Is kale really a superfood?
Yes! A member of the cabbage family, kale has dark green curled leaves and a fairly bitter taste – so may not be everyone's obvious first-choice vegetable. However, there are countless reasons to add it to your shopping trolley. 'The definition of a superfood is one that's rich in nutrients that offer numerous health benefits – so kale certainly lives up to this name,' says nutritionist Lily Soutter (www.lilysoutternutriton.com).
What are the health benefits of kale?
OK, let's list a few of those nutrients: kale is rich in vitamins, minerals, fibre and protein. It contains more iron than the equivalent weight of steak and more bone-building calcium than milk. 'With this outstanding nutrient profile, you can come close to getting your recommended daily allowance of anti-inflammatory vitamins A, C and K in just one serving,' says Soutter.
'What's more, there has been ample significant research into kale's high glucosinolate content,' she continues. 'These are antioxidants that have potent anti-cancer properties. Kale is also rich in sulphur compounds, which play a vital role in the detoxification process – making it the perfect food choice if you're in need of some liver support.'
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A few recent studies that have highlighted more of kale's benefits? Adding more green leafy vegetables, such as kale, to your diet can help slow cognitive decline and so reduce risk of Alzheimer's, according to scientists at the Rush University Medical Center in the US.
Researchers believe the effect may be due to the high vitamin K content. Boosting kale intake is also associated with a lower risk of developing glaucoma, a leading cause of blindness, says another study from Harvard Medical School.
Even ducks love it! In fact, we should be feeding them nutrient-rich kale instead of breadcrumbs, the Canal & Rivers Trust advises.
So is kale a super-healthy choice for everyone?
Actually, there are a few exceptions – one of which, perhaps surprisingly, is down to that high vitamin K content. Because vitamin K encourages the blood to clot, people who are taking anticoagulant medication to thin the blood are generally advised to steer clear of kale and other green, leafy vegetables.
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Another caveat? Kale is best avoided by anyone who suffers from hypothyroidism. 'This is due to its high goitrogen content,' explains Soutter. 'These are compounds that can suppress thyroid health by interfering with iodine uptake.'
And finally, Soutter advises, we should aim to buy organic: 'A recent report indicated that conventionally-grown kale is high in pesticides, making organic the choice to go for.'
Can you eat kale raw?
It can be difficult to digest when eaten raw, which may occasionally lead to bloating and stomach upsets. There's also that bitter taste to contend with, of course.
The solution? 'Kale is best eaten lightly steamed,' says Soutter. 'Not only does this reduce the bitterness, but it also lessens the goitrogen content – posing less of a threat to the thyroid. It allows the fibre-related components to do a better job of lowering cholesterol, too. To enhance the phytonutrient content, sprinkle lemon juice over chopped kale and allow it to sit for five minutes before steaming.'
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Alternatives to kale
Yes, there are plenty! 'Kale is a member of the wider cruciferous family, which also includes cauliflower, broccoli, Brussels sprouts and bok choy, as well as other cabbages,' says Soutter. 'All offer similar health benefits.'
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Indeed, broccoli is currently giving kale a real run for its money in the headline-grabbing superfoods stakes: it contains phenolic compounds that can significantly lower risk of cancer, heart disease and diabetes, according to a new study from the University of Illinois.
Don't like any of these veggies? Kale can also be taken in powder form, or as part of a supergreens capsule, available from health food stores and pharmacies nationwide. But it's always a good idea to check with your GP before taking any supplements.