Feijoa shows potential for cutting blood pressure

A world-first clinical trial of feijoa has provided preliminary evidence of the fruit reducing blood pressure during weight loss.

The unexpected finding was incidental to studying feijoa’s potential for preventing type 2 diabetes, says Dr Ibrahim Mohamed, of the University of Auckland’s Human Nutrition Unit.

“It’s not what we set out to find but it’s interesting and certainly warrants more research,” says Mohamed.

A study called FERDINAND investigated whether feijoa powder boosted weight loss or improved blood sugar, a marker of diabetes risk, during a six-month weight-loss programme for people with prediabetes.

The research was funded under the government’s High-Value Nutrition National Science Challenge (Ko Ngā Kai Whai Painga), which aimed to boost New Zealand’s exports of health food products by scientifically validating health claims.

The company Anagenix Ltd. supplied a whole-fruit feijoa powder product called Feiolix for the study.

The research didn’t show any meaningful effects in connection with weight loss or blood sugar. However, systolic blood pressure – the top number in a blood pressure reading – improved more for people consuming feijoa powder than for those on a placebo.

Because the evidence was not consistent across all analyses and the study was relatively small – 97 people – larger trials are needed to reach a definitive conclusion.

“Further studies in larger cohorts are warranted to fully evaluate the contribution that whole fruit feijoa powder may make to improved blood pressure,” Mohamed and his co-authors wrote in the paper published in the journal Diabetes, Obesity and Metabolism.

The study was the world’s first long-term clinical trial of feijoa powder supplementation in humans.

Scientists are fascinated by the fruit’s potential because it contains bioactive compounds including polyphenols, flavonoids, vitamin C and abscisic acid (ABA) offering antioxidant, anti-inflammatory and potentially metabolic effects.

There was a previous short-term clinical study in Iran which pointed to benefits of feijoa for patients with type 2 diabetes.

During the University of Auckland study, adults with raised blood sugar were given about a gram of feijoa powder (or a placebo) every day for six months.

Participants consumed the powder with their breakfast, either mixing it into a glass of water or into their breakfast.

In the first two months of the study, participants cut their weight through a free meal replacement programme. The following four months focused on maintaining the weight loss.

The study was conducted in collaboration with AgResearch, the Malaghan Institute and Plant and Food Research.