It’s always nice to see your suspicions confirmed by good, hard science. For many years doctors have been questioning the supposed health benefits of fruit juice, once thought of as the healthy alternative to fizzy drinks like cola and lemonade. Juice was one of your ‘five a day’; juice companies boasted of how many apples or oranges were in each glass of their product; tall Californians with great teeth were paraded as an example of what orange juice can do for a person.
It was probably the dentists who noticed first. I remember doing that experiment as a kid when you put a fallen-out milk tooth in a glass of cola, to see how it would be damaged overnight. I’d love to do the same experiment with orange juice. Fruit juice is, largely, concentrated sugar suspended in citric acid. It’s hard to imagine a cocktail of ingredients more likely to dissolve tooth enamel or kick off decay. All those children being fed ‘healthy’ juice instead of unhealthy cola were being set up for a lifetime of fillings.
And then there’s what all that sugar does to your waistline. The boasts of the juice companies about ‘five oranges in every glass’ should have alerted us. You eat five oranges, with all the associated pith and skin and fibre, and you’re full. You drink a glass of orange juice, and you want a sandwich, some crisps and maybe a biscuit to go with it. But the oranges and the juice contain the same amount of calories – you just don’t notice them in the juice. They don’t assuage your hunger.
There’s also the effect that a concentrated jolt of sugar has on your blood sugar regulation system. Humans weren’t built to process this kind of stuff – our bodies were built to digest lots of fibre, protein and complex carbohydrates, not liquid sugar. It overloads our system, does horrible things to insulin production and livers. In short, it does all the things you want to avoid if you don’t fancy type 2 diabetes.
So it was pleasing to see a study on bmj.com last week that looked at the effect of eating whole fruit, and of drinking fruit juice, on the risk of getting diabetes. It showed what I’ve often suspected – that drinking fruit juice increases your risk of diabetes, but eating whole fruits decreases it. (To see an easy-to-read summary, see the version we carried on BestHealth).
I’m less convinced by the findings that some fruits (blueberries, for example) had a bigger effect on reducing risk of diabetes than others, not least because the authors didn’t seem to review the data for socio-economic status confounding. Have you seen the price of blueberries for a tiny tub? You need to be pretty well-off not to mind paying for blueberries. Richer people tend to be healthier for all sorts of reasons, not necessarily relating to their choice of fruit.
Anyway, I’m taking it as a confirmation that eating apples is better than drinking apple juice. Even better, at this time of year, head for the hedgerows to pick blackberries (exercise as well as free healthy fruit).