Looking after our brains in perimenopause

If you’re a woman aged 40 or above, this one is for you.

As part of my ongoing professional development, I’ve recently been learning more about preventing cognitive decline in midlife, including how hormonal changes during the menopause transition can influence our brain health and function. As a perimenopausal woman who recently turned 50, I think this is an incredibly important topic, and one that doesn’t get as much attention as other menopause symptoms. In this post, I’ve shared some of the key things I’ve learnt, along with the areas I focus on with the women I see in clinic. 

Brain fog, forgetfulness and difficulty finding words are very common during perimenopause, and for most women these symptoms ease once their hormones settle after menopause. Understanding what’s happening in the brain during this time can help us make choices that support it now and in the years to come, so I’ve outlined some of the key factors below.

Declining oestrogen

Our oestrogen levels fluctuate during perimenopause before declining after menopause, and this has widespread effects throughout the body, including the brain. Oestrogen is a neuroprotective hormone, meaning it helps protect our brain cells, and it also plays an important role in helping the brain produce energy. As oestrogen levels fall, the brain becomes less efficient at fuelling itself. Oestrogen also helps to regulate the neurotransmitters serotonin and dopamine, which helps explain why many women notice mood and motivation changes as their hormone levels shift.

Sleep changes

Quality sleep is critical for brain health, as it’s when the brain consolidates memories and clears out waste products that build up during the day. Unfortunately, sleep is often one of the first things to suffer during perimenopause. Progesterone has a naturally calming effect on the brain, so as levels decline, many women find it harder to fall asleep and stay asleep. Fluctuating oestrogen can also trigger night sweats and hot flushes, which often wake us during the night and leave us waking up feeling like we haven’t slept at all.

Chronic stress

In my practice, I ask every new client to rate their stress level out of ten for the past year and the past five years. Sadly, it is very common to see high stress ratings for both categories. Our bodies are designed to cope with short periods of stress, but so many midlife women experience chronic stress for years thanks to busy lives, caring for family, demanding jobs, illness, grief and loss. When we are stressed, our adrenal glands release cortisol. If cortisol stays elevated for extended periods of time, it can disrupt the communication between the brain and adrenal glands that regulates our stress response (known as the HPA axis). The hippocampus, which helps us form new memories, and the prefrontal cortex, which is involved in focus and working memory, are both particularly sensitive to high cortisol levels over time. Chronic stress can also disturb our sleep and blood sugar balance, both of which have their own impact on the brain. 

Insulin resistance and inflammation

Oestrogen helps keep our cells responsive to insulin, so as it declines, the cells don’t respond as well and the body needs to produce more insulin to control blood glucose. Stress and poor sleep can also raise our blood glucose levels. These changes are why many midlife women start to experience weight gain around the middle (despite eating the same way), afternoon energy slumps, sugar cravings and elevated insulin and blood glucose levels on their blood tests, often leading to a diagnosis of insulin resistance. Over time, insulin resistance and type 2 diabetes are linked to a higher risk of cognitive decline.

Oestrogen has anti-inflammatory effects, so its natural decline can contribute to low-grade inflammation. Most people think of things like joint pain when they think of inflammation, but it can also affect the brain (known as neuroinflammation), which can impair learning and memory. Unfortunately, inflammation and insulin resistance tend to feed off each other, so it is important to address both. 

What you can do to support your brain through the menopause transition

Diet

• Include phytoestrogen-rich foods in your diet, e.g. soy (tofu, tempeh, edamame) and ground flaxseed

• Reduce alcohol, as it worsens both sleep quality and hot flushes

• Include protein, fibre and healthy fats in each meal to keep blood sugar steady

• Follow a Mediterranean-style diet, with plenty of colourful vegetables, legumes, extra virgin olive oil, nuts and oily fish

• Limit ultra-processed foods and refined carbohydrates

• Eat folate-rich foods, e.g. leafy greens and legumes

• Include B12 sources, e.g. meat, fish, eggs and dairy

Lifestyle

• Sleep

  • Keep a consistent bedtime and wake time, even on weekends

  • Keep the bedroom cool and dark, and get morning sunlight to support the body clock

  • Avoid caffeine after midday

• Stress

  • Build in small daily practices that calm the nervous system, e.g. slow breathing or time in nature

  • Prioritise regular meals, as skipping meals can drive cortisol and blood sugar swings

• Movement

  • Do strength training for 20-30 minutes at least twice a week, as muscle is a major user of glucose and helps improve insulin sensitivity

  • Take a short walk after meals

• Sun exposure

  • Get daily safe sun exposure to top up your vitamin D levels

Testing

Important blood markers related to cognitive function include:

