Multivitamin/Multimineral Supplementation Prevents or Reverses Decline in Vitamin Biomarkers and Cellular Energy Metabolism in Healthy Older Men: A Randomized, Double-Blind, Placebo-Controlled Study.

Despite the reported prevalence of micronutrient deficiencies in older adults, it is not yet established whether multivitamin/multimineral (MV/MM) supplements improve blood micronutrient status in individuals over the age of 65. Therefore, a cohort of 35 healthy men (>67 years) was recruited for an MV/MM supplementation trial. The primary endpoint was, as an indicator of micronutrient status, changes in blood micronutrient biomarkers from baseline to at least six months of supplementation with MV/MM or placebo. The secondary endpoint was basal O2 consumption in monocytes as an indicator of cellular metabolism. MV/MM supplementation improved blood concentrations of pyridoxal phosphate, calcifediol, α-tocopherol, and ß-carotene concentrations throughout the cohort. By contrast, those in the placebo group generally showed declines in blood vitamin concentrations and an increased prevalence of suboptimal vitamin status during the study period. On the other hand, MV/MM supplementation did not significantly affect blood mineral concentrations, i.e., calcium, copper, iron, magnesium, and zinc. Interestingly, MV/MM supplementation prevented the decline in monocyte O2 consumption rate. Overall, MV/MM use improves or prevents declines in vitamin, but not mineral, status and limits declines in cellular O2 consumption, which may have important implications for metabolism and immune health in healthy older men.

A Randomized Controlled Trial of Long-Term (R)-α-Lipoic Acid Supplementation Promotes Weight Loss in Overweight or Obese Adults without Altering Baseline Elevated Plasma Triglyceride Concentrations.

BACKGROUND: α-Lipoic acid (LA) is a dietary supplement for maintaining energy balance, but well-controlled clinical trials in otherwise healthy, overweight adults using LA supplementation are lacking. OBJECTIVES: The primary objective was to evaluate whether LA supplementation decreases elevated plasma triglycerides in overweight or obese adults. Secondary aims examined if LA promotes weight loss and improves oxidative stress and inflammation. METHODS: Overweight adults [n = 81; 57% women; 21-60 y old; BMI (in kg/m2) ≥ 25] with elevated plasma triglycerides ≥100 mg/dL were enrolled in a 24-wk, randomized, double-blind, controlled trial, assigned to either (R)-α-lipoic acid (R-LA; 600 mg/d) or matching placebo, and advised not to change their diet or physical activity. Linear models were used to evaluate treatment effects from baseline for primary and secondary endpoints. RESULTS: R-LA did not decrease triglyceride concentrations, but individuals on R-LA had a greater reduction in BMI at 24 wk than the placebo group (-0.8; P = 0.04). The effect of R-LA on BMI was correlated to changes in plasma triglycerides (r = +0.50, P = 0.004). Improvement in body weight was greater at 24 wk in R-LA subgroups than in placebo subgroups. Women and obese participants (BMI ≥ 35) showed greater weight loss (-5.0% and -4.8%, respectively; both P < 0.001) and loss of body fat (-9.4% and -8.6%, respectively; both P < 0.005). Antioxidant gene expression in mononuclear cells at 24 wk was greater in the R-LA group (Heme oxygenase 1 [HMOX1] : +22%; P = 0.02) than in placebo. Less urinary F2-isoprostanes (-25%; P = 0.005), blood leukocytes (-10.1%; P = 0.01), blood thrombocytes (-5.1%; P = 0.03), and ICAM-1 (-7.4%; P = 0.04) at 24 wk were also observed in the R-LA group than in placebo. CONCLUSIONS: Long-term LA supplementation results in BMI loss, greater antioxidant enzyme synthesis, and less potential for inflammation in overweight adults. Improved cellular bioenergetics is also evident in some individuals given R-LA.This trial was registered at clinicaltrials.gov as NCT00765310.

