The Stress Solution Read online

  But after prolonged discussion I convinced her to try. I helped her come up with five simple meals that she’d enjoy – natural, minimally processed food with a wide variety of colourful vegetables. With the support of her family, she started to cook fresh every day at home. Six weeks later I discovered that the change had been utterly remarkable. Her mood had become more stable and her daily anxiety attacks had reduced by around 70 per cent. All this simply by changing what she put into her mouth.

  DE-STRESS YOUR DIET

  Before we get too carried away, this is not a story of miraculous reversal. Biba’s problems didn’t vanish completely. Rather, this is a story about stress being a feed-forward cycle. Biba’s trauma had triggered changes in her body which made her crave highly processed food. This food threw her body into stress state and this stress state amplified her mental health problems further, which caused yet more changes in her body, and so the spiral went around and around. My intervention was enough to break that cycle. After a couple of months Biba realized she was able to cope emotionally with the psychotherapy she’d previously found so hard. Ultimately, her life was transformed, and it all started with her diet.

  Seeing the change in Biba and reading about all the new research that’s been coming out on the links between nutrition and stress have led me to completely rethink my previous assumptions. And not a moment too soon. According to the mental health charity Mind, one in four of us is going to experience a mental health problem in any given year. And yet at a recent lecture in Bristol I asked over a hundred GPs, ‘How many of you discuss food with patients who complain of stress and anxiety?’ and was disappointed to see only about 5 per cent of them put their hands up. There is an urgent need for medical training to catch up with the latest advances in scientific research.

  The response I got at the lecture was also a product of how reductionist our cultural thinking around food usually is. When we look at our meals, we need to start asking ourselves, ‘Is this going to give my brain the information it needs to thrive? Or is it going to make it think it’s under attack and cause the body to throw its defences up?’ This is the choice we make every time we put something in our mouths.

  HOW FOOD BECOMES INFORMATION

  We’re used to thinking of food simply as fuel. It goes in one end, the body breaks it down, the protein goes to our muscles, the carbohydrate gives us energy, the fat goes to our thighs, bum and belly, then all the stuff it doesn’t want is deposited out the other end. We’re not used to thinking of that cheese-and-pickle baguette as something akin to a radio station or a book. But, effectively, that’s what it is. The body reads information from that baguette then sends it to the brain. The nature of that information is the result of a three-way interaction between your food, the bugs that live in your gut and your immune system. Whenever you eat, those three systems talk to each other. The conclusion of all that complex biological chatter is then sent to the brain. It’s information, telling it whether or not the body is under attack from bad food.

  THE GUT–BRAIN AXIS

  When we talk about having a ‘gut feeling’ about something, we reveal that we’ve always intuitively known that there’s a direct line of communication between the digestive system and the brain. There are in fact several communication super-highways between them and, collectively, they’re known as the gut–brain axis. Research is ongoing in this area but so far we know that some of the information flows from the gut to the brain via the lymphatic system and some of it travels via little messenger cells called cytokines that are made in the gut and travel to the brain through the blood. Some, however, is sent directly to the brain via the longest nerve in the body, the vagus nerve.

  WHAT HAPPENS IN VAGUS

  The vagus nerve is one of the most important highways in the gut–brain axis. It emerges from a part of the brainstem called the medulla oblongata, a region that plays a crucial role in automatic functions such as breathing and sneezing. From there it takes a long and winding route to get down into the gut. And it’s bi-directional, which means it carries information from the brain down to the gut, but also from the gut back up to the brain.

  A key part of that information stream comes from an incredible and mysterious world that we didn’t have much understanding of until recently. Your gut is inhabited by massive populations of different bugs – bacteria, viruses, fungi, parasites and their respective genetic material – that, in total, weigh about as much as the human brain. This hidden world is our gut microbiome.

  These bugs interact with the body, with the food we eat and with each other. These interactions determine many aspects of our health and mental wellbeing. As amazing as it sounds, if we treat these microscopic organisms poorly, they can make us feel anxious and depressed. If we treat them well, they can lighten our mood.

