Data from Denmark has shown that as more and more Westerners shun the humble potato for other vegetables, its reputation as a carb-heavy diabetes risk is unfounded.

There are many different ways to prepare potatoes, and the data indicates that this is why they are looked at unfavourably from a health perspective.

“In previous studies, potatoes have been positively linked to incidences of diabetes, regardless of how they’re prepared – but we found that’s not true,” said Edith Cowan University Ph.D. candidate Pratik Pokharel.

To examine this, Pokharel looked at self-reported data from 54,000 people from the Danish Diet, Cancer, and Health study, a long term study with the objective to produce a dataset which could be examined for trends and patterns.

“In Denmark, people consume potatoes prepared in many different ways; in our study, we could distinguish between the different preparation methods, and when we separated boiled potatoes from mashed potatoes, fries, or [chips], boiled potatoes were no longer associated with a higher risk of diabetes. They had a null effect,” said Pokharel.

Most chips and french fries are cooked in ultra-processed vegetable oils – one of the least healthy calorie sources. Mashed potatoes also often include things like butter, cream, or cheese, which can contain a lot of calories. Further, if they’re processed once from the original source (milk) and then processed a second time (melted into the potatoes) those calories are not triggering satiety mechanisms the same way whole foods will.

Boiled or roasted potatoes on the other hand maintain the natural food matrix, preserve the rich sources of resistant starch – the fibre in potatoes – all of which means their effect on blood sugar levels is reduced.

There was another aspect of the data which Pokheral parsed out – the place of processed potatoes in a meal.

“In our study, people who ate the most potatoes also consumed more butter, red meat and soft drink – foods known to increase your risk of type 2 diabetes,” he said.

When the humble spud is prepared without fats, there’s no reason to avoid it. Roasted potatoes in the oven with their skins on, covered in rosemary and a bit of salt, and drizzled with cold olive oil is one of the great Italian preparations for the vegetable, which also contains more potassium than a banana.