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23 Feb 2020

Five things you need to know about juice and smoothie diets

Juices and smoothies have their perks, but take lofty health claims with a pinch of salt and beware sky-high sugar contents

If you're looking to get more fruit and veg in your diet, juices and smoothies can seem like a tempting quick fix.

Manufacturers of pricey juicers and blenders make lots of claims about how their products can help you achieve your nutrition goals, but it's worth being aware that it's not quite that simple.

Depending on what ingredients you use and how often you're drinking juice drinks and smoothies, you could be missing out on vital parts of a balanced diet and potentially wreaking havoc on your teeth.

From cold-pressed juice to 'nutrient extraction', we reveal which juicing and blending myths are hot air and what to be aware of if incorporating these drinks into your diet.

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1. Cold-pressed juice isn't necessarily better for you

Manufacturers of cold-pressed juices and juicers like to claim it's the gold standard of nutrient preservation.

For certain nutrients, this rings true. By keeping the ingredients cold during processing, temperature-sensitive nutrients, such as vitamin C and B-complex, are better preserved.

But others aren't converted into forms we can easily absorb; some nutrients actually fare better after being heated up - like those found in tomatoes, for example.

When we tested juices and smoothies made in different types of juicer and blender, we found that no single method universally extracted more nutrients. You can see more in our guide to juicer and blender nutrition claims.

Juice also has much less fibre than fruit and vegetables in their raw form and a higher glycaemic index - a measure of how a food raises blood sugar levels.

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2. Blenders don't magically extract nutrients

Lots of blender manufacturers make lofty claims of what their blenders can do for you.

Nutribullet says its blenders turn whole foods into 'NutriBlasts', unlocking the nutrients within and 'giving you the health benefits of eating the whole fruit and/or vegetable - fibre, pulp, seeds, skins and all'.

It's true that blending can help you get ingredients that are otherwise tricky to digest into your diet, such nutrient-rich flax, hemp or chia seeds.

But it still strips out some of the fibre from your food and converts healthy sugars in fruit into free sugars.

It's good practice to limit the amount of sugary fruits you put in your smoothies. Adding in seeds, nuts, dairy or green veg can help.

If you want to add these ingredients and still end up with a smooth blend, make sure you pick one of our Best Buy blenders.

3. Vacuum blending does have some benefits

Vacuum blenders suck air out of the jug before blending, something they claim helps to preserve nutrients by preventing oxidisation.

It sounds far-fetched, but the science does support this theory. Enzymes in fruit, such as apples and avocados, degrade when in contact with air - this is what makes them turn brown when sliced open.

Water-soluble vitamins such as vitamin C and B-complex are also affected. But, if you can take the air out of the equation, you can theoretically stop this process from happening.

Any nutritional claims should be taken with a pinch of salt, though. It's near-impossible to prove that nutrients are better retained. And, as we've seen, not all nutrients benefit from being processed in this way.

When we made a smoothie in an ordinary blender and a vacuum blender, we found the vacuum version was smoother and initially slightly brighter in colour, but it didn't seem to stay fresh for longer than the ordinary version.

One thing vacuum blenders do tend to achieve, though, is a much smoother blend. This is because there are less bubbles in the mix.

If you're keen on an ultra-silky blend, check out our vacuum blender reviews to find the best options.

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4. You can have too much of a good thing

Smoothies and juices can be a great way to incorporate a wider range of fruit and veg into your diet, and to pack in nutrient-rich extras such as yoghurt, nuts and seeds.

However, it's all too easy to rack up lots of sugar very quickly - whether through homemade or store-bought drinks.

This is why the 'serving size' of store-bought smoothies and juices, such as those from Innocent or Naked, is only 150ml despite the bottles often being much bigger.

Even the smallest home blenders have a capacity of about 600ml and it's easy to overload the container - before you know it you could have made a deceptively calorific and sugary smoothie that's all too easy to drink in one go. For example, a banana and peanut butter smoothie can clock in at well over 400 calories and 30g of sugar.

Juices and smoothies can only count towards one of your daily fruit and veg goals, too. So downing multiple portions won't help you reach the recommended five portions a day.

Aim to keep the fruit contents of your smoothies low and balance them by adding in seeds, nuts, dairy (such as yoghurt or oat milk) and veg.

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5. Take care of your teeth

The sugar content of smoothies and juices can be as high as a can of coke. This can cause the enamel on your teeth to erode, which could lead to staining and cavities in the long term.

By contrast, chewing whole, fresh fruit stimulates the production of saliva, cleansing the mouth and helping to counteract the bacteria that occur there naturally.

To limit damage, aim to drink smoothies or juices with meals, ideally with a straw to avoid as much contact with the teeth as possible. You can also swill your mouth with water after drinking.

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