Having had two parents who died of variants of Alzheimer's Disease. I can tell you from first hand experience what a horrible disease this is and how it impacts the lives of all around, especially close family members and care-givers.
This new research result is surprising, and adds weight to the claims of those of us who advocate more local and regional food systems and the greater spread of rural self-reliance. Clearly gardening, composting and food-growing in general are one way to get exposed to the dirt that is now required, if you want to reduce your chances of Alzhiemers.
It's going to be fun to watch the health nuts and the snake-oil industry scramble to provide good regular doses of all-American entrepreneurial free-market dirt to the gullible.
I'm also pleased to find out that my sister's and my own chances of contracting this disease are much less than I previously thought. This since, obviously, we otherwise have greater genetic susceptibility.
Both of us are gardeners, and raise our own vegetables.