Effects of Zinc supplementation on serum lipids: a systematic review and meta-analysis

Abstract

Zinc is a mineral that plays a vital role in many biological processes and plays an important role in insulin action and carbohydrate metabolism. It may also have a protective role in the prevention of atherogenesis. Numerous studies have evaluated the effects of Zinc supplementation on serum lipids in humans and have demonstrated varying results. We systematically evaluated the literature and performed a meta-analysis on the effects of Zinc supplementation on serum lipids. A five staged comprehensive search of the literature was conducted in the following databases; PubMed, Web of Science and SciVerse Scopus for studies published before 31st December 2014. All controlled clinical trial in humans, that included a Zinc supplement intervention, either alone or in combination with other micronutrients and evaluated effects on serum lipids (total cholesterol [TC], triglycerides [TG], LDL cholesterol [LDL-c] and HDL cholesterol [HDL-c]). A meta-analysis of selected studies was performed using RevMan v5.3. The Jaded scale was used to assess the methodological quality of the trials included in the systematic review. A total of 24 studies were included in Meta analysis, which included a total of 33 Zinc interventions, in a total of 14,515 participants in the Zinc intervention or control group. The duration of Zinc supplementation ranged from 1 month to 7.5 years. The dose of elemental Zinc supplemented ranged from 15–240 mg/day. The pooled mean difference for TC between Zinc supplemented and placebo groups from random effects analysis was −10.92 mg/dl (95 % CI: −15.33, −6.52; p < 0.0001, I2 = 83 %), while for HDL cholesterol it was 2.12 mg/dl (95 % CI: −0.74, 4.98; p = 0.15, I2 = 83 %). The pooled mean difference for LDL-c between Zinc supplemented and placebo group from random effect analysis was −6.87 mg/dl (95 % CI: −11.16,-2.58; p < 0.001, I2 = 31) and for TG it was −10.92 mg/dl (95 % CI: −18.56, − 3.28; p < 0.01, I2 = 69 %). In conclusion, Zinc supplementation has favourable effects on plasma lipid parameters. Zinc supplementation significantly reduced total cholesterol, LDL cholesterol and triglycerides. Therefore it may have the potential to reduce the incidence of atherosclerosis related morbidity and mortality.

Zinc supplementation in prediabetes: A randomized double‐blind placebo‐controlled clinical trial

“…Numerous recent studies have shown that reducing LDL‐C decreases the incidence of cardiac events and the rate of disease progression; this is especially important in patients with dysglycemia, in which cardiovascular disease is the leading cause of death . Therefore it can be postulated that zinc supplementation can also help reduce cardiovascular events by reducing LDL‐C . Several molecular mechanisms are believed to be involved in reducing serum lipid levels following zinc supplementation, and these have been summarized elsewhere …”

“…Therefore it can be postulated that zinc supplementation can also help reduce cardiovascular events by reducing LDL‐C . Several molecular mechanisms are believed to be involved in reducing serum lipid levels following zinc supplementation, and these have been summarized elsewhere …”

Effects of zinc supplementation on obesity: study protocol for a randomized controlled clinical trial

“…The treatment drug is a capsule containing elemental zinc 20 mg as the active ingredient (as zinc sulphate). The supplemented Zn dose was set based on a previous study published in the literature [14]. The placebo capsule will contain lactose monohydrate.…”

“…Studies have reported that Zn has been implicated in altered lipid markers, insulin resistance, oxidative stress, inflammatory markers [11, 12], adiposity and serum leptin level [13]. Furthermore, a recent review and meta-analysis reported that zinc supplementation has favourable effects on plasma lipid parameters and that it also significantly reduces total cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides [14]. A high prevalence of coronary artery disease (hypertension, hypertriglyceridaemia and low high-density lipoprotein (HDL) cholesterol levels), diabetes and glucose intolerance was reported in populations consuming lower intakes of dietary zinc [15].…”

Level of Zinc and Its Fractions as Reflection of a Condition of Antioxidant System at the Chronic Obstructive Lung Disease

“…Установлено, что дефицит цинка ухудшает синтез СОД, что приво-дит к увеличению выраженности оксидативного стресса [10].…”