Kiwi ‘Gold’ (400g)

BENEFITS OF EATING KIWI FRUIT (source: Michael Greger, MD, FACLM, NutritionFacts.org)

Did you know just how amazing kiwi fruit are? Making sure we eat one or two kiwis per day gives us incredible benefits. Read on if you want to know more about reducing the severity of the common cold, increasing length of sleep, improvement in IBS and DNA repair.

COMMON COLD

It is well known that deficiencies in certain vitamins and minerals can lead to significant impairment of immune function and an increased susceptibility to infection, which can be reversed by supplementation in deficient individuals.

However it is unclear to what extent supplementation may aid maintaining an optimal balance within the immune system in adequately nourished individuals.

Researchers in New Zealand found that the consumption of gold kiwifruit reduces the severity and duration of certain upper respiratory tract infection symptoms. The study was funded by the company that owns the patent to gold kiwifruits so only gold kiwifruit were studied.

A few dozen elderly individuals were randomized into one of two groups, eating two bananas a day or eating four kiwifruit a day for a month. They were then switched, one eating kiwifruits, one group eating bananas. The purpose of the study was to determine whether regular consumption of gold kiwifruit reduces the incidence, duration and severity of symptoms of upper respiratory tract infections, like the common cold. 

They found no reduction in overall incidence, but those that did get sick during the kiwifruit phase had significantly reduced severity and duration of head congestion and the duration of sore throat.

In the study which compared eating bananas, the banana eaters suffered for five days with a sore throat and congestion, compared with the kiwi eaters, who felt better after just a day or two.

The reason they studied older individuals is that they tend to be more susceptible to respiratory infections. Small children are another at-risk group.  Averaging twice as many upper respiratory tract infections as adults, four to six per year. So, 66 pre-schoolers were randomized into the same two groups, kiwi versus bananas. Not only were there again significant improvements in the symptoms to those who got sick on the kiwi study, fewer got sick in the first place. 45% lower odds of a cold or flu-like illness, which means that the children eating kiwis had almost a 50% reduction in the chance of having a cold or flu.

This suggests that kiwifruit consumption may be a daily prescription for health; however about 1 in 150 children reported being allergic to kiwifruit, which ranks them No 3 after milk and eggs and above peanuts in the survey of 3,500 children as the most common feed allergies.  So, they are not for everybody.

INSOMNIA

2 kiwifruits an hour before bed every night for 4 weeks resulted in improved sleep onset, duration and efficiency in adults with self reported sleep disturbances. Participants went from sleeping 6 hours a night to 7 hours.

IBS

Kiwifruit improves bowel function in patients with irritable bowel syndrome with constipation.  The study was for two kiwis a day for a month.  (The study was funded by the world’s largest marketer of kiwis.)

They did find such a kiwi intervention “shortens colon transit time, increases defecation frequency and improves bowel function”. No deleterious effects of kiwi consumption on psychological function or adverse events were found in these studies.

DNA PROTECTION AND DNA REPAIR

In 2003, a landmark study was published in the journal Carcinogenesis. It is well known that plant-based diets rich in fruits and vegetables can prevent the development of several chronic age-related diseases, including cancer. The mechanism behind this protective effect is not clear. We know whole plant foods are rich in antioxidants, which are capable of decreasing oxidative damage to DNA, and thus might prevent mutation and cancer

Our second line of defence against oxidative DNA damage is DNA repair. We are going to get some DNA damage in our world no matter how healthy our diets. However it is critical to find ways to up-regulate our DNA repair enzymes, to better assist with stitching our DNA back together again.

A study was carried out by the International Kiwifruit Organization. It showed significantly less DNA damage on days when participants were eating kiwifruits showing  evidence of DNA repair. It did not seem to matter how many kiwis the participants were eating, the same benefit was obtained whether they were eating one or three suggesting there is some kind of plateau effect. Possibly there is just some phytonutrient in kiwis that boosts this DNA repair enzyme system, and it is really a matter of whether we have it in our bloodstream or not, rather than how much of it is there

How you eat your kiwifruit is up to you, sliced with muesli at breakfast, putting one or two in your lunchbox or for a dessert after an evening meal.

March 2025