How to Energise Your Brain

With age, you may notice changes in your energy levels and mental sharpness. Although this is common, it's not an inevitable part of growing old. Many people who stay active and eat a balanced diet maintain their vitality and memory well into old age. Supporting brain energy starts with cellular energy, and with the right lifestyle and nutritional support, it’s possible to feel sharp and focused at any age. Discover how.

The Brain's High Energy Demands

The human brain is one of the most energy-demanding organs in the body, using around 20% of total energy despite making up just 2% of body weight.¹ It needs this energy to power constant activity, from basic functions to complex thinking and decision-making. Most of this energy comes from glucose, the fuel we get from carbohydrate-rich foods like grains, vegetables, and legumes. ²

When Energy Drops

Your brain relies on a steady supply of energy to function at its best. Without this, you may notice:

Difficulty concentrating
Memory issues
Slower mental processing
Difficulty learning and retaining information
Changes in mood

Low energy availability may also impact the brain’s ability to produce key neurotransmitters that influence motivation and emotional balance. Over time, imbalances in energy production at the cellular level can affect how well your brain performs.

What’s more, when energy sources are depleted for too long, it can also affect the functioning of mitochondria, the tiny energy factories in your cells. Emerging research is exploring the potential links between mitochondrial function and various aspects of brain health.³

Why Brain Energy Drops

Poor Diet:

Optimal brain function depends on a balanced intake of macronutrients and micronutrients. Glucose from carbohydrates is the brain’s primary energy source, while healthy fats offer sustained fuel when glucose is low. Protein gives your body the building blocks it needs to make brain chemicals and hormones that support mood, memory, and clear thinking. Additionally, vitamins and minerals provide the cofactors and coenzymes to help these processes run smoothly.

Chronic Stress:

Chronic stress raises cortisol levels, which can disrupt your body’s natural energy balance. Over time, this stress hormone can cause blood sugar spikes and crashes, interfering with sleep.⁴ High cortisol, especially at night, can make it hard to fall asleep or stay asleep, leaving you tired the next day.⁵Getting enough rest and finding ways to manage stress are key to staying mentally energised.

Mitochondrial dysfunction:

When stress is ongoing, high cortisol and inflammation can start to damage the mitochondria. This damage can slow down their ability to make energy efficiently, especially in the brain, which has a high demand for constant fuel. As mitochondrial function declines, so does mental clarity, focus, and stamina, leading to fatigue and brain fog. ^6,7

Key Nutrients for Energy Metabolism

Your body needs the right balance of nutrients to produce steady, reliable energy. Some are especially important for mental clarity and focus:

CREATINE

Creatine is a naturally occurring compound that helps the body produce and recycle ATP (adenosine triphosphate), the main energy source for cellular processes. It is particularly concentrated in tissues with high energy needs, such as the brain and muscles.

Best Food Sources: Found naturally in muscle meats such as beef, pork, fish, and chicken.

Why Supplement? Creatine supplements may benefit athletes, older adults, menopausal women, and vegetarians.

B VITAMINS

B vitamins play key roles in energy metabolism, particularly vitamins B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), and B12. These nutrients act as coenzymes that help convert carbohydrates, fats, and proteins from food into energy that the body can use. Because the brain has high energy demands, an adequate intake of these B vitamins supports its normal functioning.

Best Food Sources: Whole grains, legumes, eggs, lean meats, dairy products, green leafy vegetables, fish, mushrooms, avocados

Why Supplement? Some groups, such as older adults, vegans, or those with certain health conditions, may have higher needs

MAGNESIUM

Magnesium contributes to normal energy-yielding metabolism and supports enzymes that create ATP. This makes it particularly relevant for high-energy organs like the brain.

Best Food Sources: Leafy greens, nuts, seeds, whole grains, legumes, avocados, tofu and tempeh.

Why Supplement? People with stress, poor sleep, or absorption issues such as Crohn’s disease may benefit.

VITAMIN C

Vitamin C supports energy production by helping regenerate vitamin E and assisting in the synthesis of carnitine, which transports fatty acids into mitochondria.

Best Food Sources: Berries, kiwi, citrus fruits, guava, peppers, broccoli, Brussels sprouts, kale.

Why Supplement? People with poor diets, increased needs, such as smokers, older adults and pregnant women, may benefit.

Brain-Friendly Habits

Keep to a balanced diet - A variety of fruits, vegetables, lean proteins, and whole grains provides essential nutrients that support brain metabolism and overall health.
Stay hydrated - Sipping water throughout the day helps prevent brain sluggishness, which can lead to memory issues. Tea, especially green, white, and oolong varieties, has been shown to support brain health as well. 8,9
Top up on Protein - The brain needs amino acids for neurotransmitter function and to produce enzymes and compounds involved in brain energy pathways. Some amino acids also help regulate glucose metabolism, the brain’s primary fuel.
Move Often & Sleep Deeply - Adequate sleep and physical activity are important for restoring and maintaining cognitive health. Getting between 7-9 hours of sleep each night is essential for long-term memory and overall brain performance.

TAKE AWAY MESSAGE

Providing your brain with the right nutrients and healthy habits can support normal cognitive and psychological function. Small daily changes can go a long way toward staying mentally sharp and energised.

Written by: Jacqueline Newson BSc (Hons) Nutritional Therapy

REFERENCES

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X.-X. Zhang et al. Changed nocturnal levels of stress-related hormones couple with sleep-wake states in the patients with chronic insomnia disorder: A clinical pilot study. Sleep Medicine 117 (2024) 177–183. https://doi.org/10.1016/j.sleep.2024.03.017.
Shunsuke Katsuhara et al. Impact of Cortisol on Reduction in Muscle Strength and Mass: A Mendelian Randomization Study, The Journal of Clinical Endocrinology & Metabolism, Volume 107, Issue 4, April 2022, Pages e1477–e1487, https://doi.org/10.1210/clinem/dgab862.
Filler K, Lyon D, Bennett J, McCain N, Elswick R, Lukkahatai N, Saligan LN. Association of Mitochondrial Dysfunction and Fatigue: A Review of the Literature. BBA Clin. 2014 Jun 1;1:12-23. doi: 10.1016/j.bbacli.2014.04.001. PMID: 25147756; PMCID: PMC4136529.
Molnar T et al. Mitochondrial dysfunction in long COVID: mechanisms, consequences, and potential therapeutic approaches. Geroscience. 2024 Oct;46(5):5267-5286. doi: 10.1007/s11357-024-01165-5. Epub 2024 Apr 26. PMID: 38668888; PMCID: PMC11336094.
Shibata, S., Noguchi-Shinohara, M., Shima, A. et al. Green tea consumption and cerebral white matter lesions in community-dwelling older adults without dementia. npj Sci Food 9, 2 (2025). https://doi.org/10.1038/s41538-024-00364-w.
Junhua Li, Rafael Romero-Garcia, John Suckling, Lei Feng. Habitual tea drinking modulates brain efficiency: evidence from brain connectivity evaluation. Aging, 2019; 11 (11): 3876 DOI: 10.18632/aging.102023.

How to Energise Your Brain