There’s power in purple

Scientists from Australia, U of M launch study into key pigment


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It’s often said an apple a day keeps the doctor away.

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Hey there, time traveller!
This article was published 03/12/2018 (1394 days ago), so information in it may no longer be current.

It’s often said an apple a day keeps the doctor away.

But a group of researchers want to know if a purple plum can up ante by reversing chronic disease.

The joint study between an Australian university and the University of Manitoba is zeroing in on purple-blue pigment found in fruits and vegetables as a possible way to prevent and even treat common afflictions including obesity, metabolic disease and Type 2 diabetes.

Rich Pedroncelli / The Associated PRess

But to accomplish this task researchers need a couple of dozen seniors willing to participate in a clinical trial, in which they will be asked to eat purple cookies over a number of weeks.

“The study looks at healthy aging of the elderly population,” says Ashwini Sharma, a PhD student from the University of Southern Queensland, who is leading the human trials at the U of M.

The research team needs about 25 participants age 65 and older who are relatively healthy. They must have no chronic disease and normal ranges for blood pressure, glucose and cholesterol.

Participants will be asked to consume daily cookies made of coconut and a purple plum, called the queen garnet.

The fruit is of interest because it has very high levels of anthocyanin, a naturally occurring compound that gives fruits and vegetables their red, purple or blue colour.

“Our work for the last 15 years has been looking at the concept of food as medicine,” says lead researcher Lindsay Brown, a professor at the School of Health and Wellbeing at the University of Southern Queensland.

“And this is where the functional foods component — which is in the Richardson Centre (for Functional Foods and Nutraceuticals at the University of Manitoba) name — comes into play: Can food not only provide nutrition but also prevent and even reverse disease, especially chronic disease?”

Indeed, the Richardson Centre at the U of M is a linchpin for the research, says Dr. Peter Jones, director of the centre and Canada Research Chair in Functional Foods and Nutraceuticals.

“We have renowned expertise for running these functional food trials in humans.”

What the study aims to know is whether consuming the anthocyanin can do for humans what it’s already proven to do in rats.

Brown says his research team has already demonstrated that a diet rich in anthocyanin reduced obesity and metabolic disease in rats while decreasing blood pressure, cholesterol, blood glucose and insulin resistance.

He explains researchers have long wondered if the colour of a fruit or vegetable may have health benefits because plant pigments are known to contain compounds that are powerful anti-oxidants that may have anti-inflammatory effects.

And inflammation is thought to be a critical factor in the development of chronic disease, Brown says.

“For example, metabolic syndrome is caused by chronic, low-grade inflammation in the body.”

Yet the researchers’ interest in purple happened as a result of a chance call from a bankrupt company that had been growing purple carrots and had 50,000 litres of carrot juice it couldn’t use.

“I assumed the person had been drinking too much because I had thought there’s no such thing as a purple carrot,” Brown says.

He was wrong. After doing a little bit of homework, he realized purple carrots do indeed exist. In fact, they are the original carrot, first grown in the Middle East.

“It was one of these purely accidental reasons for doing the research — and geez, am I pleased we did.”

The purple carrot juice packed a healthy punch, eliminating many of the negative indicators of metabolic disease (an illness that’s like an apprenticeship program for Type 2 diabetes and cardiovascular disease).

The media quickly picked up on the study, and word quickly spread on the internet on health sites and blogs. Brown notes that, prior to publishing its results, his students Googled purple carrots and found them mentioned on about 200 websites. “After we published our findings, it was cited on more than 9,000.”

After their initial success, Brown and his team sought to find other vegetables and fruits with high levels of anthocyanin. They didn’t have to look far as they found the queen garnet plum, native to Australian state of Queensland, had exceptionally high levels of the compound.

“It has something like five to 10 times the amount of the anthocyanin as a normal purple plum.”

Having anthocyanin — or any potential medically beneficial compound — in abundance is critical to developing a functional food.

“It’s a matter of dose so, for example, the purple fruits and vegetables must have high enough amounts to make the dosing realistic,” he says. “So we don’t want a situation where you have to eat 10 kilograms of one thing every day to get a beneficial effect.”

If the pending U of M study shows cookies with anthocyanin reduce incidence of chronic disease in aging adults, it would represent a good starting point for creating food products individuals could take daily to prevent and even reverse metabolic disease, for example.

While the Richardson Centre has led ground-breaking studies on hemp and flaxseed as functional foods, this research would be the first looking at the benefits naturally occurring pigments.

It’s an area of research, Jones adds, that is quickly gaining momentum among food scientists.

“By antithesis, we are now more aware than ever that food without a lot of colour — white sugar, white pasta, white flour, salt — are probably the most unhealthy things you could put in your digestive system.”

While the purple cookie trial does not look to reverse disease, its results could lead to treatments in the future that are food-based.

So while it may be an overstatement that apples ward off physicians, a purple plum — or red grapes, blueberries and even saskatoons — could indeed keep your visits with the doctor to a minimum.


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