How to keep your mind
sharp as you age.

Puzzles are a small part of this answer, and a puzzle site telling you otherwise should make you suspicious. The large trials of the last decade are clear that the biggest levers are physical, medical and social, with cognitive activity as one component among several. Here is what they found and how puzzles fit.

Fourteen risk factors, about 45 percent of cases

The Lancet Commission on dementia, updated in 2024, estimates that fourteen modifiable risk factors together account for around 45 percent of dementia cases worldwide.^[1] In early life the factor is low education. In midlife: hearing loss, high LDL cholesterol, depression, traumatic brain injury, physical inactivity, diabetes, smoking, hypertension, obesity and excessive alcohol. In later life: social isolation, air pollution and untreated vision loss. Hearing loss and high cholesterol carry the largest individual shares.

Notice what is not on the list. Puzzles, brain games and crosswords are not named as risk factors or protective factors, because the evidence does not reach the standard the Commission requires. Education and cognitively demanding occupation are there, as proxies for the broader idea of cognitive reserve.

What the multidomain trials showed

FINGER, a Finnish trial of 1,260 people aged 60 to 77 at raised risk, combined diet advice, exercise, cognitive training and vascular risk monitoring for two years.^[3] The intervention group improved more on a composite cognitive score than controls who received general health advice. It was the first large trial to show that a lifestyle package could maintain or improve cognition in older adults.

US POINTER, published in JAMA in 2025, tested a similar structured programme against a self-guided version in 2,111 American adults aged 60 to 79.^[2] The structured arm included regular exercise, the MIND diet, computerised cognitive training, social and cognitive challenge, and blood pressure monitoring, with frequent peer meetings. Over two years the structured group improved more on global cognition, an effect the authors describe as roughly one to two years of slowed cognitive ageing. Cognitive training was in the package. So were four other things.

Cognitive reserve: why activity plausibly helps

The idea that ties cognitive activity to later-life resilience is cognitive reserve: the observation that people with more education, more complex work and more engaged lives tolerate the same amount of brain pathology with less cognitive impairment.^[5] In the Rush Memory and Aging Project, people who reported more cognitive activity across their lives declined more slowly, and that difference was not explained by the amount of Alzheimer’s or vascular pathology found at autopsy.^[6] Reserve is built over decades. A puzzle habit is a modest contribution; it is not a substitute for education, work and social life, but it is the kind of activity that fits the pattern.

What to actually do

1. Get your hearing and vision checked and use the aids you are prescribed. Hearing loss is the largest single modifiable factor in the Lancet analysis.
2. Know your blood pressure and cholesterol and treat them. Midlife hypertension and high LDL are both on the list.
3. Move most days. POINTER and FINGER both included aerobic and resistance exercise as a core component.
4. Stay socially connected. Isolation is a late-life risk factor, and the structured POINTER arm’s peer meetings may be part of why it worked.
5. Learn things that are new and hard. The Global Council on Brain Health recommends activities that are novel, engaging, challenging and enjoyable.^[4] A language, an instrument, a craft, a course.
6. Keep a small daily cognitive habit if you enjoy one. Puzzles, reading, a crossword, a game like Brisk. This is the smallest item on the list, and we are the puzzle site.

For why the small habit is shaped the way it is, see why a few minutes a day. For what puzzles specifically have and have not been shown to do, see do brain games work?