Long-life expert says 100-year-olds 'love' this purple superfood (2025)

A longevity expert has said these vibrant veggies are enjoyed in parts of the world where people regularly live past 100

A longevity expert says one vibrant food could play a key role in helping people live long enough to reach their 100th birthday. That's according to researcher Dan Buttner, who is known for being the founder of the 'Blue Zone' diet, which is based on foods people from the longest living parts of the world eat, and their lifestyle choices .

His 'Blue Zone' diet draws inspiration from specific areas in Greece, California, Costa Rica, and Italy. Another area is Okinawa - an island chain in southern Japan.

Here, a purple food has played a huge part in the residents' daily diet - sweet potato. This food has been championed for its wealth of anthocyanins, which contribute to anti-inflammatory effects, improved eye and heart health and may even help manage diabetes too.

The longevity research, which branded the potato a superfood, said that if you cannot get hold of the purple kind, then the common orange variety is great too. In a social media video, Dan claimed: "Want to live longer? Eat more sweet potatoes.

"Okinawan - one of the longest-lived populations on Earth - get over 60% of their daily calories from these vibrant, nutrient-packed tubers. They’re loaded with complex carbs for sustained energy, fibre for gut health and antioxidants to fight inflammation. Forget the latest diet trend—longevity is built on simple, whole foods like this. Who’s adding sweet potatoes to their next meal?"

According to research done by the official Blue Zones website, centenarians in Okinawa have got the bulk of their daily calories from this bright, sweet potato for most of their lives. Since the 1600s, it is claimed that the islanders turned to sweet potatoes, which they imported from China, as the land could not grow rice, another Japanese staple, as well as on the mainland.

These anthocyanins may also offer benefits for managing cholesterol levels. These antioxidants, which are responsible for the purple colour, have been linked to improved heart health and may help lower LDL "bad" cholesterol.

These spuds, like most fruits and vegetables, do not contribute to the build-up of LDL cholesterol. This makes them a wonderful choice if you need to make healthy swaps to control your cholesterol.

It's not impossible to get your hands on these bold and bright spuds either, certain M&S Foodhalls sell them in 1kg bags for £3. You could serve them simply steamed as a side dish alongside meat or fish - it doesn't need to be a complicated meal.

The NHS has lots of information on high cholesterol, stating it can be caused by genetic factors but can be made worse through poor lifestyle choices like eating fatty food, not exercising enough, being overweight, smoking and drinking alcohol.

It's impossible to know for sure if you have high cholesterol. Unlike other diseases and medical conditions, it rarely has any obvious signs or symptoms.

The only way to learn you have high cholesterol is through a blood test. If you are diagnosed with this, it's important to get these 'bad' levels under control to minimise the risk of a heart attack or stroke.

You can lower your cholesterol by eating healthily and getting more exercise. Some people also need to take medicine like statins.

This article is not intended to go against medical advice. You should always listen to your doctor and make sure any major changes have been thoroughly discussed beforehand to avoid serious complications.