Facts with impact

The sleep superpowers of kiwifruit

Research funded by High-Value Nutrition and supported by Zespri International Limited shows that eating two green kiwifruit a day can instantly improve sleep quality, mood, and leave you feeling refreshed in the morning.

Photo of sliced fresh green kiwifruit and the text: New Zealand's kiwifruit contain key compounds which help improve sleep

Riddet Institute PhD candidate Alex Kanon and his supervisor, Dr Sharon Henare from Massey University, researched the benefits of eating two green kiwifruit in the evening and found an immediate positive effect, with participants experiencing a better sleep the same night.

“Other studies have looked at sleep and kiwifruit over a longer period of daily consumption – around 4 weeks. We wanted to see if we could see an acute effect – can you eat kiwifruit now and feel the benefits straight away,” says Alex.

The research in healthy men (half with poor sleep and half with good sleep) saw participants eating an evening meal, followed by either two fresh green kiwifruit (without skin) or two powdered dried kiwifruit (with skin) or water. The research team then measured sleep quality, mood and urinary biomarkers.

“We found that regardless of whether you normally have good or bad sleep, kiwifruit had an immediate positive impact on different aspects of sleep quality and mood,” says Alex.

The research demonstrated that this was true after just one night of eating kiwifruit.[1]

Sleep is essential for the cellular repair of the body and can affect our immune function, psychology and increase the risk of obesity, type 2 diabetes and cardiovascular disease.  One night of sleep disturbance can affect a person’s ability to concentrate, which may increase technical errors and decrease overall mood the following day.

 “Serotonin plays a central role in the regulation of sleep-wake cycles. We saw significant increases in serotonin metabolites the morning after participants ate fresh or dried kiwifruit.”

“Both groups felt that it was easier to wake up in the morning and they felt less sleepy after eating the kiwifruit. There were also improvements in their psychological wellbeing in the morning, with significant improvements in positive mood, esteem and vigour.”

These findings are particularly relevant with the growing recognition of the role of sleep in the development of chronic disorders like diabetes. [2], [3], [4], [5], [6]  The distribution of kiwifruit globally presents an easy and relatively affordable way for people to improve their sleep on a daily basis.

 “The study shows there is potential for Aotearoa New Zealand kiwifruit-based products with health messaging related to sleep quality and mood, while also potentially bringing increased economic benefits for kiwifruit growers,” says Joanne Todd, High-Value Nutrition National Science Challenge Director.

With more funding, High-Value Nutrition can continue to uncover even more impactful facts about New Zealand’s food that could benefit population health, elevate what our country has to offer, and boost the value of our exports.

[1] Kanon AP et al (2023) Acute effects of fresh versus dried Hayward green kiwifruit on sleep quality, mood, and sleep-related urinary metabolites in healthy young men with good and poor sleep quality. Front Nutr. 2023 Mar 14;10:1079609. doi: 10.3389/fnut.2023.1079609

[2] Gottlieb, D. J., Redline, S., Nieto, F. J., Baldwin, C. M., Newman, A. B., Resnick, H. E., & Punjabi, N. M. (2006). Association of Usual Sleep Duration With Hypertension: The Sleep Heart Health Study. Sleep, 29(8), 1009-1014.

[3] Cappuccio, F. P., Taggart, F. M., Kandala, N. B., Currie, A., Peile, E., Stranges, S., & Miller, M. A. (2008). Meta-analysis of short sleep duration and obesity in children and adults. Sleep, 31(5), 619-626.

[4] Meier-Ewert, H. K., Ridker, P. M., & Rifai, N. (2004). Effect of sleep loss on c-reactive protein an inflammatory marker of cardiovascular risk. ACC Current Journal Review, 13(4), 18.

[5] Gangwisch, J. E., Heymsfield, S. B., Boden-Albala, B., Buijs, R. M., Kreier, F., Pickering, T. G., Malaspina, D. (2007). Sleep Duration as a Risk Factor for Diabetes Incidence in a Large US Sample. Sleep, 30(12), 1667-1673.

[6] Fang, J., Wheaton, A. G., Keenan, N. L., Greenlund, K. J., Perry, G. S., & Croft, J. B. (2012). Association of Sleep Duration and Hypertension Among US Adults Varies by Age and Sex. American J Hypertension, 25(3), 335-341.