2 Mar 2021

Food for thought - Andrew Scholey

From Nine To Noon, 10:08 am on 2 March 2021

Andrew Scholey researches the relationship between what we eat and how well our brain works, specifically the effects of natural products, nutrients, nutraceuticals, supplements and food on mood, brain function and wellbeing, as well as the effects of caffeine, drugs and alcohol. 

Blackcurrant berries have high polyphenol levels.

Blackcurrant berries have high polyphenol levels. Photo: Photo / 123RF

Prof Scholey* has spent about two decades looking at the interaction between nutrition and brain function and worked with some of the ‘Global 500’.

He says it’s natural to be sceptic about the claims some companies make, but urges people to “trust the science, not the funder.”

“There are all sorts of checks and balances in case in place these days, which make it actually very difficult to game the system, if anybody wanted to do that … it's important to work with industry to do good science, but it's very important not to compromise the science.”

He has now teamed up with Auckland food-tech start-up Ārepa to research and develop its blackcurrant drink, which promises clear thinking during moments of pressure and stress.


One of his research interests is looking into how cognition can be enhanced and the decline that comes with age off-set.

“For example, the New Zealand berries are loaded with vitamin C, which we know can benefit brain function particularly in things like recovering from surgery. They have these polyphenols which we know are important components of fruit and veggie which seems to be partially responsible for their health benefits.

“And in the case of the berry that this company Ārepa use, they also have this really interesting property, which is that they inhibit monoamine oxidase, which … is exactly the same mechanism that some antidepressants use and also some treatments for certain neurodegenerative diseases.”

Inhibiting this enzyme helps increase levels of a class of neurotransmitters known as the ‘happy chemicals’, like dopamine and serotonin.

He notes one research piece, published in Nutritional Neuroscience, showed “a couple of 100 grams of these berries” could lead to “total and reversible inhibition of monoamine oxidase within 15 minutes, which lasts for four hours”.

On the other hand, more trials need to be done to further examine these findings, says Prof Scholey. This research had stopped testing at four hours and resumed 24 hours later, by which time this activity returns to baseline.

Still, he believes it can have a sufficient enough impact to change moods.

“I'm not an expert on the sort of way in which enzymes interact in the body. But I have published quite a bit on various effects on mood and mental function of nutritional interventions.”

Another study on cognitive function of berries being used by Ārepa showed they can improve attention over the period which it was tested – for an hour.

“These effects are pretty much of the same magnitude as you would get with caffeine … To emphasise, these are acute effects. So these are the effects following a single dose.”

Guarana and coffee

Prof Scholey has also examined guarana - a Brazilian plant prized for its fruit – which contains a molecule that's very similar to caffeine.

Guarana plant

Photo: 123RF

“When you look at the effects of guarana on mood and cognition, the dose which is effective, we're talking here about something like say 75 milligrams of guarana, contains a very small amount of caffeine, maybe five to 10 milligrams of caffeine, which is about what you'd get in a decaf coffee.”

While caffeine has similar chemical effects to the berries, it also narrows blood vessels, which has a negative effect on brain function.

But in this instance, the chemical combination of this fruit outplayed the negative effects of caffeine, Prof Scholey says.

“If you have a situation where you have caffeine and vasodilator - this is something which widens blood vessels - it means that you can get effects at a much lower level of caffeine. And we think that that's what's going on with guarana.

“Incidentally lots and lots of foods, like these berries, but many other foods like curcumin from turmeric and others have these vasodilator effects, so they increase blood flow to the brain, which is one of the ways in which they can help brain function and actually, perhaps surprisingly, mood.

“Mood seems to be quite sensitive to increases in blood flow.”

He says most of the ways in which we consume caffeine is in combination with chemicals that have these vasodilators effects – like caffeine in tea or even in chocolate.

As for the downfalls of caffeine, he says the “jittery” reaction to having one too many can be traced back to caffeine but there needs to be more evidence on side effects.


Prof Scholey says there haven't been many clinical trials looking at the effects of curcumin or turmeric in particular on mood and cognition.

turmeric roots in the basket on wooden table

Photo: 123rf/Sommai Larkjit

“I've conducted two of the studies, there might be another two or three out there.

“Mainly the issue with turmeric and curcumin is bioavailability … So actually, if you have a turmeric latte, very little of the curcumin from that turmeric is going to be absorbed and most of it will come out at the end of the day.”

A number of food technology approaches have tried to increase its bioavailability, he says.

“It's a process called liquidation, which is adding a kind of fat molecule to the curcumin itself. And that helps it to get passed through membranes of cells, the sort of outer coating of cells in the body because they tend to be made of fat.

“There are other ways in which curcumin has been combined with piperine from black paper, which again anecdotally seems to improve the health effects.”

Promising outlook but no 'magic bullet'

Emerging research is showing that the combination of B vitamins with Omega-3s is important, Prof Scholey says

“They sort of help each other to be absorbed.”

The Mediterranean diet, was also originally explored for its effects on cardiovascular health and mortality.

“That's led to some trials looking at the effects of things like the Mediterranean diet as a whole dietary pattern on cognition and its ability to act against cognitive decline with aging … but there are also other lifestyle factors which are probably worth taking into account.”

But he warns there’s no “magic bullet” solution rather it’s the “multitude of properties rather than a single property” in food that creates the best health effects. He says the pharmaceutical approach followed this ‘top-up’ method in altering chemicals but has been largely unsuccessful in treating some conditions.

No caption

Photo: Supplied

“[That approach] had a degree of success for Parkinson's disease … that was reasonably effective for those sort of treatments at the time, but hasn't really worked for anything else.

“We know that the brain is hugely complex … if you sort of prop up a single neurotransmitter in an unregulated way, it's not likely to work.

“There hasn't been a kind of blockbuster pharmaceutical for the brain for decades. That's probably the reason it just isn't amenable to that kind of pharma drug development approach. But there are certain food stuffs which seems to have evolved with a complement of effects, like a whole raft of different properties, which can nudge multiple processes in the right direction.”

*Andrew Scholey is Professor of Human Psychopharmacology at Swineburn University in Melbourne, previously having established the Human Cognitive Neuroscience Unit at Northumbria University in the UK, and co-directing the UK's Medicinal Plant Research Centre where he remains honorary director of Neurocognitive trials.

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