Three smiling mature women walking on a beach representing healthy cognitive function.

Trophic support for cognitive impairment

The brain is very metabolically active and malleable with a great ability to change and respond to different conditions and stimuli. Therefore it requires factors that support both energy availability and also growth.

This includes presence and delivery of oxygen and nutrients to the brain, highlighting the importance of nutrient intake and optimal function of the respiratory, cardiovascular and digestive systems. Availability of energy to cells is also reliant on the normal function of hormones, in particular insulin but is also affected by oestrogen and thyroid hormones. All of these are considered trophic (growth) hormones and therefore support anabolic (tissue building) processes.

This blog looks at tropic factors that contribute to cognitive function and therefore interventions that can support cognitive health.

Nutrient intake and cognitive impairment

The nutrition gap is the difference between the levels of nutrients we are consuming and what we need for optimum health. This gap is a fundamental driver of poor health and chronic disease, including cognitive decline, and therefore it is so important to ensure optimum levels of nutrients are obtained.

Nutrients that are particularly important for cognitive function (this list is non exhaustive) include:

  • Omega 3 fatty acids – particularly DHA which support cell membrane function and neuronal signalling as well as EPA aiding a normal inflammatory response. DHA is the predominant omega 3 fatty acid in the brain1
  • B vitamins especially methyl folate and B12, these are responsible for normal nervous system function and the production of neurotransmitters. They also aid the clearance of homocysteine, a waste product which can contribute to cognitive decline.2
  • Vitamin D- modulates inflammation and a deficiency is associated with cognitive issues3
  • Zinc- major cofactor for enzymatic processes and an antioxidant, again deficiency can be associated with cognitive issues 4
  • COQ10- essential for energy production, levels are shown to decline in the brains of dementia patients2

Skip to Key Takeaways

Digestive capacity

Even if nutrient intake is optimal, these nutrients still need to be absorbed and then transported to the brain, therefore digestive and cardiovascular function are essential.

Nutrient absorption relies on adequate stomach acid, digestive enzymes and bile production, if these are compromised it can have an influence on nutrient status regardless of nutrient intake.

Although not a main focus of this blog, it is important to mention that if the integrity of the gut lining is compromised, then larger molecules can pass across the digestive lining and trigger inflammation, known as leaky gut. A similar process also occurs in the blood brain barrier, and leaky gut is associated with leaky brain. Leaky brain will increase neuroinflammation leading to damage to neuronal tissue and therefore is a contributing factor to brain fog.5

Furthermore, the microbiome is essential for the production of neurotransmitters and short chain fatty acids, communicating with the brain via the vagus nerve. Although these neurotransmitters cannot cross the blood brain barrier, they elicit a positive benefit to the brain via activation of the vagus nerve.

For example, one study showed that people with Alzheimer’s disease who took probiotics (a mixture of L. acidophilus, L. casei, B. bifidum, and L. fermentum) experienced positive effects on cognitive functions like learning power and memory.6

Considerations for digestive support include7:

Poor digestive capacity/absorption – you may see symptoms such as bloating, reflux, low appetite, food intolerance, undigested food in stool. In these cases, you can support stomach acid and digestive enzymes with a full spectrum digestive enzyme complex and betaine HCl.

Reduced integrity of gut lining – indicated for inflammatory, atopic and autoimmune conditions and food intolerances. Nutrients such as lactoferrin, vitamin A, D and zinc, those that support anti-inflammatory pathways including omega 3 fatty acids, curcumin and quercetin.  Mucous membrane support with slippery elm and marshmallow are important for repairing the digestive lining. Additionally supporting a healthy balance of digestive flora with a probiotic in order to support the production of short chain fatty acids is also useful.

Dysbiotic microbiome – indicated with many digestive issues including IBS but also for low immunity, dysbiosis often see as candida overgrowth causing thrush, and cognitive dysfunction. Live bacteria supplements containing supportive bacteria as well as prebiotic fibres support a healthy balance of digestive flora as well as supporting immunity and digestive function.

Cardiovascular function

Not only do we need to be able to consume and absorb nutrients, but they need to be delivered to the site of action. The cardiovascular system and brain function are intrinsically linked. Reduced blood flow to the brain is a driver of dementia and can be seen acutely in stroke patients.8 This is a sliding scale and therefore if cardiovascular function is impaired there is a reduction of transportation of nutrients to the brain and waste products away from the brain. Approximately 40% of dementia cases are estimated to be preventable by targeting modifiable, primarily cardiovascular risk factors.9

Factors that can play a part in the development of CVD include inflammation, obesity, lack of exercise, insulin resistance, oxidative stress, smoking and chronic stress. Therefore lifestyle factors must be considered. In addition, cardiovascular supportive nutrients play an important role these include:

