What is your opinion in the article of Onion peel tea ameliorates obesity and affects blood parameters in a mouse model of high‑fat‑diet‑induced obesity?

Question

Link of article-

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3881067/

Answer 1

As a Registered Dietitian for 40+ years and currently working on a graduate degree in Epidemiology, I find this study fascinating. The statistical analysis appears well done. I would have liked to have seen a larger sample size. Further, I see no reason why this study could not have had human subjects instead of mice. Onions have been shown to lower cholesterol; therefore, it is reasonable to say that they may have a significant effect on lipid metabolism¹

This study is not blind; therefore, there is a great potential for information and selection bias.

The greatest criticism I have of the study is that there are over 300 genes that can be attributed to obesity in humans; therefore, a singular treatment with the flavenoid, Quercetin, may be limited in humans. This consideration could introduce confounding bias into the data results.

I would like to see studies with a larger sample size and a double-blind random clinical trial of humans.

1. Egert S, et al. Quercetin reduces systolic blood pressure and plasma oxidised low-density lipoprotein concentrations in overweight subjects with a high-cardiovascular disease risk phenotype: a double-blinded, placebo-controlled cross-over study. https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/quercetin-reduces-systolic-blood-pressure-and-plasma-oxidised-lowdensity-lipoprotein-concentrations-in-overweight-subjects-with-a-highcardiovascular-disease-risk-phenotype-a-doubleblinded-placebocontrolled-crossover-study/8DB47B7FB4C09E5D3995A2F3F577D473