0 +/- 9.2%; P < 0.0001). The increases in serum cholesterol, LDL and apo B were associated with weight loss. Fasting did not affect serum concentrations of triacylglycerol and HDL cholesterol. Serum concentrations of insulin-like growth factor-I (IGF-I) decreased from 246 +/- 29 (prefast) to 87 +/- 10 microg/L after 1 wk of fasting (P < 0.0001). We conclude that, in nonobese subjects, fasting is accompanied by increases in serum cholesterol, LDL and apo B concentrations, whereas IGF-I levels are decreased.     

Dietary polyunsaturated to saturated fatty acid ratio alters hepatic LDL transport in cynomolgus macaques fed low cholesterol diets.

To determine effect of interaction between dietary cholesterol and triglyceride, i.e., polyunsaturated to saturated (P:S) fatty acid ratio, on LDL metabolism, male cynomolgus macaques were fed purified diets for 83 wk with cholesterol levels of 0.01, 0.06 and 0.50 mg/kJ and P:S ratios of 0.5 and 0.9, oleic acid constant. There were six groups of five animals each (cholesterol, mg/kJ--P:S ratio): Group 1, 0.01--0.5; Group 2, 0.01--0.9; Group 3, 0.06--0.5; Group 4, 0.06--0.9; Group 5, 0.50-0.5; Group 6, 0.50-0.9. LDL (1.019 less than d less than 1.063 kg/L) and glucosylated LDL were iodinated for turnover studies. Hepatic LDL transport was determined using 125I-tyramine-cellobiose-LDL as tracer. Plasma cholesterol increased in proportion to dietary cholesterol, and concentrations (mmol/L) at 77-78 wk were (mean +/- SEM): Group 1, 434 +/- 0.31; Group 2, 3.03 +/- 0.14; Group 3, 8.28 +/- 1.48; Group 4, 7.34 +/- 1.31; Group 5, 15.54 +/- 1.44; Group 6, 15.54 +/- 1.41. LDL cholesterol was 45% higher in Group 1 (2.43 mmol/L) than in Group 2 (1.68 mmol/L). In vivo studies showed that LDL clearance was suppressed by excess dietary cholesterol; receptor-independent LDL clearance was relatively constant. Hepatic LDL protein transport was greater in Group 2 (P:S 0.9) compared with Group 1 (P:S 0.5). The LDL protein synthetic rate was lower in Groups 2, 4 and 6 (P:S 0.9) relative to Groups 1, 3 and 5 (P:S 0.5). We conclude that in this model hepatic LDL receptor activity is altered by degree of saturation in dietary triglycerides when dietary cholesterol is minimal, and that saturated dietary triglycerides enhance LDL protein secretion when dietary cholesterol is ample.     

Green tea catechins decrease total and low-density lipoprotein cholesterol: a systematic review and meta-analysis

Green tea catechins (GTCs) have been studied in randomized control trials for their lipid-lowering effects. Studies, however, have been small and demonstrated conflicting results. The objective of this study was to perform a systematic review and meta-analysis of randomized controlled trials evaluating the relationship between GTCs and serum lipid levels, including total, low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol, and triglycerides. A systematic literature search of MEDLINE, EMBASE, Cochrane CENTRAL, and the Natural Medicines Comprehensive Database was conducted through March 2010. Randomized controlled trials evaluating GTCs vs control in human beings and reporting efficacy data on at least one of the aforementioned serum lipid endpoints were included. Weighted mean differences for changes from baseline (with 95% confidence intervals [CIs]) for lipid endpoints were calculated using random-effects models. Twenty trials (N=1,415) met all inclusion criteria. Upon meta-analysis, GTCs at doses ranging from 145 to 3,000 mg/day taken for 3 to 24 weeks reduced total (−5.46 mg/dL [−0.14 mmol/L]; 95% CI −9.59 to −1.32) and LDL cholesterol (−5.30 mg/dL [−0.14 mmol/L]; 95% CI −9.99 to −0.62) compared to control. GTCs did not significantly alter HDL cholesterol (−0.27 mg/dL [−0.007 mmol/L]; 95% CI −1.62 to 1.09) or triglyceride (3.00 mg/dL [−0.034 mmol/L]; 95% CI −2.73 to 8.73) levels. The consumption of GTCs is associated with a statistically significant reduction in total and LDL cholesterol levels; however, there was no significant effect on HDL cholesterol or triglyceride levels.     

