Researchers have long been struggling to explain the so-called obesity paradox, wherein people who are overweight or obese live longer than those with a healthy weight after being diagnosed with cardiovascular disease.
These extra pounds providing more years of life have baffled scientists, The Star reports. The explanation, it turns out, is very simple: people who are overweight or obese are diagnosed with cardiovascular disease at younger ages compared to those with healthy weights. This means that they spend more years living with their heart conditions, but don’t necessarily live longer in general.
One of the primary effects of having too much excess weight is that there are fewer years of living without some sort of disease, according to a team of researchers led by Dr. Sadiya Khan of Northwestern University’s Feinberg School of Medicine. Khan discovered these results by analyzing data from the Cardiovascular Disease Lifetime Risk Pooling Project.
The researchers gathered medical information on 190,672 Americans who had never been diagnosed with cardiovascular disease at the beginning of the survey. The participants were tracked for ten years, providing researchers with a total of 3.2 million years’ worth of health data.
The participants were divided according to age and weight. Researchers found at people between the ages of 40 and 59 and overweight had a higher risk for stroke, heart attack or congestive heart failure. After taking into account factors such as age, race, and smoking habits, Khan and colleagues determined that the higher a person’s BMI, the greater the lifetime risk of developing a cardiovascular condition.
By examining people’s health over a significant period of time, and not just after diagnosis, the obesity paradox and its significance came into view. The researchers wrote, “The obesity paradox…appears largely to be caused by earlier diagnosis of CVD. Adults who were obese had an earlier onset of incident CVD, a greater proportion of life lived with CVD morbidity (unhealthy life years), and shorter overall survival compared with adults with normal BMI.”
The study was published in the journal JAMA Cardiology.