November 30, 2020
Health gurus and influencers can often be seen starting their day by downing a glass of green juice, saying that it gives them a ‘vitamin boost,’ and helps them ‘get in their fruits and veggies’.
However, the science says that juices and smoothies may not be as ‘healthy’ as they may appear. You’re often much better off eating whole fruit and vegetables instead.
We take a look at the impact that juicing can have on your metabolism, and discover how to include fresh fruit and vegetable juices in your diet in a way that works best for you.
“Juicing is not a magic bullet to fix all your nutritional woes,” says Kirstin, our resident nutritionist. “You aren’t going to solve a vitamin deficiency by drinking a big gulp of juice if you do not have a healthy, diverse diet for the rest of the day.”
“If you are already getting a healthy, diverse diet, you’re unlikely to be deficient in most vitamins. So there’s no additional health benefit to juicing your fruits and vegetables in the hope of getting extra nutrients because your body will only absorb the vitamins you need and no more.
“Vitamin C and all of the B vitamins are water-soluble, so if you consume them in excess, you will just pee them out,” says Kirstin.
So we’re unlikely to get a vitamin boost from juices. But surely they can’t do any harm?
Our foods aren’t a simple packet of nutrients. They’re made of complex chemical and biological structures known as the food matrix.
When we eat, our bodies have to digest these structures to release the nutrients and energy inside.
Whole plant foods consist of cells with fibrous walls, which your body must break down to release vitamins, minerals, and energy in the form of starch or sugar.
“When you juice fruit, you're breaking up that food matrix and releasing all the nutrients straight away, so your body doesn’t have to do any of the work and the sugar can head right into your bloodstream,” says Kirstin.
“Depending on how your body responds to carbohydrates, this means that some people can have a high blood sugar spike after drinking juices.”
Blood sugar spikes and crashes can leave you feeling hungry and tired. And when they happen repeatedly, they can damage your metabolic health, increasing the risk of conditions including obesity and type 2 diabetes.
And because juicing also removes healthy fiber - which is great for your gut (and your poop!) - the best way to get your fruit and veggies is to eat rather than drink them.
So, should you squeeze the juice out of your diet for good?
At ZOE, we don’t say you can never have a particular food or drink if you enjoy it. It’s about being smarter about how and when you eat, based on your unique biology.
Our ZOE at home test allows you to discover how your body responds to different foods, providing personalized food scores that take into account your blood sugar responses, the amount of fiber in food, and how processed they are. Based on these scores, you can find foods - and drinks - that work best for your body. And because we are all unique, the size of the effect varies from person to person.
For example, for our nutritionist Abi an apple scores an 88 (enjoy freely), while apple juice only scores a 40 (enjoy in moderation). However, someone else may score 76 for an apple and just 27 for juice, which is likely to trigger an unhealthy blood sugar response.
Because juicing breaks down the food matrix and releases sugar more quickly, drinking lots of juice may cause unhealthy blood sugar responses for some people, while it may not be a problem for others.
If you do want to drink your fruit and vegetables, Kirstin suggests trying a blended smoothie, which maintains more of the food matrix and fiber compared to a juice.
Smart food combinations can also help, so what you add to a smoothie or eat with your juice can make a difference to your personal nutritional responses.
“If you want to have juice in a particular meal, you may want to think about how you can build a good meal so your overall ZOE score will be higher, and you’re not getting a big blood sugar spike from your juice alone,” says Kirstin.
Take the ZOE home test to find out how you can reach your best health while still enjoying your favorite foods.