According to research from the Centre for Research in Epidemiology and Population Health in France and University College London, the brain begins to lose sharpness of memory and powers of reasoning and understanding from as early as 45.

(Previously it was thought that this began around the age of 60, but the researchers found that the brains of even the youngest were already in decline. There was a 3.6% decline in the mental reasoning of men and of women aged 45 to 49 and the process appeared to have sped up in the older age groups. Men aged 65 to 70 had a decline of 9.6% while women fared a little better, at 7.4%. The good news is that there are things that can be done about it. Looking after the heart has been shown to help the head, studies show that people with high blood pressure, obesity and high cholesterol who are at high risk of heart problems, are also at higher risk of dementia. Or maybe as we get older, we simply forget to exercise and eat properly.)