A new study finds that obesity, high blood pressure and metabolic disorders can hasten cognitive decline.
Researchers defined metabolic abnormalities as consisting of two or more of the following risk factors: high blood pressure or taking medication for it; low HDL or “good” cholesterol; high blood sugar or taking diabetes medication; and high triglycerides (a type of fat found in the blood) or taking medication to lower cholesterol.
Researchers followed 6,401 people for 10 years. The average age of participants at the start of the study was 50 years old. Investigators determined body mass index (BMI) and the risk factors at the beginning of the study. The participants then took tests on memory and other cognitive skills three times over the next 10 years.
Thirty-one percent of the participants had two or more metabolic abnormalities. Nine percent were obese and 38 percent were overweight.
Of the 582 obese people, 350, or 60 percent, met the criteria for metabolic abnormality. The metabolically normal obese individuals also experienced more rapid decline.
Researchers discovered that over the course of the 10-year study, people who were both obese and metabolically abnormal experienced a 22.5 percent faster decline on their cognitive test scores than those who were of normal weight without metabolic abnormalities.
“More research is needed to look at the effects of genetic factors and also to take into account how long people have been obese and how long they have had these metabolic risk factors and also to look at cognitive test scores spanning adulthood to give us a better understanding of the link between obesity and cognitive function, such as thinking, reasoning and memory,” said study author Archana Singh-Manoux, Ph.D.
Singh-Manoux said the study also provides evidence against the concept of “metabolically healthy obesity” that has suggested that obese people without metabolic risk factors do not show negative cardiac and cognitive results compared to obese people with metabolic risk factors.
Thus participants, who were obese, yet without metabolic factors, presented significant cognitive decline as compared to non-obese participants.
The study is published in the journal Neurology.