Heart diseases cause the highest number of deaths globally every year, and over the past few years, cardiovascular complications have been noted among youngsters as well. Research has long shown that body fat accumulation can lead to harmful changes to heart structure. This can be potentially deadly later, and the risks were earlier thought to increase in middle age. However, as per Finnish and UK scientists, the most critical age for a spike in the risk of cardiac conditions is 17. Yes, this is when high levels of body fat become potentially harmful to heart health.Why is 17 a critical age for heart health?According to experts at the University of Eastern Finland, 17 is a critical age for young people, as adolescents often move towards a more independent life after that. From moving away from home to changes in diet and lifestyle habits, there is a likelihood that many may adopt unhealthy habits like drinking and smoking. This social shift can, over time, result in fat accumulation, thus posing heart disease risks in the future.On the other hand, experts say that adolescence is the best time to adopt a healthy lifestyle and lower body fat in cases of childhood obesity. It is the best time to reduce the risk of heart disease, thereby increasing the chances of a healthy adulthood.For this, scientists tracked 1,803 children aged 9–24 years. They used dual-energy X-ray absorptiometry (DXA) scans to evaluate fat levels in the abdomen and body and to calculate muscle mass. The children had the scans completed at the age of nine, and then were tested again at ages 11, 15, 17, and 24 years. Echocardiography scans were also done at 17 and 24 years to examine heart function and structure, as well as insulin, blood sugar, and cholesterol levels.Researchers found that from the age of 17, excessive fat (abdominal fat specifically) was linked to structural changes in the heart. This can lead to excessive pressure to pump blood normally, thereby contributing to a heightened risk of heart disease later. The results were published in the European Journal of Endocrinology.The role of fat in changing heart structureResearchers found that the heart’s structure can be altered by fat, and this happens primarily through inflammation and high blood pressure. Experts concluded that BMI is a poor marker for calculating fat mass in adolescents and children because they have four times more lean mass than fat mass, and BMI does not distinguish between the two. The study helps us understand that accumulated total abdominal and body fat in late adolescence can adversely affect a growing heart. Therefore, any lifestyle changes that can help lower body fat in adolescence, as early as 17 years, can be beneficial.