Over the past few years I’ve been through a personal revolution in my understanding of how important the things we choose to eat are to our psychological wellbeing. Science and Western medicine seem at last to be catching up with the Eastern and integrative systems that know ‘we are what we eat’.
I now always look at a patient’s diet if they come to me with anxiety, depression, stress or hormone-related mental health issues. I’m not saying the right food is a cure-all, but it certainly lays the right foundations and I’ve seen very positive results when a patient adopts healthier eating habits.
But what does that mean, exactly? Put simply, it’s about avoiding processed foods, favouring whole foods, a Mediterranean diet and aiming for diversity – not eating the same few meals and favourite foods week in, week out.
THE FOOD-MOOD LINK
Scientific studies are only just beginning to reveal the powerful link between food and our mental wellbeing. In 2017 a gold-standard randomised controlled test known as the SMILES trial put patients with severe depression who were already undergoing treatment on a modified Mediterranean diet of oily fish, colourful fruit and vegetables and wholegrains. Twelve weeks later, these patients had a much greater reduction in depressive symptoms than the control group who did not change their diet but were instead given social support. A third of the patients in the dietary support group even met the criteria for remission of major depression, compared to only eight per cent in the control group. Although small, this was a highly significant trial.
Researchers are trying to pinpoint exactly what it is about the diet that caused such an improvement, but I think multiple aspects of the Mediterranean diet are beneficial for our mental health. For example:
· The lack of sugars, highly processed food and the presence of wholefoods such as colourful fruit and vegetables have a calming effect on the immune and endocrine systems.
· Calming the immune system reduces inflammation, the root cause of many cases of depression.
· These foods will also have reduced ‘leaky gut’ and the amount of toxins getting into the bloodstream.
· Oily fish is rich in omega-3 fats, and we know they can have a positive effect on our mood.
· Mediterranean eating means consuming a highly diverse set of foods that will have an extremely positive effect on the gut microbiome, which in turn will send beneficial messages up to the brain.
GUT DIVERSITY RULES
The microbiome is the name given to the community of microbes – bacteria, viruses, fungi and parasites – that inhabit our guts. And unlike other bugs we might wish to eradicate, these are to be encouraged because they’re vital to our physical and mental health. They interact with each other, the body and the food we eat to determine everything from immunity to obesity and disease risk, mental wellbeing to hormone and blood-sugar balance.
If you have a hormone issue of any kind, looking after the health of your microbiome is key. It regulates, metabolises and even produces certain hormones and such is its influence, it’s even been called an endocrine organ.
Although we’re still trying to understand exactly what constitutes a healthy microbiome, we know diversity in our diets and so in our gut bacteria is crucial. The greater the number and type of bacterial strains in the gut, the healthier we’ll be and the more psychologically resilient. By bolstering our gut bugs and increasing their diversity, we can help protect ourselves from the impact of daily stressors.
Unfortunately, modern life isn’t conducive to a diverse gut profile. The Hadza tribe is Tanzania, for example, is still relatively untouched by modernity. And detailed analyses of their microbiomes compared to ours suggest that we in the West have lost up to 50 per cent of our gut-bug diversity. People in the Hadza community even have strains of bugs that are entirely absent in most of our gut microbiomes. And experts theorise that these missing microbes could explain why so many chronic non-communicable diseases like type 2 diabetes, obesity and inflammatory bowel disease, as well as food allergies and intolerances, are on the rise.
How has this happened? It turns out that these tribespeople, who still live the hunter-gatherer lifestyle we all once did, eat an incredible diversity of plant food. They have access to over 8,000 different plants and, on average, eat around 2,000 of these over the course of their lifetimes. Most of the average Western diet, meanwhile, comes from just three plants: corn, rice and wheat. The Hadza’s diverse diet provides them with bucketloads of fibre, which is exactly what our gut bugs want and need. Amazingly, they consume about 10 times the amount of fibre we do. This amounts to between 100g and 150g a day – up to 40 times the amount you’ll get from a bowl of so-called ‘high-fibre’ bran flakes.
EAT THE ALPHABET
Eating a diverse diet, rich in fibre, is one of the single best things we can do to live a more stress-free life. A diverse diet means a diverse and resilient microbiome. If we increase the variety of vegetables, low-glycaemic fruits (such as blueberries and cherries) and fibre-rich foods such as beans and legumes in our diet, we’re increasing the amount of fibre we’re eating. This will encourage the growth of different and happy gut bugs, sending signals to our brains that everything is good.
Eating the alphabet over 30 days will encourage such diversity. It will mean you’ll be getting lots of different kinds of crucial fibres, including inulin, which is found in leeks, onions, garlic and artichokes, and pectin, found in apples. A diverse diet will also be rich in a class of special nutrients called polyphenols. These help increase the growth of beneficial bacteria; one of the most polyphenolic-rich foods – berries – are a daily staple for the Hadza.
Put up a chart in your kitchen and see if you can eat the alphabet – 26 different plant foods (fruit, vegetables, pulses, nuts and seeds) – every month. So for ‘A’ you could have apples, artichokes, asparagus, apricots. For ‘B’ bananas, borlotti beans, Brazil nuts, berries… you get the idea. I think it’s a realistic and fun goal for all the family to aim for, in fact why not compete to be the first to tick off all 26?
One small caveat: if you are not used to eating this amount of fibre each day, I would suggest that you build up slowly to allow your gut – and your gut bugs – to adapt.
The Stress Solution: The 4 Steps To Reset Your Body, Mind, Relationships & Purpose, by Dr Rangan Chatterjee, is published by Penguin Life and available now.