This morning I completed an online survey that was collecting data on consumption of fizzy drinks and what influences purchase. I answered rarely/never when asked how often do I consume soft fizzy drinks and, on those occasions, I would choose sparkling water with sugar-free cordial or diet/sugar-free soda. This got me thinking about the diet soda debate and I decided to put pen to paper in a bid to debunk some of the crazy myths that are circulating about diet fizzy drinks and their impact on our health.

“Diet soda drinks linked to strokes and dementia”

“Diet drinks are FAR more dangerous than drinks sweetened with sugar”

These quotes are just some of the scaremongering headlines that are in newspapers and online articles all over the world. But should we be scared? Surely these headlines are based on some degree of science?

At present, the science suggests that, in the doses that humans typically consume, diet drinks do not have negative effects on our health. In fact, diet drinks can improve health outcomes for people who use them as a replacement for high-sugar drinks, aiding weight loss and reducing the likelihood of comorbidities such as Type 2 Diabetes, high blood pressure (hypertension) and heart disease (cardiovascular disease). Moreover, diet drinks do not contribute to tooth decay.

From a nutrition perspective, swapping a sugar-sweetened beverage for a diet version is favourable. However, swapping a diet drink for water or a milk-based drink may be even more favourable. Water, as we know, is a natural drink and we have little reason to believe that it is bad for our health. Milk, while it may be higher in calories than milk or diet drinks, is much more nutrient-dense, providing protein, calcium and B-vitamins, among other nutrients.

In Europe, the European Food Safety Authority (EFSA) govern the ingredients that are added to our foods and the claims that are made on food labels. EFSA carry out risk assessments and evaluate the safety of sweeteners before they can be authorised for use in the European Union (EU). Aspartame is a commonly used artificial sweeteners used in diet drinks. Aspartame has been subjuct to rigorous safety assessments under EFSA and has been deemed safe for humans. EFSA has set an Acceptable Daily Intake (ADI) for each sweetener tested, including aspartame, and they can confirm that the average intake by humans is well within this threshold.

On a side note, you may notice “Contains a source of phenylalanine” on the labels of diet and sugar-free drinks. Phenylalanine (Phe) is an essential amino acid that the body requires. For the majority of people we can consume Phe freely. However, for people who have an inherited metabolic disorder called Phenylketonuria (PKU), freely consuming Phe can have severe consequenes on their health due to the absense of the enzyme (phenylalanine hydroxylase) that breaks down this amino acid. For more information on PKU, click here.

To conclude, this area of nutrition research is quite grey at present, with many conflicting messages. It may be a case in years to come that the consensus will be different but right now, if we critically examine the research, there is no reason to suggest that diet drinks cannot be consumed as part of a balanced diet. Anyone who claims that diet drinks are “so bad” and judge you for drinking them are unlikely to have done their homework. My question to these opinionated people is always “Can I have the reference for that paper please?”