So, is it time for you to cut back on kale?
As that most super of superfoods gets some bad press, Ella Walker leafs through the facts about whether it's really all that good for us
Once it got plastered with the ultimate seal of "healthy" approval, being granted "superfood" status, it was all supermarkets could do to keep up with demand for the stuff.
Unlikely as it may have once seemed, kale - that dark green, iron-clad, curly-leafed cousin of the cabbage - had become one of THE must-have items of the decade, with celebs leading the way in sipping on green juices (and documenting it all on their Instagram feeds).
From raw salads, to grass-coloured smoothies or doused in butter and garlic and stir fried, kale is king.
Or is that about to become 'was king'?
New York yoga and wellness guru Lauren Imparato has announced to the world that kale might not be as good for us as we thought.
She explains that the green stuff can, in fact, cause bloating, kidney stones and can even affect your thyroid gland, slowing your metabolic rate.
But is she right, and are the online rumours that kale is 'toxic', true?
THE GOOD NEWS
Let's look at the facts. It is nutritionally accurate that kale is packed with nutrients, minerals, folic acid, fibre and vitamin A, C and K - as all good green vegetables are. There are even traces of calcium and protein to be gained from munching on it.
Award-winning nutritional therapist and author of The De-Stress Effect, Charlotte Watts, says: "Kale is one of the brassica family - including broccoli and cabbage - that is high in detoxifying sulphur compounds called glucosinolates.
"The dark green also shows rich content of fat-soluble antioxidant carotenoids that protect our fatty areas, like eyes, skin, liver and brain.
"They are also mineral and chlorophyll rich."
So far, so healthy.
THE BAD NEWS
Watts explains that humans have evolved with "plenty of leaves in our diet", so we shouldn't automatically start binning bags of kale, but admits there are issues when it comes to digesting the vegetable.
"Humans have been cooking foods for around 300,000 years and this is how we were able to digest difficult plant fibres, as we have smaller digestive tracts and less chewing time to direct energy towards our large brains. Our closest relative, the chimpanzee, can spend up to 14 hours a day chewing," she says.
"So the recent trend for juicing oceans of kale can be a bit harsh on the digestive tract, as the fibres are neither chewed (and so mixed in with digesting saliva), or broken down with long and slow cooking processes, like in a stew - my preference for darker greens.
"It is also goitrogenic when raw, (which means it) negatively affects the thyroid gland, so my advice for those with thyroid issues is to avoid all brassica veg raw."
As with all foods, from burgers to kale, moderation - and sensible preparation - is key.
"Kale is a superfood, but so is the rest of what nature can provide - we need a variety of foods," says Watts.
"Kale is wonderfully beneficial, but you can't live on the stuff, and I don't recommend juicing loads each day. Foods we easily eat raw, like celery, cucumber and carrot, are better for juices. No food is just "good" or "bad" and we need to mix it all up."
- If you are concerned about kidney stones, bloating and your thyroid gland, always seek medical advice