Understanding bioavailability is key to promoting good health


By Dr Jocelyn Eason, general manager of Food Innovation for Plant and Food Research

Food provides sustenance and enjoyment – it brings people together, makes us feel good and we like the way it tastes. Increasingly, people look to food, particularly plant foods, for long-term health benefits. Most of us are familiar with health campaigns promoting five servings of fruit and vegetables per day.

Nutrients are essential for our survival but foods also contain bioactives that can improve our health. Some of the main groups of plant-derived bioactive components include polyphenols, phytosterols, carotenoids and terpenoids.

To promote health, these bioactive compounds need to be bioavailable. Essentially bioavailability refers to how easily substances get absorbed and utilised by the body’s target tissues to deliver a biological effect, such as a health benefit.

Bioavailability is influenced by the structure of food, the chemical form of a particular nutrient, interactions between nutrients and/or bioactives and food processing. Diet, nutrient/bioactive concentration as well as the nutritional status, health and life-stage of an individual also have an impact.

Understanding bioavailability is key to developing functional foods with genuine health benefits and for establishing health claims around food components. Small changes, such as adding fat or heating to release cell components, can significantly improve the bioavailability of some components.

Some food compounds that are widely promoted for their health benefits have low bioavailability. Recently there has been a lot of research on the health benefits of curcumin (a natural polyphenol in turmeric); however, unformulated curcumin has poor bioavailability due to poor absorption, rapid metabolism, chemical instability and rapid elimination.

The pharmaceutical industry has researched bioavailability extensively but there has been less research into understanding the bioavailability of food components. Increasing our understanding of how nutrients and bioactives change through processing and digestion, will enable food scientists to enhance bioavailability through food formulation and technologies, like colloidal systems and chemical modification. Materials currently used to improve bioavailability in pharmaceutical drugs could work for bioactive food compounds.

Additionally, more research is needed to increase our understanding of how gut microbiota and microbial metabolites influence bioavailability and the mechanisms of action for health benefits.

Dr Jocelyn Eason has a PhD in Plant Physiology from Otago University and an MBA from Massey University. In her current role, Dr Eason manages Plant and Food Research’s Food Innovation Portfolio, which includes teams that investigate human responses to food, the influence of food on human nutrition and wellness, and the production and supply of nutritionally rich foods.

The information and opinions within this column are not necessarily the views or opinions of Hot Source, NZ Food Technology or the parent company, Hayley Media.