THE ESSENTIAL
- Nearly 10 million new cases of dementia are reported worldwide each year, according to the National Institute of Health and Medical Research (Inserm).
- Alzheimer’s disease accounts for 80% of these dementia cases.
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 predominant 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 and dementiaweight loss with aging may also be a risk factor for Alzheimer’s disease.
“If, after constant weight gain with advancing age, unexpected weight loss occurs after middle age, then [faudrait] consult his [médecin] and understand why”, says Professor Rhoda Au, from Boston University who participated in the study.
To arrive at their findings, the scientists analyzed data from another study, the Heart of Framingham Study, whose Massachusetts city participants were followed for four decades. Their weight was measured every two to four years. Then the scientists compared the dementia rates of all the participants, i.e. those whose weight increased, decreased or remained stable.
“These findings are important because previous studies examining weight changes did not consider how patterns of weight gain/stability/loss might signal that dementia was potentially imminent.“, points out Professor Rhoda Au.
Being overweight and obese are also risk factors for Alzheimer’s
In their work, they used the body mass index (BMI), an indicator that allows you to estimate the corpulence of an individual by dividing the weight in kilograms by the height in centimeters squared. There are therefore 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 35-40), morbid or massive obesity (over 40 years).
Results: the the researchers found that a lower body mass index 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, i.e. after the age of 40, also had a higher risk. In other words, even those who gained weight and then lost weight were at risk.
The scientists stress that this study should not be misunderstood: they absolutely do not recommend gaining weight or staying overweight or obese because these too are risk factors for many diseases other than Alzheimer’s. In fact, according to the Health Insurance, physical inactivity, lack of physical activity and poor diet are risk factors for this pathology.
