TitleEvidence-based prevention and treatment of dementia.
Publication TypeJournal Article
Year of Publication2016
AuthorsKivimäki, M, Batty, GD
JournalLancet Neurol
Date Published09/2016
KeywordsDementia, Humans, Risk Factors

Dementia has been well documented as a major public health issue worldwide. The Lancet Neurology Commission1 is therefore welcome as a landmark review on prevention of this disorder. With more than 560 references, the near 80-page document systematically summarises key evidence and future challenges in dementia research, covering the most important modifiable risk factors, including midlife obesity.2

The largest study3 on obesity and dementia to date used records of body-mass index (BMI) from 1992 to 2007 for 1 958 191 individuals aged 40 years or older, initially without dementia. These records were linked to primary care records for dementia over a median follow-up of 9·1 years, during which more than 45 000 people developed the disorder.3 The investigators found that people with higher BMI in midlife had a lower risk of dementia when at older ages.3 This association was linear from the underweight category (BMI <20 kg/m2; those with the highest dementia risk) through to the normal, overweight, obese, and severely obese categories (BMI equal to or greater than 40 kg/m2; individuals with the lowest dementia risk). The authors of that study3 suggested that evidence of a lower dementia risk associated with a high BMI should be considered by doctors, public health scientists, and policy makers in a reassessment of how best to identify individuals at high risk of dementia.

The Lancet Neurology Commission1 did not cite this evidence from the largest study3 in the field. We are curious to learn what the Commission expert group considers to be the reasons as to why these important results were not described. These findings were similarly ignored in the 2015 National Institute for Health and Care Excellence's evidence-based guidelines to prevent dementias, disability, and frailty.2

We declare no competing interests.

Alternate JournalLancet Neurol
PubMed ID27450473
Grant ListMR/K013351/1 / / Medical Research Council / United Kingdom
MR/K026992/1 / / Medical Research Council / United Kingdom