Amelia Moseley, BTN Reporter: Have you ever noticed that food can impact your mood?
Person: Ah, more unhealthy foods at the start of the day, usually affects me more, I'll be more down, I'll be able to concentrate less.
Person: Bakery foods like brownies, cakes, donuts, they, they keep me up for ages.
Person: If I'm not eating well, I might feel like grumpy more or like, not in the mood to do things.
Person: Yeah, same thing sort of like eat lots of sugar, and then you just sort of crash after.
Person: If you're eating bad foods over a long period of time, that takes a toll mentally, you feel not as good as you would if you're eating healthier, or nourishing your body.
Person: If I eat like super processed foods, I do feel that I'm like more tired and...
Person: Yeah that’s true.
Person: Lethargic. But I do like need a bit of this as well in the afternoons, a little treat. As I get older, I realised that there's such a clear link between your brain and your diet.
Well, according to scientists, like Professor Nick Spencer, that gut-brain connection goes even deeper than just your average afternoon sugar crash. So when we talk about our guts, what exactly do we mean?
Professor Nick Spencer, Neurophysiologist, Flinders University: We're talking about really a conglomerate of different cell types and really different organs. Oesophagus, stomach, small intestine, and colon. And that's what we call the gastrointestinal tract.
So Nick, when it comes to our gut, it's not always seen as the most like, glamorous or even the most important part of our body. Why is it that we should be paying more attention to it?
Nick: So, you're absolutely right Amelia. Ah, people used to just think of the gut as an organ to absorb nutrients and provide energy and expel waste. What gathering and emerging data suggests is that connections between the gut and brain, and brain and gut, can have a major bearing on our health and wellbeing, particularly mental health.
So how do you actually know all of this? How have you observed it?
Nick: The first thing that most people may not realise is that the gut’s actually evolved with its own nervous system. So, we call that the enteric nervous system. The significance of that is, is that the gut is actually able to work on its own, so we call it the, the second brain. So a lot of our research is ‘how does the second brain communicate with the first brain?’ These are actually some of the sensory nerve endings that we've photographed in the gut wall.
Our so called ‘second brain’ contains literally hundreds of millions of individual neurons. And while Nick and other researchers are trying to work out what all these nerve pathways are doing, they know that what we eat, and then what happens here could be having more of an impact on us than we realise.
Nick: What we eat is a way in which we provide the necessary ingredients for ourselves. So we need the ingredients to make the right neurotransmitters to make us feel right.
Dr Megan Lee, Senior Teaching Fellow, Nutritional Psychiatry, Bond University: Chocolate is a plant!
Dr. Megan Lee is in the field of nutritional psychiatry and says another thing to think about is our gut bacteria.
Megan: So we are actually 99 percent bacteria and only 1 percent human. So everything about us is all about this bacteria inside of us. So we have billions and billions of good and bad bacteria that live our gut and our stomach, and those guts, when they are happy, we are happy!
In fact, almost all of our body’s supply of serotonin is manufactured by our gut bacteria. And serotonin is one of the body's natural chemicals that control our mood. And that brings us back to those nerve pathways.
Megan: We’re just starting to see that 90 percent of the feel-good chemicals that we produce in our body, are actually produced in our gut and then sent kind of up to the brain.
When it comes to what we put in our gut, you probably won't be surprised to hear that there's one kind of food that isn't so great for our mood – stuff that's ultra processed.
Megan: Those are foods that has been changed so dramatically that it no longer really resembles the food that it once was. And what we're finding in the research is that the higher your consumption of ultra processed foods, the more likely you are to experience negative mental health and a decrease in mood.
Okay, that makes sense and so it's just kind of the way our bodies have evolved, I guess, because we wouldn't have had, like um ultra processed food back when we were cave people?
Megan: Exactly. And there are only a few tribes left in the world, the Hadza and the Maasai tribes in Africa who have never been exposed to ultra processed foods, and a lot of scientists and researchers are doing research on them, and their gut bacteria is so much more involved. So the more fruits, veg, nuts, seeds, raw whole foods that you eat, the better your mood and the happier your brain.
Megan, is it okay though, to sometimes just have a sweet treat or have takeout?
Megan: Absolutely. So if you have a fine balance between 80 percent wholefoods, maybe 20 percent of ultra processed foods, then you're doing a lot better than most!
That reminds me, there's one final gut question I really need answered.
Nick: You know how people say you have like a second stomach and it's your dessert stomach. Is that a real thing?
Nick: Okay, so um, well obviously we only have one stomach...
Right.
Nick: Cows do have two stomachs. Anatomically.
It’s good to know. Appreciate it.