Tag: potato

Potatoes not Linked to Type 2 Diabetes – Rather, it’s Their Preparation

Photo by Clark Douglas on Unsplash

Potatoes have long been perceived as having negative health impacts, such as possibly increasing the likelihood of developing Type 2 diabetes. New research published in Diabetes Care has shown while spuds may not have all the same benefits as some other vegetables – such as lowering risk of Type 2 diabetes – health issues associated with potatoes may actually be due to their preparation.

In the long-term Danish Diet, Cancer and Health study, more than 54 000 people reported their dietary intake.

A recent analysis of this study led by Dr Nicola Bondonno from ECU’s Nutrition and Health Innovation Research Institute, found people who consumed the most vegetables had a 21% lower risk of developing Type 2 diabetes than those who consumed the least amount of vegetables.

PhD candidate Pratik Pokharel carried out work on the analysis and said while potatoes didn’t have the same impact on Type 2 diabetes, they also didn’t have any negative effect.

“In previous studies, potatoes have been positively linked to incidence of diabetes, regardless of how they’re prepared – but we found that’s not true,” Mr Pokharel said.

“When we separated boiled potatoes from mashed potatoes, fries or crisps, boiled potatoes were no longer associated with a higher risk of diabetes: they had a null effect.”

Mr Pokharel said underlying dietary patterns were the key.

“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 you account for that, boiled potatoes are no longer associated with diabetes. It’s only fries and mashed potatoes, the latter likely because it is usually made with butter, cream and the like.”

Eat your veggies

Mr Pokharel said findings from the study indicate vegetables could play a key role in reducing Type 2 diabetes, as people who ate a lot of leafy greens and cruciferous vegies such as spinach, lettuce, broccoli and cauliflower had a significantly lower risk of developing the condition.

He said the relationship between vegetables and diabetes should be incorporated into public dietary guidelines – as should the benefits of eating potatoes.

“The finding that vegetables lower diabetes risk is crucial for public health recommendations, and we shouldn’t ignore it,” he said.

“Regarding potatoes, we can’t say they have a benefit in terms of type 2 diabetes, but they also aren’t bad if prepared in a healthy way.

“We should separate potatoes and other vegetables in regard to messaging about disease prevention but replacing refined grains such as white rice and pasta with potatoes can improve your diet quality because of fibre and other nutrients found in potatoes.”

Putting it into practice in the kitchen

Mr Pokharel said people should be advised to increase their vegetable intake – and they could include potatoes, so long as they left out some of the unhealthy extras such as butter, cream and oil.

“Potatoes have fibre and nutrients, which are good for you,” he said.

“People talk about carbs being bad, but it’s more about the type of carbs you’re having; compared to something like white rice, boiled potatoes are a good quality of carbohydrate.”

Source: Edith Cowan University

A Way to Prepare Potatoes for a Lower Glycaemic Index

Photo by Clark Douglas on Unsplash

Researchers have tested a new potato processing technique designed to slow down the digestion of potato starch. Their experiments show that the approach prevents certain digestive enzymes from reaching the potato starch as quickly, leading to a more controlled release of dietary glucose.

Foods with lower glycaemic index have a variety of health benefits, such as reducing the risk of cardiovascular disease.

“There is a perception that potato foods are unhealthy because eating a large amount of some potato foods can cause a rapid increase in blood sugar, which is a risk for people with diabetes or those who want to control body weight,” said Amy Lin, PhD, the study’s principal investigator at A*STAR. “Our team revealed that toggling the accessibility of two digestion enzymes – α-amylase and mucosal α-glucosidase – in the small intestine is a successful strategy to make dietary glucose slowly and continuously release from potatoes.”

The findings are being presented online at NUTRITION 2022 LIVE ONLINE, the flagship annual meeting of the American Society for Nutrition.

The researchers cut potatoes into cubes and blanched them in hot water with a food grade ingredient for 30 minutes., though they did not disclose what the ingredient was.

An enzyme barrier of pectin

This process causes a reaction with pectin, a water-soluble fibre in potatoes, creating a gelling structure which makes a porous barrier between starch granules and digestive enzymes. The size of the barrier’s pores can can be determined by the processing method to moderate how quickly α-amylase is able to penetrate the potato parenchyma cells and degrade starch to small molecules. Converting starch molecules to glucose relies on mucosal α-glucosidase, which is too big to penetrate those pores. Therefore, the elevation of dietary glucose of processed potatoes depends on the how quickly small starch molecules leach out of parenchyma cells and are digested by mucosal α-glucosidase.

“Without our treatment, enzymes move freely in and out of cells, and starch is quickly degraded by both enzymes and rapidly converted to glucose,” said Dr Lin. “The treatment allows the starch to be slowly degraded to prevent a spike in glycemia and then fully converted to glucose to meet our energy and nutritional needs.”

The technique is not designed to prevent the potato from being digested, but rather to slow digestion to avoid a rapid increase in blood sugar. Researchers say the modification could also help consumers feel full for a longer period after eating the treated potatoes, helping to avoid overeating.

Researchers report that the method performed well in tests with a simulated digestion process in the laboratory. Treatment increased the fraction of the starch that is considered slowly digestible from 10% to 35% and significantly reduced the ability for the enzyme a-amylase to access starch within the cell walls.

But how do they taste?

Since the process essentially pre-cooks the potatoes, treated potatoes are not shelf-stable but could be frozen and then cooked or further processed for dishes such as roasted potatoes, hash browns, soups or stir-fry, researchers say. Initial taste tests had good results in terms of digestibility and texture.

As a next step, the researchers are preparing to further test impacts on digestibility in a clinical trial. They also plan to study whether a similar approach could be used to improve other staple foods.

Source: American Society for Nutrition