  Studies on animals find that an absence of gut bugs increases our reactivity to stress. This has led to some scientists calling them ‘our brain’s peacekeepers’. Keep them happy and they keep the peace. So, how do we keep our gut bugs happy? By cutting out the highly processed and refined foods that damage them and feeding them with food that nourishes them. This includes colourful plant-derived wholefoods rich in fibre such as vegetables, fruits, legumes and pulses. Feasting on these kinds of foods means they can make highly valuable compounds such as short-chain fatty acids (SCFAs) that can communicate with the brain. These SCFAs can travel directly to the brain via the bloodstream. But they can also send signals via the vagus nerve. They send flashes of information to the brain telling it that everything is OK.

  YOUR INNER FOOD TESTER

  But it’s not only your gut bugs and your brain that are involved in this constant conversation about whether you’re safe or in danger. Your immune system is also involved in the chatter.

  Part of the immune system’s job is to sample every single thing we eat, checking whether it’s OK or potentially harmful. If we eat bad food, it responds by triggering a process called inflammation.

  This is one of our basic and ancient evolved responses to stress. It puts our bodies in a state of heightened alert, ready to fend off anything foreign and unwanted that might invade our systems as the result of an injury such as a bite from a predator, say, or a dirty cut.

  Humans are designed to experience inflammation in short, sharp doses. As we learned earlier, having it over a longer period of time – what’s known as chronic inflammation – can be extremely bad for us. Chronic inflammation is at the heart of many serious complaints that I see in my surgery every single day, whether it is insulin resistance, type 2 diabetes, obesity, high blood pressure or depression.

  The food that we eat, our gut microbiome and our immune system are intimately linked. The right kind of food promotes a healthy microbiome, which in turn helps to train and educate the immune system, making it much more likely to produce a critical type of cells called ‘regulatory T-cells’. These cells help to dial down the immune-system response, reducing inflammation in the first place and keeping us out of stress state and firmly locked in thrive.

  LEAKY GUT

  Another way that diet can throw us into stress state is by causing what’s colloquially known as ‘leaky gut’. This happens when poor lifestyle and food choices damage the integrity of a very delicate but critical barrier that sits between the gut and the rest of the body, making it too permeable. This increased permeability allows harmful substances from inside the gut to slip through and gain access to our bloodstream.

  Among the worst of these substances are lipopolysaccharides (LPSs), which sit on the outer coat of certain gut bugs. If the LPSs stay inside your gut, all is fine. But you really don’t want this stuff in your blood. If you were to inject LPSs directly into your veins, your body would start to shut down and you’d enter septic shock. Of course, when you develop a leaky gut you don’t suffer such instantaneous effects. It’s much more insidious than that. Every day your gut will leak tiny amounts of LPSs into your blood and that will put your immune system on high alert
, causing inflammation and pushing your body out of thrive state and into stress state. We know that LPSs can contribute to a number of different health problems including depression, low mood and anxiety.

  THE MODERN WORLD’S ASSAULT ON OUR GUTS

  Most of your gut bugs live in the depths of your large intestine, but rather than it being a safe, damp cave system for them to securely thrive in, your bugs are actually very vulnerable down there. Modern life, it seems, is at war with our bugs. Highly processed foods, such as ready meals, biscuits, many breakfast cereals and some highly processed breads, can have a terrible effect on their health. Some additives, emulsifiers, pesticides and artificial sweeteners can decimate them as well as antibiotics used in food production. When this happens, stressful signals will flash up to the brain via the vagus nerve and other pathways in the gut–brain axis. This is yet another mechanism by which poor nutrition can trigger us to feel psychologically unwell.

  Popular drugs, including heartburn medications and antibiotics, can have a similar annihilating effect. While some people’s microbiomes are able to recover from a course of antibiotics in about a week, others seem to be far less robust. Some can take two years or more to recover, if at all. As a GP, when I’m looking at the history of patients who are struggling with their mental health and anxiety, I now take a detailed history of how many antibiotics they’ve used.

  I’m seeing more and more of a correlation between those who have high anxiety or problems with stress and those who have had a huge intake of antibiotics, particularly as a child. I try to go as far back as I can into their medical history. Even being born via Caesarean section can lead to potential problems – incredibly, most of our microbiome is seeded when we travel through our mother’s vaginal canal.

