1st Revision: Ha Nguyen Based on an article titled “Consumption of coffee and tea and risk of developing stroke, dementia, and poststroke dementia: A cohort study in the UK Biobank”
Originally written by Zhang et al. 2021
https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003830
By: Murielle Nsiela
Dementia is a general term for a group of conditions characterised by the deterioration of brain function that causes issues such as memory loss, which inevitably affects one’s ability to live independently.1 There are two main subtypes of dementia, Alzheimer’s disease and vascular dementia. Dementia is not a disease but a clinical symptom caused by several traumatic events, mainly to the brain.
As a result of an ageing population, dementia is becoming a global health concern, causing an economic and social burden to millions worldwide. In 2019, an estimated 50 million people had dementia globally, and this number is expected to rise to 150 million by 2050.2 Due to the lack of therapeutic effects of drugs available to treat dementia, it is vital to find methods to prevent the development of the disease.
Tea and coffee are two of the most consumed beverages globally. Clinical studies have shown that there are benefits of tea and coffee separately in preventing the risks of dementia. However, the effects of the combination of both beverages are not well known.
Therefore, Zhang et al. conducted a study to determine whether coffee and tea individually and in combination could reduce risks of dementia, stroke, and post-stroke dementia. Post-stroke dementia is dementia that occurs after suffering a stroke.3
The study involved 365,682 individuals aged 50 to 74 years who reported their tea and coffee consumption. As dementia primarily affects older adults, the study did not include individuals younger than 50. After considering other health variables, the results showed that tea and coffee individually reduce the risks of dementia and vascular dementia; however, this did not lower the risk of developing Alzheimer’s disease.
Furthermore, when they studied the combination of both tea and coffee, the results also indicated that taking both beverages reduces the risks of vascular dementia but not Alzheimer’s. The results showed the lowest incidence of dementia occurred when individuals drank 0.5 to 1 cup of coffee and less than 4 cups of tea a day. Overall, those who drank a combination of both tea and coffee had a lower risk of developing dementia, vascular dementia, stroke and post-stroke dementia compared to those who only took coffee or tea alone and those who did not consume either of the beverages.
In addition, the study looked into the type of coffee the participants were drinking. They found that ground coffee reduces the risks of developing dementia, vascular dementia, and stroke compared to instant and decaffeinated coffee.
The paper highlights the benefits associated with drinking a combination of both tea and coffee and how these can have a positive effect on dementia and related diseases. However, whether consuming these beverages can improve the outcome of dementia is yet to be determined.
References:
- Iadecola, C., Duering, M., Hachinski, V., Joutel, A., Pendlebury, ST., Schneider, JA., et al., 2019. Vascular Cognitive Impairment and Dementia: JACC Scientific Expert Panel. J Am Coll Cardiol, 73(25),pp 3326-44.
- Zhang, Y., Yang, H., Li, S., Li, W. and Wang, Y., 2021. Consumption of coffee and tea and risk of developing stroke, dementia, and poststroke dementia: A cohort study in the UK Biobank. PLOS Medicine, 18(11), p.e1003830.
- Mijajlovic, D., Pavlovic, A., Brainin, M., Heiss, WD., Quinn, TJ., Ihle-Hansen HB, et al., 2017. Post-stroke dementia—a comprehensive review. BMC Med, 15(1), p11.