• Markers of insulin resistance: Fasting glucose, fasting insulin and HbA1c (marker of average blood glucose levels for the past two to three months)

• hs-CRP - marker of inflammation

• Homocysteine - raised levels are linked to an increased risk of cognitive decline and can indicate a need for more B6, B12 and folate, particularly if you have certain MTHFR gene variations

• Vitamin D - supports brain health and immune function

• Thyroid function (TSH, free T4 and free T3) - hypothyroidism becomes more common in midlife and can cause brain fog and memory issues

• Iron studies - heavy periods are common in perimenopause, and low iron can contribute to fatigue and poor concentration

• Lipids - high LDL cholesterol in midlife is a modifiable dementia risk factor

Supplements

Supplement protocols are always highly individualised but here are a few evidence-based supplements that can be helpful for supporting cognitive function in perimenopausal and menopausal women:

• Creatine - the brain uses creatine as a quick source of energy. Women naturally have lower creatine stores than men, and studies suggest that supplementation may support memory and mental performance, especially during times of poor sleep or stress

• Magnesium glycinate - magnesium supports the brain in several ways as it is involved in nerve signalling, our stress response and sleep. I recommend the glycinate form as it is gentle on the stomach and well absorbed, and glycine itself has a calming effect that can help with sleep.

• Saffron - saffron has been shown in clinical trials to improve mood and anxiety, and a few small studies suggest it may also support memory and cognitive function

• L-theanine - L-theanine is an amino acid found naturally in tea that promotes a sense of calm without causing drowsiness. Studies suggest it may help with focus and sleep quality, so it can be helpful if stress is affecting sleep.

• Vitamin D (if levels are below the optimal level of 100 nmol/L*) - there are vitamin D receptors throughout the brain, and low levels have been linked to a higher risk of cognitive decline.

• Omega-3s - Omega-3s are anti-inflammatory and DHA, a type of omega-3, is a key building block of brain cells

• B vitamins (especially for women with MTHFR variations or if homocysteine is elevated) - B6, B12 and folate help the body break down homocysteine

A quick note about hormones:

If you're struggling with perimenopausal or menopausal symptoms, it may be worth talking to your GP about whether hormone therapy would be appropriate for you. MHT (previously known as HRT) replaces some of the hormones that decline during the menopause transition and can be highly beneficial in relieving symptoms.

If you'd like support with testing or a personalised plan to look after your brain health through perimenopause and beyond, I'd love to help. You can book a consultation, either in person or online, through my website.

*Standard lab reference ranges are based on the general population, which means a result can be within normal range without being ideal. Nutritionists, naturopaths and integrative practitioners use narrower optimal ranges, which help to pick up early changes before they become a bigger issue.

References
Akhondzadeh, S., Sabet, M. S., Harirchian, M. H., Togha, M., Cheraghmakani, H., Razeghi, S., Hejazi, S. S.h, Yousefi, M. H., Alimardani, R., Jamshidi, A., Zare, F., & Moradi, A. (2010). Saffron in the treatment of patients with mild to moderate Alzheimer's disease: a 16-week, randomized and placebo-controlled trial. Journal of clinical pharmacy and therapeutics, 35(5), 581–588. https://doi.org/10.1111/j.1365-2710.2009.01133.x

Akhondzadeh, S., Shafiee Sabet, M., Harirchian, M. H., Togha, M., Cheraghmakani, H., Razeghi, S., Hejazi, S. S., Yousefi, M. H., Alimardani, R., Jamshidi, A., Rezazadeh, S. A., Yousefi, A., Zare, F., Moradi, A., & Vossoughi, A. (2010). A 22-week, multicenter, randomized, double-blind controlled trial of Crocus sativus in the treatment of mild-to-moderate Alzheimer's disease. Psychopharmacology, 207(4), 637–643. https://doi.org/10.1007/s00213-009-1706-1

Bredesen, D. (2026). The end of Alzheimer's: Preventing and reversing cognitive decline [Webinar]. Clinical Applications of Scientific Innovation series. Designs for Health.

Bredesen, D. (2017). The End of Alzheimer’s, Vermilion, London.

Grabyn, J. (2026). Optimising brain energy, mood and cognitive resilience [Webinar]. Designs for Health.

Tsolaki, M., Karathanasi, E., Lazarou, I., Dovas, K., Verykouki, E., Karacostas, A., Georgiadis, K., Tsolaki, A., Adam, K., Kompatsiaris, I., & Sinakos, Z. (2016). Efficacy and Safety of Crocus sativus L. in Patients with Mild Cognitive Impairment: One Year Single-Blind Randomized, with Parallel Groups, Clinical Trial. Journal of Alzheimer's disease : JAD, 54(1), 129–133. https://doi.org/10.3233/JAD-160304