Coconut water was the ultimate superfood of 2014 - first the celebrities were glugging it by the gallon, then the hipsters caught on. Now it's stocked in most UK newsagents.
But as we approach the new year, it seems there's a new drink du jour.
Birch extract has been used as a herbal remedy for centuries throughout the world. Many claim it to provide a plethora of health benefits - not all of which have yet been backed up by significant research.
Advocates claim birch water aids kidney function, reduces cholesterol and even eliminates cellulite.
"Extracts from the leaves have been used in herbal supplement combinations to aid detox, kidney function and bladder health by supporting the body’s natural elimination of toxins and impurities – it partly does this by acting as a diuretic," Alice Mackintosh, a nutritionist at The Food Doctor tells HuffPost UK Lifestyle.
"The tree also contains compounds called saponins that have been shown to help reduce cholesterol by binding and removing excess levels from the body - they also have anti-inflammatory effects in the body."
Mackintosh says it's important to differentiate between health benefits of a herbal tincture (which is made from the bark and leaves of the tree) and the health benefits provided by the water extracted from a tree trunk.
"Though water from the trunk may well contain hydrating electrolytes such as potassium, as well as a number of other health giving nutrients, there may not be sufficient levels to promise some of the miracles currently being proclaimed," she says.
Ann Ashworth, a spokesperson from the British Dietetic Association is also sceptical about the benefits of birch water due to the insufficient evidence on how it works for humans and if it can be harmful in any way.
"If thinking about stopping conventional medical treatment in favour of birch tree water, please talk about it with your doctor first," she adds.
Nutritionist Karen Poole points out that the popular Paleo diet advises people to avoid saponins, as although they may inhibit the absorption of fats, they can also trigger an immune response and damage the gut wall.
"Birch water is like any new fad - one shoe does not fit all. You have to take into account individual habits, concerns and lifestyle and view birch water as part of an overall approach to healthy living that adopts many healthy attitudes that compliment each other," she adds.
More research is needed around the health benefits of birch water, but at the very least the sweet-tasting liquid provides an alternative to fizzy drinks and sugar-laden, processed fruit juices.
Mackintosh warns: "Some of the birch waters available on the market also contains added sugars – so watch out for these and always check the label."
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