Recent findings on the positive impact of the Mediterranean diet – and particularly oily fish – on childhood asthma treatment might not be enough to convince picky eaters to change habits. But they certainly serve as an extra motive for their parents to keep trying.

The dietary study led by La Trobe University PhD student Maria Papamichael under the supervision of Professor of Dietetics and Human Nutrition Catherine Itsiopoulos, was based on a clinical trial conducted in Athens over a six month period with 64 mild asthma patients aged five to 12.

Half of them were put on a Mediterranean diet supplemented by two serves of oily fatty fish per week, while the rest of the participants followed their usual diet.

“What we found at the end of the six months was that children on the Mediterranean diet who were consuming the fatty fish had lower levels of an inflammatory marker which is specific to lung function, and the levels […] didn’t change on the other diet,” Professor Itsiopoulos tells Neos Kosmos.

The anti-inflammatory properties of omega-3 fatty acids found in fish like sardines, salmon and mackerel are well-known, but it is probably the first time research directly points to how these foods can help fight asthma – a condition associated with inflammation in the lungs – in children, by reducing airway inflammation.

“It’s a clinical trial so it is stronger than an association study and up to this point most of the evidence for the benefits of a Mediterranean diet in asthma in children and adults have been from cross-sectional studies or cohort studies. This is to our knowledge the first clinical trial showing the benefits of this diet on asthma in children.”

As Professor Itsiopoulos explains, the promising new set of data highlights the therapeutic potential of following a Mediterranean diet alongside conventional medical interventions not just in relation to asthma but also other conditions with regular occurrence in childhood.

“It’s a simple low-cost intervention, that is important for general health in children,” she says.

“So following a healthy Mediterranean diet with two serves of oily fish per week is important not only for managing asthma symptoms and potentially preventing asthma in high-risk individuals early in life, but also in the prevention of … diseases that are associated with obesity, like diabetes and cardiovascular disease. Generally, a healthy diet is multi-factorial, it’s not specifically just to target asthma symptoms. It’s something that should be fairly easy to implement and good for the whole family.”

Meanwhile, she points out that there is no reason why this anti-inflammatory function of the Mediterranean diet, would not also have positive effects on teenagers and adults with asthma, cautioning though that this hypothesis remains to be explored in future studies.

For now the next step for the research team would be to repeat the clinical trial with a larger number of children in Australia over a longer period of time.

“This [clinical trial] was just for six months and were only able to catch the children over two seasons; we’d like to be able to observe the effects over the whole year with children exposed to different climates throughout the year,” says Professor Itsiopoulos.

Admittedly the upcoming study would be highly relevant and useful for a country like Australia where asthma is prevalent in early childhood, considered among the leading causes of hospitalisation for kids.

“Most recent studies in Australia show that 15 to 17 per cent of children up to the age of three experience asthma symptoms. Once they’ve grown up it drops down to four per cent, but still we are in a country with asthma prevalence and it is a condition where prevalence is growing worldwide, a condition causing a lot of illness, with children suffering symptoms and staying away from school, parents staying at home to care for their children and more hospitalisations,” she explains.

As Head of La Trobe’s School of Allied Health, Professor Itsiopoulos has more than 20 years experience in studies involving the Mediterranean diet and its links to different health conditions, including cardiovascular disease, diabetes and fatty liver.

But her collaboration with PhD student Maria Papamichael marks the first time the researcher has looked into asthma through the scope of a clinical trial.
Joining the La Trobe team in this undertaking were also researchers in Athens and respiratory physicians, who helped recruit participating children and supported analysis of plasma samples and other testings.

“We have published a number of other studies where we reviewed the literature and [conducted] measure analysis of other studies where we found there was a benefit with consumption of fish versus no fish in children. We’ve known about the association, but this is the first time in this sort of trial to see an effect like this,” says Professor Itsiopoulos.

“I am now hoping to encourage Maria to do a postdoc study with me when she submits her PhD, so we can extend the clinical trial over 12 months with a larger cohort of children.”