Summary
This study looked to understand the effects of diet on
cognitive abilities. The premise was to take people and put them into a diet
program that focused on eating healthy. The study took 17 right-handed, white
adult participants aged 35-69 that did not have dementia, but did complain of
memory related issues. The group was then split into an experiment group and a
control group. The experimental group was placed on a specific diet plan that
the researchers believed would aid in brain function.
The diet plan was something made by another researcher (Small
G, Vorgan G: The Memory Prescription. New York, Hyperion, 2004) and is
ultimately impossible to locate. What the study suggests is that the experimental
group had a system of memory exercises, particular foods to eat, and daily
exercise regimens to follow. These instructions were the result of other
studies that looked at different ways to combat dementia. The dietary needs
were met via a plan that consisted of five daily meals emphasizing antioxidant
fruits and vegetables, omega-3 fats, and low glycemic index carbohydrates. The
control group were sent on their way to continue as normal.
Findings
At the end of the 14 days, the participants had their brains
scanned via positron emission tomography (PET) imaging and were tested with
various tests. What they found is that the experimental group’s brains had
changes in their function. The results section discussed sections of the brain
and how there were deceases in the PET images and how it relates to different metabolism
rates within the brain. The more general discussion section stated that
although there were shortcomings (discussed in the critique), the PET images
showed that there were specific, and positive changes within the regions of the
brain that controlled memory and verbal functions, changes that were statistically
significant. The study concluded by stating a healthy lifestyle program improved
measures of verbal fluency and reduced left dorsolateral prefrontal cortical
metabolism, suggesting that such a program may result in greater cognitive
efficiency of a brain region involved in working memory
functions.
Critique
The study was another major medical study, as per every
other study related to brain functions that seem to be selected for study. What
made this study stronger is the use of a brain imaging system to peer into the
brain to investigate the parts of the brain that control cognitive functions
and their changes. That is strong evidence that a program is indeed working and
changing how the brain works. This in turn helps to cement the verbal
experiment’s findings that the program and the diet actually worked. Where the
study stumbles is in the group size. 17 people do make for a very small group,
and the researchers do note this. Furthermore, the test group was not specifically
monitored during their 14-day routine. However, the study notes this as well
and states that sections of the brain were function higher than what would
occur in a placebo effect. It summarizes what we have heard for a long time;
diet and exercise is good for you. Now, how do you get IC analysts to lay off
the Dunkin Doughnuts?
Source
Small, G. W., Silverman, D. H. S., Siddarth, P., Ercoli, L.
M., Miller, K. J., Lavretsky, H., … Phelps, M. E. (2006). Effects of a 14-day
healthy longevity lifestyle program on cognition and brain function. The
American Journal of Geriatric Psychiatry: Official Journal of the American
Association for Geriatric Psychiatry, 14(6), 538–545.
https://doi.org/10.1097/01.JGP.0000219279.72210.ca
Posts
Rourke, interesting article you found. A question that popped out in my mind when I heard how they laid out this experiment was the impact of eating 5 presumably smaller meals a day as opposed to the normal three. That in and of itself can be a worthwhile topic to study to see the impact of diet on cognitive ability. I wonder if that could have impacted the results of the experiment in any significant way.
ReplyDeleteEric
Good observation Eroc. There are a few good experiments that could be made on this study. Breaking food consumption into smaller portions over the day most likely would allow the body to continue to absorb nutrients steadily over the day as opposed to in large lumps. It sounds more efficient at the very least.
DeleteI like your question at the end, Ruark, though it does assume that IC analysts do in fact have a penchant for donuts. This study does seem to support the common wisdom that a healthy diet and exercise is good for the body and mind, but I am often wary of statistically significant findings. The actual significance of P-values is highly debated in research communities, as it is likely that if you run enough tests you're bound to come across a result that is statistically significant. I don't say this to diminish the study's findings, but more to bring the issue of how important a P-value really is to the forefront.
ReplyDeleteI am absolutely no expert on the scientific method. Taken at face value though, the study sounds promising. Even without the fancy science stuff, you know that eating well and some exercise just makes you feel great. That greatness, if utilized, potentially translates into productivity, at the very least.
DeleteI think another potential issue with this study is that scans were not done immediately following consumption (which is when a sugar-rush would happen). Was there any mention of accounting for this immediate interaction or was it just longer term studied?
ReplyDeleteWhile definitely not a longitudinal study, they were looking beyond serotonin and were more interested in the changes to the brain as part of the healthy diet/lifestyle.
DeleteRuark, this was a very interesting article. However, were any other age groups studied besides the 35-60 range? I am curious how the results would change depending on the age group.
ReplyDeleteThere were not. My guess as to that particular age range is that it is easier to study the effects of changes on lifestyle on people who are under the average threshold. Its like when you first start lifting. You do a few weeks at the gym and you see awesome results. You do a few years at the gym and gains are hard to come by.
Delete