Sugary drinks linked to accelerated ageing

Research finds people who reported drinking a standard can of fizzy drink per day had DNA changes typical of cells 4.6 years older.

WE are accustomed to reading contradictory reports on how caffeine or alcohol can either enhance or damage our health as we age.

Now a new study suggesting a daily habit of downing soda might actually shorten our lifespan, has added further to the bad press sugary drinks have received in the past.

The researchers at the University of California in San Francisco found people who drank more sugary soda had shorter telomeres — the shoelace-like units of DNA that protect our cells from ageing.

Some scientists have begun to associate the length of telomeres with the prediction of lifespan, based on the way telomeres shorten on average, with chronological age.

The suggestion is that anything in our lifestyle that might cause telemores to shorten, could also influence how quickly we age — though much more work has yet to be done in this field.

In this case the researchers found that downing an eight-ounce (226 grams) daily serving of sugary soda corresponded to 1.9 years of additional cell ageing, while a daily 20-ounce serving (556.grams) was linked to 4.6 more years of ageing.

The study authors cautioned that they only compared telomere length and sugar sweetened soda consumption for each participant at a single point in time and that a further study aims to track people over several weeks, in real time, to explore the association more.

This is a point made by Sarah Keogh, spokesperson for Irish Nutrition and Dietetic Institute, who describes the data as a “flash in the pan”. “You need a 28-day food diary to properly analyse cause and effect – not just from one single moment. I wouldn’t be terrifying people off soft drinks yet,” she says.

She points out the researchers had found that all sugary drinks didn’t have the effect so “they kept going back, refining the research to get the result.” And she argues that some research is “interested in making the headlines.”

Irish people drink 150g-223g of fizzy drinks daily and our consumption is rising — and although those aged 50 to 80 are just very slightly below that average, their intake is also increasing.

While older people can metabolise soft drinks at the same rate as the younger population, it’s the calorie rich aspect of the drink that is unhealthy, as a contributor to weight gain and therefore unhealthy ageing, points out Keogh. “Soft drinks are empty calories — there is no nutrition in them — no vitamins, no protein — and 80% of over 55s in this country are obese or overweight.”

Sugary drinks are placed at the top of the Irish Food Safety Authority’s pyramid among the foods that are high in fat, sugar and salt with the warning that they offer no recommended servings from this group and if taken in excess they can be harmful.

The suggested portion for an occasional sugary drink is half a can – a much lower volume than the amounts consumed by the US study participants.

So, should older people just focus now on following these safe guidelines, regardless of the future outcome of research exploring links between such drinks and early ageing?

Tom Cotter, professor and chair of Biochemistry at the School of Biochemistry and Cell Biology at UCC agrees. He says he would be more concerned about the effects of sugary drinks on diseases such as obesity and diabetes which affect the quality of life of an older person, rather than the tenuous link with telomere shortening.

“Although the UCFS study was done at a reputable laboratory and the results published in a reputable journal, I find that because there was only one measurement time point taken a little disconcerting, ” he says.

“So while there may be a weak association, the biology of how this might actually work is not easy to understand at the moment either, so I am a little sceptical of the data. It will be interesting to see is a more rigorous study finds the same results.”

Cotter also point to obesity and type 2 diabetes as the big problems associated with excess sugar intake. Couple this with little or no exercise especially exacerbated, he says, in the over-50s — who don’t tend to take a lot of exercise — and there is a growing threat to ageing healthily.

“The amount of sugar in a can of cola is staggering — 10 sugar cubes or nine heaped teaspoons of sugar. I don’t think people realise how much sugar they are taking in,” he adds.

Whether the headline-grabbing initial research proves true in the longterm remains to be seen, but in the meantime all the evidence points to drinking just that odd can of soda – as always.