Dietitians taking lupins to heart
GroundCover™ Issue: 108 | Author: Melissa Branagh-McConachy
Health professionals are increasingly turning their attention to lupins’ nutrient composition, which could make it a standout grain for the growing functional-foods market.
A major study into the role that lupins could play as a processed food ingredient able to help combat cardiovascular disease and diabetes shows this erstwhile low-value grain could have a significant human foods market.
The study, led by dietitian Dr Regina Belski during her time at the University of Western Australia (UWA), found that using flour containing 40 per cent lupin beans increases the sense of satiety and helps with cholesterol and insulin concentrations and blood pressure.
Dr Belski explains that these health benefits are linked to the lupin’s nutrient structure, which is high in fibre and protein and low in fat and starch. The beans can also be easily ground into flour ready for use in food preparation.
Addressing the Pulse Breeding Australia Inaugural Pulse Conference in Adelaide in October, Dr Belski, now based at Victoria’s La Trobe University, said foods that increase satiety or that can be used as an alternative to medication to improve blood pressure, cholesterol and insulin sensitivity have the potential to be strategic weapons in the fight against heart disease.
“Cardiovascular disease is the leading cause of death in Australia. It affects 3.7 million people, kills one Australian every 12 minutes and remains one of the biggest burdens on our economy,” she said.
“There is evidence that fibre can help to improve blood pressure, cholesterol and insulin sensitivity and that protein may play a role, too. Furthermore, protein and fibre are regarded as the most satiating nutrients that may aid in weight loss.
However, combining the two can be difficult because palatability is poor and high-protein foods are usually low in carbohydrates and hence fibre, and vice versa.”
This is why there is growing interest among health professionals in lupins. The lupin bean (Lupinus augustifolius) contains about 40 per cent protein and 30 per cent dietary fibre with negligible carbohydrate.
“Lupin-kernel flour has a unique macronutrient composition that can be used to increase fibre and protein content while simultaneously reducing carbohydrates,” Dr Belski said.
In addition to findings that lupins cause people to feel fuller for longer and to eat less, she said research has shown a lupin-flour-enriched diet lowers fasting insulin concentrations and blood pressure, while isolated lupin protein and lupin fibre can reduce cholesterol in people with significantly elevated levels.
However, Dr Belski said while growers are aware of lupins’ use in crop rotation cycles, few in the community have experienced the lupin bean as a food ingredient.
“Food Standards Australia New Zealand approved lupins for human consumption in the late 1980s, but its use has been very limited,” she said. “Conversely, about 500,000 tonnes of foods containing lupin ingredients are consumed each year in Europe – primarily in wheat-based bakery products.”
To further explore lupins’ health properties and to drive consumer demand, Dr Belski worked with scientists and food manufacturers in WA, which produces 80 per cent of the world’s lupin crops – mostly for stock feed.
With researchers from UWA and the Centre for Food and Genomic Medicine at the Western Australian Institute for Medical Research, she conducted a year-long study to understand the dietary effects of lupin flour.
More than 100 overweight but otherwise healthy study participants were divided into those who ate 40 per cent lupin-enriched bread, biscuits and pasta or a control group who ate wholemeal versions of these foods. Both groups followed weight loss and maintenance programs and were monitored for heart-disease risk factors throughout the 12-month trial.
“At the end of the year, both groups had lost similar amounts of weight but the lupin group had significantly lower blood pressure and enhanced insulin sensitivity,” Dr Belski said. “So consumption of lupin flour improved health outcomes independent of weight loss.”
She said the findings were encouraging: “The research suggests lupin has real potential as a functional food; it is much easier to tell someone to change their bread than to undertake a radical change in diet.”
The research team experimented with recipes over several months to develop palatable food products from lupin flour before identifying commercial food manufacturers.
Dr Belski said many participants stuck to the diet beyond the study period, with Bodhi’s Bakehouse in Fremantle, WA, continuing to bake the bread in response to steadily rising demand.
She was hoping other manufacturers would now come on board, particularly in eastern Australia, as lupins’ commercial potential as a functional food becomes clearer.
“The results to date are exciting, but we need more long-term studies with high-risk population groups to explore the full extent of lupins’ potential as a functional food,” she said.
Dr Regina Belski
03 9479 3629
Region South, West