Healthy global population | 1 February, 2017
RESEARCH THAT’S A RECIPE FOR A HEALTHIER POPULATION
Professor Jayne Woodside’s research is focused on how diet and lifestyle factors may affect chronic disease risk, including cardiovascular disease and cancer. And she doesn’t mince her words about the importance of making an impact.
‘We can sit in our offices and our labs and do all sorts of interesting experiments and write them up for publication, but if the health and the diet of the nation don’t actually change, then what’s the point?’
Jayne is Professor of Human Nutrition within the Centre for Public Health at Queen’s and she is also Deputy Director of the Institute for Global Food Security, one of the University’s four global research institutes. She specialises in the use of biomarkers to assess dietary intake, conducting controlled dietary interventions and, finally, interventions to promote long-term dietary change.
MEASURING DIET ACCURATELY
She says, ‘It’s very difficult to measure diet accurately. We have a number of different types of questionnaire-based methods. There’s a food frequency questionnaire which is a list of around 100 foods and we ask people to remember how often they ate them over the past year. They really struggle with that.
‘Then there’s a food diary where we ask people to write down everything they eat over seven days. Eating behaviour can change when people are involved in that. For example, they don’t want to tell the researchers about a chocolate bar so they’ll not eat it – or they’ll eat it and not write it down.'
‘So what we’re trying to do is to use biomarkers to capture a picture of overall diet. This means we’re measuring what’s in the blood or the urine, rather than asking people to remember.
‘Of course, there are challenges. Nutrients turn over in the body at different rates, so you’re only going to measure recent intake, but if we can measure diet better it will help to assess the link between diet and disease more accurately. If you’re getting the measure of diet a bit wrong, then you’re not going to get the true answer.’
On the subject of dietary interventions, Jayne says, ‘We take a group of people and change their diet for up to four months. We may deliver food to them or bring them in to be observed eating. We’ve shown that with more fruit and veg, you improve heart health and immune function, for example. We’re strengthening what we know about diet and health through changing diet in a controlled way and observing the relevant outcomes.’
But these particular interventions usually involve people who are interested, who volunteer and who want to know what is good for them. What about people who are harder to reach, who are resistant to change?
Jayne recalls a time 20 years ago when researchers at Queen’s were seeking funding for a study, based on one in France which had shown that people who had had a heart attack were less likely to have another one if they adopted a Mediterranean-style diet.
‘The researchers at Queen’s were told by the funders – you’ll never get people in Northern Ireland to change their diet. But we have now done two studies – one getting people who’ve had a heart attack to change to a Mediterranean-style diet and the other with people who’re at high risk of heart disease, getting them into groups, educating them by discussion, even showing them how to cook certain foods, and we’ve shown that we can get them to make real changes.'
‘And these are people in more deprived communities, people with very poor diet. So if you look at a Mediterranean-style diet on a scale of 0–15, they are on a scale of three or lower and we’re trying to boost them to the midrange.
THE IMPACT OF JAYNE'S WORK
‘We’re seeing impact on the participants immediately. People report back that they feel much better. Some even say it’s almost as if they’ve taken back control of their lives. They may feel better in other aspects of their health. We try to capture that and measure psychological health in our studies, too.
‘We’re improving the evidence between diet and health but ultimately, to see real impact, we want to see shifts in the dietary intake of the local population as a whole and that’s much harder to achieve, much longer term. We’re at the start of that journey.’