In  a significant development, researchers of a new study discovered that viewing television for more than two hours every day significantly increases the risk of atherosclerotic cardiovascular disease (ASCVD), a condition where fat, cholesterol, and other substances build up inside the blood vessels (arteries), forming plaques, that can narrow or block blood flow, increasing the risk of heart attacks, strokes, and other heart problems. Regardless of genetic vulnerability to type 2 diabetes (T2D), these plaques can narrow or block blood flow, increasing the risk of heart attacks, strokes, and other heart problems. The study, which included 346,916 White British individuals from the UK Biobank, highlights the importance of lifestyle choices in determining heart disease risk.

A weighted polygenic risk score (PRS) was used in the study. This score figures out how different genetic variants, usually single nucleotide polymorphisms (SNPs), affect a person's chance of getting a disease or having a certain trait. It involves genes, a polygenic risk score (PRS), and how they interact with environmental factors in a complex manner. Participants are classified into low, medium, and high genetic risk groups based on 138 genetic variations related to type 2 diabetes. Participants self-reported their TV viewing time, which was divided into two categories: less than one hour and more than two hours per day. Over a median follow-up duration of 13.8 years, researchers identified 21,265 incident ASCVD cases.

The study indicated that persons who watched television for ≥2 hours per day had a 12% higher risk of getting ASCVD than those who watched for ≤1 hour per day. Notably, this connection was unaffected by T2D genetic risk.

A collaborative investigation found that people with high genetic risk for T2D but who watched less than an hour of TV per day had a lower 10-year absolute risk of ASCVD (2.13%) than people with low genetic risk but who watched more than 2 hours per day (2.46%). This shows that sedentary screen time plays an important role in ASCVD development.

The study's authors emphasise the possibility of lifestyle changes that reduce hereditary risks. "Watching television for under one hour per day may serve as an effect modifier in the pathogenetic pathways from type 2 diabetes genetic risk towards the risk of atherosclerotic cardiovascular disease," the research's authors wrote.

The findings highlight the need to minimise screen-based sedentary activities to prevent cardiovascular events, especially among people with a high hereditary risk of T2D. Future clinical trials may focus on lifestyle therapies that target sedentary behaviours in order to minimise ASCVD risk.

This study highlights the importance of restricting TV viewing as a simple but effective way to reduce the risk of heart disease. As ASCVD remains a leading cause of death worldwide, lifestyle changes such as limiting screen time may be useful as a preventive intervention, especially for people who are genetically susceptible to type 2 diabetes.