Human genetic variation influences vitamin C homeostasis by altering vitamin C transport and antioxidant enzyme function.

New evidence for the regulation of vitamin C homeostasis has emerged from several studies of human genetic variation. Polymorphisms in the genes encoding sodium-dependent vitamin C transport proteins are strongly associated with plasma ascorbate levels and likely impact tissue cellular vitamin C status. Furthermore, genetic variants of proteins that suppress oxidative stress or detoxify oxidatively damaged biomolecules, i.e., haptoglobin, glutathione-S-transferases, and possibly manganese superoxide dismutase, affect ascorbate levels in the human body. There also is limited evidence for a role of glucose transport proteins. In this review, we examine the extent of the variation in these genes, their impact on vitamin C status, and their potential role in altering chronic disease risk. We conclude that future epidemiological studies should take into account genetic variation in order to successfully determine the role of vitamin C nutriture or supplementation in human vitamin C status and chronic disease risk.

Age and gender dependent bioavailability of R- and R,S-α-lipoic acid: a pilot study.

Lipoic acid (LA) shows promise as a beneficial micronutrient toward improving elder health. Studies using old rats show that (R)-α-LA (R-LA) significantly increases low molecular weight antioxidants that otherwise decline with age. Despite this rationale for benefiting human health, little is known about age-associated alterations in absorption characteristics of LA, or whether the commercially available racemic mixture of LA (R,S-LA) is equally as bioavailable as the naturally occurring R-enantiomer. To address these discrepancies, a pilot study was performed to establish which form of LA is most effectively absorbed in older subjects relative to young volunteers. Young adults (average age=32 years) and older adults (average age=79 years) each received 500 mg of either R- or R,S-LA. Blood samples were collected for 3h after supplementation. After a washout period they were given the other chiral form of LA not originally ingested. Results showed that 2 out of 6 elder males exhibited greater maximal plasma LA and area under the curve for the R-form of LA versus the racemic mixture. The elder subjects also demonstrated a reduced time to reach maximal plasma LA concentration following R-LA supplementation than for the racemic mixture. In contrast, young males had a tendency for increased bioavailability of R,S-LA. Overall, bioavailability for either LA isoform was much more variable between older subjects compared to young adults. Plasma glutathione levels were not altered during the sampling period. Thus subject age, and potential for varied response, should be considered when determining an LA supplementation regimen.

Acetyl-L-carnitine supplementation reverses the age-related decline in carnitine palmitoyltransferase 1 (CPT1) activity in interfibrillar mitochondria without changing the L-carnitine content in the rat heart.

The aging heart displays a loss of bioenergetic reserve capacity partially mediated through lower fatty acid utilization. We investigated whether the age-related impairment of cardiac fatty acid catabolism occurs, at least partially, through diminished levels of L-carnitine, which would adversely affect carnitine palmitoyltransferase 1 (CPT1), the rate-limiting enzyme for fatty acyl-CoA uptake into mitochondria for ß-oxidation. Old (24-28 mos) Fischer 344 rats were fed±acetyl-L-carnitine (ALCAR; 1.5% [w/v]) for up to four weeks prior to sacrifice and isolation of cardiac interfibrillar (IFM) and subsarcolemmal (SSM) mitochondria. IFM displayed a 28% (p<0.05) age-related loss of CPT1 activity, which correlated with a decline (41%, p<0.05) in palmitoyl-CoA-driven state 3 respiration. Interestingly, SSM had preserved enzyme function and efficiently utilized palmitate. Analysis of IFM CPT1 kinetics showed both diminished V(max) and K(m) (60% and 49% respectively, p<0.05) when palmitoyl-CoA was the substrate. However, no age-related changes in enzyme kinetics were evident with respect to L-carnitine. ALCAR supplementation restored CPT1 activity in heart IFM, but not apparently through remediation of L-carnitine levels. Rather, ALCAR influenced enzyme activity over time, potentially by modulating conditions in the aging heart that ultimately affect palmitoyl-CoA binding and CPT1 kinetics.

