Study: Kiwifruit the answer to beating mid-afternoon energy slump

Kiwifruit consistently rank at the top of fruit in nutrition density models. Photo / File

Having kiwifruit with your morning Weetbix might be the secret to staving off tiredness and hunger between meals during the day, scientists say.

A new study by Plant and Food Research has highlighted kiwifruit's positive impact on glycaemic response, significantly slashing the uptake of sugars into the blood stream and also regulating blood sugar levels.

Scientists behind the research, being presented to a Zespri-hosted science symposium hosted in Tauranga this week, say kiwifruit should be seen as a healthy option for people with a reduced tolerance to glucose, including those who suffer from conditions such as type 1 and 2 diabetes.

They found that the fibre in kiwifruit behaves differently to other commonly eaten fibres such as the fibre in apples, oranges and wheat bran, because kiwifruit have a very high water-holding capacity.

When eaten, kiwifruit fibre swells and thickens in the stomach and, as breakfast is digested, it is broken down into smaller sugars which move more slowly through the material made thicker by kiwifruit.

This resulted in less sugar being taken up.

Both of the main kiwifruit varieties produced by Zespri, Green and SunGold, have low glycaemic indexes of 39 and 38 respectively, meaning that carbohydrates were not taken up so rapidly by the body and glucose was only slowly released into the bloodstream.

Not having sugar highs and lows in the bloodstream means you have healthy blood sugar control, which helps to avoid the feelings of tiredness and hunger between meals.

Better blood sugar control could also help with maintaining stable blood sugar levels as part of a diabetes treatment plan, losing or maintaining a healthy weight and avoiding high sugar snacks between meals.

"People talk about blood-sugar spikes - when you first eat something that's high-glycaemic, you get a big peak and gradually as it's digested the blood-sugar levels come down and you can get a dip," said Zespri's health and nutrition innovation leader, Dr Juliet Ansell.

"With kiwifruit, you are not getting the dip when you feel a bit tired and hungry, and it's really keeping that regulation in your blood sugar."

Meanwhile, another study has pointed to the benefits of kiwifruit toward regular laxation.

For the first time in human clinical trials, green kiwifruit had been found to improve digestive health function and comfort, through a unique combination of kiwifruit enzyme actinidin fibre and other components.

Professor Richard Gearry, a gastroenterologist at Otago University, presented the New Zealand results of a multi-centre clinical trial on the effect of kiwifruit on digestive and gut health functions.

The study's goal 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).

Results showed that eating two green kiwifruit each day significantly improved bowel function and frequency in people with constipation but did not lead to diarrhoea in healthy people.

Further, it showed kiwifruit consumption had the potential to contribute greatly to gastrointestinal comfort, protein digestion and gut health.