We know that multiple factors – from diet to genetics – are implicated in our risk of succumbing to dementia as we age. And we know that the brain isn’t a separate entity to the rest of our bodies – how we look after one affects the other. We also know that a disease like Alzheimer’s doesn’t arrive overnight, like the flu, it’s the result of a decades-long process in the brain. What still isn’t clear is exactly how all these factors interlink, and why Alzheimer’s is the end result.
Now attention in the science world is focussing on the point where our bodies and brains meet: the blood-brain barrier. There are many research projects underway to establish how failures in this vital interface create the conditions for Alzheimer’s. Last month, researchers in Australia claimed a breakthrough. Using mice, they found leakage from the blood to the brain occurs when microscopic capillaries in the blood-brain barrier are bombarded with amyloid-beta proteins. This causes inflammation. And we know that inflammation in the brain is closely linked to dementia. You can read more about the study here.
WHAT IS THE BLOOD-BRAIN BARRIER?
The blood-brain barrier (BBB) acts as both gatekeeper and exchange system. When it’s working well, the BBB allows vital nutrients into the brain, and filters out toxins – working like an implacable nightclub bouncer, letting in the beautiful people and keeping out undesirables. Maintaining tight junctions between the cells of the BBB tight is vital, as you can imagine – otherwise all sorts of nasties can get in. But the integrity of the BBB varies throughout our lives. During perimenopause, plummeting hormones can cause the BBB to become less efficient *eye roll*. And as we age, the BBB can become ever more leaky, contributing to cognitive decline.
HOW TO LOOK AFTER THE BBB
Apart from ageing, there are many other factors which impact the integrity of this vital mechanism. The BBB is particularly susceptible to disruptions in our sleep, for example. It uses the time we are in deep sleep to sweep out accumulated toxins which have built up during the day. Sleep deprivation has been shown to increase BBB permeability, which in turn leads to increased inflammation in the brain. So getting good sleep is vital – we’ve shared tips here and here
A healthy diet makes a huge difference too: it stands to reason that a mechanism for keeping our brains nourished responds to good nutrition itself. B vitamins, and vitamin C, get priority access to the brain via the BBB, and are found in higher concentrations there than in other parts of the body. If we don’t have enough of them, our brains will suffer. The Omega-3 essential fatty acids EPA and DHA, found in oily fish, support the blood brain barrier and help transport B vitamins to the brain to do their vital work. Curcumin (the active ingredient in turmeric) and sulforaphane (found in cruciferous vegetables like Brussels sprouts, broccoli and cauliflower) also support the BBB. Magnesium affects our neurotransmitters and supports mitochondria (the ‘batteries’ in our cells). Find it in spinach, chard, almonds, avocado, pumpkin seeds and dark chocolate. (All the links will take you to recipes for these ingredients)
NOURISH YOUR GUT:
There’s a direct link between the brain and the gut, so it makes sense that the health of one impacts the other. Research on mice bred with no gut microbiota at all found that they had leaky BBBs. But when good bacteria were introduced into their guts, their BBB permeability improved. So feed your good microbiota with leafy green vegetables, alliums such as leeks and onions, and small amounts of fermented foods such as kimchi, yogurt and kefir. Research published earlier this month linked a substance found in the herb basil with reduced neurotoxicity in the Alzheimer’s brain. We include basil in lots of our recipes – this pea and roasted garlic soup with basil and farro is a winner.
STIMULATE THE VAGUS NERVE:
We’ve written before about how the vagus nerve is the ‘information superhighway’ between our brains and our guts. It likes to be fine-tuned with deep breathing, singing, humming, meditation and cold showers. It responds better to interval training like HIIT, than endurance exercise. Stimulating the vagus nerve also helps us manage stress, which has a negative impact on the BBB.
GET VITAMIN D:
Research has found that Vitamin D supplementation helps repair damage to the BBB following a stroke. With clocks going back in the UK this weekend, getting vitamin D from sun is about to get even harder. Hopefully we don’t need to remind you to take a supplement for this essential nutrient, and to get outside when you can. (And if you’re in Australia or New Zealand, enjoy the coming of spring and the lighter evenings!)
GET THE BLOOD TO YOUR BRAIN:
Exercise, cold showers, sunlight, listening to (or making) music and dark chocolate all help promote blood flow to the brain. All good things to seek out this weekend!
ARE YOU A GOLDSTER?
I’m so excited to tell you that I’m joining Goldster as a tutor. If you haven’t come across it yet, Goldster is an online health and wellness platform for the over-50s, offering hundreds of classes from yoga to painting and strength training to happiness, all via Zoom. What I like about Goldster is that all the classes are scientifically proven to help healthy ageing, and they’re all interactive so you can ask questions and get advice directly from the experts.
I’ll be teaching an hour-long class on ageing well (of course!) each Thursday at 6pm. My first class is on Thursday November 4th. You can sign up for a free 30-day trial of the platform here- after that it’s £9.99 a month. Do come and say hello!
Photo: Larm Rmah @ Unsplash