Meta-analysis indicates that resistant starch lowers serum total cholesterol and low-density cholesterol

The effects of resistant starch (RS) on serum cholesterol levels have been previously investigated. However, the results of those studies are inconsistent. The purpose of our meta-analysis was to determine if RS affects blood lipids based on the current literature. The methods included searching databases (PubMed, Embase, Scopus, and Cochrane Library) up to September 2017, as well as hand-searching reference lists of articles published in English. The initial search yielded 1228 articles. Of these, 14 articles (20 trials) were included in our investigation focusing on the effects of RS on total cholesterol (TC; 19 trials), triglycerides (TG; 19 trials), low-density lipoprotein cholesterol (LDL-C; 16 trials), and high-density lipoprotein cholesterol (17 trials). Methodological quality was assessed using TC, LDL-C, TGs, and high-density lipoprotein cholesterol. Pooled effects were calculated using a random-effects model. The meta-analysis of these data showed that RS supplementation has an effect on lowering TC and LDL-C (TC: mean difference, -7.33mg/dL [95% confidence interval -12.15 to -2.52mg/dL]; LDL-C: mean difference: -3.40mg/dL [95% confidence interval, -6.74 to -0.07mg/dL]). Subgroup meta-analysis revealed that a longer time (>4weeks) of RS supplementation can generate more obvious effects on TC and LDL-C levels, and higher dose (>20 g/d) of RS also had a lowering effect on TG level. Future research should focus on the relationship between RS type and cholesterol-lowering effects, and the effects on subjects of different health status or those with different baseline levels of serum lipids. Moreover, the mechanism for the cholesterol-lowering effects of RS should be further explored. In conclusion, RS can reduce serum TC and LDL-C levels, particularly when administered for a duration longer than 4 weeks.