NEUROLOGIST and author of The Better Brain Book , Dr David Pelmutter says that by age 40, about two-thirds of people experience some mental decline.

This slowdown in mental function typically begins with mild memory problems or “fuzzy thinking”. By age 65, one out of every 100 people will have symptoms of dementia, such as confusion and severe forgetfulness. By age 75, that number increases to one in 10.

This mental decline occurs for the same reason the rest of the body ages — cells lose their ability to recover from damage, in particular that done by free radicals. This process is accelerated by eating nutrient-poor foods, lack of physical exercise, insufficient sleep, environmental toxins, stress, and head trauma.

Stay mentally active

Research suggests that we need to exercise our brain in order to slow its decline. The brain needs to be exposed to new challenges that exercise its different parts. If you break your routine in a challenging way, you are using brain pathways not previously used. This can involve something as simple as brushing your teeth with your non-dominant hand. This activates seldom used connections on the non-dominant side of your brain.

Here are some other suggestions:

• To maintain and improve reasoning skills, do riddles and sudoku, debate issues with family and friends, and read a book.

• For verbal skills, solve word games, for example, crossword puzzles and word jumbles, play Scrabble, learn a new language, buy a “Word a Day” calendar.

• To increase memory, play card games, commit to memory some important phone numbers.

• For visual and auditory processing, listen to books (this is a great way to pass the time while you are travelling to and from work), play an instrument.

• To maintain coordination and dexterity — learn a new skill like crocheting, learn to play table tennis or any sport that requires hand-eye coordination.

• Take advantage of calendars, planners, shopping lists, and address books to keep routine information accessible. At home, designate a place for your glasses, keys, and other frequently used items.

• When you want to remember something you have just heard or thought about, repeat it out loud. For example, if you have just been told someone’s name, use it when you speak with him or her: “So, Mary, where did you meet John?”

• Make a mnemonic. This is a creative way to remember lists. For example, you can use the phrase “Rory of York goes battling in vain “to remember the colours of the rainbow which are — red, orange, yellow, green, blue, indigo, violet.

Get physically active

Mental fitness requires physical fitness. Moving your body increases the flow of blood and oxygen to brain cells. Research has shown that exercise increases brain volume in the elderly and can reverse some normal age-related deterioration of brain structure.

Physical exercise significantly lowers the risk of heart disease, stroke and diabetes, thereby reducing some risk factors for Alzheimer’s and other dementias. (Alzheimer’s disease is strongly linked to obesity, heart disease and type-2 diabetes, leading many to consider Alzheimer’s the “type-3 diabetes”).

Remain socially active

Social activity not only makes physical and mental activity more enjoyable, but it can reduce stress levels.

Stress management

Studies have demonstrated that chronic, unbalanced stress raises blood levels of the memory-robbing hormone cortisol. Relaxation exercises such as deep breathing, yoga, or meditation are helpful.

Good sleep habits

Sleep is necessary for memory consolidation. Sleep disorders like insomnia and sleep apnea leave you tired and unable to concentrate during the day.

Feed the brain right

All the brain teasers in the world will be of no use if you do not feed your brain right. Eating antioxidant-rich fruits and vegetables, as well as foods high in omega-3 fatty acids like deep-sea fish and flaxseed all promote mental health. Since most people cannot get enough of their required daily nutrients from dietary sources, it is important to supplement. Take a high-potency multivitamin, antioxidants and B vitamins in addition to memory-specific nutrients such as vitamin E, coenzyme Q10, phosphatidylserine , pregnenolone, ginkgo biloba and the omega-3 fatty acids.

Dr Jacqueline E Campbell is a family physician, university lecturer and pharmacologist and radio show host. She is the author of the book “A patient’s guide to the treatment of diabetes mellitus.” Email her at drjcampbell14@yahoo.com