The impact that gut health can have on the functionality of the brain is a topic that’s gained increasing interest in recent years.
In 2017, researchers in Ireland decided to explore whether the gut microbiome could be linked with anxiety disorders, coming to the conclusion that there may in fact be an association between the two.
When New York Times bestselling author Sarah Wilson decided to try eliminating sugar from her diet, she hoped that it would help alleviate the inflammation in her thyroid caused by Hashimoto’s disease, an autoimmune condition that left Wilson severely unwell on a daily basis.
However, it also had a tremendous effect on her mental health, which helped her gain a greater comprehension of how inflammation can be linked to anxiety.
“We now know that inflammation causes all of the contemporary metabolic diseases. There’s a lot of new science rolling in and it’s connecting inflammation with depression and anxiety,” Wilson tells The Independent.
“We now know that the gut-brain connection is the big area where we feel we’re going to get a better understanding of anxiety and depression.”
Approximately 95 per cent of the body’s store of serotonin is produced in the gut, Dr Siri Carpenter wrote for the American Psychological Association.
Serotonin is a neurotransmitter that is commonly believed to heavily influence an individual’s state of happiness.
With this in mind, it makes sense that a healthy gut would correspond to a positive mental state.
So, where does sugar fall into the picture?
According to Wilson, excessive consumption of sugar, or more specifically fructose, can wreak havoc in your gut.
Dr Sally Norton, founder of VavistaLife and former NHS consultant, agrees with this conclusion.
"Increasing evidence is showing that a high sugar diet can affect our healthy gut bacteria," she explains to The Independent.
"As many studies are now showing a link between our gut bacteria and our risk of various diseases, obesity and even our mental health. It's a very good reason to ditch sugar."
Wilson, who wrote The Anti-Anxiety Diet programme to accompany the launch of a book about anxiety called First, We Make the Beast Beautiful, explains that sugar affects the lining of the gut by triggering dysbiosis, which is when the bacteria in the gut is imbalanced and unstable.
In this instance, the bad bacteria in the gut overpowers the good bacteria, which the sugar then feeds on.
"Recent research has shown that our microbiome (i.e. the microorganisms in our gut) can play a huge role in whether or not we develop mental health conditions such as anxiety," Uxshely Chotai at The Food Psychology Clinic tells The Independent.
"One food known to contribute to the proliferation of 'bad' bacteria and fungi in the gut is sugar," she continues.
"Therefore, eating too much sugar could negatively affect your microbiome and make you more prone to mental health conditions such as anxiety."
Everyday table sugar consists of both fructose and glucose, the latter of which is already in the majority of foods that we consume.
However, as Wilson explains, the human body isn’t built with the natural ability to metabolise fructose efficiently.
“Our liver does with sugar what it does with alcohol, and that is to store it as visceral fat,” she says.
“A lot of people think tooth decay and a little bit of obesity is what sugar causes. However, I think anxiety is the most dangerous and terrifying aspect of sugar consumption that we’re only just starting to understand.”
Reducing one’s sugar intake is far easier said than done, as many people will have grown quite a strong dependency on it over the years.
People who regularly consume an excessive amount of sugar as part of their daily diet may experience extreme fluctuations in their mood, Chotai explains.
"As the sugar rushes through the bloodstream, it causes feelings of being 'high', but then as insulin is secreted to deal with all of the sugar this often causes a 'crash' and leads to feeling 'low' whilst also causing cravings for more sugar," she says.
"These extreme highs and lows can often leave a person feeling very unstable and more vulnerable to experiencing anxiety."
Wilson has laid out a two-week plan to help anyone who’s interested in going on a sugar detox in an effort to help their anxiety from giving it a try.
The first step that the author would recommend doing over the course of the two-week experiment is cutting out all liquid sugar.
This comes in many forms, including fizzy drinks, a number of sauces and fruit juice.
However, according to registered dietitian Helen Bond, consuming nutritious fruit juices can still be beneficial.
"At a time when the UK population is failing to achieve its five-a-day, it seems irresponsible to suggest removing pure fruit juice completely from diets," Ms Bond tells The Independent.
"As well as being a high source of vitamin C, and a source of both folate and potassium, Public Health England recommends 150ml of fruit juice as one of your five-a-day, which should be consumed alongside whole fruit and vegetables."
Next, Wilson advises opting for full-fat food as opposed to low-fat products, which according to Wilson is a “revelation to many people.”
She explains that the fat in low-fat products is often replaced with harmful, sugar-heavy ingredients that are not as wholesome as they may seem.
The author also recommends keeping an eye on one’s consumption of dried fruits, as many health bars made from dried fruits often contain extremely high quantities of sugar.
“I would say sometimes the unhealthiest places to eat are health food stores,” she professes.
Dr Norton also suggests not trying to replace sugar with sweeter artificial alternatives, as sweeteners can also cause havoc on your gut.