Whole grains: the unsung heroes

Presented as part of Technology Transfer Seminars 2023

Nutrients, food and health researcher Dr Andrew Reynolds is interested in what damages our health, and what costs our health system the most. Global studies show that dietary risks are the leading cause of death, due to their impact on heart disease, diabetes, and cancers. But how does this relate to what we eat in New Zealand? One area of interest is carbohydrates intakes, which make up around 47% of the energy we consume.

Both trials and cohort studies worldwide have shown that the amount of carbohydrate we consume does not matter to our health unless it is extreme – very low or high. There is far better evidence however, that it is the type of carbohydrate that is more important.

“Carbohydrates are a diverse group, ranging from simple sugars, to starch, to complex dietary fibres” Dr Reynolds said. High sugar intakes increase body weight and dental caries, dietary sources of starch appear relatively neutral to health but depend on cooking method (with deep frying and salting bad), while dietary fibre appears highly protective. High fibre intakes reduce risk of mortality, heart disease, T2 diabetes and colorectal cancer, while increasing fibre intakes improves weight, blood pressure and cholesterol.

Dietary recommendations for fibre are to have at least 25g per day, although the average intake in New Zealand hovers around 20g. One way to increase dietary fibre is to replace refined grains in the diet with whole grains. Our daily grain intake is around 238g, with only 28g or 12% being wholegrain, so there is great opportunity there to increase wholegrain intakes. But how can we change people’s preferences when the overwhelming majority of consumers want to eat refined white bread products? “People’s preferences for refined grains are not locked in for life, so this can be slowly changed overtime by always having tasty wholegrain options available, and reinforcing health messages about why they should be chosen over refined grains. In the meantime, I’m not against boosting the fibre content in refined grain products, it’s like parents trying to hide vegetables in their kid’s meals”.

Given the clear benefits with higher fibre and wholegrain intakes, Andrew was keen to find out from those present whether the flour milling and baking industries have practical and easy ways for getting more fibre and whole grains into our food supply. Digestibility, keeping qualities, the milling of whole grain to retain their benefits, crumb structure, barriers to adding fibre to bread and consumer acceptance were all up for discussion. Andrew’s health research in this area is expanding, and he aims to incorporate the practical perspectives of working with whole grain in baking and milling into his future projects.

Latest News & Events