Most people know that smoking and being overweight can harm their physical health. Heart disease risk factors, however, can also impair the ability to think.
Being overweight can heighten the risk of high blood pressure, bad cholesterol and diabetes. Smoking is also a major contributor to coronary heart disease.
When heart disease risk factors such as these increase in adults as young as 35, their brain power may drop, according to a new study.
Hanneke Joosten, MD, nephrology fellow at the University Medical Center in Groningen, The Netherlands, led this investigation, which measured cognitive functions of 3,778 participants aged 35 to 82.
The scientists tested each patient's ability to plan and reason, and to initiate and switch tasks. A separate exam gauged memory function.
Dr. Joosten and his team also evaluated these individuals for the risk of cardiovascular events such as heart attack and stroke.
Participants with the most heart disease risks performed 50 percent worse on cognitive tests compared to participants with the lowest risk profile.
Overall, if patients had high risk scores for factors such as age, diabetes, bad cholesterol and smoking, they also had poorer cognitive scores.
Compared to non-smoking participants, those who smoked one to 15 cigarettes daily had a decrease in cognitive score of 2.41 points, and those who smoked more than 16 cigarettes daily had a decrease of 3.43 points. The memory scores had a similar association.
Cognitive function was measured with the Ruff Figural Fluency Test, which uses a scale from 0 for worst score to 175 for the best score.
Smoking and diabetes were especially strong determinants of cognitive function.
"Young adults may think the consequences of smoking or being overweight are years down the road, but they aren't," said Dr. Joosten.
She stressed that cardiovascular risk factors, especially those that are modifiable like smoking and obesity, need ongoing attention from the medical profession, government and food industry.
"Smoking cessation programs might not only prevent cancer, stroke and cardiovascular events, but also cognitive damage,” said Dr. Joosten.
Almost one in five US adults smoke, according to 2010 statistics from the Centers for Disease Control and Prevention (CDC). About one third of adults in the US are obese and about one in three children are overweight or obese, according to the American Heart Association.
Sarah Samaan, MD, cardiologist and physician partner at the Baylor Heart Hospital in Plano, Texas, told dailyRx News, “The conclusions drive home the fact that the choices we make every day—from what to have for breakfast to whether to get in a walk after dinner instead of parking in front of the TV or computer—can affect not just our heart health years down the line, but also the health and function of our brain today.”
She added that this is not the first study to find correlation between heart health and brain function; research has linked childhood obesity and poor dietary choices to cognitive ability.
“We need to get rid of the notion that we can play catch-up on our health later in life and all will turn out well in the end,” said Dr. Samaan. “This is a loud and clear wake up call to take control of our health and well-being today.”
The study was published in May in the American Heart Association journal Stroke. The Dutch Alzheimer Foundation and Dutch Kidney Foundation funded the study.