Eating more carbs could turn back your biological clock

For decades, bread, pasta and potatoes have been demonised, blamed for piling on the pounds, sending blood sugar soaring and sabotaging our hopes of healthy ageing.

But now, new research from the University of Sydney suggests eating more of them could not only help us age better, but may even help turn back the biological clock.

The study divided adults aged 65 to 75 into four groups and put each group on a different diet for four weeks. Those who followed the “omnivorous high-carbohydrate diet” – where 14 per cent of their calories came from protein, 28 to 29 per cent from fat and 53 per cent from carbohydrates – showed the strongest improvement in markers used to estimate biological age.

People on this diet finished, on average, looking about three and a half years “younger” than at the start of the study.

“People fear carbs, but we need to reframe them,” says Emma Bardwell, a nutritionist and author of The Fibre Effect. “Quality carbs give us fibre and a wide range of micronutrients and plant compounds. They’re vital to help us age well.”

Which carbs should you choose more of after 50?

“When many people think of carbs, they conflate them with junk food – pizza, croissants and cakes,” says Bardwell. “We’ve been far too quick to lump them all together. There’s a world of difference between a bowl of chickpeas and a packet of biscuits.”

In the new study, participants ate minimally processed food, with their carbs coming from fruits, vegetables, legumes such as beans and lentils, and wholegrains, “such as oats, barley, wholegrain bread, brown rice and quinoa”, she says. These are the carbs we should be prioritising in our diet as we age.

In white or refined carbs, including white bread, pasta and rice, most of the nutrients and fibre have been lost, so they cause our blood sugar to spike after eating them.

“With minimally processed foods, most of the natural structure is left intact, which means the body has to work much harder to break them down,” she says. “They release their energy more slowly and don’t elevate your blood sugar as sharply.”

Over time, blood sugar spikes can cause chronic inflammation, leading to problems including obesity, heart disease, type 2 diabetes and stroke.

Can a high-carb diet help you age well?

“One of the biggest advantages of quality carbs is their fibre content,” says Bardwell. “Fibre not only makes meals more satisfying, but also supports gut health and helps regulate cholesterol and blood glucose, which are particularly important over the age of 50.”

Research consistently shows a link between adequate fibre intake and a reduced risk of all-cause mortality, coronary heart disease, stroke, type 2 diabetes and colon cancer.

One way quality carbohydrates help is through their impact on our gut microbiome. Fibre-rich carbs feed beneficial gut bacteria, which produce short-chain fatty acids that help regulate inflammation. They also contain plant compounds that protect cells from damage by neutralising harmful free radicals.

A large Japanese study published this year, involving more than 41,000 adults, suggested fibre protects brain health, too. It found that people with the highest fibre intakes had a significantly lower risk of disabling dementia than those consuming the least.

Despite this wealth of evidence, Bardwell says that “96 per cent of people in Britain aren’t getting their recommended 30g of fibre per day – and a diet rich in quality carbs can help to achieve that”.

Will it lead to weight gain?

If eating more carbs sounds like a recipe for an expanding waistline, Bardwell says that’s not the case – as long as you keep an eye on the quality and quantity.

“Less processed, fibre-rich carbs are more filling, helping us feel satisfied for longer and making it easier to manage our appetite,” she says. Indeed, almost all the participants in the University of Sydney study lost weight, despite that not being the aim.

By contrast, a diet heavy in “bad” carbs such as sugary drinks, sweets and refined, low-fibre foods can make it easier to consume excess calories. The key is to choose your carbs wisely, keep portions sensible and eat them as part of a balanced diet that also includes enough protein and healthy fats.

How to follow the diet

You don’t need to count every gram of carbohydrate to adopt the diet. Aiming to include a quality source at every meal is the simplest way to approach it.

For breakfast, Bardwell recommends a classic bowl of hearty porridge. “I use 30-40g of oats and add chia seeds, psyllium husk or ground flax, or all three. Then I’ll take it off the heat and mix through some Greek yoghurt to add protein and good fat.”

Essentially, the advice is to build meals around fibre-rich carbohydrates, add a source of protein and include some healthy fats. That way, you can enjoy the benefits of quality carbs while still consuming the nutrients your body needs to stay strong and healthy as you age.

“Add pulses to meals,” says Bardwell. “Chickpeas in curries, kidney beans in chilli and cannellini beans in soups count towards your carbohydrate intake, but also increase fibre, protein and plant diversity without much extra effort.”

Choosing wholemeal bread, brown rice and wholewheat pasta are all simple swaps that make a difference, too, while “pre-cooked brown rice or quinoa pouches make eating well easier when you’re pushed for time”.

Bardwell also suggests varying carbs to keep meals interesting. “Try pearl barley instead of white rice, bulgur wheat instead of couscous, or porridge made from rye flakes instead of oats,” she says. “Boiled, baked and roasted potatoes are nutritious carb sources, too, and make for a quick, easy lunch option. They also provide potassium, vitamin C and some fibre, particularly when you eat the skin.”

How long should you eat this way?

In the study, changes to the participants’ overall biological age scores were evident after just four weeks. The researchers calculated these scores using 20 biomarkers, including cholesterol, insulin and C-reactive protein, a marker of inflammation. They stated that they don’t yet know whether these changes persist beyond that time frame.

“If you swap refined carbs, which are high in fat, sugar and salt, for quality ones, you’ll notice a difference very quickly, particularly in your energy levels,” says Bardwell. “This is a way of eating for life rather than for a short period of time.”

A three-day high-carb meal plan

Day one

Breakfast: Creamy porridge made with jumbo oats (or rye flakes or oat bran for extra fibre) and chia seeds, topped with Greek yogurt (for added protein), raspberries, blueberries and a tablespoon of mixed seeds.

Lunch: Chicken (or crispy tofu cubes), chickpea and quinoa Buddha bowl with mixed salad leaves, diced peppers, cucumber, cherry tomatoes and a tahini dressing.

Dinner: Pan-fried salmon with new potatoes (skins on), broccoli and green beans, with a squeeze of lemon and fresh mixed herbs.

Day two

Breakfast: Two slices of wholegrain toast topped with scrambled eggs (or scrambled smoked tofu for a vegan option), rocket and mushrooms. Add a kiwi on the side for extra fibre.

Lunch: Hearty lentil, barley and vegetable soup with a slice of grilled cheese on rye bread.

Dinner: Lean mince (or Quorn for a veggie option) and three-bean chilli with brown rice and grated Parmesan.

Day three

Breakfast: Overnight oats made with Greek yoghurt, jumbo oats, chia seeds and milk of choice, topped with pomegranate seeds and ground flax.

Lunch: Wholemeal wrap filled with mashed avocado, a sliced mozzarella ball, tomatoes and fresh basil. Have an apple or pear on the side for extra fibre.

Dinner: Wholewheat pasta with prawns, cannellini beans, cherry tomatoes, courgette, spinach, garlic and olive oil.

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