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Dementia is a global issue and affects people of many different cultures, with 55 million people worldwide estimated to be living with the disease in 2020. This number is expected to soar to a frightening 153 million by 2050. However, certain populations appear to be exceptions to the growing geographical trend of rising dementia rates. In recent years, these seemingly idyllic communities have been exemplified as the gold standard of longevity. One such example is the Greek island of Ikaria. Nicknamed the “island of Immortals” by National Geographic, the region is known for its high proportion of centenarians (people older than 100 years of age)- the island piqued the interest of many when it was named as one of the 5 regions proclaimed a Blue-Zone by author Dan Buettner. Not only are centenarians found in higher abundance on Ikaria, with more than 30% of habitants living until at least 90, they are also more often free of the hallmark signs of physical and cognitive decline that usually accompany the aging process- this is evident by the rare occurrence of dementia amongst its population.

What are the key features of the Ikarian lifestyle that prevent cognitive decline?

One key causal factor linked to age-related cognitive decline is stress. According to Alzheimer’s society, the stress hormone cortisol has been implicated in memory related issues, depression and anxiety- all of which contribute to a lower-life expectancy. The Ikarians slower- paced, more simplistic way of life and fondness for napping combats this. 

The people in Ikaria also benefit from the Mediterranean diet that they strictly adhere to which avoids ultra-processed foods. It is composed of high fibre foods such as fruit and vegetables, healthy fats, whole grains, legumes, fish, olive oil and red wine in moderation. Wild and garden greens foraged on the island are often ingested (whether in meals or through herbal teas) which are high in diuretic properties- reducing blood pressure. This may be associated with the lower incidences of Alzheimer’s as research has linked hypertension to the presence of Alzheimer’s biomarkers in spinal fluid. Furthermore, a diet rich in compounds known as flavonoids (which are found in tea and red wine) has also been found to reduce dementia risk.

What is the influence of lifestyle on dementia risk?

Having a genetic predisposition for a disease does not always dictate that you will get it. In the case of dementia, there is a degree of influence attributed to an individual’s lifestyle choices such as diet, exercise level and whether they indulge in habits such as smoking: research commissioned by the Lancet has identified 12 lifespan risk factors that can delay/prevent dementia in 40% of cases. Fiona Carragher, Director of Research and Influencing at Alzheimer’s Society acknowledges the multifactorial nature of diseases such as Alzheimer’s, noting that “The news that 40% of dementia cases are, in theory, now preventable is certainly welcome, but stopping thousands of people from being stripped of their memories, relationships and identities will rely on more than just this knowledge alone”.

It is therefore important for governments to prioritise and fund public health initiatives to educate and empower individuals to change their lifestyle as early as possible to reduce their risk of developing dementia. One such agenda, inspired by the Ikarians, that could be advocated for more thoroughly in the United Kingdom is the Mediterranean/ MIND diet. The benefits of this diet have been supported by a large population-based cohort study from Oliver Shannon and fellow researchers at the UK Biobank, which followed more than 60,000 participants and revealed that higher/stricter adherence to the Mediterranean Diet is associated with lower risk of incident all-cause dementia.

Reference list

Alzheimer's Society (2022). Can stress cause dementia? | Alzheimer’s Society. [online] www.alzheimers.org.uk. Available at: https://www.alzheimers.org.uk/blog/can-stress-cause-dementia.

Alzheimer’s Society. (2024). The Lancet: 40% of dementia cases could be prevented or delayed by targeting 12 risk factors throughout life. [online] Available at: https://www.alzheimers.org.uk/news/2024-11-22/lancet-40-dementia-cases-could-be-prevented-or-delayed-targeting-12-risk-factors.

Buettner, D. and Skemp, S. (2016). Blue Zones: Lessons from the World’s Longest Lived. American Journal of Lifestyle Medicine, 10(5), pp.318–321. doi:https://doi.org/10.1177/1559827616637066.

Institute for Health Metrics and Evaluation (2022). The Lancet Public Health: Global dementia cases set to triple by 2050 unless countries address risk factors | The Institute for Health Metrics and Evaluation. [online] www.healthdata.org. Available at: https://www.healthdata.org/news-events/newsroom/news-releases/lancet-public-health-global-dementia-cases-set-triple-2050.

Jennings, A., Thompson, A.S., Tresserra-Rimbau, A., O’Neill, J.K., Hill, C., Bondonno, N.P., Kühn, T. and Cassidy, A. (2024). Flavonoid-Rich Foods, Dementia Risk, and Interactions With Genetic Risk, Hypertension, and Depression. JAMA Network Open, [online] 7(9), p.e2434136. doi:https://doi.org/10.1001/jamanetworkopen.2024.34136.

Shannon, O.M., Ranson, J.M., Gregory, S., Macpherson, H., Milte, C., Lentjes, M., Mulligan, A., McEvoy, C., Griffiths, A., Matu, J., Hill, T.R., Adamson, A., Siervo, M., Minihane, A.M., Muniz-Tererra, G., Ritchie, C., Mathers, J.C., Llewellyn, D.J. and Stevenson, E. (2023). Mediterranean diet adherence is associated with lower dementia risk, independent of genetic predisposition: findings from the UK Biobank prospective cohort study. BMC Medicine, [online] 21(1). doi:https://doi.org/10.1186/s12916-023-02772-3.

Sible, I.J., Yew, B., Jang, J.Y., Alitin, J.P.M., Li, Y., Gaubert, A., Nguyen, A., Dutt, S., Blanken, A.E., Ho, J.K., Marshall, A.J., Kapoor, A., Shenasa, F., Rodgers, K.E., Sturm, V.E., Head, E., Martini, A. and Nation, D.A. (2022). Blood pressure variability and plasma Alzheimer’s disease biomarkers in older adults. Scientific reports, [online] 12(1), p.17197. doi:https://doi.org/10.1038/s41598-022-20627-4.

Slattery, C. (2024). Eat beans and live longer: One reason why many Ikarians live to be 100. [online] www.bbc.com. Available at: https://www.bbc.com/travel/article/20240322-eat-beans-and-live-longer-one-reason-why-many-ikarians-live-to-be-100.

Walker, K. (2023). Exploring Ikaria, Greece’s island of immortals. [online] Travel. Available at: https://www.nationalgeographic.com/travel/article/exploring-ikaria-greece-island-immortals.