Stay smart, stress less. How does stress affect cognition?

How does stress show up in your body and mind? For many, it can be sleepless nights, food cravings, weight fluctuations, shifting menstrual cycles and more. For many, these symptoms may not show up physically but rather mentally as mood changes, or cognitive difficulties such as problems with memory, focusing, learning or with mental tasks that were previously simple.  

The intricate relationship between stress and cognition is influenced by various factors, including genetic predispositions and lifestyle choices. In this blog, we will explore how stress impacts cognitive functions, with a particular focus on the role of the COMT gene polymorphisms and the potential benefits of botanicals like Rhodiola rosea in managing cognitive health during stressful periods. 

How Stress Affects Cognition 

Cognition encompasses various mental processes including memory, attention, problem-solving and decision-making. Stress can impair these cognitive functions in multiple ways: 

1. HPA axis dysregulation: The hypothalamic-pituitary-adrenal (HPA) axis is a central stress response system. Chronic stress leads to sustained HPA axis activation, resulting in elevated cortisol levels. High cortisol can damage the hippocampus, a brain region critical for learning and memory, thereby impairing cognitive function. 

2. Neurotransmitter imbalance: Stress affects the balance of neurotransmitters such as dopamine, serotonin and norepinephrine, which are crucial for mood regulation, attention and memory. Disrupted neurotransmitter levels can lead to cognitive deficits and emotional disturbances. 

3. Inflammation: Chronic stress triggers an inflammatory response in the body. Elevated levels of pro-inflammatory cytokines can cross the blood-brain barrier, causing neuroinflammation. This inflammation can negatively impact brain function and cognitive abilities. 

The Genetic Influence: COMT Gene Polymorphisms 

Genetic factors can significantly influence how individuals respond to stress-induced cognitive changes. With the availability of at home genetic lifestyle testing, individuals can better understand and predict how stress may impact cognition based on neurotransmitter function.  One such genetic factor is the catechol-O-methyltransferase (COMT) gene, which plays a crucial role in the metabolism of dopamine, a neurotransmitter essential for cognitive function. 

COMT Enzyme Function: The COMT enzyme degrades dopamine in the prefrontal cortex, a brain region responsible for executive functions such as decision-making, working memory and cognitive flexibility. The efficiency of this enzyme is determined by variations (polymorphisms) in the COMT gene. 

Val158Met polymorphism: The most studied COMT polymorphism is the Val158Met variant. The Met allele is associated with a stronger cortisol response and is associated with heightened HPA axis activity, it may be related to anxious traits in low stress. While the Val allele is associated with poorer prefrontal mediated tasks in low stress. Individuals with the Val/Val genotype have higher COMT activity, leading to faster dopamine degradation and lower dopamine levels in the prefrontal cortex. Conversely, those with the Met/Met genotype have lower COMT activity, resulting in higher dopamine levels. 

Cognitive implications: While the cognitive implications of various genotypes is still under examination, one hypothesis is that the Val/Val genotype is associated with better performance under low-stress conditions due to optimal dopamine levels for cognitive function. However, under high-stress conditions, rapid dopamine degradation can impair cognition. In contrast, individuals with the Met/Met genotype may experience relatively more cognitive deficits in low-stress situations but perform better under stress due to sustained dopamine levels.  

Some researchers have described a “worrier/warrior” model whereby the Met allele is associated with enhanced anxiety at rest but improved cognitive performance in stress. While the Val allele has increased resilience to stressors with poorer performance in executive tasks in stressful situations. However, as mentioned this is a simplified hypothesis and the intensity and type of stressor, along with age and neurodevelopmental status all may influence this response.  

Botanicals for Cognitive Support During Stress 

Genetics are important in understanding our propensity to certain responses or behaviours. Providing the general framework for how we are most likely to respond to these stressors. However, the exposure to stress itself as well as environmental, lifestyle and nutrition factors will significantly impact genetic expression. Meaning, it is imperative we address multiple factors when correcting or modifying stress related cognitive impairment.  

Several botanicals have been studied for their potential to support cognitive function during periods of stress.  Rhodiola Rosea: This adaptogenic herb has been used traditionally in Eastern Europe and Asia to enhance physical and mental endurance. Modern research supports its use in managing stress and improving cognitive function. 

• Mechanisms of action: Rhodiola rosea (Rhodiola) is thought to help regulate the HPA axis, thereby modulating cortisol levels and reducing stress-induced cognitive impairments. It also influences neurotransmitter levels, enhancing dopamine and serotonin availability in the brain. 

• Clinical evidence: Studies have shown that Rhodiola rosea can improve attention, memory and mental performance, particularly in individuals experiencing stress. For example, a study published in Phytomedicine found that participants who took Rhodiola extract exhibited reduced fatigue and improved cognitive performance compared to a placebo group. 

Bacopa Monnieri: Another well-researched botanical, Bacopa monnieri (Bacopa), has been traditionally used in Ayurvedic medicine to enhance memory and cognitive function. 

