Updated: Mar 21, 2019
We’re constantly encouraged to eat more fruit and veg.
Up to seven (or even ten) portions per day are believed to beneficial for our health.
Some might be tempted by a quick fix, starting the day with one big smoothie or juice.
For example, if I make a juice from a banana, an apple, a handful of berries, a carrot and a kiwi, wouldn’t that be five portions before I’ve even started my day?
Well, not exactly, unfortunately.
According to Public Health UK, fruit juices and smoothies count for only one portion, no matter how many fruits go into the making of it. And one juice or smoothie per day is the recommended limit.
Fruit is amazing… but with a few caveats
Fruit is fabulous. It’s full of minerals, vitamins, polyphenols and other phyto-compounds that help us to fight ageing and to stay sharp and healthy. Fruit is rich in carbs and water – just what our brains need to function at full power. Also, fruit is packed with dietary fibre, supporting our digestive system and feeding our microbiota (the beneficial bacteria that thrive in our guts).
What complicates the picture is that fruit is usually quite high in sugar. From a nutritional point of view, this is okay because whole fruit doesn’t tend to spike your blood glucose level, thanks to its fibre content which regulates glucose absorption into the bloodstream. But dentists don’t have the same opinion: eating lots of fruit means that you have a lot of sugar in contact with your teeth – mouth bacteria will thrive on it, putting your teeth at risk of decay.
Juices and smoothies - a concentrate sugar
With juices and smoothies, fruit sugar content becomes a nutritional concern. In the making of a juice or a smoothie, we use many pieces of fruit. While there is only around 10g of sugar in an orange, you can have as much as 30-40g in just 200ml of juice. This means you ingest a lot more sugar than you would if you were eating whole fruit. While this dose of sugar might be fabulous for an athlete after their workout, for most of us it puts an unnecessary strain on the pancreas, requiring a major insulin response to stabilise our blood glucose level.
An unfortunate loss of fibre
Another effect of juicing and making smoothies is that it reduces the fibre content of what we ingest. Juicing extracts all the sugar encapsulated into the matrix of the fruit and gets rid of all the fibre. In other words, juice is full of free sugars which will instantly translate into a big sugar rush without any fibre to tame its absorption.
Smoothies, which are the result of blending rather than juicing, are a bit better because the fibre is still there. However, the cell walls have been damaged and the benefit of the fibre has been partially lost.
Fruit vs. juice – a possible different effect on appetite and energy intake?
Finally, although the current state of research on this is not conclusive, it is possible that drinking juices and smoothies might have different effect on satiety and hunger compared to eating whole pieces of fruit and, therefore, could lead to eating more, at least for some people.
So, does this mean we should avoid drinking juices and smoothies?
No, not at all, as they are both fabulous way of getting a wide variety of nutrients that the Western diet tends to lack.
But one juice or smoothie per day is probably enough. Instead, pick up a whole fruit or, even better, top up your plate with vegetables – they tend to have far less sugar while bursting with phytochemicals and dietary fibre. And you will be full of beans!