  • NAC – through its capacity to synthesize glutathione, NAC has displayed many health-promoting properties with regards to CV health10
  • Flavonoids – high in antioxidants, including phenolic acids, anthocyanins, and flavonoids. Epidemiological research indicates that a diet abundant in fruit and vegetables offers protection against CVD, and this may be attributed, in part, to the flavonoid content11
  • Vitamin C – a powerful antioxidant that has received considerable interest for its possible role in heart health7
  • B vitamins – without sufficient B vitamins, homocysteine can build up and bring about damage to arteries7
  • Physical exercise is linked to longevity and can significantly reduce the risk of CVD, diabetes, high blood pressure, and obesity
  • Chronic stress can contribute to high blood sugar, high blood pressure, insulin resistance, decreased absorption of nutrients, all of which impact adversely on CV health

The role of hormones in cognitive function

Whilst both bioavailability of nutrients and healthy function of mitochondria are essential, the ability to produce or utilise energy is also governed by the presence, or absence, of hormones.

Neuroendocrine communication is essential for healthy cognition, and it is worth noting that endocrine dysregulation is the only independent risk factor for cognitive decline.


Firstly, insulin is a trophic hormone as is responsible for the delivery of glucose to the cell. Therefore, mitochondrial function is reliant (in most instances) on the action of insulin for delivery of glucose into the cell in order to produce Most, if not all, tissues of the body, including the brain, express insulin receptors and are insulin sensitive.12 Accumulating evidence suggests that brain insulin signalling not only plays a key role in regulation of metabolism, but also in regulation of mood, behaviour, and cognition. In addition, there is comorbidity between dementia and type 2 diabetes.12

Alzheimer’s disease has been referred to a type 3 diabetes and the brain may become insulin resistant as much as 20 years before someone is diagnosed with type 2 diabetes. Defects in insulin signalling is associated with an increase of amyloid plaques in the brain, particularly in temporal lobe, hippocampus, and cerebellum.13

Therefore, improving insulin sensitivity, as early as possible, is an essential intervention for individuals experiencing cognitive impairment.


Many women complain of changes in their cognitive function during the menopause transition, with the majority reporting worsening of memory and depression. Several large prospective cohort studies have shown a three-fold increased risk of a major depressive episode during perimenopause compared with pre-menopause. Even women with no history of depression are still three times more likely to experience depression during the menopause transition compared with the pre-menopause.14,15

Oestrogen is a growth promoting hormone and therefore can stimulate the growth and development of nerve cells, particularly within the brain. It is known that oestrogen affects cholinergic (acetylcholine), dopaminergic (dopamine) systems and mitochondrial function within the brain. Oestrogen also stimulates synaptic plasticity, via activation of BDNF (brain derived neurotropic factor) and elicits neuroprotective effects.

The drop in oestrogen, due to menopause, has been shown to reduce nerve function within the brain, and physiological changes can be observed as reduced dendritic spines, decreased synaptic density, decreased numbers of specific synapses, changes in connectivity, and increases or reductions in grey matter volume in specific areas. There is also reduce acetyl choline and dopamine signalling, these essential neurotransmitters play a role in cognition and mood.14


Testosterone is essential for cognitive health and function in both men and women. It is supportive for wellbeing and vigour and a reduction of testosterone which occurs as we age can contribute to low mood and anxiety, there can also be physiological changes leading to depression. A study has shown that low testosterone and obesity independently and cooperatively can contribute to neuroinflammation which is consistent with low mood and depression as well as a risk factor for cognitive issues such as dementia and Alzheimer’s.16,17 Low serum testosterone has also been associated with Alzheimer’s disease.18

Low testosterone is also associated with muscle loss known as sarcopenia. Muscle is considered by some to be the “Anti-Ageing God” because maintaining muscle mass as we age helps to prevent falls but helps to improve insulin sensitivity, which as mentioned is important for cognitive health.


Studies have found that among people aged 65 years or older, those with a history of hypothyroidism were associated with an 81% increased risk of having dementia and among those, there was a more than 3-fold increased dementia risk with thyroid conditions that required thyroid hormone replacement treatment.19,20

Abnormal concentrations of thyroid hormones can lead to deterioration of cognitive processes through changes in neurotransmission, intensification of oxidative stress, or impact β-amyloid transformation and glucose metabolism in the central nervous system.21

Thyroid hormones are crucial for brain development, and influence brain function throughout life. In adults, hypothyroidism causes lethargy, hyporeflexia, and poor motor coordination, is associated with bipolar affective disorders, depression, or loss of cognitive functions. Subclinical hypothyroidism is often associated with memory impairment.21


