School’s back in session, so we did a little studying ourselves. Whether you’re in college, grad school, or just affected by a student’s schedule (hi moms and dads), improving certain aspects of your life can better equip you for this unpredictable new school season. This school year, focusing on our immunity has become just as important as improving our cognition. We often tend to think of our brain and immune system as completely separate entities, but they share a fascinating link that we'll dive into. Research also continues to demonstrate that a healthy body weight and proper diet and nutrition are some of the most powerful tools we have to protect our body from pathogens. In this blog, we'll also discuss ways to use nutrition to mentally and physically prepare both you and your children for the school year ahead.
The secret connection between immunity and cognition starts with the gutThe secret to protecting both our mind and body starts with our colon. Yes, the colon—more commonly known as the large intestine. Why our colon? Because it's home to trillions of microorganisms! The majority of these microorganisms are made up of bacteria, and recent research has found that these bacteria play a significant role in almost every system in our body, including both immunity and cognition.
The colon contains a diverse set of bacteria, meaning both good and bad strains live there. In a healthy functioning body, the good bacteria flourishes and rewards us by enhancing our health and reducing inflammation throughout our body. When things run amuck, unhealthy microbes thrive, causing damage and inflammation to our body—commonly referred to as "dysbiosis." Therefore, maintaining a healthy gut is key in keeping our body happy.
The gut/brain axis connects the microbiome with neurotransmittersThe gut and the brain share a special connection known as the gut/brain axis, and the two engage in constant communication with each other. How exactly? The gut’s microbiome promotes mental health by stimulating and producing neurons that send signals to the brain.[2,3] For example, 90% of serotonin, a neurotransmitter associated with the regulation of mood, sleep, and memory, is produced in the gut. To optimize our brain’s capability, we must also improve the health of the gut.
The immune system lives in the gut, supporting the need for a healthy microbiomeDid you know that 70% of the immune system lives in the gut? A single layer of cells separates our microbiota from our immune system. Your gut contains a rich community of healthy microbes that compete against invading pathogens, acting as your body’s first defense against infection. Research, especially of late, has found that your microbiome is a key component of a healthy immune system and your body’s ability to fight off viral and bacterial infections.
Proper nutrition= happy gut= healthy brain
Just like humans, bacteria needs proper nutrition to flourish and thrive. Your food choices influence your gut bacteria because everything we eat becomes food for them. Fortunately, several foods can stimulate our gut’s health. Fiber, often called a prebiotic (a term for dietary compounds that feed probiotics in the gut), passes undigested through our gastrointestinal tract, serving as food for the good bacteria. With ample dietary fiber, the bacteria can nourish, thrive, and hinder the growth of unhealthy bacteria. Whole grains like oatmeal and quinoa, legumes, and many fruits and vegetables are rich sources of fiber making them excellent fuel for the gut microbiome.
Phytonutrients, the compounds that give fruits and vegetables their unique colors, also play a role in promoting gut health. Phytonutrients reduce inflammation in the gut and promote diversity among the good bacteria. Furthermore, fermented foods naturally contain probiotics which help replenish the good bacteria in our intestines. Sources of these probiotics include kefir, yogurt, kimchi, and sauerkraut. A diet rich in fiber, phytonutrients, and probiotics promote a healthy microbiome and thus, a happy brain.
Anti-inflammatory foods help to protect the brain and boost cognitionNow that we’ve touched upon the gut, let’s switch our attention to the brain. A healthy brain works best in an anti-inflammatory state. By filling our diets with unsaturated fats and abundant sources of antioxidants, we can lessen inflammation. Fatty fish, chia seeds, flax seeds, and walnuts are rich sources of omega-3 fatty acids, a type of anti-inflammatory fats that contribute to healthy brain function. Lycopene, a powerful antioxidant, prevents dangerous free radicals from damaging our DNA. Therefore, foods high in lycopene may protect the brain and thus, reduce the effects of age-related conditions like Alzheimer's or dementia.7 Lycopene gives fruits and vegetables their red color, so grab foods like tomatoes, watermelon, papaya, and red bell peppers for your daily dose of lycopene.
Certain foods can even enhance focus and memory
While certain foods promote a healthy environment for our brain, others may directly bolster our focus and memory. Dark chocolate contains many natural stimulants, like caffeine, which enhance focus and concentration. Munch on a piece of chocolate before test time for razor-sharp focus. Blueberries, a true superfood, directly improve memory. A recent study showed that the intake of blueberries increased brain blood flow, brain activation, and memory in older adults.9 Incorporate blueberries into your diet and studying for your next exam could be a whole lot easier.
Food additives can disrupt gut bacteria and increase hyperactivity in childrenNow let’s quickly touch upon some foods to avoid in our diet. Research on hyperactivity and attention-deficit disorder is shifting focus from sugar to artificial colors, dyes, and preservatives. Compelling research shows these additives significantly increase hyperactivity in children. The results of these studies led the European Union to issue a mandate forcing companies to label products containing certain food dyes with the warning: “May have an adverse effect on activity and attention in children.” Furthermore, these additives have also been shown to disrupt gut bacteria causing damage and inflammation. While more research is warranted to solidify the effects of these additives on attention span, especially in adults, our recommendation: avoid them when possible.
Prep your body and brain for the new school year: a summary
- Protecting both our mind and body starts with our colon, specifically our gut bacteria.
- Our gut bacteria has the ability to support or damage cognition and immunity.
- A diet rich in fiber, phytonutrients, and probiotics nourishes our gut’s bacteria, allowing it to communicate effectively with the brain and immune system.
- Healthy fats and antioxidants create the ideal environment for a working brain while dark chocolate and blueberries can enhance focus and memory.
- Avoid food additives and preservatives to enhance focus and a healthy gut microbiome.
Diana Licalzi, MS, RD
- Diana is a Content Strategist and Team Nutritionist at InsideTracker. As a Registered Dietitian and self-proclaimed "biohacker," Diana enjoys researching and testing the latest trends and technology in the field of nutrition and aging. You'll often find Diana , completing a 24-hour fast, conducting self experiments, or uncovering strategies to increase longevity. Follow her on Instagram at @dietitian.diana.
(1) Cryan JF, Dinan TG. Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. Nature Reviews Neuroscience. 2012;13(10):701-712. doi:10.1038/nrn3346.
(2) Bull MJ, Plummer NT. Part 1: The Human Gut Microbiome in Health and Disease. Integrative Medicine: A Clinician’s Journal. 2014;13(6):17-22.
(3) Galland, L. The Gut Microbiome and the Brain. Journal of Medicinal Food. 2014;17(12):1261-1272. doi:10.1089/jmf.2014.7000.
(5) Duda-Chodak A, Tarko T, Satora P, Sroka P. Interaction of dietary compounds, especially polyphenols, with the intestinal microbiota: a review. European Journal of Nutrition. 2015;54(3):325-341.
(6) Rai A, Jeyaram K. Health Benefits of Functional Proteins in Fermented Foods. Health Benefits of Fermented Foods and Beverages. 2015:455-474.