For instance in one study, 12 overweight women drank 500ml of orange juice every day for four weeks. At the end of the trial period, the women had significantly lower blood pressure. Although the composition of the gut microbiome itself did not change, the bacteria upped their production of chemicals known as short-chain fatty acids (SCFAs) – which are known to reduce inflammation.
Which orange juice is best?Â
However, both nutritionists the BBC spoke to were keen to emphasise that whole fruit remains the preferred option and the healthier choice. Not only do oranges contain more fibre, but they also retain more flavonoids that are so beneficial for health. Polyphenols are the wider class of plant compounds to which flavonoids belong.
“When you eat a fresh orange, the vitamin C and some of the more oxygen-sensitive nutrients [such as flavonoids] don’t oxidise as much because they’re still encapsulated within the fibre,” says Amati. “Whereas when you juice an orange, you destroy the food matrix and those nutrients become exposed to the air, and so they oxidise, which reduces their potency.”
As fibre is so hard to digest, it also helps to carry polyphenols and flavonoids all the way to the colon where they can be feasted on by beneficial microbes, enhancing their benefits.Â
However, if juice is your preferred choice, then freshly squeezed oranges at home or in a restaurant will retain more health benefits than commercially available juice, as more fibre will remain. Industrially produced orange juice, on the other hand, will have been pasteurised and heated – which could kill off some of the more oxygen-sensitive nutrients, such as vitamin C.Â