Proof of a long life is in the porridge

With a combined age of 1,075 years and 68 days, the 13 Donnelly siblings of County Armagh in Northern Ireland can proudly lay claim to being the world's oldest family.

Their ability to defy the passing years has won them a Guinness world record.

But what can now be revealed is the secret behind the family's longevity - traditional porridge oats.

Having grown up on a farm, their diet has always been made up of locally sourced ingredients, free-range pigs and chickens for bacon and eggs, and vegetables grown in their back yard.

But the Donnelly clan are convinced that what has really guaranteed their longevity is their habit of eating porridge, not just for breakfast every day, but for supper, too.

"The key is that you need to get your oats at night," said Leo Donnelly, who at 72 is the youngest of the siblings.

"We've always followed daddy's habit of that nice warm bite before sleep. Porridge at around 10pm, then porridge again for breakfast at 7am.

"Cooked oats, milk, perhaps a spot of jam on top. It has always stood us well, porridge before sleep and after sleep. People thought it was unusual but now the proof is there for all to see."

The family's reliance on oats and the grain's apparently beneficial effects have prompted scientists at the International Longevity Centre in the UK to study the Donnellys' diet.

Porridge has been shown to lower blood pressure, combat diabetes, reduce cholesterol and protect against heart disease.

Oats are naturally high in vitamin B12, a crucial component in regulating the body's melatonin levels, which influence sleeping and waking patterns. The grain is also naturally loaded with beta-glucan, a "magic genie" that lowers "bad" cholesterol and reduces heart disease.

Porridge was labelled a superfood when it was discovered that avenanthramides, antioxidants that are found only in oats, minimise plaque build-up in artery walls and reduce the hardening of arteries.

But for the Donnellys, tucking into a bowl of porridge is just part of their fundamentally wholesome diet and lifestyle.

They also steer clear of alcohol.

"Our diet has never been from processed or polluted foods," said Leo.

"The vegetables we eat we have grown, the fruit we picked, the eggs were from our chickens, the bacon from our pigs, the bread we made by hand.

"There has never been a fat Donnelly." - The Sunday Telegraph