Can Broccoli and B-Vitamins Prevent Alzheimer’s?
Meryl Comer: Just slowing the progression for five years for families builds quality of life, but from a societal point of view saves billions and billions of dollars. Let’s look at the notion of maintaining your brain so you don’t get it. Dr. Gandy, a 15-member panel of experts at the National Institute of Health reported: forget the crossword puzzles, forget the exercise, forget learning French, none of it is going to help. How do you respond to that?
Dr. Gandy: Well I don’t think they quite said it that negatively. What they said was that we currently don’t have sufficient evidence to guide therapy, to guide doctors to tell their patients: yes, take six ounces of broccoli, do the crossword puzzle on Wednesday and Friday and then you run four days a week. The challenge with all these lifestyle issues is that they have to be evaluated with what are called randomized clinical trials, the way a drug is evaluated. And the challenge is turning crossword puzzles and broccoli into drugs. And that is really the challenge for all of us. We think that there are benefits there, but we don’t have the evidence yet and getting the evidence is not easy.
Meryl Comer: Let’s go quickly through some of these. B vitamins, large doses are supposed to reduce the rate of brain shrinkage by half.
Dr. Troncoso: Well I think that the case of B vitamins that have many targets. It is possible they may work for Alzheimer’s disease. We don’t know that. But clearly it has probably some very good affect in the protein metabolism preventing vascular disease, so it may be that it is good, but the point is that it’s not... it hasn’t been demonstrated that it effectively prevents Alzheimer’s disease. It may prevent some brain shrinkage as determined by imaging, but... and I think that this committee that you were quoting there they really they were negative just for being negative. One of the important points is to protect actually the patients and caretakers from individuals or systems that may try to start commercializing puzzles for Alzheimer’s disease or this medication. We don’t want people to have false expectations, at the same time spend tremendous amount of monies in useless treatments.
Meryl Comer: Well one good example of that is 110 million dollars spent annually by Americans on ginkgo biloba and a 30-million-dollar study saying it doesn’t work, so that is one of the challenges. How about the latest study that just was released in the Wall Street Journal about smoking in your 50s doubles your rate of acquiring Alzheimer’s?
Dr. Gandy: Yeah, that sort of what the study shows, and I think there were no obvious flaws in the study that anyone has picked out so far, looking to see if it looks authentic. Obviously all studies, like all experiments, must be replicated by someone to prove that they are true. I mean the most important thing about the smoking paper though is that that is a modifiable factor. Head injury is difficult to modify unless you’re going to wear a helmet and never engage in any activities that are risky—basically don’t leave your house. But the smoking is modifiable. Meryl Comer: You wanted to make a point?
Dr. Troncoso: I think that many of these risk factors that have been implicated like being in good physical shape, smoking, they all may in the long term contribute and are positive, but there is not a clear guarantee. There is other factors that have become... is demonstrated. For instance, education. So, it’s very clear that if individuals that have longer years of education have some degree of protection compared with the ones that don’t. In fact, we have examined that in a particular study, the Nun Study. It’s very clear that in those subjects the issue of environment is really reduced to minimum. We could clearly see that the nuns that had a longer period of education had less risk of Alzheimer’s disease than the ones that were not, so there are many factors that usually apply in early life that can either increase or decrease the risk for Alzheimer’s disease.
Dr. Guarente: I've always been intrigued by the Nun Study and I wonder to what extent does that represent a sort of a reserve that people have who have had a lot of education and use their brains a lot and as opposed to really protecting at the level of individual neurons and the tissue itself?
Dr. Troncoso: What I can tell you is that when we looked at the group of nuns that had asymptomatic AD compared with the ones that had dementia, the number of those nuns that were in... that had graduate education it was significantly higher than the other ones. It was really an amazing difference.
Dr. Gandy: But as compelling as those data are they’ve still not randomized clinical trials, which is what we need to use to recommend to people what they can do. I mean it’s difficult to tell people in their 50s that they should have gone to graduate school.
Meryl Comer: Exercise, exercise, exercise, that is a prophylactic for many diseases, or proposed. Now the study comes out that walking a mile increases your gray matter. Why should I worry about gray matter in the brain?
Dr. Arancio: The philosophy behind it would be that if you exercise you increase the gray matter, the communication between the cells and strengthen the synapse, and build up the brain just like a muscle and that would help the time... during that time when there is damage to the brain, so you have more reserve to the brain. That could be the philosophy behind it, but with all of this what you have said and that is what Sam was saying, we should take everything being very cautious because none of these things vitamin, exercise, wine, et cetera have so far showed to have solved the problem. The fact is that people still get Alzheimer’s. Millions of people have it and we have not solved it. So it’s unlikely that any of these things that we have so far seen alone will have such a striking affect to solve the disease.