Researchers at The University of Queensland have begun clinical trials into whether an extract from mangosteen, a tropical fruit found in Indonesia, can help treat schizophrenia.
Queensland Brain Institute Professor John McGrath is conducting the trial into the role of mangosteens in easing symptoms of psychosis.
Previous research has indicated that the very potent antioxidants in mangosteen rind might provide a safe and effective treatment, with no side-effects.
“This is a gentle and safe intervention which evidence so far suggests could improve symptoms, and it’s important we investigate its potential as a matter of urgency,” Professor McGrath said.
“We aren’t suggesting this is a wonder drug, but we must investigate potential new treatments which are safe, effective and don’t have the current medication’s side-effects like weight gain, which can lead to other major health problems.
“Finding better treatments for schizophrenia is difficult, it will take decades, so let’s start now.”
Mangosteen is a tropical evergreen fruit native to Indonesia. The thick purple rind of the fruit contains compounds called xanthones which are often used in herbal teas and traditional medicines.
Antioxidants are thought to work because they restrict potentially damaging molecules known as free radicals, which can build up in certain disease states.
“I’ve found over the years that when you talk to patients or their relatives they say ‘I just don’t want anyone else to go through this,” Professor McGrath said.
“When people join a clinical trial like this, they become our citizen scientists, part of our research team.
“That is an inspiring and heart-warming trust which we hope will ultimately lead to better lives for all patients, even if it’s only a modest improvement.”
Curcumin is the component of turmeric (Curcuma longa) that gives the spice its bright yellow colour. It is one of more than 5,000 flavonoids, a group of plant-based compounds thought to contribute to the health benefits of fruit and vegetables.
The purported medical effects of curcumin have a long history, going back at least to the 18th century. In 1937, a paper in the Lancet medical journal described successful case studies using curcumin in the treatment of inflamed gall bladders.
Around 150 curcumin studies are under way to investigate the effects of curcumin (alone or in combination with other drugs) on cancer, heart disease, diabetes and dementia. While any meaningful clinical effects are far from proven, at least the trials have a scientific foundation.
There are already some promising results from studies of curcumin in healthy people. For example, one study in healthy middle-aged volunteers showed that taking 80mg of curcumin a day for four weeks reduced markers of inflammation and oxidative stress. These are implicated in a number of disease processes, including those observed in cardiovascular disorders, diabetes and dementia, among others.
While half a tablespoon or so of turmeric might contain 80mg of curcumin, gaining these health benefits is not as simple as ingesting this amount of the spice every day. First, there is large variability in the levels of curcumin in commercial turmeric. Second, native turmeric has low bioavailability. This means that, under normal circumstances, little is absorbed from the gut into the body.
Various methods have been used to try to increase bioavailability. The preparation used in the study above is lipid-conjugated. This means that the curcumin molecules are bound to lipids (molecules which make up cell membranes), allowing the curcumin to pass through tissue much more readily. This makes it up to 60 times more bioavailable.
Our lab is researching the cognitive and mood effects of a range of bioactive nutrients. Unlike many pharmaceuticals, which are often aimed at single targets, these may affect multiple biological processes involved in cognitive decline and dementia.
Compounds that increase the activity of certain neurotransmitters (chemical signalling molecules) or the delivery of the basic energy substrates (glucose and oxygen) to the brain have the potential to improve aspects of cognitive function. Those that, like curcumin, decrease inflammation and oxidative stress may have longer-term benefits for the ageing brain.
Indeed, there is converging evidence from both human population and animal studies that curcumin may help prevent age-related cognitive decline.
One study of around 1,000 Singaporeans found that those who ate more curry had higher scores on a broad measure of cognitive ability.
While such findings need to be interpreted with caution, they suggest that some component of curry may contribute to the effect. The possible role of curcumin as the key ingredient is supported by numerous animal and test tube studies which show that the compound possesses a host of properties, including many relevant to brain function.
Our placebo-controlled, double-blind study examined the effects of 80mg of the lipid-conjugated curcumin in a cohort of healthy older people. For full transparency, note the study was funded by a grant from the company that makes the extract – though it had no input into the design, interpretation or publication of the study.
We randomly allocated 60 participants (with mean age 69 years) to receive curcumin capsules (the intervention) or a matching placebo (a dummy). Neither group knew whether they were receiving curcumin or a placebo.
The volunteers underwent a training day to familiarise themselves with the computerised cognitive and mood tests. Then they undertook the tests before taking the capsule, then one and three hours after a single dose. They underwent testing at the same three time points following 28 days on curcumin or placebo.
We found that, compared with the placebo group, those in the curcumin group performed better on working memory tasks one hour after the first dose. This effect disappeared by the third hour, by which time blood levels of curcumin would have dropped.
After 28 days, the participants’ working memory was still significantly better than those in the placebo group. Those taking curcumin were also significantly less fatigued at the 28-day assessment.
Sitting computerised cognitive tests for any length of time has negative effects on mood for people in their 60s and 70s. It makes them significantly less alert, content and calm, while increasing stress and fatigue. These mood effects were significantly reduced in the curcumin group, suggesting they were protected to some degree against mental workload stress.
These are early results from a single trial but are encouraging and merit further exploration. We are conducting a replication study, which includes additional measures such as brain imaging to try to better understand the effects of curcumin as a cognitive and mood enhancer.
In the absence of effective new pharmaceutical interventions to treat cognitive decline, it is important that we continue to explore the potential for bioactives like curcumin, and other nutritional interventions, to improve mental function.
Today leading experts on infectious disease and urinary tract infections (UTIs) will gather in London to discuss the alarming state of antibiotic resistance and present findings from a landmark study that conclusively shows that cranberries can be a nutritional approach to reducing symptomatic UTIs, and as a result, may be a useful strategy to decrease worldwide use of antibiotics.
According to the study, recently published by the American Journal of Clinical Nutrition, drinking an 240 ml glass of cranberry juice a day reduces symptomatic UTIs by nearly 40 percent in women with recurrent UTIs – reducing the burden of UTIs and reducing the antibiotic use associated with treating recurrent UTIs.
“Currently the primary approach to reducing symptomatic events of UTI is the use of chronic antibiotics for suppression, an approach associated with side effects and development of antibiotic resistance. This study shows that consuming one 8-ounce (240 ml) glass of cranberry juice a day reduces the number of times women suffer from repeat episodes of symptomatic UTI and avoids chronic suppressive antibiotics,” said Dr. Kalpana Gupta, infectious disease specialist and Professor of Medicine at Boston University’s School of Medicine.
An author on the study and panelist at today’s session, Dr. Gupta believes that cranberries can help to reduce the worldwide use of antibiotics and significantly improve the quality of life for women who suffer from recurrent UTI symptoms.