Benefits of Kiwifruit
Updated: Aug 27
Let's dive into the benefits of kiwifruit for gut health & nervous system function!
Firstly:
Consuming the whole kiwifruit (including the skin) significantly boosts nutrient intake compared to eating only the flesh. It increases fibre content by 50%, vitamin E by 32%, & folate by 34%.
Most mood-specific research focuses on gold kiwifruit, because it contains nearly 70% more vitamin C than the green variety.
Gut Health & Kiwifruit
The quick benefits:
Improves stool consistency due to fibre content
Reduces constipation
Aids protein digestion and the breakdown of gluten
Vitamin C content supports iron absorption and the immune system
Soluble fibres help support the gut microbiome
Anti-inflammatory
Let's break that down:
Stool consistency & constipation
Kiwifruit contains a mix of soluble and insoluble fibre. Soluble fibre dissolves in water and forms a gel-like substance, while insoluble fibre doesn't dissolve and adds bulk. Together, these fibres have a great capacity for water retention and swelling, which increases faecal bulk (the size/weight of stool) and softness. This allows for better lubrication and propulsion of waste through the colonm improving stool consistency and reducing transit time (how long it takes food to move through the digestive system), which helps reduce constipation.
Feeding your gut bacteria
The soluble fibres in kiwifruit are fermented by bacteria in the colon to produce short-chain fatty acids (SCFAs), beneficial compounds made when gut bacteria break down fibre. These SCFAs may further stimulate colonic motility (movement of the colon) and promote a favourable colonic microbial community, otherwise known as "good" gut bacteria.
Protein digestion
Kiwifruit contains actinidin, a natural proteolytic enzyme (an enzyme that breaks down protein) that aids protein digestion in the stomach and small intestine. Beyond aiding digestion, actinidin has been specifically linked to a reduction in gastrointestinal transit time, which also helps improve constipation. In small intestine models, kiwifruit was particularly effective at breaking down whey protein, gluten, gliadin, and zein, which may be especially beneficial for individuals with compromised digestive function.
Reducing inflammation
A specific protein in kiwifruit called kiwellin can be processed into a smaller peptide known as kissper. Kissper reduces oxidative stress (a build-up of unstable molecules that can damage cells) at the gastrointestinal mucosal interface (the lining of the gut) and displays anti-inflammatory effects.
Vitamin C, iron & immunity
Kiwifruit is high in vitamin C. When iron-rich foods are paired with vitamin C-rich foods, the vitamin C aids iron absorption. Vitamin C also supports the immune system and since most of the immune system is housed in the gut, supporting gut health further supports immune function.
Nervous System & Kiwifruit
The quick benefits:
Improves sleep onset, maintenance, and sleep quality (supports melatonin production)
Improves mood, depression, and fatigue
Vitamin C is a cofactor for dopamine and serotonin production
Vitamin C is depleted when stressed (the adrenals need vitamin C)
Kiwifruit contains serotonin
Acts as an antioxidant to reduce inflammation
Gut support also supports the brain, via the gut-brain axis
Let's break that down:
Sleep
Kiwifruit has been shown to increase sleep onset (the time it takes to fall asleep) and total sleep time, with significant decreases in waking time after sleep onset and a reduction in the number of nightly awakenings — overall improving sleep quality. This is because kiwifruit contains high concentrations of serotonin, which is a precursor to melatonin (meaning the body converts it into melatonin) and plays a vital role in regulating the sleep-wake cycle and REM sleep.
Sleep disorders are often linked to increased levels of oxidative stress. Kiwifruit is rich in antioxidants, including vitamins C and E, which may help suppress inflammatory cytokines (signalling molecules involved in inflammation) and free radical expression that can interfere with sleep.
Folate deficiency is a known contributor to insomnia and restless leg syndrome. Kiwifruit is a good source of raw folate, which may help mitigate these neuropsychiatric causes of poor sleep.
Try this: For optimal results, eat two medium-sized kiwifruits (skin included) approximately one hour before bed.
Mood & neurotransmitters
Vitamin C serves as an essential cofactor (a helper molecule an enzyme needs to function) for several enzymatic reactions in the brain, including the production of dopamine and adrenaline. It's also an essential cofactor in the metabolism of tryptophan, a necessary step in the synthesis of serotonin and low serotonin levels are frequently associated with lowered mood states. On top of this, vitamin C in kiwifruit enhances the absorption of iron, which is essential for dopamine and serotonin synthesis.
Vitamin C & stress
Vitamin C is depleted when we're stressed, because it's readily used up by the adrenal glands. If you're under stress, including vitamin C-rich foods is an important way to support adrenal health.
Whole food vs. supplements
Daily consumption of two gold kiwifruit is associated with significant reductions in mood disturbance, fatigue, and depression. Research indicates that gold kiwifruit provides greater benefits for subjective vitality than vitamin C supplements alone, suggesting that "whole food" delivery of nutrients is more effective than isolated vitamins.
Kiwifruit also contains other mood-regulating micronutrients, including vitamin E, folate, magnesium, and zinc. Vitamin E, in particular, may work synergistically with vitamin C in an antioxidant capacity to support mood regulation.
The gut-brain connection
Finally, the high fibre content in kiwifruit improves gastrointestinal function (as spoken about) and because the gut and brain are so intertwined, this gut support also benefits mental health & the nervous system.
Tailored Support For You
If you’re ready for a more personalised approach, book a 1:1 naturopathic consultation for tailored support designed around your unique symptoms, lifestyle & health goals.
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