A simple potato extract may limit weight gain from a diet that is high in fat and refined carbohydrates, according to research from McGill University in Canada.
The study, published in the November 2014 issue of the Molecular Nutrition and Food Research journal, examined the impact on mice of including potato extract in the diet.
Study method
The researchers fed mice an obesity-inducing diet for 10 weeks. The results soon appeared on the scale: mice that started out weighing on average 25 grams put on about 16 grams. But mice that consumed the same diet but with a potato extract gained much less weight: only 7 more grams. The researchers said the benefits of the extract were due to its high concentration of polyphenols, a beneficial chemical component from the fruits and vegetables we eat.
“We were astonished by the results,” said Professor Luis Agellon, one of the study’s authors. “We thought this can’t be right – in fact, we ran the experiment again using a different batch of extract prepared from potatoes grown in another season, just to be certain,” he said.
The rate of obesity due to over-eating continues to rise in Canada, affecting 1 in every 4 adults. Obesity increases the risk of cardiovascular disease and cancer. According to the McGill University study, potato extracts could be a solution for preventing both obesity and type 2 diabetes.
Extract derived from 30 potatoes
“The daily dose of extract comes from 30 potatoes, but of course we don’t advise anyone to eat 30 potatoes a day, as that would be an enormous number of calories,” said Stan Kubow, principal author of the study.
What the investigators envisage instead is making the extract available as a dietary supplement or simply as a cooking ingredient to be added in the kitchen.
Popularly known for its carbohydrate content, the potato is also a source of polyphenols.
“In the famous French diet, considered to be very healthy, potatoes – not red wine – are the primary source of polyphenols,” Mr Kubow said. “In North America, potatoes come third as a source of polyphenols – before the popular blueberries,” he said.
A low-cost solution
Mr Kubow said potatoes had the advantage of being cheap to produce, and that they already formed part of the basic diet in many countries.
“We chose a cultivated variety that is consumed in Canada and especially rich in polyphenols,” Mr Kubow said.
Clinical trials still needed
Although humans and mice metabolise foods in similar ways, clinical trials are absolutely necessary to validate beneficial effects in humans. The optimal dose for men and women also needs to be determined, according to the researchers, since metabolisms differ between the sexes.
The team hopes to patent the potato extract, and is currently seeking partners, mainly from the food industry, to contribute to funding clinical trials.
This study was funded by the Natural Sciences and Engineering Research Council of Canada, the Canadian Institutes of Health Research and the Canada Foundation for Innovation.
