Fruit juice is tasty stuff – but did you know that many juices contain more sugar than soda? Really and truly.
For instance, 12 ounces of Coke contain 40 grams of sugar; 12 ounces of apple juice, 42 grams. Grape juice is even higher: 60 grams of sugar.
This is why nutritionists say to get your fruit from the whole food, not the juice. This is better for your teeth, too. Whole fruit delivers fiber, vitamins, minerals and other nutrients along with sugar. Fruit juice delivers its nutrients in concentrated sugar. It’s also very acidic. Sugar + acids = a great recipe for enamel erosion and cavities.
So what to make of a new study published in Caries Research suggesting that both whole produce and their juice have an equally bad effect on your teeth?
Probably not much.
For starters, the study was very small. Just 10 subjects took part.
Volunteers wore removable mandibular appliances carrying pre-demineralised human enamel slabs and consumed one of the test foods 7 times a day for 10 days. The test foods were apples, oranges, grapes, carrots, and tomatoes, consumed either whole (sugars located intrinsically) or as a juice (extrinsic or free sugars). Raisins containing 64% sugars, but intrinsic by definition, were also studied. The mineral profile of the enamel slabs was studied before and after the test period using transverse microradiography and showed further demineralisation for all test foods, irrespective of the form of consumption. Significant demineralisation was also observed with raisins. No significant differences were found between the solid and juiced foods. In conclusion, sugars present intrinsically on consumption had a similar demineralising potential as free sugars and could not be considered less cariogenic.
According to Dr. Bicuspid’s summary of the paywall-protected article, solutions of 10% sorbitol and 10% sucrose were used as controls. It’s not at all clear whether the researchers took the rest of each participant’s diet into account. Even though they were told to remove the appliance when eating or drinking non-test foods, all foods affect the make-up of oral flora (microbes in the mouth).
It’s also not clear how the appliances were cleaned. Were they worn during brushing so the test enamel would be treated as that of every other tooth? If so, it would interfere with normal hygiene. But if they were taken out for cleaning, then the researchers wouldn’t be accurately mimicking oral conditions.
As it was, even low-sugar test foods such as carrots seemed to contribute to demineralization – something that surprised the researchers, too.
But perhaps the most telling detail is who funded the study: the Sugar Bureau and the Biscuit, Cake, Chocolate, and Confectionary sector of the Food and Drink Federation. Both are British trade groups.
Remember the candy-may-keep-kids-from-getting-fat study brought to us earlier this year by the National Confectioners Association?
Or maybe you heard the news earlier this month that apples are worse for your teeth than soft drinks – the sensationalistic popular spin put on tooth enamel research recently published in the Journal of Dentistry. As the Mail reported,
Eating apples can be up to four times more damaging to teeth than carbonated drinks, according to new research.
Wine and lager also increase the risk of dental damage but pickled onions and grapefruit, which are consumed less frequently, do not.
‘It is not only about what we eat, but how we eat it,’ says Professor David Bartlett, head of prosthodontics at King’s College London Dental Institute, who led the study.
And that’s true…insofar as it goes. But the confusion has already been spun, with soda seemingly sanctioned as “healthier” than apples, despite the fact that it’s nothing but sugar water, with zero nutritional value. Apples, on the other hand, are full of good-for-you stuff like fiber, antioxidants, minerals, enzymes and phytochemicals such as flavonoids and polyphenols.
For just as whole fruit is more than its sugars, it’s also more than its acidity – facts that studies such as these tend to obscure.