WASHINGTON >> Seek a good education. Control blood pressure and diabetes. Get off the couch. There are some hints, but no proof yet, that these and other lifestyle changes just might help stave off dementia.

A provocative report in the British journal Lancet today raised the prospect that a third of dementia cases around the world could be delayed or even prevented by avoiding key risks starting in childhood that can make the brain more vulnerable to memory loss in old age.

A recent U.S. report was much more cautious, saying there are encouraging clues that a few lifestyle changes can bolster brain health and that more research is critical.

Still, it’s never too early to try, said Lancet lead author Gill Livingston, a psychiatry professor at University College London.

“Although dementia is diagnosed in later life, the brain changes usually begin to develop years before,” she noted.

Early next year, a $20 million U.S. study will begin rigorously testing if some simple day-to-day activities truly help older adults stay sharp.

“We are in a frustrating position science-wise in terms of what are our options?” said cognitive neuroscientist Laura Baker of Wake Forest School of Medicine in North Carolina, who will lead the new study to find out.

In the meantime, Alzheimer’s specialists say there’s little down side to following some common-sense recommendations.

Consider physical activity, crucial for heart health. “If in fact it should also improve the prospects for cognitive function and dementia, all the better,” said Dr. Richard Hodes, director of the U.S. National Institute on Aging and an avid exerciser.

“Increased health of the body supports increased health of the brain,” Baker added.

Here’s the latest from this week’s Alzheimer’s Association International Conference on possible ways to guard your brain:

KEY RISKS

A Lancet-appointed panel created a model of dementia risks throughout life that estimates about 35 percent of all dementia cases are attributable to nine risk factors — risks that people potentially could change.

Their resulting recommendations: Ensure good childhood education; avoid high blood pressure, obesity and smoking; manage diabetes, depression and age-related hearing loss; be physically active; stay socially engaged in old age.

The theory: These factors together play a role in whether your brain is resilient enough to withstand years of silent damage that eventually leads to Alzheimer’s.

DOES CHANGING THESE OR OTHER LIFESTYLE FACTORS REALLY HELP?

Last month, the U.S. National Academies of Sciences, Engineering and Medicine reported there’s little rigorous proof. That report found some evidence that controlling blood pressure, exercise and some forms of brain training — keeping intellectually stimulated — might work and couldn’t hurt.

Why? What’s good for the heart is generally good for the brain. In fact, high blood pressure that can trigger heart attacks and strokes also increases risk for what’s called “vascular dementia.”

And exercising your gray matter may bulk up the brain, whether it’s from childhood education or learning a new language as an adult. The more you learn, the more connections your brain forms, what scientists call cognitive reserve. Some U.S. studies have suggested that generations better educated than their grandparents have somewhat less risk of dementia.

Other factors have less scientific support. Studies show people with hearing loss are more likely to experience memory problems, and have speculated that it’s because hearing loss leads to depression and social isolation — or that the brain works harder to deal with garbled sound, at the expense of other thinking skills. But so far there aren’t studies proving hearing aids reverse that risk.

In fact, the strongest evidence that lifestyle changes help comes from Finland, where a large, randomized study found older adults at high risk of dementia scored better on brain tests after two years of exercise, diet, cognitive stimulation and social activities.

HUNTING PROOF

Would those strategies help Americans, who tend to be sicker, fatter and more sedentary than Scandinavians? The Alzheimer’s Association is funding a study to find out, with enrollment of 2,500 cognitively healthy but high-risk older adults to begin next year.

Want to try on your own? They’ll test:

—Walking — supervised, so no cheating. Wake Forest’s Baker puts seniors on treadmills at the local YMCA to avoid bumpy sidewalks. She advises exercise newbies to start slow — about 10 minutes a day for a few days — and work up to longer walks, and go with a buddy so it’s harder to back out.

—A diet that includes more leafy greens, vegetables, whole grains, fish and poultry than the typical American menu.

—Certain brain games and what Baker called an “intellectual stimulation barrage,” outings and other steps that keep people social, not sitting home on a computer, while they exercise their brains.

—Improving control of medical conditions like high blood pressure and diabetes that are toxic to the brain.