  THINGS THAT CAN DAMAGE THE MICROBIOME

  • Eating highly processed food

  • Drinking too much alcohol

  • Smoking

  • Drinking sugary soft drinks

  • A lack of diversity in your diet

  • Overuse of antibiotics and other medications

  • Psychological stress

  • Over-exercising

  • Lack of sleep

  • C-section birth

  • Living in urban environments

  • Hyper-cleanliness and the use of too many antibacterials

  • Eating foods containing emulsifiers (chemicals that are added to lots of highly processed foods, to keep the texture consistent)

  • Artificial sweeteners – animal studies have shown that they can be detrimental to our gut microbes. While more research takes place, I urge caution.

  If several of these apply to you, please don’t worry. In the twenty-first century, pretty much all of us will have experienced at least one, if not many more, of these attacks on our microbiome. We can’t change the past, but we can make positive changes to improve our gut health in the future. Following the recommendations in this chapter will help you feed and repair your microbiome, and growing evidence suggests that high-quality probiotics can be a helpful adjunct for some.

  THE SCIENCE OF EATING HAPPY

  Scientific studies are only just beginning to reveal the powerful link between food and our mental wellbeing. In 2017 a gold-standard randomized 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. Remarkably, about one-third of the patients in the dietary support group had met the criteria for remission of major depression, compared to only 8 per cent in the control group. This was a hugely significant reduction.

  Although only sixty-seven patients took part in it, there’s no question that this was a highly significant trial, and it’s one I expect to see fully replicated in larger sample sizes over the coming years. Researchers are already trying to figure out what exactly it is about the diet that caused such an improvement, but I don’t think they’ll end up finding just one thing.

  Multiple aspects of this diet are beneficial for our mental health. The lack of highly processed food and the presence of wholefoods such as colourful fruit and vegetables will have had a calming effect on the immune system. This would have reduced inflammation, the root cause of many cases of depression. These foods will also have reduced ‘leaky gut’ and the amount of toxic LPSs that are getting into the bloodstream. Oily fish is rich in omega-3 fats, and we know they can have a positive effect on our mood. In addition, the Mediterranean diet contains 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.

  DIVERSITY RULES

  Although we’re still trying to understand exactly what a healthy microbiome looks like, one thing that’s become clear is that diversity in your diet and so in your gut bacteria is crucial. The more diverse your gut bacteria, the healthier you’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 Micro Stress Doses (MSDs).

  Unfortunately, all the evidence suggests that modern life is especially bad at supplying us with diversity (see box here). Recently, some staggering statistics have been coming out of Tanzania, where detailed studies have been carried out on populations that are still relatively untouched by modernity. The Hadza community is one such tribe. Analyses of their microbiomes 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. As Martin Blaser theorized in his brilliant Missing Microbes, those missing gut bugs may be a big part of the reason 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 ten times the amount of fibre we do. This amounts to between 100g and 150g a day – up to forty times the amount you’ll get from a bowl of so-called ‘high-fibre’ bran flakes.

  EATING 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 your brain that everything is good.

  Eating the alphabet over thirty 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, which is 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. Cocoa is known for being rich in a particular group of polyphenols called flavonoids which encourage the growth of healthy bacteria.

  Put up a chart in your kitchen and see if you can eat the alphabet every month. I think a realistic goal is to aim for twenty-six different plant foods a month.

  Please use the chart overleaf as a guide only – feel free to tweak! The goal is t
o have at least twenty-six different plant foods every single month. Why not involve your friends and family in this as well?

  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!

  IRRITABLE BOWEL SYNDROME

  Irritable bowel syndrome (IBS) affects up to 20 per cent of the UK population and can be a major cause of distress and disability for the people who suffer it. The symptoms can be widespread and include abdominal pain and cramps, bloating and nausea. Many sufferers experience a sudden, overwhelming urge to go to the toilet and, when they do, it’s often diarrhoea. Others get horrendously constipated.

  I recently treated a patient whose IBS was so severe it ended up derailing her career. Belinda was a researcher at a broadcast company and the layout of her office was such that she had to pass her boss’s desk every time she wanted to use the bathroom. She became so distressed by the number of times she had to walk past him she quit. I decided to put her on what is called a ‘low FODMAP’ diet under the supervision of a nutrition professional. FODMAP stands for ‘fermentable oligosaccharides, disaccharides, monosaccharides and polyols’ – they’re easily fermentable sugars that are found in certain foods, like leeks, garlic, onions as well as apples, bread and milk. Over the past few years it has become clear that eating large amounts of FODMAPs can cause symptoms to flare up in some IBS sufferers. By removing them from Belinda’s diet, I saw a quick improvement.