Your gut and your mental health

Just like so many other things in your body, your brain is paramount to gut function and has a direct link to your intestines. For example, the very thought of eating can release the stomach’s juices before food gets there. On the flip side, a troubled intestine can send signals back to the brain. Therefore, a person’s stomach or intestinal distress can be the cause or the product of anxiety, stress, or depression.

The connection between your brain and your gut

Within your gastrointestinal tract is the enteric nervous system (ENS). Here, two layers of more than 100 million nerve cells quietly control your digestion, from swallowing to the release of enzymes that break down food to the control of blood flow that helps with nutrient absorption and elimination. 

While scientists have known of the ENS’ power to control digestion and the gut’s direct connection to our brain via the vagus nerve (a major component of the autonomic nervous system which enables you to breathe, digest food, and swallow automatically) for generations, recent research has uncovered just how much the ENS can trigger emotional shifts. 

Indeed, researchers are finding evidence that irritation in the gastrointestinal system may send signals to the central nervous system (CNS) that trigger mood changes. These findings can explain why those who suffer from irritable bowel syndrome (IBS) and functional bowel problems such as constipation, diarrhoea, bloating, pain and stomach upset have a higher chance of experiencing anxiety and depression. 

This revelation is particularly important because approximately 30-40 per cent of the population has functional bowel problems at some point in their lives!

While poor digestion may be impacting moods, the connection works the other way too. Given how closely your gut and brain are intertwined, it becomes easier to understand why you might feel nauseated before giving a presentation, or feel intestinal pain during times of stress. 

This doesn’t mean that functional gastrointestinal conditions are imagined or “all in your head.” Psychology combines with physical factors to cause inflammation, pain and other bowel symptoms and impact movement and contractions in the gut. In addition, many people with functional gastrointestinal disorders perceive pain more acutely than other people do because their brains are more responsive to pain signals from the gastrointestinal tract. Stress can make the existing pain seem even worse.

Your diet and your mental health 

While both professional mental health/or and dietary care can help those who are suffering from ongoing gut or mental health issues, our day-to-day diet can also shape how we feel both mentally and physically on a long-term basis. 

Felice Jacka, a nutritional psychiatrist at Deakin University in Australia and author of “Brain Changer: The Good Mental Health Diet” champions this philosophy. “The data regarding the importance of nutrition for mental and brain health is now extensive and highly consistent”, she says. 

Although there are many potential mechanisms, the Mediterranean diet has been shown to increase the diversity of gut bacteria, and reduce other physiological changes such as chronic inflammation that also seems to accompany depression.

This phenomenon has been demonstrated in multiple studies. In one such study from Spain, people eating the traditional Mediterranean diet were roughly half as likely to be diagnosed with depression over a four-year period. 

So, what is the Mediterranean diet? In generalised terms, it is a catch-all description that incorporates a diet that consists of the following:

• Whole grains and nuts
• Olive oil, avocados and other healthy oils
• Plenty of fish and seafood
• Lots of vegetables and fruit, particularly tomatoes Plenty of high-protein, low-fat natural yoghurt
• One or two serves of other dairy (milk and cheese) each day
• Small serves of red meat – but not every day
• Almost no sugar except the naturally occurring sugars found in fruit and vegetables and small amounts of honey

A typical day on the Mediterranean diet could be fruit with a small amount of granola (especially those granolas that have lots of nuts in them) and natural Greek yoghurt for breakfast. Alternatively, avocado, tomatoes and feta cheese (with or without an egg) on wholegrain toast is another good choice. 

For lunch, especially during winter, a hearty bowl of soup is a good idea. Soups that contain high protein vegetables such as carrot and cashew nut or minestrone and nuts, ensure a meal filling enough to sustain you through the afternoon. Adding in some Greek yoghurt or shredded chicken is also helpful if you are finding your energy levels dropping in the late afternoon.

Dinner time has lots of tasty possibilities. Seafood is always a winner on the Mediterranean diet, served with plenty of vegetables, rice or potatoes. Other dinner choices include meatballs, chicken breasts, moussaka and paella. If you fancy an occasional dessert, baking fruit like nectarines, peaches or apricots with honey is delicious. Or look for chocolate mousse recipes that use low-fat yoghurt and dark chocolate.

If you get hungry in the middle of the day, try avoiding heavily processed foods whenever you can. Nuts, fruit, vegetables, cheese, boiled eggs and yoghurt are all excellent choices.

While the Mediterranean diet is a simple example of healthy eating, not everyone (and every gut) is the same. Keeping a food diary for a week and correlating what you have eaten to your moods and bowel movements can be a good start into uncovering what foods have a positive and negative impact on your body. If you are struggling to find a solution, a mental health professional or a dietitian can help you come up with strategies to deal with the stressors in your life, and also ease your digestive discomforts.