THE ESSENTIAL
- Nearly 10 million new cases of dementia are reported each year worldwide, according to the National Institute of Health and Medical Research (Inserm).
- Alzheimer’s disease accounts for 80% of these cases of dementia.
In France, 1.2 million people have Alzheimer’s disease, according to theHealth Insurancewhich makes it the most frequent neurodegenerative pathology in France.
Weight loss, a risk factor for Alzheimer’s disease
The preponderant factor in the onset of Alzheimer’s disease is age since 15% of people over 80 are affected. But, according to a study published in the journal Alzheimer’s & Dementiaweight loss with aging may also be a risk factor for Alzheimer’s disease.
“If, following a steady increase in weight as one ages, there is unexpected weight loss following midlife, it [faudrait] consult his [médecin] and understand why”, says Professor Rhoda Au, from Boston University who participated in the study.
To arrive at their results, the scientists analyzed data from another study, the Framingham Heart Study, whose participants from the city of Massachusetts have been followed for four decades. Their weight was measured every two to four years. So the scientists compared the dementia rates of all the participants, that is, those whose weight increased, decreased or remained stable.
“These results are important because previous studies that analyzed changes in weight did not consider how patterns of increase/stability/loss of weight might signal that dementia was potentially imminent.“, emphasizes Professor Rhoda Au.
Overweight and obesity are also risk factors for Alzheimer’s
In their work, they used the body mass index (BMI), an indicator which makes it possible to estimate the corpulence of an individual by dividing the weight in kilograms by the height in centimeters squared. There are thus different categories: malnutrition (below 16.5), thinness (from 16.5 to 18.5), normal corpulence (from 18.5 to 25), overweight (from 25 to 30), moderate obesity (from 30 to 35), severe obesity (from 35 to 40), morbid or massive obesity (over 40).
Results: the researchers found that lower BMI was associated with a higher risk of developing dementia. On the other hand, they also observed that a subgroup, whose BMI had increased and then decreased in middle adulthood, that is to say following the age of 40, also had a higher risk. In other words, those who had gained weight and then lost weight also had risks.
The scientists emphasize that this study should not be misinterpreted: they absolutely do not advise gaining weight or remaining in a situation of overweight or obesity because these are also risk factors for many diseases as well as for the of Alzheimer’s. Indeed, according to Health Insurance, physical inactivity, lack of physical activity and poor diet are risk factors for this pathology.
