Protecting against cognitive decline
November 13 clarification: risk reduction is not a guarantee
Do not start drinking alcohol to prevent cognitive decline. Older observational reports of lower risk among some drinkers do not establish that alcohol protects the brain. The 22% figure in the older source is a relative association from one study, not a 22 percentage-point increase in an individual's risk or proof of cause. Its drinking categories are historical study definitions, not current Australian limits.
Current NHMRC guidance for healthy adults is no more than 10 Australian standard drinks a week and no more than four on any one day; less is lower risk. One Australian standard drink contains 10 grams of alcohol and may be less than a glass or serving. These are harm-reduction limits, not targets or a guarantee of safety. People under 18 should not drink. Those pregnant or planning pregnancy should not drink; not drinking is safest when breastfeeding. Individual health conditions or medicines may require different advice from a clinician.
There is no known cure for Alzheimer's disease, but this does not mean no treatment exists. Dementia Australia describes treatments that may slow progression in some people and other care that helps with symptoms and daily life. Eligibility, benefits and risks need individual medical assessment. Exercise, diet, sleep and social or mental activity do not guarantee that a person will avoid dementia, and the older study figures below should not be read as an individual prediction. New or worsening memory problems deserve medical review.
No treatment today can prevent or cure dementia, but researchers have pinpointed several factors that may shield you from cognitive decline.
Exercise
Few habits deliver as many health benefits as exercise. Beyond helping your brain directly, staying physically active lowers your risk of:
Heart disease
Type 2 diabetes
High blood pressure
Colon cancer
Breast cancer
Physical activity also eases insomnia, anxiety, and depression - and it may help hold off cognitive decline and dementia themselves.
In some studies, people with existing memory problems who took up regular exercise showed improved cognitive function. The benefits may run especially deep for carriers of the APOE4 gene variant, which raises susceptibility to Alzheimer's disease.
A Mediterranean-style diet
This way of eating has long been linked to better cardiovascular health and a lower risk of certain cancers, and it may also guard against cognitive decline. A Mediterranean-style diet appears to reduce the chances of developing mild cognitive impairment (MCI) and to slow the move from MCI to dementia.
A Mediterranean-style diet centers on:
Fruits
Vegetables
Whole grains
Beans
Nuts and seeds
Olive oil
Fish, poultry, and dairy products
Alcohol
Older research hinted that averaging one alcoholic drink a day might be tied to lower dementia risk. Even so, no expert advises drinking to protect your brain. If you enjoy an occasional drink, cap it at one per day.
In one study, heavy drinkers - more than four drinks a day or 14 a week for men, and more than three a day or seven a week for women - faced a 22% higher Alzheimer's risk than nondrinkers.
Sleep
Your body depends on a steady ration of sleep for many essential functions, a large share of them in the brain. People who routinely sleep less than the recommended seven to eight hours a night tend to score lower on tests of mental function - perhaps because learning and memories are consolidated during sleep.
Mental stimulation
Many researchers now think formal education matters less for a healthy aging brain than the habit of staying mentally engaged. One study found that cognitively intact people in their 70s and 80s who took part most often in mentally stimulating activities were only half as likely to develop mild cognitive impairment as the least engaged. Such activities included reading, writing, crossword puzzles, board or card games, group discussions, and playing music.
Social contacts
Social connection shapes health and longevity in powerful ways - evidence suggests strong ties may matter as much as exercise and a good diet. People with rich social networks experience less cognitive decline than those who are isolated. Socializing calls on attention, memory, and other key mental processes, which helps sustain cognition. Regular engagement reinforces neural networks, slowing ordinary age-related decline, and may build cognitive reserve, which can postpone the onset of dementia.
A strong circle of people who support and care for you also keeps stress in check. Depression, which often travels with loneliness, is linked to faster cognitive decline.