In a Finnish study, identical twins were compared against each other in the consequences of active vs. inactive lifestyles. As some people would expect, the more active twin had fewer health problems with increasing age. As some would be surprised, both twins had similar diets, which would suggest nutrition alone is not the turning factor of good health.
However, while nutrition is for the most part similar, the fact that the twins are so different in terms of their metabolic profile suggests that exercise is the key that unlocks their genetic “destiny”. It makes sense that if they’re eating roughly the same things (and the main difference is one exercises and the other doesn’t), how that food is processed through the bodies will be different in on than in the other. Therefore, it should be no surprise if the inactive twin has problems with insulin production or resistance, cholesterol levels, and higher body fat.
What may be surprising is that the brains end up being different also. The more active twin has substantial increased areas of grey matter, especially in areas that control motor skills and coordination. What’s interesting is that upon dementia onset, it’s not just memory that’s affected – many times it is physical abilities (such as fine motor skills and coordination) that suffer.
In other words, if only one aspect of life can be changed to prevent dementia, it might as well be exercise because there is a direct link to the prevention of deterioration in physical abilities. It’s possible that that direct link is the development of muscle memory – that is to say, we are often only concerned with mental memory (and afraid of losing it), when perhaps we should also be considering other forms of memory.