March 21st 2017
Why the colour of your carbs could make all the difference
June 7th 2018 / 0 comment
Doctors are now suggesting that the colour of your carbs rather than their calories is significant in terms of health, weight loss and even fertility. Here's what to load your plate with
Carbs: from the humble spud to your farmhouse loaf to a plate of pasta, the warm comfort and satiety of the common carb has been demonised by many a diet book over the decades, and while most of us are more than aware that daily cake and a biscuit or 12 before bed probably isn’t the best route to glowing health, is eating your regular, everyday starchy carb really a recipe for health problems and weight gain?
A BBC show aired last night came to a ‘yes and no’ conclusion, with presenter of The Truth About Carbs, Dr Xand van Tulleken examining the health effects of different kinds of carbs, loosely deducing that “beige carbs are the ones the avoid”. He himself is a confirmed carb fan but lost six stone by learning to be smarter about the carbs he consumed. The team of doctors and overweight volunteers found that the beige and white varieties of starchy carbs such as potatoes, pasta, bread and rice caused blood sugar spikes and that the glucose contained within them was more likely to be stored as fat in the body.
Before you throw out the bread bin, however, the carb conviction wasn’t quite so clear-cut, as cooking style can seemingly dramatically affect how your body responds to starchy carbs.
Dr Xand showed that cooling carbs such as bread and pasta and subsequently reheating them before you eat them can increase the amount of resistant starch in your food. The cooling process makes starch more resistant to digestion due to the effect of the fat molecules in food attaching themselves to the starch molecules, meaning you get fewer calories from your slice of bread (our bodies only take around half the calories from resistant starches, says Dr Xand).
Resistant starch makes blood sugar surges less likely and also helps to feed the good bacteria in your digestive tract, in theory leading to a healthier gut microbiome. Top tip from Dr Xand for upping the resistant starch quotient of your bread - freeze it and then toast it straight from the freezer. He's now a convert to reheated porridge for breakfast - another top source of resistant starch.
Short of freezing all of your carbs before you eat them, however, the team advocated swapping out beige carbs for unprocessed, complex carbs that are naturally rich in resistant starch such as lentils, beans, wholegrains and pulses, to benefit from the additional vitamins, minerals and fibre that they bring to the table. Dr Xand also highlighted the health benefits of so-called “green” carbs - an umbrella term for fibre-rich fruit and vegetables rather than a prescriptive colour chart. These include veg such as butternut squash and celeriac as healthier swaps for potato and which are an important source of fibre that benefits everything from gut to gums.
While the programme showed impressive results in terms of patient weight loss (all the volunteers lost half a stone in just two weeks of swapping out white/beige carbs without counting calories), steadier blood sugar levels and even putting type 2 diabetes into remission in one case, some nutritional experts in the Twittersphere pointed out that comparing the sugar content of a jacket potato to a bowl of strawberries is possibly unhelpful given the very different nutritional profiles of the two, plus the fact that potato skins, when simply cooked, are in themselves fibrous, filling and rich in vitamin C in particular.
Could there be a link between refined carbs and fertility? It's certainly an area of emerging research. Dr Xand spoke to Grace Dugdale, reproductive biologist and researcher at the Leeds Centre for Reproductive Medicine, who is using low carb diets to help couples conceive. She explained that the sugar spike from excessive refined carbs damages the mitochondria of the egg and sperm, the battery that powers them.
As always, fearing a food group isn’t productive or healthy overall, but the evidence showed that most of us will benefit from increasing our intake of resistant starch and fibre (in the UK most of us barely reach half the recommended daily target of 30g of fibre a day), while considering green over beige more often could help us to become healthier as a nation. In fact, the findings of the programme are set to be rolled out to GPs as a way of helping patients avoid or potentially reverse type 2 diabetes, currently costing the NHS millions in medication.