Effect of onion on blood lipid profile: A meta‐analysis of randomized controlled trials

Abstract

Background Studies indicate that onion supplementation may be effective in the treatment of dyslipidemia; however, the results remain controversial. This meta‐analysis was conducted to evaluate potential benefits of onion on lipid profile. Methods Up to 12 October 2020, PubMed, Cochrane Library, Web of Science, and Scopus were searched for randomized controlled trials evaluating the effects of onion on lipid profile. Mean differences (MD) and 95% confidence intervals (CI) were calculated. Meta‐analysis was conducted using the fixed‐effects model. Results Ten trials with 446 participants in total were included in the meta‐analysis. The pooled findings of 10 studies suggested that onion supplementation significantly improved high‐density lipoprotein cholesterol (HDL) (MD: 2.29 mg/dl; 95% CI: 0.87, 3.72; I2 = 0%) and low‐density lipoprotein cholesterol (LDL) (MD: −6.64 mg/dl; 95% CI: −10.91, −2.36; I2 = 32%),while onion supplementation did not significantly lower triglycerides (TG) (MD: −6.55 mg/dl; 95% CI: −15.64, 2.53; I2 = 45%). Analysis of nine trials showed a significant reduction in total cholesterol (TC) (MD: −5.39 mg/dl; 95% CI: −10.68, −0.09; I2 = 49%) in patients with onion supplementation compared to the control group. Conclusion In summary, supplementation of onion was beneficial to control dyslipidemia, including improving levels of HDL, LDL, and TC, but could not reduce TG level. The therapeutic benefits of onion for dyslipidemia need to be treated with caution considering that some of the results are not robust.

Diet Fortification with <i>Curcuma longa</i> and <i>Allium cepa</i> Ameliorates 2,3,7,8-Tetracholorodibenzop-dioxin-induced Dyslipideamia and Oxidative Stress in Wistar Rats

“…These could be attributed to its rich fibre and flavonoids (Hamauzu et al, 2011). Our result is consistent with the finding of Huang et al (2021) who reported that supplementation of onion has beneficial effect on dyslipidemia. It is evident from our finding that diet supplementation with onion could prevent atherosclerosis, a common feature of dioxin toxicity since according to Mattiuzzi et al (2020), controlling blood lipid decreases the risk of atherosclerosis and/or cardiovascular disease.…”

The beneficial effect of Allium Cepa bulb extract on reproduction of rats; A two-generation study on fecundity and sex hormones

“…Cepa demonstrated potential benefits in maintaining the animal’s good health [ 67 ]. A study also reported that onion extract has blood lipid levels reducing potential [ 68 ]. Thus, we can conclude that Allium Cepa can efficiently decrease the health risk of cardiovascular events in both genders as it is rich in fiber and flavonoids [ 69 , 70 ].…”