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13 May 2021

The truth about health drinks

From Kefir to Kombucha to juice shots - we look at the evidence behind popular health drinks and if their wellness claims stack up
Shefalee Loth

Supermarkets, health food shops and even coffee shops are filled with teas, lattes, shots and other drinks claiming to offer health benefits above and beyond a standard coffee or glass of juice. 

But are these claims valid? And do we need to be including these products in our diets for optimum health?

Here we look at some of the most popular products and uncover the facts behind the headline-inducing health claims.

Turmeric drinks

Turmeric, the bright yellow spice, is a popular addition to many drinks from milky teas and lattes to juice shots.

Turmeric contains curcumin, an antioxidant that's claimed to have anti-inflammatory properties and to reduce joint pains and your risk of chronic diseases such as diabetes and cancer.

However the evidence available doesn't support these claims, and the European Food Safety Authority (EFSA) concluded in 2017 that a cause and effect relationship between the consumption of curcumin and maintenance of joint health had not been established. 

This is because many of the studies these claims are based on are animal studies and we can't assume the same will be seen in humans. They also contained very high doses of curcumin, between 1,000 and 4,000mg taken at least once a day.

Comparatively, the levels of curcumin in turmeric are very low (around 2-3%) and it's poorly absorbed. This means that a drink containing a teaspoon of turmeric will contain around 60mg of curcumin. As such it's hard to get high-enough levels of curcumin through diet for it to have a medicinal effect.

While drinking a latte or juice containing turmeric is perfectly safe, you should be wary of taking high dose turmeric or curcumin supplements which are increasingly popular. EFSA has set a safe acceptable daily intake of up to 3mg of curcumin per kg of body weight a day. That means a 65kg woman could safely consume 195mg curcumin a day.

Green tea and matcha powder

Green tea is made by adding hot water to green tea leaves whereas matcha powder is made from green tea leaves that are dried and ground into concentrated powder. Matcha powder is added to milk to make matcha lattes or hot water to make matcha tea.  

Green tea leaves are high in a polyphenol, catechin, which is an antioxidant. Claims around the benefits of green tea include that it helps increase metabolism so it is often touted as helping weight loss; however this claim has been disproven. 

Other research shows it might help reduce cholesterol and blood pressure, and the risk of liver disease, stroke, dementia and certain types of cancer. However overall there's not enough evidence to prove this or support using green tea to help with these conditions. Cancer Research UK says 'there is not enough reliable evidence to say [green tea] might prevent certain cancers'.

Green tea contains tannins (as does black tea) which interferes with iron absorption so shouldn't be drunk with meals. It also contains caffeine (though not as much as black tea or coffee) so drinking too much can affect your sleep.

Be wary of high-dose supplements of green tea or matcha that contain 800mg of EGCG (one of the catechins) - these have been shown to cause serious liver damage. But green tea and matcha drinks are perfectly safe to drink in moderation.

Charcoal lattes

Charcoal lattes are popular on social media - the dark grey or black drink is very photogenic.

Charcoal lattes are usually made up of milk, a flavouring such as vanilla or honey and a teaspoon of activated charcoal powder. Claims include that charcoal can help you detox and cleanse, and that it helps digestion. 

Activated charcoal absorbs chemicals in our gut and because of this is used to treat cases of poisoning and drug overdoses. It binds to the chemical and removes it from the gut, thereby reducing absorption.

But activated charcoal isn't selective in what it binds to so it also restricts the absorption of good nutrients such as calcium and even oral medications, reducing their effectiveness.

While the dose of activated charcoal in a latte won't be as high as when it is used in a medical emergency, there's not enough strong scientific evidence to support its use in lattes and other foods.

If you're on any oral prescription or over-the-counter medicine you should avoid food and drinks that contain it.

Kefir

Kefir is fermented milk which is made by mixing milk with kefir grains that contain live yeast and lactic acid bacteria. The end product contains live bacteria similar to those found in probiotic supplements. 

It tastes like a liquid yoghurt (and increasingly is available in yoghurt form too, as well as drinks) and is a good source of calcium and protein. Kefir Water is a dairy-free option, but watch out for sugar content added for flavour.

The scientific evidence behind kefir and other probiotics is limited and these products have no authorised health claims. However some people report they help with gut and digestive issues by improving the balance of bacteria in the gut.

