If you’re trying to lose weight, anything that can provide a helping hand in a healthy, sustainable way is a bonus – and according to researchers at RMIT university, that may just be what the humble roselle plant has to offer.
Led by PhD candidate Manisha Singh, a team of scientists has revealed that the antioxidants hidden within the vibrant red fruit of the roselle plant have anti-obesity properties that could help in food alternatives to current weight management medications.
Antioxidant compounds called polyphenols in the roselle have similar digestive enzyme-inhibiting properties as some obesity management medications, in that they inhibit a digestive enzyme called lipase. Naturally occurring in the body, lipase helps break down fats into small fractions so the body can absorb them through the intestine, and the excess fats are then turned into fat cells. However, when polyphenols inhibit the lipase enzyme, the fat cannot be absorbed so it passes through the colon as waste.
This discovery could be an absolute game changer for anyone who is taking medication as part of an obesity management plan, due to these medications’ potential side effects. While they can be effective at controlling weight, many of the medications used to treat obesity may also have a negative impact for the body, for example, the kidneys and liver, and blood pressure.
However, “Because these polyphenolic compounds [found in the roselle] are plant-derived and can be consumed, there should be fewer or no side effects,” Singh explains.
Roselle IRL
Now that they know all about the plant’s superpowers, the RMIT research team are exploring how they might be made readily available to the public – and it looks like food is the answer.
“The phenolic extracts from the roselle could help create a health-food product that is [not only] effective in interfering with the formation of fat cells, but also bypass[es] the bad side effects of some medications,” says Professor Benu Adhikari, from RMIT’s Food Research and Innovation Centre, who supervised the new study and believes the roselle – which is native to Africa – might just become a big player in the Australian health food industry.
Plus, this member of the hibiscus family is the ideal plant to grow Down Under. “Australia has the perfect climate for farming the roselle,” says Adhikari. “The plant is hardy, disease resistant and it doesn’t need a lot of space or water to grow.”
The best option for getting these benefits into health-food products, the team say, is encapsulating roselle’s phenolic extracts. “Phenolic extracts oxidise easily, so not only does encapsulation extend its shelf life, but it lets us control
how they are released and absorbed by the body,” Adhikari adds. “If we don’t encapsulate the extract, it could break down in the stomach before we can reap its benefits.”
Currently, the researchers say the extracts could be turned into little beads and used to make a refreshing drink – and if you’ve ever tasted the roselle’s alien-esque calyces (the fleshy red ‘cup’ containing the plant’s seeds), you’ll know what a delicious prospect this is! Hibiscus tea, anyone?
