Alpha-Lipoic Acid Improves Vascular Tone in Overweight Youth

by | Mar 11, 2019 | 2019, Alpha Lipoic Acid, Antioxidants, Infant and Children's Health, Obesity

Written by Angeline A. De Leon, Staff Writer. Three months of alpha lipoic acid supplementation significantly improved vascular tone and clinical and metabolic risk factors, offering a potential beneficial effect on cardiovascular health in overweight and obese youth.

weight controlWhile obesity has represented a world-wide public health challenge for several decades now, years, the recent prevalence of childhood obesity has become increasingly concerning. 1. Obese children may exhibit signs of cardiovascular dysfunction 2, one of the most critical symptoms being endothelial dysfunction, which precedes the development of atherosclerosis 3. The endothelium is a membrane lining the inside of the heart and blood vessels and is involved in controlling vascular contraction and relaxation as well as blood flow. Damage to the endothelium can reduce the availability of vasodilators like nitric oxide (NO, a relaxing factor) and/or increase contracting factors, resulting in impaired vasodilation (dilation of blood vessels) and chronic inflammation which can lead to atherosclerosis 3. Antioxidant therapy with natural compounds capable of protecting against oxidative damage may be helpful in mitigating endothelial dysfunction and other obesity-related CVD risk factors. In this context, alpha-lipoic acid (ALA), a powerful antioxidant found in red meat and dark green leafy vegetables 4, is a promising supplement, as it demonstrates the ability to improve endothelial-dependent NO-mediated vasodilation in patients with type 2 diabetes and metabolic syndrome 5 as well as in youth with type 1 diabetes 6. Studies have also shown that ALA’s anti-inflammatory properties may protect against high cholesterol levels and hypertension 7,8. In 2019, researchers at the University of Rome conducted the first investigation 9 looking at the effects of ALA on the cardiovascular health of overweight/obese youth, evaluating endothelial function and various metabolic factors following a three-month period of ALA supplementation.

A total of 67 overweight/obese children (aged 8-16 years, body mass index (BMI) > 85th percentile based on respective age group and gender) and 22 normal-weight, metabolically healthy controls (also aged 8-16 years) were enrolled in a double-blind, parallel-group, placebo-controlled randomized trial. Overweight subjects were randomly allocated to consume ALA (800 mg/dose) or matching placebo once daily for 12 weeks. All patients were prescribed a balanced low-calorie diet and encouraged to perform moderate exercise daily during the treatment period. Researchers conducted an ultrasound measure of the flow-mediated dilation (FMD) of the brachial artery in the upper arm (a measure of endothelium-dependent relaxation of the artery) and computed a maximum FMD value (expressed as percentage change from basal diameter). Participants also completed a physical examination which included measurements of weight, BMI, waist circumference, and blood pressure. Fasting blood samples were collected to determine glucose, insulin resistance using the homeostasis model assessment of insulin resistance (HOMA-IR), total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, and alanine aminotransferase (ALT), an indicator of liver damage.

At baseline, the FMD of the ALA and placebo groups were similar (12.5% for both) and categorically lower, as compared to normal-weight controls (24%, p = 0.045). After three months of treatment, no significant differences were apparent for ALA and placebo groups on anthropometric and metabolic variables nor for FMD. However, the basal and peak diameter of the brachial artery was seen to significantly increase following ALA treatment vs. treatment with placebo (p = 0.036, p = 0.01, respectively), indicative of peripheral vasodilation and improved arterial tone.

Evidence from the study points to an association of ALA supplementation with significantly increased basal and peak vessel diameters, reflecting vasodilatory effects and improved vascular tone. However, no significant changes were apparent in terms of the actual FMD index nor any of the other markers of cardiovascular health. It also remains unclear whether the improvement seen in arterial tone was due to enhanced endothelial function and greater release of NO. The lack of significant findings and the inability to draw conclusions about the mechanisms involved in the vasodilatory effects observed may be related to the primary limitations of the study: a small sample size, a relatively short treatment duration, and the failure to include a measure of oxidative stress in the study. Although the evidence is weak, the investigation does suggest favorable effects of ALA on the cardiovascular health of overweight youth.

Source: Tromba L, Perla FM, Carlotta G, et al. Effect of alpha-lipoic acid supplementation on endothelial function and cardiovascular risk factors in overweight/obese youths: a double-blind, placebo-controlled randomized trial. Nutrients. 2019; 11: 375. DOI: 10.3390/nu110200375.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access Article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

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Posted March 11, 2019.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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