Gerry Gajadharsingh writes:
“I’ve written a lot about fruit juices before and I think most people are getting it, but here is the latest regarding a small glass of orange juice and cancer risk. Drinking the occasional fruit juice is fine just don’t regularly consume it thinking you are being healthy. The next time a patient comes in and tries to tell me about their healthy smoothies, I’ll try and not to roll my eyes.”
A daily small glass of orange juice could increase the risk of cancer, research has suggested.
A study of 100,000 people showed that consuming as little as 10 grams of sugar a day in drinks — the equivalent of 100ml of orange juice — was associated with an 18 per cent rise in the overall risk of getting cancer.
For women, the likelihood of breast cancer in particular increased by about 22 per cent. The study looked at any drink that contained more than 5 per cent sugar, including pure fruit juices and fizzy drinks. On average, every extra 100ml consumed was linked to an 18 per cent increase in the risk of being diagnosed with cancer.
A daily cup of tea with two teaspoons of sugar would also meet the threshold. Mathilde Touvier, of the epidemiology and statistics research centre at the Sorbonne Paris Cité, who led the study, said that an occasional sweet drink was not a problem but that sugary tea every day was “not a good idea”.
The researchers urged a cautious interpretation of the study, which could not prove cause and effect.
The report, in The BMJ, looked at 100,000 healthy French adults with an average age of 42. They filled in questionnaires to track their diet for three days every two years. They were followed for an average of five years.
Other well-known risk factors for cancer such as age, sex, educational level, family history of the disease, smoking status and physical activity, were taken into account.
Nearly 2,200 cases of cancer were diagnosed — or about 22 per 1,000 people. Graham Wheeler, of the UCL Cancer Trials Centre, who was not involved with the study, said: “If 1,000 similar participants increased their daily sugary drink intake by 100ml, we would expect the number of cancer cases to rise from 22 to 26 per 1,000 people over a five-year period.
“This assumes that there is a genuine causal link between sugary drink intake and developing cancer, and this still needs further research.”
The study was observational, which means that it could not prove that soft drinks cause cancer. Other chemicals such as additives in soft drinks may play a role, the researchers said.
It has been speculated that sugar consumption affects visceral fat, which is stored around organs such as the liver, as well as blood sugar and inflammation, all of which have been linked to a higher risk of cancer.
Sugary drinks also contribute to obesity, which is a strong risk factor for many cancers. When the drinks were split into fruit juices and other sugary drinks, the consumption of both was associated with a higher overall risk of cancer. No association was found between the drinks and prostate and colorectal cancers.
Artificially sweetened diet drinks were also not associated with a heightened risk. However, the scientists again called for caution in interpreting this finding because of a low consumption among the subjects.
Ian Johnson, of the Quadram Institute Bioscience, in Norwich, said: “Total consumption of sugary drinks might be acting as a marker for some other unidentified aspect of a dietary pattern linked to higher risk of cancer.
“But if we assume that a real causal link between consumption of sugary drinks and cancer does exist, then we can speculate that the mechanism may be related to an increased risk of obesity, which is a well-established risk-factor for various types of cancer, or perhaps to the frequent spikes in blood sugar levels that may be associated with habitual consumption of such drinks.”
A small glass of fruit juice has about 10 grams of sugar, equivalent to:
- A cup of tea with two sugars
- Just over a quarter of a can of cola, which has 35g of sugar in total
- About one third of a small can of Red Bull energy drink, which contains 26g of sugar in total