R-α-lipoic acid does not reverse hepatic inflammation of aging, but lowers lipid anabolism, while accentuating circadian rhythm transcript profiles.

To determine the effects of age and lipoic acid supplementation on hepatic gene expression, we fed young (3 mo) and old (24 mo) male Fischer 344 rats a diet with or without 0.2% (wt/wt) R-α-lipoic acid (LA) for 2 wk. Total RNA isolated from liver tissue was analyzed by Affymetrix microarray to examine changes in transcriptional profiles. Results showed elevated proinflammatory gene expression in the aging liver and evidence for increased immune cell activation and tissue remodeling, together representing 45% of the age-related transcriptome changes. In addition, age-related increases in transcripts of genes related to fatty acid, triglyceride, and cholesterol synthesis, including acetyl-CoA carboxylase-ß (Acacb) and fatty acid synthase (Fasn), were observed. Supplementation of old animals with LA did not reverse the necroinflammatory phenotype but, intriguingly, altered the expression of genes governing circadian rhythm. Most notably, Arntl, Npas2, and Per changed in a coordinated manner with respect to rhythmic transcription. LA further caused a decrease in transcripts of several bile acid and lipid synthesis genes, including Acacb and Fasn, which are regulated by first-order clock transcription factors. Similar effects of LA supplementation on bile acid and lipid synthesis genes were observed in young animals. Transcript changes of lipid metabolism genes were corroborated by a decrease in FASN and ACC protein levels. We conclude that advanced age is associated with a necroinflammatory phenotype and increased lipid synthesis, while chronic LA supplementation influences hepatic genes associated with lipid and energy metabolism and circadian rhythm, regardless of age.

Vascular oxidative stress and inflammation increase with age: ameliorating effects of alpha-lipoic acid supplementation.

Increased oxidative stress and inflammation causally contribute to cardiovascular diseases, for which advanced age is a major risk factor. We found that indicators of oxidative stress, including NADPH oxidase activity and superoxide levels, were significantly increased in aortas of old (22-24 months) versus young (3-4 months) male F344 rats, whereas superoxide dismutase (SOD) activity was decreased. Aortic mRNA and protein levels of NOX4, the principal catalytic subunit of NADPH oxidase in vascular cells, also were increased with age, but not NOX2 and p22(phox). Indicators of inflammation, including activation of NFkappaB and upregulation of vascular cell adhesion molecule-1 (VCAM-1) in aorta, and monocyte chemotactic protein-1 (MCP-1) in plasma, also were significantly increased in old rats. Supplementation with 0.2% (wt/wt) (R)-alpha-lipoic acid (LA) for 2 weeks caused a nonsignificant decrease in NADPH oxidase activity in aged aorta and a significant decrease in mRNA--but not protein--levels of NOX4 and VCAM-1. Furthermore, LA reversed the age-dependent changes in aortic SOD activity and plasma MCP-1 levels. Hence, vascular oxidative stress and inflammation increase with age and are ameliorated by LA supplementation.

Alpha-lipoic acid as a dietary supplement: molecular mechanisms and therapeutic potential.

Alpha-lipoic acid (LA) has become a common ingredient in multivitamin formulas, anti-aging supplements, and even pet food. It is well-defined as a therapy for preventing diabetic polyneuropathies, and scavenges free radicals, chelates metals, and restores intracellular glutathione levels which otherwise decline with age. How do the biochemical properties of LA relate to its biological effects? Herein, we review the molecular mechanisms of LA discovered using cell and animal models, and the effects of LA on human subjects. Though LA has long been touted as an antioxidant, it has also been shown to improve glucose and ascorbate handling, increase eNOS activity, activate Phase II detoxification via the transcription factor Nrf2, and lower expression of MMP-9 and VCAM-1 through repression of NF-kappa B. LA and its reduced form, dihydrolipoic acid, may use their chemical properties as a redox couple to alter protein conformations by forming mixed disulfides. Beneficial effects are achieved with low micromolar levels of LA, suggesting that some of its therapeutic potential extends beyond the strict definition of an antioxidant. Current trials are investigating whether these beneficial properties of LA make it an appropriate treatment not just for diabetes, but also for the prevention of vascular disease, hypertension, and inflammation.

