Found in the Amazon rainforest in Peru and Brazil, camu camu fruit has gained popularity around the world in recent years as the latest "superfood." Boasting an extraordinarily high vitamin C content of as much as 2 to 3 percent its weight, the fruit is rich in flavonoids and antioxidants and has long been used by Amazonian natives for food and medicine. Now a new study has found that an extract of camu camu can prevent mice fed a high-fat and high-sugar diet becoming obese.

Having previously demonstrated the beneficial health effects of polyphenol-rich berries, researchers at Université Laval and the Quebec Heart and Lung Institute Research Centre decided to examine the health effects of camu camu, which pack five times more polyphenols than blackberries. Specifically, they set out to examine the effects of camu camu on obesity and metabolic disease.

The team split some mice into two groups and fed them both a diet rich in sugar and fat for a period of eight weeks, with one group also given camu camu extract each day. At the end of the eight weeks, the mice jumped on the scales, which revealed the mice fed camu camu extract gained 50 percent less weight than those that weren't. The weight gain of the camu camu group was also found to be comparable to that of a control group of mice fed a low-sugar, low-fat diet.

The researchers say the fruit's effect on weight gain could be due to it increasing the resting metabolism of the mice, resulting in higher energy expenditure. They found that camu camu increased glucose tolerance and insulin sensitivity, while reducing metabolic inflammation and concentrations of endotoxins in the blood. Unsurprisingly, the fruit also had a beneficial impact of the gut microbiome of the mice.

"All these changes were accompanied by a reshaping of the intestinal microbiota, including a blooming of A. muciniphila and a significant reduction in Lactobacillus bacteria," says André Marette, a professor at Université Laval's Faculty of Medicine and principal investigator for the study.

Further proof camu camu can produce positive metabolic effects, at least partially through modulation of the gut microbiome, came when the team transplanted intestinal microbiota from the camu camu group into germ-free mice with no intestinal microbiota, resulting in similar metabolic effects temporarily.

Of course, the question now is whether the fruit is capable of producing similar metabolic effects in humans, which is what Dr. Marette wants to examine next.

The team's study appears in the journal Gut.