Still knocking back green juices for breakfast?

Time for a rethink, as they may do more harm than good

Most health trends come and go, but some linger. One such lingerer is green juice, especially green vegetable juice. You can buy these off the shelf or make your own, if you have a juicer. But should you?

Green juices are usually made from various types of leafy greens, mainly spinach, with the addition of apple or some other fruit to make them more palatable. Because without heavy camouflage, their earthy bitterness would make them hard to swallow.

But flavour is no obstacle to vogue; green juices have been riding high for years. The hook is their purported cleansing and detoxifying qualities, crowned with a plant-based halo.  If you can put a spin on green sludge, you can put a spin on anything.

And well spun they are, commonly described as ‘packed’ with superfoods that ‘optimise health’ and ‘purify the system’. They give you an energy boost and reduce the risk of heart disease. On top of all that, they make you radiant as you lose weight -  ‘even though there is no strong scientific evidence to support these claims.’

The real science is there, but you won’t find it in the marketing material.

When you drink a green juice in the morning, you are loading your body with toxins called oxalates. If you do that for a prolonged period, you risk damaging your kidneys.

Oxalates, also known as oxalic acid, are naturally occurring toxic compounds found in plants, some more than others. We eat them in food and our bodies also make them. They are a waste product of the breakdown of ascorbic acid (vitamin C) and are excreted in urine.

A normal intake of oxalates from the diet is no cause for concern. The kidneys can deal with that. It’s when those levels exceed normal that problems arise. Juicing is a direct route to exceeding those levels.

A high oxalate intake results in increased oxalate concentration in urine, and over time this accumulation becomes a condition called hyperoxaluria.