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How omega-3s, B-vitamins, polyphenols and regular movement work together to strengthen your brain
The idea that what we eat and how we move can reshape the brain is not new, but the scientific picture has sharpened considerably over the past decade. A 2025 systematic review published in Bioengineering by Clemente-Suarez and colleagues synthesised a wide body of evidence on the interplay between targeted nutrition and structured physical activity, focusing on how these two lifestyle pillars jointly influence neuroplasticity, cognitive performance and mental resilience. [1]
At the heart of the findings sit two signalling molecules that most readers outside neuroscience will never have encountered: brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1). Both act as chemical fertilisers for the brain, supporting the growth, survival and connectivity of neurons. When their levels rise, the brain becomes more adaptable; when they fall, cognitive decline tends to follow. The review makes a compelling case that the fastest, most sustainable way to elevate BDNF and IGF-1 is through the combination of specific dietary patterns and regular exercise, rather than either approach alone. [1][2]
This blog post distils those findings into a practical guide. It walks through the key nutrients the review highlights, explains why exercise is so potent a driver of brain plasticity, and then pulls the threads together with week-by-week suggestions you can fold into ordinary life.
The Nutritional Triad: Omega-3s, B-Vitamins and Polyphenols
Omega-3 Fatty Acids
Docosahexaenoic acid (DHA) is the most abundant omega-3 fatty acid in the brain, concentrated heavily in the hippocampus, the prefrontal cortex and the cerebral cortex, areas that underpin memory, executive function and decision-making. [3] DHA is a structural component of neuronal cell membranes, and its presence determines how fluidly those membranes function. Greater membrane fluidity translates into more efficient synaptic transmission, which is the basis of all learning and information processing. [4]
The review draws on randomised controlled trials showing that omega-3 supplementation improves memory, attention and executive function in older adults, with particularly strong results in populations already showing early signs of cognitive decline. The proposed mechanism is multi-layered. Omega-3s promote the production of BDNF, reduce the activity of pro-inflammatory cytokines such as TNF-alpha and IL-1-beta, and lower oxidative stress by scavenging free radicals. In preclinical models, DHA supplementation increased neuron counts in the hippocampus and modulated the expression of genes related to neurogenesis. [5][6][7]
From a practical standpoint, the richest dietary sources of DHA and EPA (eicosapentaenoic acid, the other key omega-3) are oily fish such as salmon, mackerel, sardines and anchovies. Two to three portions per week is a sensible baseline. For those who do not eat fish, algae-derived DHA supplements offer a direct, plant-based alternative.
B-Vitamins
Folate (B9), pyridoxine (B6) and cobalamin (B12) occupy a unique position in brain biochemistry. Together, they regulate homocysteine metabolism. Homocysteine is an amino acid that, when elevated, is associated with vascular damage, neuroinflammation and synaptic dysfunction, all of which accelerate cognitive decline. By converting homocysteine into the less harmful amino acid methionine, B-vitamins exert a protective effect on neuronal health. [8][9]
Beyond homocysteine regulation, the B-vitamins are co-factors in the synthesis of neurotransmitters including serotonin, dopamine, norepinephrine and GABA. Research from the Nurses' Health Study has shown that adequate intake of folate, B6 and B12 is linked to better long-term cognitive health. [10] The review also cites evidence that B-complex supplementation, combining several B-vitamins rather than isolating one, can improve cognitive performance, memory and attention in both younger and older adults. [11]
Good dietary sources include leafy greens and legumes (folate), poultry and potatoes (B6), and animal products such as eggs, dairy and meat (B12). Individuals following a vegan or largely plant-based diet should pay particular attention to B12, as plant foods contain negligible amounts.
