The ambiguous nature of food science

What is it about food science that makes it so difficult to single out a single food-based compound or element as the cause for a clearly observed benefit or hindrance?

This conundrum was one of the focal discussion points at the inaugural Go Grains Conference — an annual gathering of national and international food scientists, nutritionists and manufacturers to investigate the role of grain foods and legumes in the prevention and management of lifestyle diseases.

With the conference themed 'Harvesting the science, refining the facts', many of the presentations touched on the frustrating, ambiguous and often inconclusive nature of food-based research — something that food scientists are keenly aware of.

Chris Seal, Professor of Food and Human Nutrition and leader of the Food Quality and Health research group at Newcastle University (UK), first broached the subject in his keynote speech.

According to Seal, evidence from observational studies clearly shows the link between wholegrain consumption and disease risk at the population level. The data shows that increased consumption of wholegrain foods reduces the risk of developing chronic diseases such as coronary heart diseases, some cancers and Type 2 diabetes. The reductions are large and potentially have great significance for the health in the general population.

The problem is, despite all the research, scientists are still unsure what aspect of wholegrains is so beneficial.

"The global consensus is that wholegrains are good for health, however we don't really understand how or why," Seal said.

To address the need for well-controlled, comprehensive studies on the benefits of wholegrains, Seal and his colleagues recently completed the WHOLEheart dietary intervention study, a strictly controlled program which studied the effects of set wholegrain intake levels in approximately 300 overweight people in the UK.

However, rather than clarifying the issue, the study clouded it further. Against expectations, the results showed that plasma total, HDL and LDL cholesterol and triacylglycerol concentrations were not affected by the increased intake of wholegrains. Markers of inflammation and endothelial function were also unaffected. And wholegrains, in this study, did not affect markers of cardiovascular disease risk.

Associate Professor Peter Williams further highlighted the ambivalent nature of food studies. In his work to identify a link between a diet high in wholegrains and legumes with a lowering of the BMI, waist circumference and successful dieting, he has found that while there are numerous studies and analyses on the topic, they all report only minimal to modest weight improvements.

"Only four studies in 11 found any difference in weight loss diets with higher grain intake — and they were mostly short-term studies," Williams said.

These inconclusive or mixed findings, Prof Seal said, are indicative of the problems food scientists face when trying to associate a perceived benefit to a single food item, which is invariably ingested as part of a complex meal, which makes up just one part of a regular diet. Identifying and isolating the possible effects of one ingredient from those of any other sustenance ingested over the period of the study is incredibly difficult.

"We need to find out what compounds or elements are beneficial, but intervention studies are inconclusive," he said.

Professor Linda Tapsell, director of the Smart Foods Centre, University of Wollongong, said that the problem stems from the clinical approach scientists take towards studying food, and believes that a more holistic approach is required.

"Clinical studies are inconclusive because of the nature of food. When we're looking at the benefits of foods, we need to look at whole foods, whole diets and food components, rather than try to analyse the effect of a single part of an entire cuisine," said Tapsell.

"The types of studies that suits pharmaceuticals and medicine, focusing on clinical health benefits from a single substance, are not completely suitable.

"We are starting to understand this now, and we are beginning to appreciate food in its whole right, rather than its separate parts."

Although the presentations were the highlight of the conference, its main goal was to serve as a platform to launch the '4+ serves a day' campaign and logo. The logo is available for food manufacturers to use on healthy grain-based foods to denote the food quality. The labelled foods first need to meet certain eligibility criteria to ensure they are of a healthy standard.

For more information on the program and the selective criteria, visit www.gograins.com.au.