Brain Fog: Causes & Cures

Exercise to reduce chances of brain fog

Are you befuddled by brain fog?

We know the feeling!

Never fear, we got our intrepid biochemist on the case. So without further ado here’s what brain fog is, why it happens and what we can do courtesy of the scientist himself.

What Is Brain Fog?

Also commonly known as brain fatigue, brain fog can be a mild to severe episode of mental confusion that strikes without warning. As a result of this, it’s common to experience a lack of focus, poor memory recall and reduced mental acuity.

Indeed, the first signs usually occur after 40 years, in the period before menopause called perimenopause. And it usually begins with minor memory lapses.

Studies, Estrogen & Brain Fog

Studies on the effects of estrogen and memory back up the idea that estrogen depletion during perimenopause causes memory loss, and that memory improves after menopause.

Studies back up the idea that estrogen depletion causes memory loss. Click To Tweet

For example, a large 2004 study called The Penn Ovarian Aging Study supports the finding that hormone changes during perimenopause often cause a decline in verbal memory. What’s more, it found these effects are separate from the natural effects of ageing.

And this study provides the basis for many current studies.

Another four-year study found that women couldn’t learn as well during perimenopause. After menopause though, women returned to the learning levels they demonstrated before perimenopause.

review published in the Journal of Steroid Biochemistry and Molecular Biology also identified reduced memory and thinking skills in women during perimenopause and menopause. Many of the women in the study reported problems, especially with forgetfulness and concentration.

As the years tick by, and perimenopause progresses towards clinical menopause the memory lapses get overtaken by brain fog and in some cases mental confusion, vertigo (dizziness) and disorientation.

Consequently, women can become quite disconcerted. They report feelings of ‘not thinking straight’, of ‘losing their mind’ or of ‘feeling weird’.

Perimenopause woman with brain fog

What Causes Brain Fog?

There are numerous explanations for why brain fog occurs. However, once you identify the underlying cause, you can begin fixing the problem.

Here are six possible causes.

1. Hormonal changes

Hormonal changes are the main trigger for brain fog. As a result of these perimenopause can begin with forgetfulness, poor concentration, and cloudy thinking.

2. Lack of sleep

Poor sleep quality can also interfere with how well your brain functions. Aim for eight to nine hours of sleep per night because sleeping too little can lead to poor concentration and cloudy thoughts.

3. Stress

Chronic stress can increase blood pressure, weaken the immune system, and trigger depression. It can also cause mental fatigue. Subsequently, your brain is exhausted and it becomes harder to think, reason, and focus.

4. Diet

Diet can also play a role in brain fog. Vitamin B12 supports healthy brain function, and a vitamin B12 deficiency can bring about brain fog.

If you have food allergies or sensitivities, brain fog may develop after eating certain foods. Possible culprits include:

  • MSG
  • aspartame
  • peanuts
  • dairy

It’s important to realise that removing trigger foods from your diet may improve signs.

5. Medications

If you notice brain fog while taking medication, talk with your doctor. One reason could be that brain fog may be a known side effect of the drug. Therefore, lowering your dosage or switching to another drug may improve your signs. What’s more, brain fog can also occur after cancer treatments.

6. Medical conditions

Medical conditions associated with inflammation, fatigue, or changes in blood glucose level can also cause mental fatigue. For example, brain fog is a sign of chronic fatigue syndrome, which involves persistent fatigue for longer than six months. People who have fibromyalgia may experience similar fogginess on a daily basis. Other conditions that may cause brain fog include anaemia, depression, diabetes and dehydration.

What to do when you have Brain Fog

If you’re aged between 40 and 65 then declining estrogen levels will be the main cause. so balancing your natural hormone levels is recommended.

Also, if you’re anaemic, iron supplements may increase your production of red blood cells and reduce the fog.

Or, if you’re diagnosed with an autoimmune disease, your doctor may recommend a corticosteroid or other medication to reduce inflammation or suppress the immune system.

Sometimes, relief is a matter of correcting a nutritional deficiency, drinking more water, switching medications or improving the quality of your sleep.

Home remedies include:

  • sleeping eight to nine hours per night
  • managing stress by knowing your limitations and avoiding excessive alcohol and caffeine
  • exercising and rehydrating
  • strengthening your brain power (try solving brain puzzles)
  • finding enjoyable activities
  • increasing your intake of protein, fruits, vegetables, and healthy fats

healthy food to help with reducing brain fog

Final Thoughts

Brain fog can be frustrating, but relief is possible. Don’t ignore the signs. If left untreated, it can impact the quality of your life. However, once the underlying cause is addressed, your mental clarity can improve.

Peter Lehrke
Nutritional Biochemist

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This is the time when menstruation is well and truly over, the ovaries have stopped producing high levels of sex hormones and for many ladies, perimenopause symptoms subside.

Estrogen has protective qualities and the diminished levels mean organs such as your brain, heart and bones become more vulnerable. It’s also a key lubricant so your lips may become drier, your joints less supple and your vagina might be drier. In addition, your thyroid, digestion, insulin, cortisol and weight may alter.

At this juncture, a woman might experience an increase in the signs of reduced estrogen but she should have a decrease of perimenopause symptoms. That said, some women will experience symptoms like hot flushes for years or even the rest of their lives.


Peri = ‘near’

Most females begin to experience the symptoms of perimenopause in their mid-forties. Your progesterone levels decline from your mid-30s but it’s generally from around 40 that the rest of your sex hormones begin to follow suit. 

Perimenopause is a different experience for every woman and some women may barely notice it. The first indicators are usually changes to the monthly cycle. This means that for some ladies, this can be accompanied by things like sore breasts, mood swings, weight gain around the belly, and fatigue as time goes on.

For those with symptoms it can be a challenging time physically, mentally and emotionally.

Importantly, perimenopause lasts – on average – four to 10 years. The transition is usually a gradual process and many women enter perimenopause without realising.