• Mechanisms of action: Bacopa monnieri possesses antioxidant properties that protect brain cells from oxidative stress. It also modulates neurotransmitter levels, including serotonin, dopamine and acetylcholine, which are vital for cognitive processes. 

• Clinical evidence: Clinical trials have demonstrated that Bacopa monnieri supplementation can enhance memory, attention and cognitive processing speed, especially in older adults and individuals with cognitive decline. 

Withania somnifera: Known for its stress-relieving properties, Withania somnifera (Ashwagandha) is another adaptogen that supports cognitive health. 

• Mechanisms of action: Ashwagandha reduces cortisol levels, thereby mitigating the negative impact of stress on cognition. It is also an anti-inflammatory that may mitigate underlying inflammation of the central and peripheral nervous system blocking proper parasympathetic mediated cellular signalling. 

• Clinical evidence: Research published in the Journal of Dietary Supplements indicated that Ashwagandha supplementation improved cognitive function and reduced anxiety in stressed adults. 

Integrating Botanicals with Lifestyle Interventions 

While botanicals like Rhodiola, Bacopa, and Ashwagandha offer promising benefits for cognitive support during stress, their effectiveness is enhanced when combined with healthy lifestyle practices. Here are some additional strategies to support cognitive health: 

• Mindfulness and meditation: Regular mindfulness practices and meditation can reduce stress and enhance cognitive function by promoting relaxation and improving attention and memory. 

• Physical xercise: Engaging in regular physical activity boosts brain health by increasing blood flow to the brain, promoting neurogenesis and reducing stress. 

• Balanced diet: A diet rich in antioxidants, omega-3 fatty acids and essential nutrients supports overall brain health and cognitive function. Foods like berries, fatty fish, nuts and leafy greens are particularly beneficial. 

• Adequate sleep: Quality sleep is crucial for cognitive health, as it allows the brain to consolidate memories and perform essential maintenance processes. 

Conclusion 

Stress can significantly impact cognitive function, but understanding the role of genetic factors like COMT polymorphisms and incorporating evidence-based botanicals such as Rhodiola rosea can help mitigate these effects. By combining these interventions with a healthy lifestyle, individuals can better manage stress and maintain optimal cognitive performance. Embracing a holistic approach to stress management and cognitive support is essential for thriving in today’s fast-paced world. 

Key references 

Domes, G., & Frings, C. (2020). Stress and Cognition in Humans. Experimental Psychology, 67(2), 73-76. 

Al-Shargie, F., Taresh, S., & Al-Ezzi, A. (2024). Mental Stress and Cognitive Deficits Management. Brain Sciences, 14(4), 

Armbruster, D., Mueller, A., Strobel, A., Lesch, K., Brocke, B., & Kirschbaum, C. (2012). Children under stress – COMT genotype and stressful life events predict cortisol increase in an acute social stress paradigm. International Journal of Neuropsychopharmacology, 15(9), 1229-1239. 

Zareyan, S., Zhang, H., Wang, J., Song, W., Hampson, E., Abbott, D., & Diamond, A. (2021). First Demonstration of Double Dissociation between COMT-Met158 and COMT-Val158 Cognitive Performance When Stressed and When Calmer. Cerebral Cortex, 31(3), 1411-1426. 

Grosso, C., Santos, M., & Barroso, M. (2023). From Plants to Psycho-Neurology: Unravelling the Therapeutic Benefits of Bioactive Compounds in Brain Disorders. Antioxidants, 12(8), 

Spasov, A., Wikman, G., Mandrikov, V., Mironova, I., & Neumoin, V. (2000). A double-blind, placebo-controlled pilot study of the stimulating and adaptogenic effect of Rhodiola rosea SHR-5 extract on the fatigue of students caused by stress during an examination period with a repeated low-dose regimen. Phytomedicine, 7(2), 85-89. 

Cropley, M., Banks, A., & Boyle, J. (2015). The Effects of Rhodiola rosea L. Extract on Anxiety, Stress, Cognition and Other Mood Symptoms. Phytotherapy Research, 29(12), 1934-1939. 

Downey, L., Kean, J., Nemeh, F., Lau, A., Poll, A., Gregory, R., Murray, M., Rourke, J., Patak, B., Pase, M., Zangara, A., Lomas, J., Scholey, A., & Stough, C. (2013). An Acute, Double‐Blind, Placebo‐Controlled Crossover Study of 320 mg and 640 mg Doses of a Special Extract of Bacopa monnieri (CDRI 08) on Sustained Cognitive Performance. Phytotherapy Research, 27(9), 1407-1413. 

Pingali, U., Pilli, R., & Fatima, N. (0168). Effect of standardized aqueous extract of Withania somnifera on tests of cognitive and psychomotor performance in healthy human participants. Pharmacognosy Research, 6(1), 12-18. 

Rashid IQBAL, M., SHARMA, S., &, (2022). Withania somnifera extract improves cognitive, behavioral and mood disorders in animal model of bipolar disorder. Journal of Research in Pharmacy,