Serum lipid response to the graduated enrichment of a Step I diet with almonds: a randomized feeding trial

BACKGROUND: Frequent consumption of nuts may lower the risk of cardiovascular disease by favorably altering serum lipid and lipoprotein concentrations. OBJECTIVE: We compared the effects of 2 amounts of almond intake with those of a National Cholesterol Education Program Step I diet on serum lipids, lipoproteins, apolipoproteins, and glucose in healthy and mildly hypercholesterolemic adults. DESIGN: In a randomized crossover design, 25 healthy subjects (14 men, 11 women) with a mean (+/- SD) age of 41 +/- 13 y were fed 3 isoenergetic diets for 4 wk each after being fed a 2-wk run-in diet (containing 34% of energy from fat). The experimental diets included a Step I diet, a low-almond diet, and a high-almond diet, in which almonds contributed 0%, 10%, and 20% of total energy, respectively. RESULTS: Inverse relations were observed between the percentage of energy in the diet from almonds and the subject's total cholesterol (P value for trend < 0.001), LDL-cholesterol (P < 0.001), and apolipoprotein B (P < 0.001) concentrations and the ratios of LDL to HDL cholesterol (P < 0.001) and of apolipoprotein B to apolipoprotein A (P < 0.001). Compared with the Step I diet, the high-almond diet reduced total cholesterol (0.24 mmol/L or 4.4%; P = 0.001), LDL cholesterol (0.26 mmol/L or 7.0%; P < 0.001), and apolipoprotein B (6.6 mg/dL or 6.6%; P < 0.001); increased HDL cholesterol (0.02 mmol/L or 1.7%; P = 0.08); and decreased the ratio of LDL to HDL cholesterol (8.8%; P < 0.001). CONCLUSIONS: Isoenergetic incorporation of approximately 68 g of almonds (20% of energy) into an 8368-kJ (2000-kcal) Step I diet markedly improved the serum lipid profile of healthy and mildly hypercholesterolemic adults. Total and LDL-cholesterol concentrations declined with progressively higher intakes of almonds, which suggests a dose-response relation.     

Plasma zinc concentration increases within 2 weeks in healthy Senegalese men given liquid supplemental zinc, but not zinc-fortified wheat bread

The responsiveness of plasma zinc concentration to zinc fortification is uncertain. Our objective in this study was to determine whether plasma zinc concentration changes in response to consuming zinc-fortified foods or liquid zinc supplements. We conducted a 4-wk double-blind, randomized trial among 132 healthy Senegalese men ≥ 18 y. Participants received 1 of 4 interventions: 1) (control) 200 g/d of wheat bread fortified with iron and folic acid, but not zinc, and a liquid multivitamin supplement without zinc between meals; 2) (zinc supplement) the same bread and the same multivitamin supplement with 15 mg zinc as ZnSO(4) added; 3) (moderate zinc fortification) the same bread cofortified with 7.5 mg zinc as ZnO and the same multivitamin supplement without zinc; or 4) (high zinc fortification) the same bread cofortified with 15 mg zinc as ZnO and the same multivitamin supplement without zinc. Fasting blood samples were collected twice at baseline and at d 15 and 29 of the intervention. There was no significant interaction between group and study day (P = 0.11). However, at d 15, the mean change in plasma zinc concentration in the zinc-supplemented group was greater than in the placebo and fortification groups ( 0.72 μmol/L vs. -0.09 to 0.03 μmol/L; P = 0.05). At d 29 there were no significant group-wise differences. Across all time points, the zinc-supplemented group was the only group where plasma zinc concentration increased from baseline (P = 0.006). These results suggest that plasma zinc concentration may not be a sufficiently sensitive indicator to evaluate short-term responses to zinc fortification.     

Dietary cholesterol from eggs increases plasma HDL cholesterol in overweight men consuming a carbohydrate-restricted diet

Carbohydrate-restricted diets (CRD) significantly decrease body weight and independently improve plasma triglycerides (TG) and HDL cholesterol (HDL-C). Increasing intake of dietary cholesterol from eggs in the context of a low-fat diet maintains the LDL cholesterol (LDL-C)/HDL-C for both hyper- and hypo-responders to dietary cholesterol. In this study, 28 overweight/obese male subjects (BMI = 25-37 kg/m2) aged 40-70 y were recruited to evaluate the contribution of dietary cholesterol from eggs in a CRD. Subjects were counseled to consume a CRD (10-15% energy from carbohydrate) and they were randomly allocated to the EGG group [intake of 3 eggs per day (640 mg/d additional dietary cholesterol)] or SUB group [equivalent amount of egg substitute (0 dietary cholesterol) per day]. Energy intake decreased in both groups from 10,243 +/- 4040 to 7968 +/- 2401 kJ (P < 0.05) compared with baseline. All subjects irrespective of their assigned group had reduced body weight and waist circumference (P < 0.0001). Similarly, the plasma TG concentration was reduced from 1.34 +/- 0.66 to 0.83 +/- 0.30 mmol/L after 12 wk (P < 0.001) in all subjects. The plasma LDL-C concentration, as well as the LDL-C:HDL-C ratio, did not change during the intervention. In contrast, plasma HDL-C concentration increased in the EGG group from 1.23 +/- 0.39 to 1.47 +/- 0.38 mmol/L (P < 0.01), whereas HDL-C did not change in the SUB group. Plasma glucose concentrations in fasting subjects did not change. Eighteen subjects were classified as having the metabolic syndrome (MetS) at the beginning of the study, whereas 3 subjects had that classification at the end. These results suggest that including eggs in a CRD results in increased HDL-C while decreasing the risk factors associated with MetS.