Science is dedicating increasing time and resources to improve our knowledge of the growing phenomenon of obesity. Defined as a Body Mass Index over 30, obesity is a risk factor for a host of illnesses including heart disease, hypertension, diabetes and respiratory disease.
Fresh figures show numbers are far from levelling off, with more than 200 million adults across the EU overweight or obese.
And far from being an adult problem, the number of European kids overweight is rising by a hefty 400,000 a year, according to the data from the International Obesity Task Force (IOFT).
But the link between obesity and dementia risk has not been extensively studied, and long-term follow-up studies performed to date have yielded somewhat conflicting results, say scientists the Karolinska Institutet in Sweden.
Miia Kivipelto and colleagues re-examined participants in the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) study to investigate the relationship between midlife body mass index (BMI; weight in kilograms divided by square of height in meters) and a group of vascular risk factors, and subsequent dementia and Alzheimer's disease.
After an average follow-up of 21 years, 1,449 individuals aged 65 to 79 years participated in the 1998 CAIDE reexamination.
"The researchers discovered dementia and AD to be prevalent significantly more among those with a higher midlife BM," claim the study findings.
One-third of the participants had a BMI lower than 25 (normal weight), half had a BMI from 25 to 30 (overweight), and the remaining 16 per cent had a BMI higher than 30 (obese) at midlife.
Confirming previous studies, a history of heart attack and diabetes mellitus were more prevalent in those with the highest midlife BMI .
Mid-life obesity, high SBP, and high total cholesterol level were all significant risk factors for dementia, each of them increasing the risk around two times," conclude the researchers.
Clustering of these vascular risk factors increased the risk of dementia and AD in an additive manner so that persons with all three risk factors had around a six times higher risk for dementia than persons having no risk factors, they add.