The theory behind previous research is that people with higher education have a higher brain or cognitive reserve, maybe a larger number of brain cells or more efficient brain systems or networks. These people with higher education have more redundancy or reserve so they can cope if part of the brain is destroyed.

When more and more of the disease accumulates in the brain they are able to compensate for a long time, but at some point they cannot cope with it anymore and they manifest the disease.

We couldn't find any other explanation for it.

That is a pretty significant effect.

They go downhill faster. We think it's because they have delayed the onset so long that a lot of the brain changes have accumulated and when they reach the point of clinical manifestation, they can't compensate any more and they sort of crash.

We tried to single out which of the components of the diet are driving its effect, but none of them is prominently responsible. But, when we put them together, the effect was there.