Could trendy ‘superfoods’ have a significant impact on your brain health?
Studies suggest that ‘superfruits’ and ‘super-vegetables’ such as broccoli and blueberries may potentially aid in increasing memory and cognitive function, and also help minimise stroke symptoms.
Sulforaphane, a powerful phytochemical compound naturally occurring in cruciferous vegetables, has been known to protect against multiple, and in some cases, life-threatening diseases. It is interesting to note that Sulforaphane is found in over 200 foods; the richest source of the sulphur-rich compound being, broccoli.
Sulforaphane induces the activation of nuclear factor erythroid 2-related factor 2 (or, NrF2), which is involved in the antioxidant-response pathway. This means that sulforaphane, acquired through the consumption of broccoli and other cruciferous vegetables, can upregulate NrF2, which in turn has a direct positive impact on the availability of multiple antioxidants in the body. These antioxidants are essential in protecting the nervous system against stroke and other pathologies.
Zhao et. al. in their 2006 study, found that rodents, when given 5 mg/kg of sulforaphane, had only a reduced volume of the brain affected after a stroke; relative to rodents that did not receive sulforaphane in any quantity. This, as a result, suggests that broccoli consumption prior to stroke is beneficial in minimising the area of injury, which consequently, can help improve stroke prognosis and quality of life. It can also reduce the impact of existing symptoms.
It is, however, important to note that normal dietary consumption of broccoli equates to merely 1 µm of sulforaphane. Even people who can be categorised as consuming high, if not extremely high amounts of broccoli, can only consume 7 µm of sulforaphane through their diet (while pharmacological and industrial doses of sulforaphane are up to 100µm). This affirms the need for further translational studies to identify the quantities of consumption and the direct effect of broccoli supplementation in humans. That said, there is still a level of converging evidence from a growing number of investigators suggesting that broccoli is still effective in increasing the concentration of sulforaphane in the system, which has been shown to attenuate post-stroke influence on brain function.
Another superfood that has been long established as beneficial for both cardiovascular and brain health is the humble blueberry. Blueberries contain high quantities of anthocyanin compounds (a class of flavonoid polyphenols), which possesses anti-inflammatory and antioxidant properties. A large body of animal studies suggests that blueberry consumption has a reversal effect on age-related motor and cognitive decrements, contributing to improved cognitive performance overall.
Boespflug et. al. (2018) conducted the first human neuroimaging study to identify the functional effects of blueberry consumption. They recruited 21 individuals, aged 68 or older, with increased risk of developing dementia. They divided them into two groups; while one group consumed daily placebo shakes, the other consumed 148g of a blueberry shake, daily, for 16 weeks. Both groups were asked to perform several tasks to assess their motor and cognitive skills, while being imaged to determine their brain activation during specific task performance. Post 16 weeks of daily blueberry or placebo supplementation, they found that the group that consumed blueberry shakes showed significantly higher brain activation levels, at specific brain regions, that were associated with the given tasks.
These conclusions, by no means suggest that these superfoods are capable of ‘supercharging’ your brain, and instantly improving on motor and cognitive functions. It is however our understanding that both broccoli and blueberries contain naturally occurring chemical compounds that are highly effective in protection and enhancement of various cognitive and motor tasks, and further research could potentially provide us with a helpful analysis regarding the correlation between these foods and brain health.
Boespflug, E. L., Eliassen, J. C., Dudley, J. A., Shidler, M. D., Kalt, W., Summer, S. S., Stein, A. L., Stover, A. N., & Krikorian, R. (2018). Enhanced neural activation with blueberry supplementation in mild cognitive impairment. Nutritional neuroscience, 21(4), 297–305.
Zhao, J., Kobori, N., Aronowski, J., & Dash, P. (2006). Sulforaphane reduces infarct volume following focal cerebral ischemia in rodents. Neuroscience Letters, 393, 108-112.