Can Diet Prevent Alzheimer’s Disease?

• Alzheimer's
• Curing Alzheimer's

No. Then why do I even bring this up? Yesterday, a patient asked me if Alzheimer’s disease could be prevented (or made less likely) if you ate the “right” diet. It’s a question that strikes not to the core of the pathology, but to the depth of our fears.

Historical precedents offer useful parallels and one of the most poignant of these is the polio epidemic that drew to a close with the advent of the Salk polio vaccine in 1954. In the 21st century, few of us understand how terrifying polio was then. Polio is easy to prevent now, but in 1950, polio was a nightmare: rampant, frightening, and enigmatic. How could you keep your children from dying, from ending up on an iron lung, or from being permanently crippled by a sudden, unexpected fever, quickly followed by disaster?

Just as with Alzheimer’s disease now, we groped for straws then, trying anything we could think of to avoid our horror. Then it was children, now it is parents and ourselves, but the tragedy is equally ubiquitous and equally terrifying. Polio scared us then, Alzheimer’s scares us now. Ironically, many of the same remedies were hawked then as are hawked now, although we have gussied up the terms a bit. Then it was nursing care, muscle therapy, oxygen, and diet; now it is nursing care, music therapy, monoclonal antibodies, and … diet.

In 1951, a book, Diet Prevents Polio, argued that the right diet could prevent polio or minimize its consequences. People took it seriously then because there was nothing else that anyone could do to protect their children from death and disability.

In 2015, people wonder if the right diet could prevent Alzheimer’s or delay its consequences. Some people take it seriously because there is nothing else that anyone can do to protect themselves or their loved ones from death and disability.

Asking if diet can help is like asking if you can make your car last longer by having the right fuel. It’s true that having the wrong fuel can shorten the life of your car markedly, but the difference between normal unleaded and a more expensive version isn’t going to make much difference. The life of your care depends on whether the car is poorly made or the used car is a “lemon”, you never check your oil, you ignore the engine warning light, you have bald tires and never replace them, or you drive like a fool. Almost without exception, the car’s lifespan is determined by how it’s made and how you drive it, not by the fuel you use.

Medically speaking, there are bad diets (all sugar and no protein, for example) that will lead to medical disaster, including obesity, diabetes, heart disease, and any number of other problems, but no diet could prevent polio in 1951 nor prevent Alzheimer’s disease now.

If you wanted to prevent polio, we needed a vaccine.

If you want to prevent Alzheimer’s, we need a cure.