Could you have a leaky blood-brain barrier?

Could you have a leaky blood-brain barrier?

We can often take our health, including that of our brain, for granted. In order to keep our body humming along, there are a huge number of body systems our brain oversees – hormones, digestion and muscles to name a few.

Sadly, conditions of the brain are rampant in society nowadays.

Why is this the case? There are often several underlying factors including inflammation, gut microbial imbalance and toxins. In functional medicine, we look for the root cause(s).

I have presented webinars on the gut-brain connection before, and now research is finding a leaky gut can be associated with a leaky brain, or the protective blood-brain barrier (BBB).

Dr Alessio Fasano [MD, chief of pediatric gastroenterology and nutrition at MassGeneral Hospital for Children, Boston, Massachusetts], has worked extensively on the role of gluten and intestinal permeability. His research has shown how gluten stimulates the production of zonulin, and zonulin makes the bowel hyperpermeable, which allows proteins access to the bloodstream, where they might normally have been excluded. More importantly, what Dr. Fasano’s research has revealed is that the same mechanism is involved—gluten-stimulating zonulin—in increasing the permeability of the blood–brain barrier. While clinicians may be concerned about patients having leaky bowels, I can promise that having a leaky brain is certainly of much more concern. A compelling finding in his work is that 100% of humans have this gluten-zonulin signalling cascade to some degree.

So when we have leaky blood-brain barrier, larger molecules fit through the membrane than should usually get through. This leads to brain inflammation (cytokine model of cognitive function), and can be associated with depression, anxiety, brain fog and auto-immune brain conditions. Medications for example anti-depressants are often ineffective where there is brain inflammation because the underlying reason for brain inflammation has not been addressed.

So if you think you have brain inflammation, what can you do?

  1. Avoid brain zappers – sugar, highly processed foods, preservatives, artificial sweeteners. High blood sugar increases the risk of cognitive dysfunction (thinking problems) as well as shrinkage of the brain. Trial 2-4 weeks off gluten and see if you experience any difference in brain fog or mental energy.
  2. Manage stress – mindfulness, yoga, tai chi can all mitigate the effects of stress. Acute stress can increase leakiness of the blood-brain barrier.
  3. Exercise – aerobic exercise increases Brain Derived Neurotrophic Factor (BDNF) which promotes the health of the brain and nerve cells.
  4. Consider a functional medicine approach to brain health. Comprehensive testing for brain health includes markers such as homocysteine, a marker of detoxification, and HbA1C. This is a marker of sugar attaching to a protein over the past three months. If this marker is raised, it is likely other proteins are also becoming glycated. This in turn increases free radical production and oxidative stress in the body. This marker is well researched in monitoring the risk of Alzheimer’s Disease. The empowering part is that you have control on your HbA1C level – it depends on the foods you choose to eat.
  5. Look into the health of your microbiome. In clinic I often test the gut-brain axis through a stool test as an unhealthy gut can lead to an unhealthy brain. In particular bacterial imbalance or yeast overgrowth can have neurological implications. A good diversity of gut bacteria including Lactobacillus and Bifidobacterium species is important for good mental health.

Perlmutter D. Rethinking Dietary Approaches for Brain Health. Alt Comp Therap 2014;20:2.
Fasano A. Zonulin and its regulation of intestinal barrier function: The biological door to inflammation, autoimmunity, and cancer. Physiol Rev 2011;91:151–175.
Enzinger C, Fazekas F, Matthews PM, et al. Risk factors for progression of brain atrophy in aging: Six-year follow-up of normal subjects. Neurology 2005;64:1704–1711.