Polyphenols
Polyphenols are bioactive compounds found in fruits, vegetables, tea, coffee, red wine and dark chocolate. They act through antioxidant and anti-inflammatory pathways, and the review highlights two classes in particular. Flavonoids, especially the anthocyanins abundant in blueberries and other deeply coloured berries, have been shown to boost BDNF production and support synaptic plasticity in the hippocampus. Regular berry consumption is associated with enhanced cognitive performance across age groups. [12][13]
Epigallocatechin gallate (EGCG), the principal catechin in green tea, offers a complementary mechanism. EGCG reduces oxidative stress, inhibits the activation of pro-inflammatory microglia, and in preclinical models has been shown to interfere with the aggregation of beta-amyloid plaques and alpha-synuclein fibrils, the protein deposits implicated in Alzheimer's and Parkinson's disease respectively. [14]
What makes polyphenols especially interesting in the context of this review is the convergence point with omega-3s. Both nutrient classes upregulate BDNF expression, but they arrive at that outcome through different signalling cascades. Polyphenols activate the Nrf2 antioxidant pathway and modulate kinases such as ERK and CREB, while omega-3s work through membrane fluidity and direct neurotrophic signalling. The result is that, consumed together, they appear to amplify each other's neuroplastic effects. [1]
Exercise as a Neuroplasticity Engine
If the three nutrient groups described above supply the raw materials for brain remodelling, physical exercise provides the catalyst. The review dedicates considerable space to the mechanisms by which exercise reshapes neural architecture, and the evidence is striking.
Aerobic exercise, activities such as running, cycling, swimming or brisk walking performed at a moderate-to-vigorous intensity, is the most extensively studied modality. It elevates circulating BDNF, promotes the transport of BDNF across the blood-brain barrier, and stimulates the release of IGF-1 and vascular endothelial growth factor (VEGF), both of which support the survival and maturation of new neurons. The hippocampus is the primary beneficiary: studies in older adults have demonstrated that regular aerobic activity can actually increase hippocampal volume, reversing age-related shrinkage and correlating with measurable improvements in memory. [15][16]
Resistance training contributes through a related but distinct pathway. It improves insulin sensitivity and metabolic function, indirectly supporting the brain's energy supply. Both modalities reduce chronic neuroinflammation by dampening microglial activation and lowering concentrations of inflammatory cytokines such as TNF-alpha and IL-1-beta. They also boost the brain's internal antioxidant defences, counteracting the oxidative stress that accumulates with age. [7][17]
The review also addresses the role of exercise in epigenetic regulation. Chronic aerobic training modifies histone acetylation and DNA methylation patterns in ways that favour the transcription of plasticity-related genes, including BDNF, synapsin I and CREB. [18] High-intensity interval training (HIIT) produces acute spikes in BDNF that, over time, contribute to sustained neural adaptation. The key message is that different exercise formats target overlapping but not identical biological pathways, which means variety in a training programme is beneficial.
Perhaps most importantly for the thesis of this post, the review underscores that exercise and nutrition are not simply additive in their effects; they are synergistic. Exercise primes the brain to make better use of the nutrients it receives, while the right nutrients ensure that exercise-induced growth factors have the substrates they need to promote neurogenesis and synaptic remodelling. It is the pairing of the two that produces the most robust and lasting cognitive gains. [1]
The Synergy in Practice: How Diet and Exercise Amplify Each Other
The review frames the relationship between nutrition and exercise as a positive feedback loop. Omega-3 fatty acids enhance membrane fluidity, making neurons more receptive to the BDNF released during exercise. Polyphenols reduce the oxidative stress that exercise can temporarily generate, protecting newly formed neurons during the vulnerable period after their creation. B-vitamins keep homocysteine in check and ensure that neurotransmitter synthesis proceeds smoothly, which is essential for the mood and motivational benefits that keep people exercising in the first place. [1]
The authors also point to gender-specific dynamics. Hormonal differences between men and women influence how each responds to both dietary and exercise interventions. Women, for example, may derive particular benefit from omega-3s and iron during phases of the menstrual cycle and during pregnancy, while exercise-induced BDNF release interacts with oestrogen to enhance mood and stress resilience. Men, conversely, may show faster improvements in reaction-speed-related cognitive tasks following resistance training. The practical takeaway is that a one-size-fits-all programme is unlikely to be optimal; some degree of personalisation, even if informal, is worth pursuing. [19]
Genetic variation adds another layer. The BDNF Val66Met polymorphism, carried by a significant minority of the population, reduces activity-dependent BDNF release. Individuals with this variant may need to be more deliberate about combining nutrient-rich diets with consistent exercise to achieve the same neuroplastic benefits that come more easily to others. [20] While genetic testing is not necessary for the average person, the point reinforces why both pillars, diet and exercise, matter: relying on one alone leaves potential gains on the table.
Actionable Suggestions for Everyday Life
What follows is a set of practical recommendations drawn from the review's findings. They are not prescriptions; they are starting points intended to be adapted to individual preferences, schedules and dietary requirements.
