What is BDNF?
BDNF or brain derived neurotrophic factor is a protein that is encoded by the BDNF gene. BDNF improves the function of neurons, encourages their growth, and strengthens/protects them against premature cell death. It also binds to receptors at the synapses, to improve signal strength between neurones. BDNF is critical for allowing the mechanics of neuroplastocity and new neurone growth to occur and can regenerate the memory centre in 1-2yrs.
But before it becomes BDNF-which is essentially “brain growth hormone”, it is in a different form that has to be broken down by an enzyme into the active form we want. This form is called Pro-BDNF, that needs to be cleaved to become BDNF. Pro-BDNF damages neurones whereas BDNF is like brain “fertiliser.
There is lots of this enzyme available to cleave Pro-BDNF in areas of the brain that are highly active. But not in areas of low activity. This causes parts of the brain with low activity to slowly degenerate and be destroyed. Whereas areas of high use are constantly having new neural connections laid down and being re-wired and strengthened. The old adage if you don’t use it you loose it applies here.
This is so important when it comes to the types of thoughts we have…I want you to have a think now about what part of the brain you are activating.
What pathways are you constantly going down and reenforcing?
Are you thinking positive thoughts or negative thoughts?
The beauty of this is, you might have a clean pathway through the forest to “negative land” at the moment, as it is the path of least resistance because you have so well trodden that route. But you are just as capable -with a little effort initially, to clear a new path and lead your mind to positive thoughts so it becomes the main default pathway. That way the road to “negative land “can become overgrown by the forest again and hard to walk down without effort.
Low BDNF levels have also been linked to depression and it is thought that BDNF may also help combat the feelings of anxiety. BDNF has been linked to learning difficulties and declines with age; this decline occurs faster if you have a particular polymorph val66met and 1 in 3 people are said to have this polymorph.
So what can we do to stimulate BDNF production:
Exercise - can turn genetics on to express more BDNF, particularly if the exercise is aerobic. Exercise affects the brain both structurally and functionally. Aerobic exercise daily was shown to be more affective than this type of exercise being carried out every other day. The benefits of exercise also declined once it was stopped for only 2 weeks; with reduced production of BDNF. Resistance exercise can be beneficial for BDNF production too but it is the caloric expenditure that’s important- the more calories burnt the better. So essentially every time you exercise particularly aerobically you are getting a free stem cell transplant for your brain! 45-60mins of walking is all that is needed to help the Hippocampus increases in size. So what are you waiting for get moving today!
Herbs stimulate BDNF- such as Turmeric (most evidence), Ginkgo biloba, Withania (Ashwaganda), Bacopa, Gotu kola, Korean Ginseng, Rhodiola & Sage (increases acetyl choline & enhances BDNF).
Nutrients that assist BDNF- L-theanine, resveratrol, Coffee fruit (pulp from the berry around the coffee bean is a potent stimulator of BDNF).
DHA- in particular from omega 3 stimulates BDNF production. While there are many sources of omega-3 fatty acids like nuts, flax seeds, and chia seeds, there is insufficient evidence to show that they have the same benefits as omega-3 from fish. Omega-3 fatty acids from deep-water fish contain DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which are essential to many of the benefits it provides. So increase your oily fish intake or supplement with a good quality fish oil. Oils have a bad habit of oxidising and going rancid so you want o make sure you purchase good quality brands that are kept in dark glass containers. Once opened i like to keep it in the fridge to avoid to oil oxidising as quickly. If you are getting “fishy burbs” this might be a sign the fish oil you are taking is off. I prefer the liquid versions to the capsules are they tend to sit on the shelf exposed to all kinds of temperatures and often are rancid.
Keto Diet- is great for BDNF due to beta-hydroxybutyrate produced in this diet. But butyrate in general is good whether from this diet or not- butyrate is a ketone made by gut bacteria fermenting fibre rich food & stimulates BDNF production. The Mayo clinic found when carbohydrates are used as a main source of energy there is a 80-85% increase risk of Alzheimer’s. Those with more fat had a 44% risk reduction. But remember some fats are bad such as corn oil, safflower oils etc So when I talk about fats you want to be consuming the good fats such as avocado, coconut oil etc. Caffeine also increases production of beta-hydroxybutyrate & is great to combine with coconut oil in stead of milks- aka “bullet proof coffee”.
Low homocysteine - (less than 18) as homocysteine shrinks the hippocampus, which is not great for BDNF production. Taking vitamins to assist in keeping homocyestine levels in check such as: Vitamin B6, B12, B9 and Vitamin D -all are high protective. We want Vitamin D levels around 80-90 not at the lower end of the scale. So if you think your levels might be low it would be a good idea to get this tested.
Low HbA1C- Keep HBA1C low,- this blood test shows your 3 month blood glucose control -the higher the value the worse control and this correlates with decreased hippocampus size. Also look at CRP as a marker of inflammation in the brain in general. Inflammation is not a good thing especially for the brain and often poor blood glucose control drives inflammation.
Low Lipopolysaccharide -it is a marker of inflammation and is made from sugar and fat, it is produced by gram negative bacteria and indicates the gut health status/permeability.
Probiotics/Prebiotics - Gut bacteria determine the set point of inflammation in body. If the gut bacteria are upset you will have inflammation & a “leaky gut” etc. Nurture the gut with prebiotic fibre and then support with probiotics. Kombucha is a prebiotic drink that is a good alternative to soft drink. The bacteria identified as most beneficial for BDNF production are: Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus brevis, Bifodobacterium lactis, and Bifidobacterium longum. It is however good as a principle to choose a probiotic with multiple strains (at least 10-15 different strains). But if you want to obtain this good bacteria from dietary, sources here are the common foods in which you can find each strain:
Lactobacillus plantarum: sauerkraut, pickles, brined olives, kimchi, Nigerian ogi, sourdough, fermented sausage, stockfish, and some cheeses (such as cheddar)
Lactobacillus acidophilus: yogurt, kefir, miso, and tempeh
Lactobacillus brevis: pickles, saurkraut, and beer hop
Bifodobacterium lactis: yogurt, miso, tempeh, pickled plum, pickles, kim chi, and many other forms of fermented and pickled fruits/vegetables that have not gone through the manufacturing process
Bifidobacterium longum: yogurt, milk, fermented dairy foods, saukraut, and soy-based
Intermittent fasting- Fasting for a meal or a whole day is good for you. It improves signalling with your vagus nerve- if on occasion you let yourself be hungry. Im not talking about starving yourself here- but a selected period of time of no food intake followed by balanced eating practices. It is beneficial to have low level stress on the body and that’s what this type of fasting does- it allows gene to code for antioxidants, and detoxification to be turned on. Studies show intermittent fasting can increase brain-derived neurotrophic factor (BDNF). Dietary restriction seems to stimulate the production of new neurons, increase the brain’s ability to resist aging and restore function to the brain following injury. More specifically, intermittent fasting appears to result in a stress response at a cellular level that stimulates neuronal plasticity and the production of certain proteins, like BDNF.
Decrease stress- Prolonged stress is detrimental to so many aspects of health. To allow healthy BDNF production we need to decrease stress and cortisol- as it causes blood sugar dysregulation etc. which is inflammatory and counters the environment required for BDNF stimulation.
Sleep- is a brain tonic. It is now one of the most important aspects to get right for brain health. Adequate sleep does more for you than exercise and diet will. If i had to choose one thing you need to get right, the most important thing to sort our would be sleep. During sleep you get rid of debris in the brain- however too much sleep is bad & too little not good either. You want just the right amount for you; and that is on average 6-8hrs every night.
There is lots more to be said on sleep and stress which will be covered in future post.