How many animals, fruits or countries can you name in one minute? If you recall more than 20 in a single category you’re a winner. For those who can only remember 10-15, animals for example, you might need to spend more time outdoors or watch more of Sir David Attenborough’s magnificent documentaries, aside from doing scrabble and/or crosswords. Without raising too many alarm bells if you’re consistently scoring less than 15 you might need to see your doctor.
With regard to preventing heart disease and mental decline, ‘The Wellness Guide to Preventing the Diseases of Ageing,’ has an excellent chapter on each of these disorders.