How to Grow New Brain Cells with Dr Sandrine Thuret #44
Neuroscientist Dr. Sandrine Thuret from King's College London discusses neurogenesis, the adult brain's ability to grow new neurons in the hippocampus. She explains how lifestyle factors like diet, sleep, exercise, and stress management can significantly impact neurogenesis, influencing mood, memory, and cognitive health.
Deep Dive Analysis
12 Topic Outline
Introduction to Neurogenesis and its Historical Understanding
The Hippocampus: Location and Function of Neurogenesis
Impact of New Neurons on Learning, Memory, and Mood
Negative Factors Affecting Neurogenesis: Stress and Aging
Positive Factors Affecting Neurogenesis: Exercise and Sleep
Dietary Impact on Neurogenesis: Western vs. Mediterranean Diets
Intermittent Fasting and Calorie Restriction for Neurogenesis
Specific Foods that Promote Neurogenesis: Flavonoids and Omega-3s
Impact of Food Texture (Chewing) on Neurogenesis
The Role of Sex in Promoting Neurogenesis
Personal Lifestyle Changes Inspired by Research
Key Takeaways for Brain Health
4 Key Concepts
Neurogenesis
Neurogenesis is the production or birth of new neurons. While once thought to cease after brain development, it has been robustly shown to occur in the adult human brain, specifically in a restricted area called the hippocampus.
Hippocampus
The hippocampus is a specific, three-legged area of the brain that is crucial for learning and memory (the dorsal part) as well as mood and emotion (the ventral part). It is the only known site of significant adult neurogenesis in the human brain.
Pattern Separation
Pattern separation is the brain's ability to distinguish between very similar memories, such as remembering where you put an item on different occasions. New neurons in the hippocampus are critical for this function, and blocking neurogenesis impairs it.
Cloto (Longevity Hormone)
Cloto is referred to as a longevity hormone, and its increased levels in the blood have been correlated with improved pattern separation and enhanced neurogenesis in human studies involving calorie restriction and intermittent fasting.
8 Questions Answered
Neurogenesis is the birth of new neurons, a process once thought to stop after development. In adult humans, it is robustly shown to occur primarily in the hippocampus, a brain region vital for memory and mood.
Newly born neurons are more excitable and connect to the existing circuitry of the hippocampus and other brain areas, playing a crucial role in spatial learning, memory retrieval, pattern separation (distinguishing similar memories), and influencing mood and emotion.
Chronic mild stress significantly decreases neurogenesis, potentially leading to symptoms of depression and memory decline. Aging naturally reduces neurogenesis rates, though it can still be stimulated.
Regular physical exercise, particularly running (in mice studies), and adequate sleep are shown to increase neurogenesis. Avoiding chronic stress and adopting a healthy diet like the Mediterranean diet also promote it.
Diets high in saturated fat and sugar (typical Western diet) can decrease neurogenesis, while diets rich in fruits (especially dark-skinned berries containing flavonoids), vegetables, and fish (omega-3 fatty acids) are associated with increased neurogenesis and better cognitive function.
Both intermittent fasting (e.g., 5:2 diet) and daily calorie restriction (20-30% less intake) have been shown in human studies to improve pattern separation and increase levels of the longevity hormone cloto, suggesting a positive impact on neurogenesis.
Studies in rodents suggest that chewing or mastication can increase neurogenesis, possibly by improving blood flow to the brain or through direct nerve stimulation. This highlights the importance of food texture and maintaining good dental health.
No, for brain health, EPA and DHA are the crucial omega-3 fatty acids. ALA, found in many plant-based sources, is inefficiently converted to EPA and DHA in the human body, so direct sources of EPA and DHA (like fatty fish or algae supplements) are preferred.
10 Actionable Insights
1. Manage Chronic Stress
Actively manage and reduce chronic stress, as even mild chronic stress decreases neurogenesis, which can lead to memory decline and symptoms of depression.
2. Prioritize Quality Sleep
Ensure adequate and undisturbed sleep, as even fragmented sleep can drastically reduce neurogenesis by up to 50%, negatively impacting brain function.
3. Engage in Enjoyable Exercise
Regularly engage in physical activity that you genuinely enjoy, as this can increase neurogenesis by up to 30% and improve blood flow to the brain, yielding greater benefits.
4. Adopt Brain-Healthy Diet
Avoid high-fat, high-sugar processed Western diets, which decrease neurogenesis. Instead, follow a Mediterranean-like diet rich in whole foods to promote neurogenesis and cognitive sharpness.
5. Practice Intermittent Fasting
Implement intermittent fasting (e.g., 5:2 diet or a daily 12-hour eating window) or moderate calorie restriction (20-30% less daily) to improve pattern separation and boost longevity hormones, benefiting neurogenesis.
6. Consume Flavonoid-Rich Foods
Incorporating dark-skinned fruits like blueberries, strawberries, and grapes into your diet can increase neurogenesis, improve memory, and enhance brain blood flow due to their high flavonoid content.
7. Ensure Adequate Omega-3s
Consume fatty fish or choose omega-3 supplements specifically containing EPA and DHA, as these forms protect against depression and are crucial for brain health, unlike ALA.
8. Eat Chewy, Unprocessed Foods
Prioritize eating foods that require chewing and mastication over soft or liquid diets, as chewing can stimulate neurogenesis and contribute to brain health.
9. Maintain Good Oral Health
Maintain good oral health, including healthy teeth, throughout life to ensure the continued ability to chew effectively, which is important for stimulating neurogenesis.
10. Engage in Sexual Intercourse
Engage in sexual intercourse, as rodent studies suggest it can increase neurogenesis, potentially contributing to brain health.
6 Key Quotes
Everything may die, nothing may be regenerated. But, you know, unfortunately, it was proven wrong.
Sandrine Thuret
So, the pattern separation is distinguishing between very similar memories.
Sandrine Thuret
I think it's important that people are aware that, as you said, you know, all this lifestyle, you know, do not impact just exactly how you look. Maybe, you know, a lot of people will do that for that, but actually how you can preserve your cognition or even your happiness. We could go that far, you know, to prevent, you know, depression.
Sandrine Thuret
So, and then what we could see is that contrary to our hypothesis, because this is science, we thought, oh, yeah, surely we will see, you know, a difference only to the people doing intermittent fasting because that's what we saw in Rodan. But no, in humans, the calorie restriction, you know, of, you know, every day, so basically every day the people ate a little bit less, had a similar effect than intermittent fasting.
Sandrine Thuret
I think it's safe to say we're not designed to eat food all the time. From the minute we wake up to the minute we go to sleep, seven days a week, 365 days a year.
Dr. Rangan Chatterjee
I think, you know, if we want to summarize the whole thing and give, you know, an easy tip, it's like don't eat your food too processed. And if you do that, you probably will do quite well.
Sandrine Thuret
2 Protocols
Intermittent Fasting (5:2 Diet) for Humans
Sandrine Thuret- Eat normally for five days of the week.
- On two non-consecutive days, consume only 600 kilocalories, ideally within a restricted eating window (e.g., 16 hours fasting).
General Brain Health Lifestyle Recommendations
Sandrine Thuret- Prioritize good sleep and actively work to limit or balance out stress.
- Adopt a healthy diet rich in fruits (especially dark-skinned berries), vegetables, and fatty fish (if not vegan/vegetarian).
- Engage in regular physical exercise that you enjoy, as increasing blood flow to the brain is likely beneficial.
- Consume less processed foods to benefit from chewing and fiber content.