Cognitive Decline Expert: The Disease That Starts in Your 30s but Kills You in Your 70s - The Diary of a CEO with Steven Bartlett Recap

Podcast: The Diary of a CEO with Steven Bartlett

Published: 2026-02-05

Duration: 2 hr 5 min

Guests: Louisa Nicola

Summary

Alzheimer's disease, often seen as inevitable with age, is largely preventable through lifestyle changes. Louisa Nicola emphasizes the importance of exercise, diet, and sleep in maintaining brain health and preventing cognitive decline.

What Happened

Louisa Nicola, a neurophysiologist and human performance coach, argues that Alzheimer's is largely a disease of lifestyle rather than genetics. She notes that 95% of cases are preventable if one maintains healthy habits starting as early as in their 30s. The disease typically manifests in the 60s or 70s, but it begins much earlier, which underscores the necessity of proactive health measures.

Nicola highlights the significance of exercise, particularly resistance training, for brain health. She explains that exercise releases myokines, which enhance cognitive performance and stimulate neuron growth in the hippocampus. Strong legs are particularly crucial, as they correlate with better cognitive function and reduced Alzheimer's risk.

The episode delves into the impact of sleep on Alzheimer's prevention. Nicola reveals that just one night of sleep deprivation can increase the risk of amyloid beta, a hallmark of Alzheimer's, by 4%. She emphasizes the role of deep sleep in clearing amyloid beta through the glymphatic system and suggests training for better sleep hygiene.

Hormone replacement therapy (HRT) emerges as another preventive measure, especially for women undergoing menopause. Nicola explains that menopause can trigger a 30% reduction in brain glucose metabolism, leading to cognitive issues. HRT can mitigate these effects and reduce Alzheimer's risk by up to 30%.

Nicola also discusses the role of diet, advocating for a ketogenic diet to support brain health, particularly during Alzheimer's. This diet can address the metabolic crisis in the brain by providing alternative energy sources.

The conversation touches on the importance of cognitive reserve, which is built through challenging activities like exercise and reading. A larger cognitive reserve helps the brain withstand stress and maintain function despite aging or disease.

Nicola stresses the significance of cardiovascular health for brain function, noting that VO2 max is a strong predictor of mortality. Maintaining cardiovascular health through regular aerobic exercise can enhance cognitive longevity.

Key Insights

• Alzheimer's disease, often manifesting in the 60s or 70s, can begin in the 30s, with 95% of cases being preventable through lifestyle changes such as exercise and healthy habits.
• Resistance training is beneficial for brain health as it releases myokines, which improve cognitive performance and stimulate neuron growth in the hippocampus. Strong leg muscles are linked to reduced Alzheimer's risk.
• One night of sleep deprivation can increase amyloid beta levels by 4%, heightening Alzheimer's risk. Deep sleep is crucial for clearing amyloid beta through the glymphatic system, emphasizing the need for good sleep hygiene.
• Hormone replacement therapy can reduce Alzheimer's risk by up to 30% in menopausal women, as menopause can cause a 30% reduction in brain glucose metabolism, leading to cognitive issues.