This week I popped down to the Feed Your Mind festival at Kings College London to listen to neurologist Dr Sandrine Thuret give a lecture on diet and brain health, with a focus on two areas of research – omega 3 and calorie restriction / fasting. Here’s a summary of what I heard…
These are the familiar long chain fats that can’t made by the body and so must come from our diet.
In particular, it’s the very long chain EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) fatty acids which are beneficial for mental health. Low intakes of omega 3 are associated with cognitive decline in the elderly – but around 400mg / day of EPA or DHA is associated with a fourfold reduction in risk.
Interestingly, research also shows that EPA at one gram a day is as effective as prozac in controlling depressive symptoms. Add both together, and patients experience better symptom improvement than using either therapy along.
Omega 3 fats also encourage new stem cell generation in the brain, and protect against the negative effects of increased cortisol (as a result of stress).
So how much omega 3 is needed for mental wellbeing? Based on research presented, around one gram a day – that’s around 85 grams of oily fish a day, or an equivalent amount in supplement form.
Unfortunately the short chain omega 3 oils in seeds and walnuts aren’t as beneficial (at least for mental health) as the body can’t easily convert them to the longer chain EPA and DHA.
Disclaimer: the studies on intermittent fasting, calorie restriction and brain health are mostly in animal models. That said, there are some promising indications in humans. In one 2012 study, three months of 30% calorie restriction improved memory scores in older adults.
Animal models also show that biomarkers for Alzheimers disease improve with calorie restriction. Mice who have mental defects show improved survival and less decline in mental capacity when undergoing intermittent fasting.
But why is calorie restriction helpful? Dr Thuret’s research shows that it increases the generation of new neural pathways and brain cells Granted there’s much more work to be done, but it was interesting to hear that the results are convincing enough for Dr Thuret and her co-workers to practice intermittent fasting.
So omega 3 and intermittent fasting appear to be beneficial. But what else and how much?
- flavanoids – blueberries, tea and cocoa in particular. 100-800mg used in human studies…that’s equivalent to around 40grams of very dark chocolate or 1-3 cups of tea a day. Cocoa can boost blood flow to the brain and has been found to improve memory scores and cognitive function in older adults.
- curcumin (active component of turmeric) – active levels achieved with one dish per day made with turmeric
- zinc (red meat / oysters / liver / nuts) – effective quantities in 1 oyster / 100g beef / 8 tbsp wheat germ
- caffeine – small amounts are beneficial up to around 100mg e.g. one espresso
- foods with crunch (neurotrophic factors appear to be decreased with a soft diet / less mastication)
The bottom line? Enjoy more fish, plenty of berries and tea. Cook with spices, say yes to a coffee and a few squares of dark chocolate.
If you can’t get enough omega 3 in your diet, consider a supplement. Consider the occasional fast, and take time out to relax – psychological stress puts the brakes on neurogenesis.