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Damning New Research Links Diet Soft Drinks + Ultra-Processed Foods with Depression

Researchers from Harvard University have confirmed the mental health dangers of ultra-processed food, but their findings on soft drinks with artificial sweeteners comes as a shock to many. Your diet Coke might not be the healthy alternative you think it is! 

The research, published in JAMA Network Open, uncovered a concerning connection between the consumption of ultra-processed foods and an elevated risk of depression. These ultra-processed foods, described as energy-dense and highly palatable, raised alarm bells, particularly when it comes to artificially sweetened beverages. While the relationship between diet and depression has been a subject of growing interest – and we’ve seen a hefty amount of research linking excess sugar to the condition – the study by Harvard University delves into the largely unexplored territory of ultra-processed foods and their potential impact on mood disorders. Until now, no research has examined specific ultra-processed foods or ingredients or the timing of their consumption concerning the development of depression. This study aims to fill that knowledge gap – but the researchers also note that statistical associations do not automatically imply causation. For instance, when we’re under stress, we often turn to processed foods for convenience, potentially confounding the relationship between food and depression. In some cases, it may not be the food itself, but rather the predisposition to depression that leads individuals to opt for processed choices.

Why Artificially-Sweetened Drinks Raise Our Risk For Depression


The relationship between artificial sweeteners, such as those found in diet sodas like Coke Zero, and an increased risk of depression is a complex and not fully understood topic. While some studies have suggested a potential association between the consumption of artificial sweeteners and mood disorders, the exact mechanisms are not entirely clear. Here are some factors that have been proposed:
  • Neurotransmitter Effects: Some artificial sweeteners, like aspartame, have been linked to changes in neurotransmitter levels in the brain. Neurotransmitters, such as serotonin and dopamine, play a role in mood regulation. Altered neurotransmitter levels may potentially affect mood and contribute to depressive symptoms.
  • Gut-Brain Connection: Emerging research shows there is a bidirectional communication between the gut and the brain, known as the gut-brain axis. Changes in gut microbiota composition due to artificial sweetener consumption could impact this communication, potentially influencing mood and mental health.
  • Metabolic Changes: Artificial sweeteners may affect metabolism and appetite regulation. Some studies have suggested that artificial sweeteners could lead to increased cravings for sweet and calorie-dense foods, potentially contributing to mood disturbances.
  • Individual Variability: Responses to artificial sweeteners can vary widely from person to person. Some people may be more sensitive to the potential effects of artificial sweeteners on mood, while others may not experience any noticeable changes.
  • Association vs. Causation: It's important to note that most studies on this topic have found associations rather than direct causation. This means that while there may be a link between artificial sweeteners and depression, other factors, such as overall dietary patterns, lifestyle, and individual predispositions, could also play a role.
  • Reverse Causation: It's possible that people who are already at risk of depression or have depressive symptoms may be more likely to consume artificial sweeteners as a way to manage their calorie intake or sweet cravings.

As for ultra-processed food, we’ve already got a documented history of research linking the stuff with obesity, type 2 diabetes and, yes, depression. These diets promote inflammation in the gut and they also lead to concerning changes to gut bacteria. One of the major problems with excess sugar consumption is that it can lower microbial diversity, according to research, which in turns lowers immunity and stimulates the growth harmful bacteria. In particular, studies have found a high-sugar diet causes higher levels of Proteobacteria, and this is a marker for dysbiosis. Here’s where the effect on mental health comes in – an out of whack gut leaves has a knock-on effect with our hormones – and the research backs this concerning result. Studies have shown rates of depression are greater in those who eat a high-sugar diet, while another study shows anxiety is reported in higher numbers in people over 60 who consume sugar in excess. One study found people who drank 2 soft drinks a day had stress hormone levels 22% higher than those who did not, showing an undeniable link between mental health, the gut and sugar – from short-term symptoms like irritability and stress to more chronic illnesses that interfere with our lives. But with the average Aussie consuming 17 teaspoons of added sugar a day, there is reason for concern, especially considering our sky-high rates of mental health disorders. 

What Can You Do?

It’s no secret that a sugar habit is a tough one to beat – wherever you go, sugar is there. Unlike ditching alcohol or illicit drugs, there are few places where sugar is unwelcome. From birthday parties and functions to the office pantry, Sunday markets and the supermarket. Is it any wonder that so many of us find it hard to quit the stuff? That’s why it can also help to join a program like ours – our 8-Week Program is based on accountability, support and providing the essential resources to set you up for success. We’ll help you change the way you look at food – and that doesn’t mean you have to follow restrictive diets or miss out on your favourite foods; we believe you can still enjoy delicious food without jeopardising your health. With celebrity chef Sarah Glover on our panel of experts, you’ll have an array of fun recipes at your fingertips, along with our own exclusive armoury of simple, tasty and healthy recipes for everything from daily meals to impressive entertaining. We know it can be hard to stick to your health goals – especially when you’re trying to manage it alone. When you sign up with us, you’ll have access to clear-cut meal plans, community support and exclusive access to our sugar-free content. Here’s what’s on offer:

  1. 8 weeks of meal plans and shopping lists.
  2. 90+ member-only recipes.
  3. Community forums to share your journey.
  4. Support and guidance from the I Quit Sugar team.
  5. Exclusive content from our panel of experts.

So, if you’re ready to ditch sugar and the host of maladies that come with it, it’s not too late to join. We’d love to help you get started on your health journey. Sign up HERE today!

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