Defending carbohydrates – As published in a recent report

August 23, 2024

Carb avoidance may have negative effects, so a recent report has revealed.

Recent studies have suggested that carb avoidance, particularly popular for weight-loss, may have negative effects from artery clogging, unbalanced gut microbiome and even ageing of our organs.

“Low-carb diets, for so long flavour of the month as a miracle weight-loss fix, are being eyed with growing scepticism in the world of nutrition,” says Alex Ruani, researcher in nutrition science at University College London and chief science educator at the Health Sciences Academy.

A study published this month, Javier Gonzalez, professor in the Centre for Health, Nutrition and Metabolism at the University of Bath, looked at the effects of either cutting carbs or reducing sugar. After a 12 week study, results published in Cell Reports Medicine showed that both groups lost excess body fat — the keto dieters shedding an average of 2.9kg and the low-sugar group an average 2.1 kg — without changing their exercise levels.

However, Blood tests revealed that their levels of a protein called apolipoprotein B, an artery clogger, were 26 per cent higher than those of the control group. The low-density lipoprotein (LDL) “bad” cholesterol scores were also raised by 16 per cent in the keto group, whereas those just cutting excess sugar fared well, their LDL cholesterol dropping 10 per cent lower than the control group.

And while fasting blood-sugar levels taken first thing in the morning were lowest in the keto group, which is beneficial when it comes to staving off metabolic disorders, Gonzalez says the diet also seemed to reduce their body’s ability to handle any carbs from a meal. “Low-carb diets are notoriously difficult to stick to. And as soon as carbs passed the lips of the keto dieters, their blood-sugar levels shot up a lot.”

Part of the problem when we cut down on carbs is that, by default, our intake of dietary fibre also declines — and low fibre intakes are linked to heart disease, type 2 diabetes and obesity. Wholegrain bread, cereals and pasta, as well as fruit and vegetables, are among the biggest providers of fibre in our diets. Our gut microbiome, which thrives on fibre as a food source for beneficial bacteria, suffers when they are excluded. 

Over time the obliteration of good gut bugs could potentially exacerbate long-term health issues, resulting in an increased risk of digestive disorders such as irritable bowel disease, intestinal infections and a weakened immune function.

That said, where the underlying goal of a low carb diet is a state of ketosis, can be beneficial for some conditions, according to Dr Linia Patel, a researcher in the department of clinical sciences and community health at the Università degli Studi di Milano in Italy and a spokesperson for the British Dietetic Association. “Keto diets are prescribed for people with epilepsy as they seem to reduce their symptoms and cut down on seizure frequency,” she says. “And there is also a bit of evidence they might benefit other neurological disorders, such as Parkinson’s disease and Alzheimer’s disease.” 

Patel says that, as a rough guide, we should aim for a handful of carbohydrate-containing foods at each main meal and should shun high sugar and processed varieties, opting for wholegrain options where possible.

Read our Post on Good Carbs Bad Carbs.