Science & technology | Keeping your marbles
How to reduce the risk of developing dementia
A healthy lifestyle can prevent or delay almost half of cases

Aug 5th 2024

Some of the best strategies for reducing the chances of developing dementia are, to put it kindly, impracticable. Don’t grow old; don’t be a woman; choose your parents carefully. But although old age remains by far the biggest risk factor, women are more at risk than men and some genetic inheritances make dementia more likely or even almost inevitable, the latest research suggests that as many as 45% of cases of dementia are preventable—or at least that their onset can be delayed. ... That is the conclusion of the latest report, published on July 31st, of the Lancet commission on dementia, which brings together leading experts from around the world, and enumerates risk factors that, unlike age, are “modifiable”. It lists 14 of these, adding two to those in its previous report in 2020: untreated vision loss; and high levels of ldl cholesterol. Most news about dementia seems depressing, despite recent advances in treatments for some of those with Alzheimer’s disease, much the most common cause of the condition. Most cases remain incurable and the numbers with the condition climb inexorably as the world ages. That the age-related incidence of dementia can actually be reduced is a rare beacon of hope.

The modifiable risk factors include smoking, obesity, physical inactivity, high blood pressure, diabetes and drinking too much alcohol (see chart). The best way to reduce the risk of developing dementia is to lead what has long been considered to be a healthy life: avoiding tobacco and too much alcohol and taking plenty of exercise (but avoiding those forms of it that involve repeated blows to the head or bouts of concussion, a list which includes boxing, American football, rugby and lacrosse).

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Chart: The Economist

It also means having a good diet, defined in one study cited by the commission as: “Eat at least three weekly servings of all of fruit, vegetables and fish; rarely drink sugar-sweetened drinks; rarely eat prepared meat like sausages or have takeaways.” So it is not surprising that ldl cholesterol has been added to its not-to-do list. It is also important to exercise the brain: by learning a musical instrument or a foreign language, for example—or even by doing crossword and sudoku puzzles.

Some physical ailments do not bring heightened risks of cardiovascular disease or cancer but have been shown to make dementia more likely. One is untreated hearing loss. The Lancet commission’s report from 2020 concluded this was the biggest of its 12 risk factors, a conclusion shared by this latest study. People with hearing loss are about twice as likely as others to develop dementia. The wider availability and use of hearing aids would probably be the single intervention most effective in reducing the incidence of dementia.

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