Nutrition: phytosterols pose risk
Atherosclerosis is a condition in which deposits form in the walls of arteries, obstructing and blocking blood flow. Too much cholesterol in the blood can contribute to this. Scientists from the Faculty of Medicine at Leipzig University, in cooperation with other European study groups, have found that phytosterols – plant lipid compounds added to certain foods for their cholesterol-lowering effect – increase the risk of coronary heart disease themselves.
Phytosterols are ingested with food, for example nuts or vegetable oils. In some foods, such as yoghurt or margarine, the lipid compounds are artificially added in high doses because they structurally resemble cholesterol and inhibit its absorption in the intestine. This leads to a lowering of the cholesterol level. However, due to this similarity to cholesterol, phytosterols can also be deposited in vascular walls. The amount of phytosterols the body absorbs depends on individual genetic factors.
Blood samples from 10,000 study participants examined
In order to shed more light on the role of phytosterols in connection with genetic predispositions, the Leipzig scientists and their colleagues examined blood samples of nearly 10,000 subjects. "It appears that phytosterols can directly increase the risk of coronary heart disease, in addition to the effect of cholesterol," said study leader Prof. Dr. Markus Scholz from the Institute of Medical Informatics, Statistics and Epidemiology (IMISE) at Leipzig University. "Although this does not yet allow an immediate conclusion regarding the addition of phytosterols to food, high phytosterol concentrations are a risk factor that should be taken into account." The results have been published in the renowned journal "Nature Communications".
Potential targets for future drug development
The scientists identified a total of seven regions in the genome that are associated with phytosterol concentrations in the blood, five of which were previously unknown. By means of bioinformatic analyses, they were able to derive plausible candidate genes, meaning genes with biological effects in sterol metabolism. "This greatly expands our understanding of the genetic regulation of phytosterol concentrations in the blood. These genes, or their products and functions, represent potential targets for future drug development," said Prof. Scholz.
Biosamples from LIFE studies laid foundation
A large part of the blood samples examined belonged to the cohorts of the Leipzig Research Centre for Civilisation Diseases (LIFE). The Leipzig Medical Biobank (LMB) is responsible for the biobanking of these samples and also provided scientific support for the study. The LMB is a state-of-the-art biobank for the quality-assured collection, processing, storage and provision of biospecimens and has been a partner in the German Biobank Alliance (GBA) since 2017. "Due to the excellent characterisation of the study participants, epidemiological studies such as LIFE form an essential basis for investigating connections between genetic and non-genetic risk factors and the occurrence of diseases," says Dr. Ronny Baber, head of the LMB. "Thanks to standardised processes at the Leipzig Medical Biobank, we ensure the optimal quality of the biosamples that are so important for this purpose. First-rate research results show that our work is worthwhile."
Source: An original version of this text was published as a press release by the Leipzig University.
Photo credits: Leipzig Medical Biobank
Markus Scholz et al. Genome-wide meta-analysis of phytosterols reveals five novel loci and a detrimental effect on coronary atherosclerosis. Nat Commun 13, 143 (2022). DOI: 10.1038/s41467-021-27706-6 https://www.nature.com/articles/s41467-021-27706-6
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