🧠 Midlife and Late-Life Obesity and the Risk of Dementia

Midlife obesity may increase dementia risk, but later in life, extra weight could be protective.

Published In: Archives of Neurology
Date: March 2009
Authors: Fitzpatrick et al.
Link to Study: Read the full study

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Summary

This study investigated how body weight in midlife (around age 50) and later life (age 65+) relates to the risk of developing dementia. Researchers found that being obese in midlife significantly increased the risk of dementia. However, among older adults, being underweight was linked to a higher dementia risk, while being obese was associated with a lower risk—highlighting the so-called “obesity paradox.”

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Key Takeaways

✅ Obesity at age 50 was associated with a 39% higher risk of developing dementia later in life.
✅ Being underweight after age 65 increased the risk of dementia by 62%.
✅ Obesity in later life was linked to a 37% lower risk of dementia.
✅ The protective effect of late-life obesity may reflect physical changes or preclinical dementia-related weight loss.
✅ These findings suggest that weight trends over a lifetime may be more telling than a single BMI measurement.

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Why It Matters for You

Maintaining a healthy weight in midlife may help reduce your risk of dementia later on. For older adults, sudden or unintentional weight loss could be a warning sign and should be discussed with a healthcare provider.

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Citation

Fitzpatrick, A. L., Kuller, L. H., Lopez, O. L., Diehr, P., O’Meara, E. S., Longstreth Jr, W. T., & Luchsinger, J. A. (2009). Midlife and Late-Life Obesity and the Risk of Dementia. Archives of Neurology, 66(3), 336–342. https://doi.org/10.1001/archneurol.2009.8