Fortifying energy drinks with a calcium concoction could reduce the damage they do to teeth, but it isn’t clear whether this would affect their taste.

Studies suggest that dental enamel, teeth’s protective outer covering, starts to dissolve when exposed to liquids with a pH of less than 5.5 – which most energy drinks fall well below.

Looking for a way to get around this, Erik Jácome at the State University of Rio Grande do Norte in Brazil and his colleagues added calcium and other minerals to traditional Red Bull energy drinks to see how this affected their pH.

The most promising combination was calcium, phosphorus and potassium, with the highest concentration taking the pH from 3.96 – that of the unmodified Red Bull – to 5.27, while dicalcium malate and calcium citrate malate both made the drinks more acidic.

Next, the researchers exposed samples of enamel from donated human teeth to the different fortified energy drinks for 2 minutes, then analysed them for changes in roughness and hardness, indicators of enamel erosion.

All of the calcium-fortified drinks had less of an effect on the samples’ roughness compared with unmodified Red Bull, despite some versions having a lower pH. The researchers think this is due to calcium’s role in remineralisation, the deposition of minerals into enamel to repair natural losses.

The formulation with 2.15 grams of the calcium-phosphorus-potassium combination and the one with 2.5 grams of dicalcium malate also preserved enamel hardness. But the former had the greatest overall protective effect, which the researchers put down to its dual action: supplying calcium and reducing acidity.

Future studies should try to identify the most effective form of calcium and the minimum concentration needed to reduce enamel erosion, the researchers write in their paper. They should also test whether calcium fortification affects a drink’s taste and if people would still consume it.

Ahead of further research, David Bartlett at King’s College London says it is too soon to change energy drink formulations. “Our approach is to recommend not drinking acidic foods or drinks between meals.” Consuming acidic food or drinks with meals is thought to be less damaging due to the increased saliva production washing some of the acid away.

A spokesperson from the British Soft Drinks Association says: “It’s worth reiterating that all soft drinks are safe to consume as part of a balanced diet and healthy lifestyle, which includes good dental hygiene.”

Red Bull didn’t respond to a request for comment.