Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that affects memory, thinking and behaviour. It is the most common form of dementia and affects millions of people worldwide. Often it develops over time, gradually interfering with activities of daily living such as recalling familiar names, managing routines, and making decisions. While aging is often the great risk factor, AD is not considered a normal part of aging and has been associated with complex changes in the brain including the build-up of abnormal proteins, inflammation and the gradual loss of nerve cell function.(1)(2)(3)(4) Pathological changes often begin years or even decades before clinical symptoms may appear, highlighting the importance of early intervention and preventative strategies.


Oxidative stress occurs when there is an imbalance between free radicals and our body’s ability to counteract them. This process is frequently mentioned in discussions of brain aging and neurodegenerative conditions such as AD, as it contributes to cellular damage including damage to our brain cells.(1)(5) This connection with oxidative stress and damage to our brain cells have led some researchers to explore the potential role in using antioxidants such as Coenzyme Q10 for their role in supporting normal brain function as people age.(1)(5)


Coenzyme Q10 (CoQ10) is a naturally occurring antioxidant that is found in nearly every cell of the body. It primarily supports the production of energy within our cells by helping mitochondria (the powerhouse of our cells) convert nutrients into usable energy. In addition to its role in energy production, CoQ10 is a potent lipid-soluble antioxidant. This means it helps neutralize free radicals and regenerates other antioxidants, thereby contributing to the reduction of oxidative damage within cells.(1)(4)(7) Research has also shown that as we age our CoQ10 levels decline. In addition, CoQ10 levels can decrease with various medications including statins, which are utilized to manage high cholesterol levels.(7) Reduced CoQ10 availability may impair mitochondrial efficiency and increase susceptibility to oxidative stress, particularly in aging tissues such as the brain.(1)



Due to the decline, dietary sources of CoQ10 have gained attention. Food rich in CoQ10 include fatty fish (such as salmon, tuna and sardines), organ meats, whole grains, nuts, seeds, and legumes. While dietary intake contributes to overall CoQ10 levels, the amounts obtained from food alone may be relatively modest, leading some individuals to consider supplementation.(1) Studies have suggested that CoQ10 supplementation has been shown to improve mitochondrial function, reduce oxidative damage and modulate inflammatory pathways. However, results from trials examining CoQ10 supplementation in Alzheimer’s disease specially have been mixed and remain inconclusive.(2)(4)(5)(6)(8)(9)


It is important to emphasize that CoQ10 is not a treatment, cure, or preventive therapy for Alzheimer’s disease or dementia.(2) Rather, it is considered a supportive therapy that may contribute to overall cellular and mitochondrial health.(5) Alzheimer’s disease is multifactorial in nature, influenced by a complex interplay of genetic predisposition, environmental exposures, cardiovascular health, metabolic function, diet, physical activity, sleep quality, and cognitive engagement.(10)(11) No single nutrient or supplement can address all these contributing factors.


For individuals considering CoQ10 supplementation, safety and personal health history must be carefully evaluated. CoQ10 is generally well tolerated, with mild gastrointestinal symptoms (nausea, vomiting, upset stomach and diarrhea) being the most reported side effects.(7) However, it may interact with certain medications, therefore, consultation with a qualified healthcare professional is strongly recommended prior to initiating supplementation, particularly for individuals managing chronic illnesses or neurological conditions.


References

1. Fišar, Z., & Hroudová, J. (2024). CoQ10 and Mitochondrial Dysfunction in Alzheimer's Disease. Antioxidants (Basel, Switzerland), 13(2), 191. https://doi.org/10.3390/antiox13020191

2. Knight, E., Geetha, T., Broderick, T. L., & Babu, J. R. (2023). The Role of Dietary Antioxidants and Their Potential Mechanisms in Alzheimer's Disease Treatment. Metabolites, 13(3), 438. https://doi.org/10.3390/metabo13030438

3. Ngah, W. Z. W., Ahmad, H. F., Ankasha, S. J., Makpol, S., & Tooyama, I. (2024). Dietary Strategies to Mitigate Alzheimer's Disease: Insights into Antioxidant Vitamin Intake and Supplementation with Microbiota-Gut-Brain Axis Cross-Talk. Antioxidants (Basel, Switzerland), 13(12), 1504. https://doi.org/10.3390/antiox13121504

4. Rauchová H. (2021). Coenzyme Q10 effects in neurological diseases. Physiological research, 70(Suppl4), S683–S714. https://doi.org/10.33549/physiolres.934712

5. Chong, Z. Z., & Souayah, N. (2025). Oxidative Stress: Pathological Driver in Chronic Neurodegenerative Diseases. Antioxidants (Basel, Switzerland), 14(6), 696. https://doi.org/10.3390/antiox14060696

6. Jiménez-Jiménez, F. J., Alonso-Navarro, H., García-Martín, E., & Agúndez, J. A. G. (2023). Coenzyme Q10 and Dementia: A Systematic Review. Antioxidants (Basel, Switzerland), 12(2), 533. https://doi.org/10.3390/antiox12020533

7. Sood B, Patel P, Keenaghan M. Coenzyme Q10. [Updated 2024 Jan 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK531491/

8. Young, A. J., Johnson, S., Steffens, D. C., & Doraiswamy, P. M. (2007). Coenzyme Q10: a review of its promise as a neuroprotectant. CNS spectrums, 12(1), 62–68. https://doi.org/10.1017/s1092852900020538

9. Zhang, X. Y., Li, Y. Q., Yin, Z. H., Bao, Q. N., Xia, M. Z., Chen, Z. H., Zhong, W. Q., Wu, K. X., Yao, J., & Liang, F. R. (2024). Supplements for cognitive ability in patients with mild cognitive impairment or Alzheimer's disease: a protocol for systematic review and network meta-analysis of randomised controlled trials. BMJ open, 14(4), e077623. https://doi.org/10.1136/bmjopen-2023-077623

10. Puoyan-Majd, S., Parnow, A., Rashno, M., Heidarimoghadam, R., & Komaki, A. (2025). Effects of Pretreatment With Coenzyme Q10 (CoQ10) and High-Intensity Interval Training (HIIT) on FNDC5, Irisin, and BDNF Levels, and Amyloid-Beta (Aβ) Plaque Formation in the Hippocampus of Aβ-Induced Alzheimer's Disease Rats. CNS neuroscience & therapeutics, 31(2), e70221. https://doi.org/10.1111/cns.70221

11. Śliwińska, S., & Jeziorek, M. (2021). The role of nutrition in Alzheimer's disease. Roczniki Panstwowego Zakladu Higieny, 72(1), 29–39. https://doi.org/10.32394/rpzh.2021.0154