Low consumption of dietary cholesterol may prevent type 2 diabetes

The results, published in Nutrition, Metabolism and Cardiovascular Diseases, advise low dietary cholesterol intake for type 2 diabetes prevention, particularly for populations with high cardiovascular (CV) risk.

Dietary cholesterol (DC) is a prevalent nutrient in daily life, present in several foods such as red meat, animal viscera, edible oil, and butter. Experimental studies have suggested that high cholesterol levels impair pancreatic β cell function, thereby disturbing glycemic metabolism. The results from clinical studies, however, are ambiguous.

"Some trials showed a positive dose-response relationship between cholesterol consumption and type 2 diabetes incidence, while others reported null association," the authors stated. "Also, there is a variation in the dietary guidelines from ADA (American Diabetes Association) for DC consumption." The ADA recommended DC restriction to less than 300 mg daily in 2013. This recommendation, however, has changed and set no definite upper limit for DC intake in 2015.

Against the above background, Yuehua Li and colleagues from China evaluated the dose–response relationship between the consumption of dietary cholesterol and T2DM incidence in a meta-analysis.

The team included prospective studies with the endpoint of type 2 diabetes. A random-effects model was used, weighted by inverse variance. The dose-response relationship was estimated using restricted cubic splines regression models. A total of 11 prospective studies consisting of 355 230 subjects were included.

The study led to the following findings:

• Compared to the lowest DC consumption, the highest dietary cholesterol consumption was associated with an increased risk of T2DM (RR 1.15).
• Subgroup analyses revealed that the positive association was more evident in western and eastern countries (RR 1.19 VS 1.34).
• For a 100 mg/d increment in dietary cholesterol intake, the pooled RR was 1.05, 1.06, and 1.01 for the incidence of T2DM in western and eastern countries, respectively.

To sum up, the findings from the study suggest a positive relationship between dietary cholesterol consumption and T2DM incidence. Furthermore, the research team performed dose–response analyses. For a 100 mg/d increment in dietary cholesterol intake, T2DM incidence was increased by 5%. This positive association was more evident in people from western countries than in eastern countries.

"Our results advise low intake of dietary consumption for type 2 diabetes prevention, particularly for the population with high cardiovascular risk," the authors wrote.

Reference:

Li Y, Pei H, Zhou C, Lou Y. Dietary cholesterol consumption and incidence of type 2 diabetes mellitus: A dose-response meta-analysis of prospective cohort studies. Nutr Metab Cardiovasc Dis. 2022 Aug 31:S0939-4753(22)00319-2. doi: 10.1016/j.numecd.2022.07.016. Epub ahead of print. PMID: 36411220.