Diet drinks: Not all they're cracked up to be

23:55, Mar 05 2014
FIZZING UP: While diet drinks may seem like the healthy option, various health issues appear to be associated with regular consumption.

You may think choosing a diet soft drink over a can of sugary fizz is a healthy choice. After all, they contain virtually no kilojoules right? Think again.

There is a growing body of evidence that points to negative health outcomes associated with regularly consuming diet drinks, including damage to teeth, weight gain, kidney disease and weakened bones.

No wonder sales of diet drinks are falling faster than regular soft drinks - a trend reported by The Wall Street Journal in December.

"The biggest drag is health fears about artificial sweeteners found in diet soda - mainly aspartame, but also sucralose and acesulfame potassium," it said.

Melanie McGrice, Advanced Accredited Practising Dietitian and spokeswoman for the Dietitians Association of Australia, believes it is time to swap the chemical cocktail for healthier options, from unsweetened tea and coffee to just plain water.

She outlines some of the health risks. Diet soft drinks "are quite high in acid and so they can be very bad for your teeth and bones. Caffeinated drinks will impair the absorption of calcium and so that could certainly have an impact on bone density," she says.


Australian nutritionist Dr Rosemary Stanton agrees.

"Diet soft drinks are at least as acidic as regular soft drinks and therefore damage tooth enamel. They maintain the taste for sweet drinks and they contain the same artificial colourings, flavourings and preservatives as regular soft drinks."

She adds: "There is some evidence (although it is conflicted by other studies which do not find problems) that diet drinks have some adverse effects. For example, chronic kidney disease. Asthma and wheeze in children increased when mothers used diet drinks during pregnancy. An altered response to sweet taste may occur in the brain and could lead to people seeking more rewards - that is, a desire to enjoy more foods, especially sweet foods. This in turn could account for the association between diet drinks and obesity, or it is possible that those who are already overweight drink diet drinks. The research on adverse effects still has some way to go."

Research is inconclusive about the impact of diet drinks on weight, says McGrice. "Even though they don't contain any kilojoules there are a few studies that suggest that they may possibly have an impact on weight, so I guess it's a 'watch this space situation'."

McGrice recommends that if you really must have a diet beverage then have a drink of water or milk afterwards.

"That would be the best thing particularly before going to bed. And the other thing is that they provide very little nutritional value. Instead of diet drinks we would rather see people drinking water or low fat milk, which are going to provide important nutrients. They are the best drinks for hydration and nutrition."

She says as a dietician she is often surprised by what people do not know about nutrition. "I would love to see more being done to educate people about the benefits of water and reduced fat milk instead of diet drinks."

The 2013 Australian Dietary Guidelines discuss the advantages of drinking water over many commercially available drinks, including sugar-sweetened or low-kilojoule soft drinks, "sports" and "energy" drinks, according to a spokesperson for the National Health and Medical Research Council.

If you would like more advice about your diet, make an appointment to see an accredited practising dietitian.

Sydney Morning Herald