We eat food every day, but have you ever wondered how the food you eat affects you? You’ve probably heard that it gives you energy and that is true, but it can also affect your mood, brain and behavior! Keep reading below to learn more about the benefits that certain foods can provide.
Some research has found a link between eating green vegetables and a slower cognitive decline and a lower risk of dementia. This has been shown in studies with leafy greens (kale, spinach, broccoli, etc.) that are high in vitamin K, lutein, folate, and beta carotene. Eating leafy green vegetables has also been linked to a lower risk of cardiovascular disease, and because they contain fibre, they aid in the health of the digestive system, which is important given the gut-brain connection.
Fatty fish, such as salmon, cod, and canned light tuna, are high in omega-3 fatty acids. According to research, omega-3 fatty acids are linked to lower levels of the protein that forms the clumps in the brain seen in Alzheimer's disease (AD). It is important to note that this does not imply that omega-3 fatty acids can prevent or cure Alzheimer's disease. A 2018 review article concluded that omega-3 fatty acids can help prevent Alzheimer's disease and improve memory in cases of mild Alzheimer's disease. However, once Alzheimer's disease has begun, omega-3 fatty acids cannot reverse it, and they appear to have no effect in moderate to severe cases of the disease.
Don't worry if you don't eat fish! Omega-3 fatty acids can also be obtained from walnuts, avocados, flaxseeds, and omega-3 supplements. In fact, by eating walnuts, you are also providing your body with tryptophan, a chemical in the body that aids in the production of serotonin and the regulation of the immune system!
High flavonoid levels in berries like blueberries and strawberries, according to researchers, are responsible for slowing cognitive and memory decline. In some studies, for example, episodic memory (ie. memory of events) and executive functioning improved after blueberry consumption. So, how long do these advantages last, and how many berries must be consumed? In a 2019 study, 40 adults were given cognitive tasks before half of them drank a mixed berry smoothie or a low-flavonoid smoothie, as well as two, four, and six hours later. The mixed berry group showed better selective attention and mental flexibility (as assessed by cognitive tasks) six hours after drinking the smoothie than the adults who drank the low-flavonoid smoothie. Some researchers suggest having at least two servings of high flavonoid berries a week to reap their benefits.
Tea & Coffee
Caffeine, which is commonly found in coffee and tea, is known to increase alertness and reaction time. According to a John Hopkins University study, consuming moderate amounts of caffeine may help to strengthen new memories and thus improve recall. This effect was observed for at least 24 hours after caffeine consumption. This could be due to caffeine's effect on alertness and attention- if a person is more alert and paying attention to a specific event or fact, they are more likely to remember it. More research is needed, however, to reach a consensus on how caffeine affects memory.
Note: Caffeine’s effects are dose-dependent, with moderate doses leading to positive effects but high doses leading to anxiety and worse cognitive performance.
Extra Dark Chocolate
Consuming extra dark chocolate (70 percent cacao or higher) may benefit brain health, according to some studies. According to a nutritional psychiatrist at Harvard Medical School, the nutrients in dark chocolate (antioxidants, flavonoids, and fibre) help keep brain cells healthy, reduce brain inflammation, and may improve cognitive functioning (e.g., verbal memory) for short periods of time.
Another way in which extra dark chocolate can benefit the brain and body is by improving gut health! One study found that daily consumption of 85% cacao dark chocolate for three weeks led to a statistically significant increase in gut microbiota diversity compared to a group which had no chocolate for three weeks. That same study also found that the 85% cacao group had less negative moods compared to the control group!
Curcumin, one of turmeric's main components, has been linked in some studies to a reduction in age-related cognitive decline. According to a 2018 article that reviewed studies on curcumin and Alzheimer's disease, curcumin may reduce the risk of chronic health problems such as obesity and diabetes. This in turn reduces the risk of Alzheimer's disease because those chronic health problems are risk factors for the disease. Curcumin has also been shown in rodent studies to improve memory. A small amount of black pepper added to turmeric can help activate the curcumin and increase the rate at which the body can use it.
The human body has a gut-brain connection, which allows messages from the gut to be transmitted to the brain and vice versa. According to research, improving our gut health may also improve our cognition and mood. When we talk about gut health, we really mean the number and diversity of microorganisms that live in the gut. Researchers believe that the amount of neurotransmitters (body chemicals such as serotonin and dopamine) secreted in the gut by these microbiota can influence the levels of those neurotransmitters in the central nervous system (i.e. brain and spinal cord). These neurotransmitters have the potential to influence our brain, behavior, and mood.
Serotonin, for example, aids in digestion, sleep, mood, and happiness regulation, and the gut produces over 90% of the body's serotonin! So, how do fermented foods benefit our digestive health? The fermentation process, among other things, produces lactic acid, which can lead to the growth of beneficial bacteria in our gut! Homemade kimchi, yogurt, miso, sauerkraut, and kombucha are all examples of fermented foods.
Note: We want to emphasise that we are not making cause-and-effect statements below (that is, we are not claiming that these foods prevent, cure, or cause anything). Researchers will have a better understanding of which conclusive statements they can make as more studies are conducted. While we cannot guarantee that these foods will make you live longer or prevent cognitive decline, we do recommend eating them as part of a balanced diet to ensure that your body receives the nutrients they contain.
Armstrong, L. (2021, October 8). A Harvard nutritionist and brain expert shares the 5 foods she eats every day to sharpen her memory and focus. Make It. https://www.cnbc.com/2021/10/08/foods-that-sharpen-brain-health-memory-and-focus-according-to-harvard-nutritional-psychiatrist.html
Chen, M., Du, Z., Zheng, X., Li, D., Zhou, R., & Zhang, K. (2018). Use of curcumin in diagnosis, prevention, and treatment of Alzheimer's disease. Neural Regeneration Research, 13(4), 742-752. https://doi.org/10.4103/1673-5374.230303
Gatlin, L. (2014, January 12). Caffeine has positive effect on memory, Johns Hopkins researchers say. The Hub. https://hub.jhu.edu/2014/01/12/caffeine-enhances-memory/
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La Rosa, F., Clerici, M., Ratto, D., Occhinegro, A., Licito, A., Romeo, M., Di Iorio, C., & Rossi, P. (2018). The gut-brain axis in Alzheimer’s disease and omega-3. A critical overview of clinical trials. Nutrients, 10(9), 1267. https://doi.org/10.3390/nu10091267
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McLellan, T. M., Caldwell, J. A., & Lieberman, H. R. (2016). A review of caffeine’s effects on cognitive, physical and occupational performance. Neuroscience and Biobehavioral Reviews, 71(C), 294-312. https://doi.org/10.1016/j.neubiorev.2016.09.001
Shin, J., Kim, C., Cha, L., Kim, S., Lee, S., Chae, S., Chun, W. Y., & Shin, D. (2022). Consumption of 85% cocoa dark chocolate improves mood in association with gut microbial changes in healthy adults: A randomized controlled trial. The Journal of Nutritional Biochemistry, 99, 108854-108854. https://doi.org/10.1016/j.jnutbio.2021.108854
Whyte, A. R., Cheng, N., Butler, L. T., Lamport, D. J., & Williams, C. M. (2019). Flavonoid-rich mixed berries maintain and improve cognitive function over a 6 h period in young healthy adults. Nutrients, 11(11), 2685. https://doi.org/10.3390/nu11112685