Neuroscientist: If You Don’t Have These 3 Things After 40, Your Brain Is at Risk For Dementia

Summary

Dementia risk is modifiable, but not fully controllable. The guest cites estimates that roughly 45% of dementia cases may be linked to potentially modifiable risk factors. A separate analysis suggests the theoretical proportion could be as high as 70% if risk factors were removed across a population.

These are population-level estimates, not guarantees for any individual, and they are not meant to blame people who develop dementia. Genetics, environment, social conditions, and interacting risks all matter.

The speakers also challenge the assumption that cognitive decline is inevitable with age. While some people experience decline, studies that follow people over time have found that many retain cognitive abilities well into later life. Expecting decline may discourage people from learning, moving, or taking on challenges; staying engaged can help preserve function.

The 3S framework for brain health

• Stimulate the brain: Choose activities that involve learning, skill-building, attention, and active participation. Examples include learning a language or musical instrument, dancing, making art, playing complex games, developing challenging movement skills, and interacting socially.
• Supply the brain: Support circulation and provide the brain with the resources it needs.
  • Regular physical activity supports blood flow and cardiovascular and metabolic health.
  • Movement breaks may help attention and mood, especially during long periods of sitting or studying.
  • Aim for a nutritious diet that provides essential nutrients. The guest mentions vitamin D, iron, omega-3 fats, B vitamins, antioxidants, and minerals such as magnesium and zinc, with an emphasis on getting nutrients through food where possible.
• Support adaptation and recovery: The brain needs time and suitable conditions to adapt to stimulation.
  • Prioritize sleep and recovery.
  • Reduce factors that may undermine health, including smoking, excessive alcohol, chronic stress, and persistent inflammation.
  • Social connection and oral health are also discussed as relevant to overall health and dementia risk.

The three parts reinforce one another. For example, movement can support blood flow, sleep, and learning, while better rest may make it easier to exercise and engage with other people. The speakers recommend choosing a manageable starting point rather than treating brain health as a long checklist.

Practical self-care and productivity ideas

• Focus on a process you can control. The guest says high performers tend to concentrate on improving their process rather than fixating on outcomes they cannot guarantee.
• Avoid overloading yourself. Start with one change that seems practical and worthwhile. Doing a little may still be beneficial.
• Use social media deliberately. Comparing yourself with highly curated or exceptional content can create social stress. Consider reducing scrolling, curating what you see where possible, and using platforms to maintain real relationships rather than as a substitute for in-person contact.
• Structure the workday around attention.
  • Protect a short block—even 30 minutes—during your most alert part of the day for focused, demanding work.
  • Separate focused work from meetings, email, and other interruptions where feasible.
  • Take brief breaks between demanding work periods. A short walk or stepping away from the screen may help you reset.
  • Looking at greenery briefly and watching something amusing are mentioned as possible ways to refresh.
• Wind down by clearing mental clutter. Write down unfinished tasks or worries before bed instead of repeatedly rehearsing them mentally.
• Notice stress before it accumulates. Short, regular breaks—ideally including some movement—may help prevent the day’s demands from becoming overwhelming.
• Don’t confuse exhaustion with a need for more effort. The example of an overtrained runner illustrates that adjusting training, travel, nutrition, and recovery can sometimes improve performance more than adding work.

Presenters and sources mentioned

Presenters

• Dr. Rangan Chatterjee — host
• Dr. Tommy Wood — neuroscientist and guest

Research and other sources cited in the conversation

• The Lancet Commission reports on dementia prevention (2020 and 2024)
• A British Biobank analysis attributed in the subtitles to Professor Yintai’s group
• Ellen Langer
• The Seattle Longitudinal Study and Warner Schaie
• Alia Crum
• Steve Cole and George Slavich
• Gloria Mark
• James Hewitt
• Sir William Osler
• The article “Creative Experience and Brain Clocks”

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