MDedge Neurology
By Joann E. Manson, MD, DrPH
A new report on the preventability of dementia is both exciting and paradigm-shifting. The new study, published in The Lancet by the Lancet Commission on Dementia, estimates that close to 50% of cases of dementia worldwide can be prevented or delayed by improving 14 modifiable risk factors.
This is paradigm-shifting because dementia is often perceived as an inevitable consequence of the aging process, with a major genetic component. But this study suggests that modifying these risk factors can benefit everyone, irrespective of genetic risk, and that it’s important to have a life-course approach. It’s never too early or too late to start to modify these factors.
We’ve known for a long time that many chronic diseases are highly preventable and modifiable. Some that come to mind are type 2 diabetes, coronary heart disease, and even certain forms of cancer. Modifiable risk factors include cigarette smoking, diet, physical activity, and maintaining a healthy weight. This study suggests that many of the same risk factors and more are relevant to reducing risk for dementia.
Let’s go through the risk factors, many of which are behavioral. These risk factors include lifestyle factors such as lack of physical activity, cigarette smoking, excessive alcohol consumption, and obesity. The cardiovascular or vascular-specific risk factors include not only those behavioral factors but also hypertension, high LDL cholesterol, and diabetes. Cognitive engagement–specific risk factors include social isolation, which is a major risk factor for dementia, as well as untreated hearing or vision loss, which can exacerbate social isolation and depression, and low educational attainment, which can be related to less cognitive engagement.
They also mention traumatic brain injury from an accident or contact sports without head protection as a risk factor, and the environmental risk factor of air pollution or poor air quality.
Two of these risk factors are new since the previous report in 2020: elevated LDL cholesterol and untreated vision loss, both of which are quite treatable. Overall, these findings suggest that a lot can be done to lower dementia risk, but it requires individual behavior modifications as well as a comprehensive approach with involvement of the healthcare system for improved screening, access, and public policy to reduce air pollution.
Some of these risk factors are more relevant to women, especially the social isolation that is so common later in life in women. In the United States, close to two out of three patients with dementia are women.
So, informing our patients about these risk factors and what can be done in terms of behavior modification, increased screening, and treatment for these conditions can go a long way in helping our patients reduce their risk for dementia.
Dr. Manson is professor of medicine and the Michael and Lee Bell Professor of Women’s Health, Harvard Medical School, chief, Division of Preventive Medicine, Brigham and Women’s Hospital, Boston, and past president, North American Menopause Society, 2011-2012. She disclosed receiving study pill donation and infrastructure support from Mars Symbioscience (for the COSMOS trial).
A version of this article appeared on Medscape.com.
