News on Exercise and Young Onset Alzheimer's Disease

If you read Beating the Dementia Monster you know science has established that physical exercise is a powerful weapon in the battle to stop the progress of Alzheimer's disease.  But so far, this has only been shown to be true for "sporadic Alzheimer's disease."  It has not been shown to be helpful for "familial Alzheimer's disease," sometimes called "younger onset Alzheimer's."

In familial Alzheimer's, symptoms appear when the person is in their 50s or even 40s.  It is genetically determined, so there is a pretty well defined population of people carrying the gene.  And if you carry this gene, the probability is quite high that you will develop the disease.  Fortunately it's pretty rare.  I read once that there may only be 300 or so families in the whole world carrying the gene.  The most famous family is in Columbia, and they are studied carefully.

Sporadic Alzheimer's is all other Alzheimer's disease.  It's sometimes called older-onset or late onset Alzheimer's.  You may be at increased risk of Alzheimer's because you carry the ApoE4 gene, but that's not familial Alzheimer's, and it's far from certain that the gene will cause you to develop the disease.  So I have sporadic Alzheimer's disease. 

In this past week's edition of ALZFourms there was an article about a study of exercise and familial Alzheimer's.  It found that there was, in fact, improvement in patients who got regular physical exercise.  In fact, the researchers were surprised by the strength of the correlation between exercise and cognitive function.

In familial Alzheimer's, it's much easier to predict when someone will develop the disease.  Therefore it was easier to study how the point of intervention with respect to age affected how effective the exercise is.

Participants were categorized by how much exercise they got.  A minimum of 2.5 hours per week was necessary for participation, with the high end at 6.5 hours.  Many exercised 5 hours per week, playing tennis, walking, and hiking.  (I spend 5.5 hours per week on the treadmill.) 

Peak cognitive improvement was at 6.7 hours.  One odd thing was that exercising more that 8 hours per week may have actually caused decline in cognition.  This was not seen in the control population, so it appears to be related to the disease.  Of course, the worst decline was among those who got no exercise. 

All non-control test subjects had familial Alzheimer's.  Does this mean that the optimal exercise for us with sporadic Alzheimer's is also 6.7 hours (just shy of an hour per day)?  Or if we go more that 8 hours per week we'll experience decline?  I don't know, but I'm having great success with 5.5 hours per week.