Many of us have long been waiting for a justifiable reason to indulge in chocolate that did not first involve having a migraine. It is with great excitement that this writer must announce that our day is coming nearer. A fairly recent trial found that older adults who have a high dietary intake of flavanols, like those found in cocoa, have heightened memory performance on object-recognition tasks. Additionally, it also increased neural activity in the dentate gyrus of our hippocampi as measured by a fMRI.
Brickman et al. tracked 38 individuals over a period of 12 weeks. During that time, half of the sample population received a high intake diet of flavanols and the remaining sample followed the low intake diet. The team found that those receiving high intakes of flavanols had measurably improved neural activity, increased blood flow in the dentate gyrus and increased memory functioning on object recognition tasks. They noted that the increased blood flow was a direct correlation to improvement in memory functioning but needed to go a step further to prove this theory.
In addition to a massive amount of data collection, the team created a digital test called the ModBent. They designed the ModBent to be an extremely difficult memory recognition task that activated the dentate gyrus. It was designed to activate this region of the brain without triggering other areas known to be specific to memory. To establish the validity of the ModBent, Brickman et al. organized a double-dissociation study using the tool in healthy adults. The study confirmed that the measure did in fact only activate the dentate gyrus but that it also was receptive to the age of the examinee. The group used this information and designed two different versions of the ModBent. They administered one test at the beginning of their study and one at the end. Having two versions of the assessment prevented the participants from potentially experiencing repeat assessment practice effects.
The study found that high-flavanol group’s performance was on average 630 ms higher than the low-flavanol group. They compared the difference in performance to knock-out mice studies measuring for memory loss. It was noted that such a difference paralleled the results of aging in the brain by approximately three decades. This correlation was extremely significant to their findings. Brickman et al. established clear evidence that including flavanols in one’s diet would be beneficial to degree in reversing cognitive decline in memory.
Brickman, Adam M., Khan, Usman A., Provenzano, Frank A., Yeung, Lok-Kin, Suzuki, Wendy, Schroeter, Hagen, Wall, Melanie, Sloan, Richard P., & Small, Scott A. Enhancing dentate gyrus function with dietary flavanols improves cognition in older adults. Nature Neuroscience. 12, 1978-1806 (2014).
It should be noted that Brickman et al. hypothesized that combining a high-flavanol diet with the added benefits of exercise (peak oxygen levels in our blood) would produce even greater results on the ModBent. However, in collecting data and measures for the comparison, they found that there was no difference in the aerobic group versus non-exercise group when measuring for peak oxygen intake. Therefore, they did not move forward with the study and the effects of a high-flavanol diet combined with exercise are still currently unknown.
WKPIC Doctoral Intern