Effect of Oat (Avena sativa L.) Consumption on Lipid Profile With Focus on Triglycerides and High-density Lipoprotein Cholesterol (HDL-C): An Updated Systematic Review

Hypercholesterolemia is a significant risk factor for heart disease. The soluble fiber in oat (Avena sativa L.), beta-glucan has been shown to significantly lower serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels but not triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) according to previous studies, reviews, and meta-analyses. However, the effect of oat consumption on the TG and HDL-C is controversial and has not been expanded enough. We did this review study to find out about the effect of oat on lipid profile especially TG and HDL-C more specifically and meticulously with their details. After searching PubMed, Web of Science, and Google scholar we included 17 studies in our review. Our results similar to other reviews showed that oat reduced the TC, VLDL, and LDL-C more significantly than TG. Of 17 included studies 6 studies reported reduction of TG level, and only 1 study reported HDL-C improvement followed by oat consumption. A more detailed review of studies that reported positive effects of oat/ beta-glucan consumption on TG showed that in healthy people with normal lipid profile oat intake might reduce TG effectively and also in overweight people/those with diabetes or metabolic syndrome if a higher amount of oat or/and longer duration applied. Consuming oat in conjunction with calorie-reducing diets or using it with DHA can cause a significant TG reduction. It may be concluded that, in addition to lowering TC and LDL-C, a considerable improvement in TG or HDL-C can be accomplished by adjusting factors such as oat consumption dose or consumption duration or utilizing oat in conjunction with a proper diet program. To conclude, more research on this topic is required.