Grey Matters: Blood Sugar, Brain Health, and Training for Longevity

This week, we'll explore the powerful connection between metabolic health and brain function. We'll dive into HbA1c as a key biomarker for long-term blood sugar control, examine how refined carbohydrates impact your cognitive health, and share exercise wisdom from longevity expert Dr. Peter Attia to help maintain both body and brain health as you age.

 Featured Biomarker

HbA1c (Hemoglobin A1c)

What it is: HbA1c measures your average blood sugar levels over approximately 3 months, providing a clearer picture of your long-term glucose control than single-point glucose readings.

Why it matters: Even mildly elevated blood sugar can damage brain cells over time. Recent studies suggest that chronic hyperglycemia, often signaled by elevated HbA1c, may have a significant role in the onset and progression of Alzheimer's disease and other forms of dementia. High blood sugar creates oxidative stress and inflammation, impairs blood flow in the brain, and leads to neuronal damage that affects cognitive function.

How to improve it: Focus on limiting refined carbohydrates and added sugars, while incorporating regular physical activity into your routine. Both resistance training and cardio are effective at improving insulin sensitivity. Ensure adequate sleep (poor sleep raises blood sugar) and consider time-restricted eating, which can improve glucose metabolism even without changing what you eat. 

Key insight: Monitoring HbA1c is critical because glucose dysregulation often begins 10-15 years before a diabetes diagnosis. This "silent" metabolic dysfunction can damage your brain long before clinical symptoms appear.

BetterBrain Tip: HbA1c provides an average picture of your glucose over time, but doesn't show the daily spikes and fluctuations that can be equally damaging. Consider pairing HbA1c monitoring with occasional continuous glucose monitoring (CGM) to capture the full picture of your metabolic health.

You can read more about HbA1c and relevant techniques to improve your levels on our BetterBrain App.

Technique Spotlight

Control Sugar And Refined Carb Intake

Think refined carbs and sugars are just bad for your waistline?

Think again. These foods create blood sugar spikes that can silently damage your brain over time, even if you're not overweight or diabetic.

The Science: Refined carbohydrates and sugar intake is closely associated with several systemic diseases and particularly linked to type II diabetes, which is a major risk factor for AD. Besides reducing the energy available to your brain, diabetes disrupts the blood vessels in your brain and causes breakdown in the blood-brain barrier, which is essential in maintaining the brain's highly regulated environment.

The Simple Solution: Reduce the presence of foods with high sugar (e.g., breakfast cereals, candy, flavored yogurts) and refined carbs (e.g., white bread, white rice, pastries). Be sure to also stay mindful of sugary beverages like sodas, energy drinks, processed fruit juices, and sports drinks.

Quick Tips:

• Replace refined grains with whole grains (brown rice, quinoa, oats)
• Choose whole fruits over fruit juices
• Read food labels for hidden sugars (ingredients ending in "-ose")
• Pair carbohydrates with protein and healthy fats to slow glucose absorption
• Begin meals with protein and vegetables before consuming any carbs

BetterBrain Insight: Most people notice improved energy levels, better concentration, and reduced brain fog within just 2-3 weeks of reducing refined carbs and sugar intake.

CONTENT CORNER

Training for The Centenarian Decathlon with Peter Attia

Bottom line: Dr. Peter Attia's concept of the 'Centenarian Decathlon' offers a powerful framework for maintaining cognitive and physical function throughout life, emphasizing preparation for what he calls the "marginal decade" – the period where maintaining independence becomes challenging.

About the episode: In this episode of The Drive, Dr. Attia shared his perspective on training for longevity: "I would never want anybody to come away from this thinking, 'I'm too old to do anything about it.' I think as long as you're breathing, you have a chance to do something about it."

The Four Pillars of Training:

1. Zone 2 cardio – Low-intensity, steady-state exercise that builds cardiovascular efficiency and mitochondrial health. This type of exercise has been shown to improve brain blood flow, reduce inflammation, and enhance neuroplasticity.
2. VO₂ max training – Higher intensity interval training that builds cardiorespiratory fitness, a key predictor of cognitive health. Research shows people with higher VO₂ max scores have better cognitive function in later life.
3. Stability – Balance and coordination exercises that become increasingly important with age. Falls are a leading cause of disability in older adults, and stability training helps preserve independence.
4. Strength training – Resistance exercise to maintain muscle mass and function. Stronger muscles support better mobility, metabolism, and surprisingly, better cognitive function through various signaling pathways.

Minimum effective dose: Dr. Attia suggests that even modest amounts of exercise across these four domains can yield significant benefits. For those just starting, aim for:

• 30 minutes of Zone 2 cardio 2-3x/week
• 1 session of high-intensity intervals weekly
• 2 strength training sessions weekly
• Daily balance/stability work (even 5 minutes helps)

Brain health connection: Exercise is one of the most powerful interventions for brain health, working through multiple mechanisms:

• Increases BDNF (brain-derived neurotrophic factor)
• Improves insulin sensitivity
• Enhances cerebral blood flow
• Reduces inflammation
• Promotes healthy sleep patterns

BetterBrain Takeaway: Each of these mechanisms directly counteracts processes involved in cognitive decline, making regular, varied exercise a cornerstone of any brain health protocol.