Are carbohydrates the secret to longevity?

 (Getty Images)
(Getty Images)

"Carbohydrates aren’t essential!" a flushed Jordan Peterson insisted recently on low-carb advocate and best-selling author Max Lugavere's podcast, The Genius Life. From Keto to Atkins to carnivore diets, carbohydrates have become a bogeyman of nutrition. It's easy to see why – many of the unhealthiest foods we consume, from refined sugars to processed white bread, are carbs. But this animosity often misses the mark and stems from a misunderstanding of what carbohydrates really are.

We live in an age of nutritional absolutism. First came the “truth” that carbs are evil; now we have the “post-truth”, celebrating them as the secret ingredient to longevity, as seen in a recent Times piece by the author of The Happiest Diet in the World, Giulia Crouch. Crouch touches upon an important point, discussing the prevalence of carbs in the diets of the world’s blue zones: a term coined by author and explorer Dan Buettner to denote regions with an above-average number of centenarians. Then again, blue zones may be a myth, as the recent Ig Nobel prize winner and UCL researcher, Dr Saul Newman, sought to demonstrate. (His research showed that poverty and pressure to commit pension fraud were far more reliable indicators of reaching ages over 100 than anything to do with lifestyle choices.)

One thing remains certain: carbohydrates are the most misunderstood ingredient on the plate. Carbohydrates break down into glucose: the body’s favourite source of energy. Complex carbohydrates – those from whole grains, legumes, and vegetables (are carbs, yes) – are broken down slowly, providing steady energy without the blood sugar spikes linked to refined carbohydrates. Whole-food carbs are nutrient-dense, providing vitamins, minerals, and antioxidants essential for cellular repair and disease prevention. A study for Cell demonstrates the enormous long-term benefits of high-carb diets, concluding from hundreds of samples that mid to high levels of unrefined carbohydrates can extend your lifespan. Dr Valter Longo, a co-author of the study, said the promoted diet “is intended as a nutritional lifestyle and not as a ‘weight-loss strategy’.”

 (Getty Images)
(Getty Images)

A blue zone staple

So why are we so carb-phobic? Giles Yeo, Professor of Molecular Neuroendocrinology at the University of Cambridge, and author of Gene Eating, says it’s down to people wanting “simple answers”. “With most things there is a kernel of truth: refined carbs are not great for you if eaten excessively. But what people have started to do is blame one thing, because it’s easier to give up just one thing.” Equally, in an age where beauty standards take precedence and people are looking for a quick fix to lose weight – with Ozempic readily available to those who can afford it – carbohydrates become an easy scapegoat. Dr Tim Spector, author of The Diet Myth and founder of the ZOE app, sees it as part of a shifting trend in the field of food science: “A couple of decades ago, fat was considered the enemy of good health. Now, carbs are in the crosshairs.”

Yet carbohydrates are a staple in the world’s Blue Zones, areas around the world where people live extraordinarily long lives. These include Ikaria in Greece, Okinawa in Japan, Loma Linda in California, Nicoya in Costa Rica, and Sardinia in Italy. In the Okinawan diet, carbohydrates account for 85% of the total, compared with 58% in the average modern Western diet. Okinawan women on average live to 87 years old, ten years longer than the average American woman.

Meanwhile, in Sardinia, where life expectancy is around 83 years, whole grains and legumes make up nearly half of the caloric intake. Their diet also includes lots of cheese, whole meal bread, and pasta. Buettner claims that when paired with beans – Pasta E Fagiole-style – you get a great mix of slow release and fast release energy. “The secret to a long life? Lots and lots of pasta!” he said excitedly to his Instagram followers last June. Onwards to Nicoya, Costa Rica, where the dietary staples are black beans, rice, and corn: whole foods high in fibre, protein and essential vitamins. Ikaria and Lorna Linda follow similarly unprocessed carb-oriented diets. But it's not just diet that determines these long lifespans. Community, general stress-free existence, and consistent exercise are all vital factors, Buettner argues.

Or not, says Dr Newman, whose research suggests the common thread between Blue Zones are lax checks and balances on local areas government records – for example, birth certificates. Many in so-called Blue Zones may be claiming to be much older than they are for reasons such as tax relief. The official Blue Zone website rebutted Newman’s claim, saying all their data had been through expert “validation”.

Newman has seen “Buettner’s responses and personal attacks”, and finds the term “validation” comical. “It’s as if the entire Olympics were based on a drug test called ‘validation’ that everyone passed,” he tells me, “before 82%-100% of athletes were later discovered as cheats.”

“Every Olympics, over and over again. Personally, I don’t need a fad diet, with some cultural appropriation sprinkled on top, to tell me the bleedingly obvious.” It’s not so black and white, says Tim Spector, who discussed Blue Zones with Buettner on the ZOE podcast. Spector thinks Newman’s work is probably “overstating things”, arguing “longevity in Blue Zones isn’t some quirk of statistical manipulation, as Dr Newman suggests.”

 (How to Live to 100)
(How to Live to 100)

So where does that leave carbohydrates? Dr Megan Rossi, AKA The Gut Health Doctor, cuts through the noise: "Instead of focusing on dietary recommendations from one person, it’s important that we follow the recommendations backed by many research studies – that being the Mediterranean diet." Not as sexy as Buettner's Blue Zone manifesto, or as dramatic as the carb-free crusade, but perhaps that's the point. Not all carbs were created equal – but the world’s longest living people aren’t surviving on steak alone. So next time you’re considering Keto, pop to Padella for some Pasta E Fagiole instead.