Dietary alpha-lipoic acid supplementation inhibits atherosclerotic lesion development in apolipoprotein E-deficient and apolipoprotein E/low-density lipoprotein receptor-deficient mice.

BACKGROUND: Vascular inflammation and lipid deposition are prominent features of atherosclerotic lesion formation. We have shown previously that the dithiol compound alpha-lipoic acid (LA) exerts antiinflammatory effects by inhibiting tumor necrosis factor-alpha- and lipopolysaccharide-induced endothelial and monocyte activation in vitro and lipopolysaccharide-induced acute inflammatory responses in vivo. Here, we investigated whether LA inhibits atherosclerosis in apolipoprotein E-deficient (apoE-/-) and apoE/low-density lipoprotein receptor-deficient mice, 2 well-established animal models of human atherosclerosis. METHODS AND RESULTS: Four-week-old female apoE-/- mice (n=20 per group) or apoE/low-density lipoprotein receptor-deficient mice (n=21 per group) were fed for 10 weeks a Western-type chow diet containing 15% fat and 0.125% cholesterol without or with 0.2% (wt/wt) R,S-LA or a normal chow diet containing 4% fat without or with 0.2% (wt/wt) R-LA, respectively. Supplementation with LA significantly reduced atherosclerotic lesion formation in the aortic sinus of both mouse models by approximately 20% and in the aortic arch and thoracic aorta of apoE-/- and apoE/low-density lipoprotein receptor-deficient mice by approximately 55% and 40%, respectively. This strong antiatherogenic effect of LA was associated with almost 40% less body weight gain and lower serum and very low-density lipoprotein levels of triglycerides but not cholesterol. In addition, LA supplementation reduced aortic expression of adhesion molecules and proinflammatory cytokines and aortic macrophage accumulation. These antiinflammatory effects of LA were more pronounced in the aortic arch and the thoracic aorta than in the aortic sinus, reflecting the corresponding reductions in atherosclerosis. CONCLUSIONS: Our study shows that dietary LA supplementation inhibits atherosclerotic lesion formation in 2 mouse models of human atherosclerosis, an inhibition that appears to be due to the "antiobesity," antihypertriglyceridemic, and antiinflammatory effects of LA. LA may be a useful adjunct in the prevention and treatment of atherosclerotic vascular diseases.

Thiol supplementation inhibits metalloproteinase activity independent of glutathione status.

Matrix metalloproteinases (MMPs) are proteolytic enzymes that regulate both integrity and composition of the extracellular matrix (ECM). Excessive ECM breakdown by MMPs is implicated in many physiological and pathological conditions, such as atherosclerosis. Activated macrophages, especially in the atherosclerotic lesion, are a major source of reactive oxygen species (ROS). Antioxidants protect against ROS-induced MMPs activation and inhibit gelatinolytic activity. We sought to determine whether the antioxidants glutathione (GSH), N-acetylcysteine (NAC), or lipoic acid (LA) affect gelatinase production and secretion. The results show that thiol compounds affect MMPs expression and activity in different ways. MMP-2 activity is directly inhibited by NAC and GSH, while LA is ineffective. On the contrary, MMP-9 expression is inhibited by LA at a pretrascriptional level, and MMP-9 activity is stimulated by GSH through a direct interaction with the gelatinase itself. Although all thiols, these compounds have different properties and different cellular uptakes and metabolic characteristics, and this could explain, at least in part, their differential effects on MMPs.