May 15th 2018
Nightshade vegetables: should you avoid them?
September 12th 2017 / 0 comment
The nightshade family of vegetables has been blamed for causing everything from joint inflammation to calcium deficiency, but should we really be cutting them from our diets?
Sure, calling a group of vegetables “the nightshade family” makes said veg sound sinister and dangerous, but given that we’re repeatedly told to shovel down our vegetables by public health bodies and nutritional experts (whether that be three or ten servings a day- seemingly no one can decide), how can such humble plants possibly be dangerous? And what is a nightshade anyway? We did some digging.
The nightshade family tree
Dr Duane Mellor, Senior Lecturer in Human Nutrition at Coventry University, explains what makes a nightshade vegetable:
“It’s a vegetable linked to the Solanaceae family of plants, which includes potato, tomatoes, aubergine, peppers, and if you include fruit, even goji berries, which of course have also been lauded as a superfood (even though superfoods don’t really exist).”
Noted, and so far, so healthy sounding, so why on earth are the likes of Gisele and elite football players reducing their intake of nightshade vegetables or banning them altogether?
Nutrition Scientist Sarah Coe of the British Nutrition Foundation underlines some perceived downsides of consuming nightshade vegetables:
“Nightshade vegetables contain bitter-tasting alkaloids, chemicals that occur naturally in the plant to protect it from pests. Some alkaloids have been linked to increased inflammation, but there are very few studies that have investigated this link. Those that have studied the subject have found no evidence for any negative health outcomes thus far.”
So the argument for nightshade vegetables spiking inflammation is shaky, and Duane emphasises that, in fact, nightshade vegetables could well have an anti-inflammatory effect:
“At a stretch fried potato, eaten in the form of crisps or chips, could be argued as being a problem, but this is more related to how they are eaten and the fact they are fried. Dietary patterns rich in tomatoes (especially cooked in olive oil with onions and garlic, known as sofrito) are a key component of the Mediterranean diet, which is linked to lower inflammation and a reduced risk of heart disease. Aubergines were included as part of the Portfolio Diet which in Canadian research has been shown to reduce cholesterol by over a fifth.”
That’s inflammation put to bed then, but how about the notion that nightshade vegetables can block the absorption of calcium in the body (the reasoning for Liverpool football players’ limiting them)? Duane doesn’t mince his words on this one:
“This is a myth, based on the false belief that they are high in oxalic acid which can reduce calcium absorption.”
The bottom line
For the great majority of us, nightshades should be warmly welcomed onto the family dining table, as Sarah qualifies:
“Some people may show sensitivity to the chemicals in nightshades, as you can in almost any case of food allergy or intolerance. The scientific evidence available does not support limiting or avoiding nightshade vegetables in the diet for most people.”
Clearly Duane concurs:
“For most people these vegetables should be eaten more, rather than less, to increase intakes of the key vitamins, minerals and fibre that they contain. Nightshade vegetables have been part of what we consider to be the Mediterranean diet since the 17th century, and any encouragements to avoid them amount to just another restrictive way of eating based on rumour and assumption. The only benefit may be eating a few less chips, but the negative of avoiding many vegetables associated with a long and healthy life is not a good one.”
See you down the allotment.