Modifying 12 risk factors over a lifetime could delay or prevent 40% of dementia cases, according to an updated report by the Lancet Commission on dementia prevention, intervention and care presented at the Alzheimer’s Association International Conference (AAIC 2020).

Twenty-eight world-leading dementia experts, including researchers from the Keck School of Medicine of USC, added three new risk factors in the report — excessive alcohol intake and head injury in midlife and air pollution in later life. These are in addition to nine factors in different phases of life that were previously identified by the commission in 2017:

Early in life:

• Less education

Midlife:

• Hearing loss
• Hypertension
• Obesity

Later in life (ages 65 and up):

• Smoking
• Depression
• Social isolation
• Physical inactivity
• Diabetes

“We are learning that tactics to avoid dementia begin early and continue throughout life, so it’s never too early or too late to take action,” said commission member and AAIC 2020 presenter Lon Schneider, MD, co-director of the USC Alzheimer Disease Research Center’s clinical core and professor of psychiatry and the behavioral sciences and neurology at the Keck School.

Dementia affects some 50 million people globally, a number that is expected to more than triple by 2050, particularly in low- and middle-income countries where approximately two-thirds of people with dementia live, according to the report. Women are also more likely to develop dementia than men.

However, in certain countries such as the United States, England and France, the proportion of older people with dementia has fallen, probably in part due to lifestyle changes. These numbers demonstrate the possibility of reducing dementia through preventive measures, Schneider said.

Schneider and commission members recommend that policymakers and individuals adopt the following interventions:

• Aim to maintain systolic blood pressure of 130 mm Hg or less from the age of 40.
• Encourage use of hearing aids for hearing loss and reduce hearing loss by protecting ears from high noise levels.
• Reduce exposure to air pollution and secondhand tobacco smoke.
• Prevent head injury (particularly among high-risk occupations).
• Limit alcohol intake to no more than 21 standard servings per week.
• Stop smoking and support others who are trying stop smoking.
• Provide all children with primary and secondary education.
• Stay active for as many years as possible.
• Reduce obesity and the linked condition of diabetes.

The report also advocates for holistic, individualized and evidence-based care for patients with dementia, who typically have more hospitalizations for conditions that are potentially manageable at home and are at greater risk for COVID-19. In addition, it recommends providing interventions for family caregivers who are at risk for depression and anxiety.

The commission members conducted a thorough investigation of all the evidence in the field, including systematic literature reviews, meta-analyses and individual studies, to reach their conclusions.

— Alison Rainey