Weekly Exercise Framework
Aim for at least three sessions of moderate-to-vigorous aerobic exercise per week, each lasting 30 to 45 minutes. Brisk walking, jogging, cycling and swimming all qualify. On two additional days, incorporate some form of resistance training, whether that is bodyweight exercises, free weights or resistance bands. If you enjoy it, one HIIT session per week can provide an acute BDNF boost that complements the steadier gains from moderate activity. The overarching principle is consistency over intensity: a moderate programme maintained for months will outperform an extreme programme abandoned after a fortnight.
Dietary Priorities
Eat oily fish (salmon, mackerel, sardines, anchovies) two to three times per week, or supplement with algae-derived DHA if you follow a plant-based diet. Include a daily serving of deeply coloured berries, whether fresh, frozen or blended into a smoothie. Drink green tea regularly; two to three cups per day is a reasonable target for EGCG intake. Build meals around folate-rich foods such as spinach, broccoli, lentils and chickpeas. If you eat animal products, eggs and dairy will cover most of your B12 needs; if not, a B12 supplement is a sensible precaution.
Beyond the specific nutrients highlighted by the review, a broader dietary pattern aligned with the Mediterranean model, high in vegetables, fruits, whole grains, legumes, nuts and olive oil, and low in processed foods and refined sugars, provides the best overall context for brain health. [21]
Timing and Pairing
There is emerging evidence that consuming polyphenol-rich foods or omega-3s in the hours surrounding exercise may maximise the synergistic effects, though the review stops short of making specific timing recommendations. A practical approach might be to have a handful of blueberries or a cup of green tea before a workout and a meal containing oily fish or omega-3-rich seeds (flax, chia, hemp) afterwards. This is not about rigid meal planning; it is about making it easy for the right nutrients to be available when your brain is primed to use them.
Sleep and Stress Management
While the review's primary focus is nutrition and exercise, it acknowledges that sleep quality and chronic stress both modulate neuroplasticity. Poor sleep disrupts memory consolidation, and chronic stress elevates cortisol, which can damage hippocampal neurons over time. Exercise itself is one of the most effective tools for improving sleep and reducing stress, creating yet another positive feedback loop. Prioritising seven to nine hours of sleep per night and incorporating stress-reduction practices, even something as straightforward as a daily walk in green space, will support the neuroplastic gains from diet and exercise. [22]
A Note on Limitations
No single review, however thorough, closes the book on a topic this broad. The authors acknowledge several limitations. Much of the mechanistic evidence comes from animal models, and while translational relevance is strong, human physiology introduces variables that rodent studies cannot fully capture. Many human trials are short in duration, making it difficult to assess the long-term sustainability of cognitive gains. And the interaction between genetics, sex, age, baseline health and lifestyle factors means that individual responses to any intervention will vary.
That said, the convergence of evidence from epidemiological studies, randomised controlled trials and preclinical research all pointing in the same direction lends considerable weight to the review's central thesis: that the combination of targeted nutrition and regular exercise represents one of the most accessible and effective strategies available for protecting and enhancing brain function across the lifespan.
In a nutshell
The brain is not a static organ. It is a living, adaptive structure that responds continuously to the signals we send it through what we eat, how we move and how we rest. The 2025 review by Clemente-Suarez and colleagues pulls together a compelling body of evidence showing that omega-3 fatty acids, B-vitamins and polyphenols, when combined with regular aerobic and resistance exercise, create a neurobiological environment in which BDNF and IGF-1 can do their best work: building new neurons, strengthening synaptic connections and protecting existing neural circuits from the wear of ageing and stress. [1]
None of this requires exotic supplements or gruelling training regimes. It requires oily fish a few times a week, a daily handful of berries, some green tea, plenty of vegetables and legumes, and a consistent habit of moving your body with enough vigour to raise your heart rate. The science suggests that these ordinary habits, sustained over time, add up to something extraordinary: a brain that remains resilient, adaptable and sharp well into later life.
References
[1] Clemente-Suarez, V.J., Martin-Rodriguez, A., Curiel-Regueros, A., Rubio-Zarapuz, A. and Tornero-Aguilera, J.F. (2025) 'Neuro-Nutrition and Exercise Synergy: Exploring the Bioengineering of Cognitive Enhancement and Mental Health Optimization', Bioengineering, 12(2), p. 208. doi:10.3390/bioengineering12020208.
