Mental decline typically begins before the age of 40, yet few people look after their brain as well as their heart or muscles. But there are many things you can do to help keep your brain healthy and sharp.

To mark Brain Awareness Week, here are some top tips from the Brain Foundation that could help protect against degenerative brain disorders such as dementia and Alzheimer's, and keep your brain fit — no matter what your age.

1. Like your body, your brain needs to be exercised and challenged. Avoid using calculators, swap TV for a book, learn a new skill such as playing a new instrument or play games that involve memory (such as bridge) or thinking ahead (chess).

2. Fill up on the right foods. A meta-analysis (a study that investigates many other studies) published in BioMed Research International found that a higher intake of fruits, vegetables, fish, nuts, legumes and cereal seemed to be associated with reduced risk of Alzheimer's disease. A lower intake of meat, high-fat dairy, sodium (salt), sweets and refined grains was also associated with a reduced risk of Alzheimer's.

3. Don't cut out sugar entirely. Glucose (sugar) is the fuel that keeps brain cells alive and functioning, reports the Brain Foundation. When your concentration wanes in the afternoon, try eating a snack containing natural sugar, such as a piece of fruit.

4. Exercise daily, if possible, advises the Brain Foundation. Just 3 sessions of 60 minutes' exercise per week could make a difference, according to a study by the University of British Columbia. After 6 months, participants aged 56 to 96 who did 3 aerobics classes weekly showed significant improvement in cognitive function, including memory. The research also showed that exercise could slow down the effects of mini-strokes, which can cause dementia.

5. Prioritise sleep. If you're reading this in bed, put your phone down: even dim light can interfere with your circadian rhythm (the 'body clock' that tells you when to sleep and when to wake) and melatonin production (the hormone that induces sleep). Getting enough rapid eye movement (REM) sleep helps the brain store the information you learned that day, while poor sleep leads to poor memory, concentration and mood.

Support brain research with trivia

While there's nothing trivial about brain disease and injury, the Brain Foundation is asking Australians to organise a trivia night with family and friends to raise much-needed funds for research. Learn more about how to be a trivia night host, brain health and how funds raised will be spent at Bigtrivia.org.au.