Stress has been shown to be a contributing factor to many aspects of cognition including brain fog, depression and dementia. This is due to multiple pathways such as activation of the HPA (hypothalamus-pituitary-adrenal) axis, interference to sleep, increased inflammation, oxidative stress. In addition, cortisol (our stress hormone) itself has been shown to be a catabolic hormone and can cause atrophy of brain tissue – particularly in the hippocampus which is responsible for short term memory.22,23 Studies looking at patients with depression showed brain atrophy was associated with increased cortisol.24

Systematic reviews have shown activated HPA axis is associated with an increased risk of Alzheimer’s disease. It is hypothesised that HPA activation can mediate glucocorticoid priming of the immune cells of the brain, microglia, to become pro-inflammatory and promote a neurotoxic environment resulting in neurodegeneration.23

Supporting hormone regulation for healthy cognitive function 

It can be seen that supporting hormone balance is essential for cognitive function. Consider supporting hormone regulation by:

Balancing blood sugar – consuming high fibre foods such as vegetables and wholegrains with lean protein and healthy fats slows down the release of sugar into the blood. Also, nutrients such as magnesium, chromium, zinc as well as cinnamon can support glucose uptake.

Improve insulin sensitivity – exercise and fasting for at least 12 hours over night have both been shown to improve insulin sensitivity.25

Support the adrenal glands – essential during menopause as the adrenal glands take over oestrogen production form the ovaries. It also important for blunting the HPA axis to reduce cortisol. Practising relaxation techniques such as mindfulness, meditation and yoga is useful. Adaptogenic herbs such as ashwagandha26 and nutrients including B vitamins (B5 and B6), vitamin C and magnesium are also useful.

Support testosterone – consider Fenugreek shown to increase total testosterone through an aromatase and 5α reductase inhibition, thereby blocking testosterone conversion to oestrogen and dihydrotestosterone, respectively. 27

Consider thyroid – it is important to investigate thyroid function (seek medical advice) if suspect dysfunction especially if concurrent with cognitive problems. Thyroid hormones require tyrosine, iodine, zinc and selenium for production and these nutrients can be useful in some cases.7

The above list is a good start, but it may be important to consider further interventions depending on factors that are most influencing each individual.

Key Takeaways

  • The brain is highly metabolically active and requires a high amount of trophic support from nutrient intake, absorption and delivery as well as the normal regulation of the endocrine system.
  • Inadequate intake of nutrients can influence brain function due to suboptimal levels of supportive nutrients. Of particular importance are omega 3 fatty acids, B vitamins, Vitamin D, zinc and magnesium as well as antioxidants
  • If the digestive and cardiovascular systems are impaired this can impact the availability of nutrients to the brain and therefore should be considered in cognitive impairment.
  • Insulin resistance is a major driver of cognitive decline due to multiple factors mainly by reducing energy availability to brain cells.
  • During menopause insulin resistance increases whilst levels of oestrogen decrease, both of these affect cognitive function due to reduced trophic support
  • The thyroid is responsible for metabolic rate in every cells in the body including neurones and other brain cells and is essential for cognitive development. Hypothyroidism increases risk of dementia.
  • Stress is associated with increased brain fog, depression and dementia. Cortisol has been shown to cause atrophy of neuronal tissue and therefore is associated with neurodegeneration.


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If you have questions regarding the topics that have been raised, or any other health matters, please do contact our team of Nutritional Therapists.
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Last updated on 3rd January 2024 by cytoffice


9 thoughts on “Trophic support for cognitive impairment

  1. I found this article well written and researched, and in fact very useful. The synthesis between brain and gut and the way in which the various factors interlink and cross-connect is presented in a direct, simple and easily comprehensible style, minimising medical jargon. It’s far easier to wrap my head around the big picture when I don’t have to interrupt myself to go and look up obscure terms every two sentences! The nutritional suggestions for how and why to support the various systems are integrated and useful; I know you guys sell supplements and formulations which are relevant to the content of the article, but they aren’t presented herein as advertising or a hard sell. So the flow and shape of the information is uninterrupted and thus easier to get a grip on. We have a few issues (and potential issues) in my family around the areas covered by this article so I’ve done quite a lot of reading across these areas over the years. I can tell you it is reasonably rare to come across an article that concisely summarises the needed information so effectively. My guess is that it will make a great contribution to your credibility as a company so keep doing it. From my perspective articles like this really help me figure things out. Feeling empowered to take control of one’s own health is a great gift.

  2. Fascinating and hugely helpful.
    Do you have suggestions for resolving brain fog combined with POTS and endometriosis please? A bright and formerly active young woman I know is suffering badly from all three and is completely debilitated by them. Medics stumped!

  3. Second question: Would your suggested supplements assist a 10 year old boy to recover from Chronic Fatigue Syndrome? He is recovering slowly after many months of brain fog, low energy and muscle aches, but something to boost his return to his former energetic, intellectual self would be so welcome.

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