A US randomized controlled trial showed that compared with nonmeat as the major protein source, diets high in saturated fatty acid (SFA) and/or meat result in higher concentrations of lipids and lipoproteins, indicating other effects of red meat consumption could contribute to adverse effects on the risk of cardiovascular disease (CVD). The trial randomly assigned generally healthy men and women (21–65 y, body mass index 20–35 kg/m2) to 1 of 2 parallel arms (high or low SFA) and within each, allocated to red meat, white meat, and nonmeat protein diets consumed for 4 wk each in random order. The analysis included participants who completed all 3 dietary protein assignments (61 for high SFA; 52 for low SFA). Low-density lipoprotein (LDL) cholesterol and apoB were higher with red and white meat than with nonmeat, independent of SFA content. This was due primarily to increases in large LDL particles, whereas small + medium LDL and total/high-density lipoprotein cholesterol were unaffected by protein source. There was no significant difference between red and white meat. Independent of protein source, high compared with low SFA increased LDL cholesterol, apoB, and large LDL. The other effects of red meat consumption contributing to higher CVD risk may be through trimethylamine-N-oxide, a metabolite derived from intestinal bacterial metabolism of carnitine, heme iron, as well as preservatives and their by-products. The findings support current dietary recommendations to adopt dietary patterns with high plant content. Source: https://academic.oup.com/ajcn/
