Your gut is an amazingly complex world, which is so much more than simply a place for digestion. Housing 70% of our immune system, the gut hosts a high-level network of cells known as our gut-associated lymphoid tissue.
It makes sense for the immune system to have such a prominent role here, as this is a key entry point into our bodies with some areas only a single cell thick. The gut doesn’t act alone; it is supported by the array of microbes that reside in it, which train our immune system, just like going to the gym. But my focus today is on gut microbiota and its relationship with the brain.
Gut microbiota and the brain
Your gut microbiota is incredibly dynamic, showing natural fluxes throughout the day, however it is easily damaged through use of medication, sleep disturbance, and dieting. Antibiotics are known to change your bacterial population permanently, resulting in loss of the ‘good guys’, but over a quarter of non-antibiotic medications can impact it too.
Sleep, shiftwork and jet lag interrupts our microbiota’s ‘sleep-wake’ cycle, i.e. circadian rhythm, with evidence suggesting this plays a role in an increased risk of weight gain and diabetes. Short intense diet overhauls can alter the functional roles of your pre-existing microbes, essentially changing the chemicals they produce. This results in different effects on the body and is thought to be responsible for rapid weight gain following extreme yoyo dieting.
We have all felt that ‘gut-feeling’ experience, from butterflies in your stomach, nervous whirls before a big event, and an inability to stomach something. There is constant two-way communication from our gut to our brain known as the gut-brain axis.
Recent research is suggesting that tapping into our gut-brain axis could play a key roll in our mental health. With one in four of us likely to experience mental health challenges this year, understanding and supporting your gut is incredibly important. Studies are now reporting that simple dietary changes and modifications can help manage mental health conditions such as depression. Furthermore, nourishing the microbiome through non-diet and diet methods has a suggestive roll in preventing depression and anxiety in the first place.
Eating for your mental health
So what should we be eating for our mental health? The strongest body of evidence points to the Mediterranean diet. A dietary pattern characterised by a high intake of fruit, vegetables, whole grains and legumes, olive oil, and moderate fish and meat intake.
A huge study known as the ‘SMILES’ trial was a 12-week trial looking at dietary intervention as an adjunctive tool in treating moderate to severe depression. The intervention group received seven individual nutritional consulting sessions from a clinical dietician. The control group received seven support group sessions with no nutritional advice. The results were fascinating, showing after 12 weeks the dietary support group showed significantly greater improvements in mental health compared to the social support group. In the dietary support group, 32% of participants achieved full remission and were no longer considered depressed.
The Mediterranean diet
When advising a client on the Mediterranean diet, I always tell them to eat like they are on holiday in Greece (sadly this doesn’t include cocktails at happy hour). Diets packed full of organic seasonal vegetables with every colour from purples, greens, yellows, reds, and oranges. An array of legumes and whole grains, plus carbohydrates are not to be demonized, but should be respected in all their natural glory as a powerhouse of phytonutrients and fibre.
Search for real bread, sourdough made of ancient grain without an ingredients list. Snack on seeds and nuts, particularly walnuts and pistachios. Quality protein sources consumed on occasion, organic and holistically farmed. Plenty of good extra virgin olive oil, in fact in areas of high longevity they consume around 60ml a day, so don’t fear the fat! Strive for quality, we live in a time where access to better foods is simply a website click away; make a change from the supermarkets. I have added links a few of my favourite companies below.
It’s worth mentioning fermented foods, which has a growing body of evidence demonstrating their positive effects on stress relief and memory enhancement. The process of fermenting changes the chemical within the food itself, increasing the number of bioactive peptides, phytochemical, and neuroprotective effects. These chemicals can then directly influence the gut microbiome, encouraging the production of brain-messenger chemicals. Specifically, gamma-aminobutyric acids (GABA) have a calming effect on the brain, with low levels triggering panic attacks, anxiety, sleep disturbances, and restlessness.
Food and attitude
It’s easy to think that simply eating a ‘perfect diet’ will solve all your woes, however don’t forget the gut-brain axis is a two-way relationship. Your thoughts and mood play a key role in influencing your gut health. Non-diet therapy through yoga and cognitive behavioural methods are just as effective in treating gut symptoms, particularly in IBS.
Life is now so busy that many of us underestimate how stressed we truly feel. In so many cultures being in a high state of stress is the norm and can almost be said with pride. How can we tell if our stress is at a level that is damaging? Look at your sleep, mood, and gut issues. If any of these are regularly out of balance, it’s very important to get on top of your mental health to support your physical health.
A dysfunction between the gut and the brain axis via the vagus nerve can be triggered through our emotions and is thought to be the cause of most gut-related issues, with sensitisation to food becoming a trigger. It’s important to remember this, as cutting an array of foods out of your diet may provide some relief but it’s like sticking a plaster on a wound that needs stitches.
It’s why every person’s health should be assessed using a holistic approach. The body is a beautiful but complex place with multidirectional relationships within your internal environment and your mental state. Nourishing your body and your mind is key for health and happiness; you have to feed both the best you can. Real home-cooked foods, shared with people you love around a dinner table with no technology can go a long way.