BackgroundVegetarian diets exclude all animal flesh and are being widely adopted by an increasing number of people; however, effects on blood lipid concentrations remain unclear. This meta‐analysis aimed to quantitatively assess the overall effects of vegetarian diets on blood lipids.Methods and ResultsWe searched PubMed, Scopus, Embase, ISI Web of Knowledge, and the Cochrane Library through March 2015. Studies were included if they described the effectiveness of vegetarian diets on blood lipids (total cholesterol, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and triglyceride). Weighted mean effect sizes were calculated for net changes by using a random‐effects model. We performed subgroup and univariate meta‐regression analyses to explore sources of heterogeneity. Eleven trials were included in the meta‐analysis. Vegetarian diets significantly lowered blood concentrations of total cholesterol, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and non–high‐density lipoprotein cholesterol, and the pooled estimated changes were −0.36 mmol/L (95% CI −0.55 to −0.17; P<0.001), −0.34 mmol/L (95% CI −0.57 to −0.11; P<0.001), −0.10 mmol/L (95% CI −0.14 to −0.06; P<0.001), and −0.30 mmol/L (95% CI −0.50 to −0.10; P=0.04), respectively. Vegetarian diets did not significantly affect blood triglyceride concentrations, with a pooled estimated mean difference of 0.04 mmol/L (95% CI −0.05 to 0.13; P=0.40).ConclusionsThis systematic review and meta‐analysis provides evidence that vegetarian diets effectively lower blood concentrations of total cholesterol, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and non–high‐density lipoprotein cholesterol. Such diets could be a useful nonpharmaceutical means of managing dyslipidemia, especially hypercholesterolemia.

Breast milk samples and 24-hour food records were obtained from lactating mothers on day 1 (colostrum), day 14 (transitional milk) and day 42 (mature milk) from Hangzhou (n = 202), Lanzhou (n = 133) and Beijing (n = 142), China. Fatty acid methyl esters were prepared by standard methods, separated and quantified by gas chromatography. We aimed to investigate the fatty acid composition (% of total fatty acid) in human milk of three lactating stages from three regions in China and the relationship with maternal dietary intake during lactation. Present results showed that the fatty acid composition of breast milk varied with lactating period and geographical regions in China. In all the milk samples, the total saturated fatty acid (SFA) remained stable. However, C10:0 and C12:0 increased over the lactation period, total monounsaturated fatty acid (MUFA) significantly increased from colostrum (34.50%) to transitional milk (37.06%), and total polyunsaturated fatty acid (PUFA) showed its highest percentage in colostrum (29.58%). In particular, C22:6n-3 and C22:5n-3 were lowest in mature milk (0.38% and 0.41%, respectively), and C18:3n-3 (1.83%) was lowest in colostrum. There were significant differences among the three regions in total MUFA and PUFA in breast milk. The Hangzhou samples had the lowest C18:1n-9 and highest C22:6n-3. Additionally, C22:6n-3, total PUFA and n-3 PUFA were lowest in the Lanzhou samples. Different dietary habits were largely the drivers behind the different fatty acid profiles among the three regions.

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