Kiwifruit orchardist have long believed the fruit they grow has exceptional nutritional qualities, and in Tauranga today scientists have revealed just how good kiwifruit really is.

From the digestive system to immunity and metabolic health, an increasing body of research demonstrating how beneficial kiwifruit is for human health is being presented by leading scientists at the first ever International Symposium on Kiwifruit and Health.

Keynote speaker Professor Jaap Seidell from Vrije Universiteit in Amsterdam addressing the crowd at the International Symposium on Kiwifruit and Health. Photo: Supplied

The two-day symposium has brought together nearly 200 global health experts to consider the role of fruit, in particular kiwifruit, in a healthy diet. The event is initiated by the Riddet Institute of New Zealand and sponsored by Zespri, and presents the most recent studies and the research underway into the health benefits of kiwifruit within the areas of digestive health, health and vitamin C and metabolic health.

Among key findings presented:

• Kiwifruit regulates sugar highs and lows in your blood stream.
• For the first time in human clinical trials, Zespri Green kiwifruit has been found to improve digestive health function and comfort. This is through a unique combination of actinidin (a kiwifruit enzyme), fibre and other components.
• Kiwifruit boosts your immunity. Eating kiwifruit daily is very effective at increasing blood levels of vitamin C as well as levels in other parts of the body.

The keynote speaker at the event, Professor Jaap Seidell from Vrije Universiteit in Amsterdam, is the Netherlands' foremost obesity specialist.

'Today, there is general consensus that for much of the world, nutrient-poor food is a key driver in escalating rates of obesity and related chronic disease.

'Improved health outcomes are associated with diets high in nutrient-rich, low energy-dense fruit – such as kiwifruit.”

Dr Juliet Ansell, Zespri's Innovation Leader for Health and Nutrition, says: 'the findings are great news for Zespri consumers. We know that the more people hear about the health benefits of kiwifruit the more they consume, and this week we have heard exciting research results from new scientific studies.

'One particular highlight at this symposium is the finding by Dr John Monro from Plant & Food Research on the glycaemic impact of kiwifruit, which shows that kiwifruit helps to regulate blood sugar levels.

'We have also heard results from Zespri's New Zealand arm of a global clinical trial, which show that eating two green kiwifruit a day significantly improves bowel function. The body of scientific evidence for the health benefits of kiwifruit continues to grow.”

Distinguished Professor Paul Moughan, co-director of the Riddet Institute, says this is the first time anywhere in the world that so much expertise on kiwifruit and health science has been brought together in one place.

'Continued investment in world-class research on the health benefits of kiwifruit has value both for Zespri, for health practitioners, and for consumers around the world, as the importance of a healthy and balanced diet becomes ever-more important and understood.”

Riddet Institute co-director Professor Paul Moughan. Photo: Supplied

Nearly 30 per cent of the worldwide population is affected by at least one of the several functional gastrointestinal disorders with functional dyspepsia, irritable bowel syndrome (IBS)1 and chronic constipation (CC)2 being the most common.

These conditions can negatively affect quality of life and represent a significant health burden. Fortunately, they can be easily prevented through diet and lifestyle changes. Green kiwifruit has been found to promote laxation in people with constipation. Another study has shown improvement of bowel function.

'These promising results suggest that the effect of kiwifruit on IBS-C and Chronic Constipation (CC) merits further investigation,” says Professor Giovanni Barbara.

Building on the above conclusions, Professor Richard Gearry presented the New Zealand results of a multi-centre clinical trial on the effect of kiwifruit on digestive and gut health functions3 The goal of this study was to demonstrate the efficacy of kiwifruit as a food intervention for the relief of constipation and associated symptoms in functionally constipated adults, and those with irritable bowel syndrome constipated type (IBS-C).

The results have shown that eating two Zespri Green kiwifruit a day significantly improves bowel function and frequency in people with constipation but importantly does not lead to diarrhoea in healthy people.

'Even more exciting are the significant changes we have seen with respect to digestive comfort, which has a major impact on the quality of life constipated people.”

Kiwifruit consumption has the potential to contribute greatly to gastrointestinal comfort, protein digestion and gut health, saya Dr Carlene Starck. The natural digestive enzyme actinidin improves digestive comfort by increasing the breakdown of proteins and facilitating gastric digestion (emptying of the stomach).

Recently, investigations have also focused on kiwifruit fibre and its digestibility. It has been found that the fibre in green kiwifruit has a high capacity for retaining water and thus creating larger and softer stools, facilitating intestinal transit through our digestive system.

Vitamin C is an essential vitamin – contributing to the functioning of the immune system, reducing tiredness and fatigue and contributing to normal skin function. It cannot be synthesized by the human body.

Therefore, it needs to be obtained on a daily basis through the diet. However, most people do not consume enough fresh fruit and vegetables to maintain saturating plasma levels of vitamin C. It has been demonstrated that eating kiwifruit daily is very effective at increasing blood levels of vitamin C as well 1 as levels in other parts of the body, says Prof Margreet Vissers and Dr Anitra Carr.

Zespri's Innovation Leader for Health and Nutrition Dr Juliet Ansell. Photo: Supplied