[2] Cotman, C.W. and Berchtold, N.C. (2002) 'Exercise: A Behavioral Intervention to Enhance Brain Health and Plasticity', Trends in Neurosciences, 25(6), pp. 295-301.
[3] Dyall, S.C. (2015) 'Long-Chain Omega-3 Fatty Acids and the Brain: A Review of the Independent and Shared Effects of EPA, DPA and DHA', Frontiers in Aging Neuroscience, 7, p. 52.
[4] Gomez-Pinilla, F. (2008) 'Brain Foods: The Effects of Nutrients on Brain Function', Nature Reviews Neuroscience, 9(7), pp. 568-578.
[5] Yurko-Mauro, K. et al. (2010) 'Beneficial Effects of Docosahexaenoic Acid on Cognition in Age-Related Cognitive Decline', Alzheimer's & Dementia, 6(6), pp. 456-464.
[6] Calder, P.C. (2017) 'Omega-3 Fatty Acids and Inflammatory Processes: From Molecules to Man', Biochemical Society Transactions, 45(5), pp. 1105-1115.
[7] Cotman, C.W., Berchtold, N.C. and Christie, L.A. (2007) 'Exercise Builds Brain Health: Key Roles of Growth Factor Cascades and Inflammation', Trends in Neurosciences, 30(9), pp. 464-472.
[8] Smith, A.D. et al. (2010) 'Homocysteine-Lowering by B Vitamins Slows the Rate of Accelerated Brain Atrophy in Mild Cognitive Impairment', PLoS ONE, 5(9), e12244.
[9] Reynolds, E.H. (2006) 'Vitamin B12, Folic Acid, and the Nervous System', The Lancet Neurology, 5(11), pp. 949-960.
[10] Kang, J.H. et al. (2006) 'A Randomized Trial of Vitamin E Supplementation and Cognitive Function in Women', Archives of Internal Medicine, 166(22), pp. 2462-2468.
[11] Kennedy, D.O. (2016) 'B Vitamins and the Brain: Mechanisms, Dose and Efficacy', Nutrients, 8(2), p. 68.
[12] Rendeiro, C. et al. (2012) 'Blueberry Supplementation Induces Spatial Memory Improvements and Effects on Hippocampal BDNF', Psychopharmacology, 223(3), pp. 319-330.
[13] Spencer, J.P.E. (2010) 'The Impact of Fruit Flavonoids on Memory and Cognition', British Journal of Nutrition, 104(S3), pp. S40-S47.
[14] Mandel, S.A. et al. (2008) 'Simultaneous Manipulation of Multiple Brain Targets by Green Tea Catechins: A Potential Neuroprotective Strategy for Alzheimer and Parkinson Diseases', CNS Neuroscience & Therapeutics, 14(4), pp. 352-365.
[15] Erickson, K.I. et al. (2011) 'Exercise Training Increases Size of Hippocampus and Improves Memory', Proceedings of the National Academy of Sciences, 108(7), pp. 3017-3022.
[16] Voss, M.W. et al. (2013) 'Exercise, Brain, and Cognition Across the Life Span', Journal of Applied Physiology, 111(5), pp. 1505-1513.
[17] Gleeson, M. et al. (2011) 'The Anti-Inflammatory Effects of Exercise: Mechanisms and Implications for the Prevention and Treatment of Disease', Nature Reviews Immunology, 11(9), pp. 607-615.
[18] Fernandes, J. et al. (2017) 'Epigenetic Regulators of BDNF in Exercise-Induced Neuroplasticity', Journal of Physiology, 595(14), pp. 4759-4773.
[19] Barha, C.K. and Liu-Ambrose, T. (2018) 'Exercise and the Aging Brain: Considerations for Sex Differences', Brain Plasticity, 4(1), pp. 53-63.
[20] Egan, M.F. et al. (2003) 'The BDNF Val66Met Polymorphism Affects Activity-Dependent Secretion of BDNF and Human Memory and Hippocampal Function', Cell, 112(2), pp. 257-269.
[21] Scarmeas, N. et al. (2009) 'Mediterranean Diet and Mild Cognitive Impairment', Archives of Neurology, 66(2), pp. 216-225.
[22] Walker, M.P. (2009) 'The Role of Sleep in Cognition and Emotion', Annals of the New York Academy of Sciences, 1156(1), pp. 168-197.