Kombucha

Kombucha is another fermented product but this time made from tea. A live culture of bacteria and yeast, known as a SCOBY, is added to sweetened black or green tea. The sugar in the tea feeds the bacteria and allows them to multiply.

Like kefir, kombucha contains live bacteria but the evidence behind the benefits of these drinks is still limited. Because the tea is sweetened, Kombucha can often be high in sugar so check the label when choosing.

You can also feed the friendly bacteria in your gut by eating a varied diet that contains a range of fibre-rich foods such as onions, garlic, leeks, oats, apples and bananas.

Find our more in our full guide to probiotics and gut health.

Apple cider vinegar

Many people swear by downing a 'shot' of apple cider vinegar in the morning or before a meal. 

The claimed health benefits of drinking apple cider vinegar range from boosting weight loss to lowering blood sugar levels to improving digestion and immunity. 

However the studies that show these results aren't very robust and there isn't a strong body of evidence to support these claims - for every study that shows a benefit there's another that doesn't.

While the benefits of apple cider vinegar may not be proven, there is a real risk of consuming it on a daily basis, especially by drinking it - tooth erosion. 

To minimise dental damage, it's best to consume it as part of a meal, for example as part of a salad dressing.

Teas and infusions

Wander down the tea aisle and you'll see plenty of health-focused teas promising to detox you, support your immune system and metabolism - and more besides. But don't be fooled, many of these claims are overblown or an expensive way to get your fix.

Twinings Cold Infuse Metabolism teabags contain zinc which is needed to metabolise carbohydrates but it won't boost your metabolism. At 37p a teabag it's a pricey way to get this nutrient which is found in meat, fish, dairy foods, and wholegrains and cereals. 

Products labelled as 'detox' are banned from being advertised in the UK and EU as they imply a health benefit. However Pukka teas and Twinings still sell 'Detox' teas. This is because under the current regulation these can continue to be sold until 2022.

These teas won't rid your body of 'toxins' or do anything your body doesn't already automatically do. We have an in-built detox system - our liver and kidneys.

Vitamin drinks

Flavoured waters with added vitamins tend to be low calorie drinks with added vitamins or minerals, for example vitamins C and D. 

However they're not the most efficient way to get your nutrients - you'd need to drink 500ml of the mango and passionfruit 'Get More' vitamin D to get your daily dose of vitamin D at £1 a serving. 

You could get the same from a vitamin D supplement costing as little as 3p. This serving would also give you 15% of your daily calcium requirement. 

V Water pomegranate and blueberry contains vitamins C and E, selenium and zinc -500ml of it will give you all the vitamin C you need for the day and 75% of the zinc you need but set you back £1.35. 

Vitamin C and zinc are widely found in foods such as citrus fruits, green leafy veg, meat and fish so it's not necessary to buy these drinks.

Smoothies 

Smoothies are a staple of the health drinks market and they can be a good way to increase your nutrient intake thanks to the blend of different fruits, veg and extras such as yoghurt or oats.

However they can only count towards one portion of your five-a-day regardless of how much you drink. This is because while the smoothie will contain the vitamins and minerals from the fruit and veg contained in it, the blending process breaks down much of the fibre. 

Smoothies can also be high in sugar because of all the fruit in them. Once blended or juiced this sugar counts as free sugars which are damaging to teeth and which we should limit our intake of.

If you're making your own, try to use mainly vegetables with one or two fruits to reduce the sugar content.

5 things you need to know before embracing a juice or smoothie diet - see more tips from our nutrition expert

Juice shots

Small bottles (60-100ml) of juice that cost around £2 each are becoming increasingly popular. 

They usually contain ingredients such as ginger and turmeric and are sold as a ‘boost’ or ‘lift’ to your day. While much is made of the anti-inflammatory or antioxidant properties of these ingredients the benefits aren’t proven. 

These drinks don’t offer anything you wouldn’t get from eating the foods and spices contained in them - you’d also get more fibre from eating the whole fruit and vegetable as opposed to them being juiced. 

Some also have vitamins added to them but again this is an expensive way to boost your nutrient intake.

Which? verdict on health drinks

If you're on medication you should avoid charcoal lattes, and other foods and drinks containing charcoal. 

If you like any of these other drinks and juices, there's no harm in continuing to drink them. However they are very unlikely to offer any benefits above what you would get from a healthy, varied diet, despite often costing a lot more than alternatives. 

It's also worth keeping an eye on sugar levels and if you are going to drink them, do so with meals to protect your teeth.