Introduction

Hair and nail conditions for many people are important aspects of their appearance, however, healthy nails and hair signify proper nutrition and wellbeing. The quality of both the nails and hair can be influenced by diet, hydration, and other lifestyle choices. The hair on your head provides important protection against the sun and helps maintain moisture in the scalp, while the hair follicles on the skin act as a sensor in our environment as well as contribute to wound healing and closure, there is also nasal hair which acts as a barrier to dust and germs.

Nails are also important; they protect the soft tissues of the tips of fingers and toes and also provide support to the fingertips and toes enabling gripping and pushing movements. Kiwi is important for nail and hair health due to its rich vitamin C content, and antioxidants, which support the growth, strength, and appearance of nails and hair.¹ This article will discuss in more detail how kiwi fruit promotes hair and nail health and how it can easily be incorporated into your diet to maximise its nutritional benefits.

Kiwi nutritional breakdown

Kiwis are a very nutrient-dense food that offers a variety of health benefits. The two most commonly consumed varieties are the Actinidia deliciosa and Actinidia chinensis.¹ The Actinidia delciosa is the more commonly available “green kiwi” with a fuzzy brown outer skin and green flesh. This has a more tangy taste compared to the Actindia chinensis also known as the gold kiwi due to its yellow flesh and bronze skin. This gold kiwi has gained popularity over recent years for its sweeter taste. Despite their taste differences, both contain high levels of vitamin C, antioxidants, and minerals which are important for your health. One serving is typically around 70 -100 grams, per 100g contains the following:¹

• 83.1 grams of water
• 61kcal of energy
• 1.14 grams of protein
• 14.7 grams of carbohydrates
• 3 grams of fibre – Around 12-15% of the recommended intake
• 9 grams of sugar
• 92.7 mg of vitamin C – These are high levels exceeding the recommended daily intake, around 120²
• A range of other antioxidants vitamin E, polyphenols, and carotenoids that play an important role in hair and nail health

Benefits of vitamin C for the hair

Vitamin C has a variety of biological functions which makes it important in protecting hair. One of its most important functions is its involvement in collagen production. Vitamin C is needed by the enzymes that make collagen in the body, which is a protein that is vital for hair strength. It helps to protect against damage by providing structural support to hair follicles making them less prone to damage. It also supports hair growth, reduces thinning, and hydrates the hair. As the fact that collagen supports the regrowing of dead skin cells on the scalp. This supports the cell by aiding new growth and removing debris and dead cells of the skin. 

Vitamin C also protects hair follicles from what is known as oxidative stress, this is stress caused by an imbalance between reactive molecules that damage the cells known as free radicals and antioxidants. Antioxidants such as vitamin C neutralize these molecules preventing hair damage. It must be noted that antioxidants are very important throughout the entire body.

Oxidative stress commonly causes inflammation which can irritate the scalp, Vitamin C can reduce this inflammation and help to maintain a healthy scalp full of moisture through numerous mechanisms:

• Antimicrobial properties - Vitamin C is needed in the immune system and boosts our ability to fight off bacteria and fungi to prevent dandruff and other scalp conditions from occurring
• Lipid synthesis – Vitamin C supports lipid synthesis, which helps to retain water and moisture in the scalp, keeping the hair hydrated and less prone to irritation
• Scalp oil – Vitamin C helps to regulate the levels of sebum, which are the oils on the skin, this ensures the scalp does not become too dry or too oily

Together, these mechanism ensure the scalp and hair are properly hydrated, strong, and protected from damage.^1,2

Benefits of vitamin C for nail health

Vitamin C is also important for nail health and is similarly beneficial through its involvement in collagen production and its antioxidant properties. Collagen is essential to the nail by providing the structural support, strength, and flexibility. A study showed that collagen and vitamin C supplementation increased nail growth by 12%, decreased nail breakage by 64% and over 80% of those involved in the study reported a noticeable increase in nail health and appearance e.g. a brighter appearance.³ A vitamin C deficiency can often result in brittle, slow-growing nails.

As mentioned, vitamin C has important antioxidant effects, protecting the body from reactive molecules known as free radicals, this specifically helps to protect the nail matrix from damage and is the region at the base of the nail responsible for new cells that contribute to nail growth. The nail matrix is constantly growing, unlike the hair follicles which have periods of rest. It is therefore crucial the nail is protected as any damage can lead to various nail abnormalities such as ridges, discolouration, and changes in thickness and size.

Other Kiwi Vitamins and minerals for nail and hair health 

Kiwis contain a variety of other vitamins and minerals that are beneficial in hair and nail health and, although found in moderate amounts, support the condition and growth of both nails and hair:

• Vitamin E – supports scalp health by improving circulation and reducing oxidative stress, creating an environment for hair growth. Like vitamin C vitamin E acts as an antioxidant, protecting hair follicles and nails from damage caused by free radicals
• Vitamin K supports protein synthesis, contributing to the maintenance of strong and healthy hair strands and nails
• Folate (Vitamin B9) - Essential for DNA synthesis and cell division needed for cells to grow and regenerate to maintain healthy hair and nails
• Potassium - Helps to maintain electrolyte balance and hydration levels in the body, including the scalp and nail matrix
• Fibre - Although not directly linked to nail and hair health, fibre promotes healthy digestion and nutrient absorption, ensuring that the body receives the vitamins and minerals necessary for nail and hair health
• Polyphenols & Carotenoids - More antioxidants that protect the nails and hair from damage^1,2,3

Practical Ways to Incorporate Kiwi into Diet 

As described, kiwis contain many nutrients that play a big role in maintaining healthy nails and hair but what is the best way to incorporate kiwis into your diet? Here are a few examples:

• Eating raw kiwi as a snack – The green kiwi for more of a tangy taste, the golden kiwi for a sweeter taste
• Adding kiwi slices to salads or yoghurt
• Incorporating kiwi in desserts e.g crackers and ice cream
• Using kiwi as a topping for cereal or porridge
• In a smoothie with some of your favourite sweets
• You can eat the skin to maximise nutritional benefits
• Pair with rich iron foods, vitamin C in kiwi increases iron absorption from plant-based iron foods such as spinach and lentils

FAQs

What are the differences between green kiwi and gold kiwi

Green kiwi (Actinidia deliciosa) has a tangier taste and a fuzzy brown outer skin with green flesh, while gold kiwis (Actinidia chinensis) have a sweeter taste with yellow flesh and bronze skin. Both varieties are rich in vitamin C and other nutrients beneficial for hair and nail health.

Can kiwi fruit help with scalp conditions like dandruff or itchiness?

Yes, the vitamin C and antimicrobial properties in kiwi fruit may help alleviate scalp conditions by fighting off bacteria and fungi that contribute to dandruff and irritation.

Is there a difference in nutrient content between ripe and unripe kiwi fruit?

A- While ripe and unripe kiwi fruit contain similar nutrients, the vitamin C content may be slightly higher in ripe kiwis. However, unripe kiwis may be firmer and have a slightly tangier taste.

Summary

Kiwis are packed full of nutrients that promote healthy growth and protection of both nails and hair. They have particularly high levels of vitamin C which is important in collagen production, hydrating the scalp, and protecting hair follicles and the nail matrix. Kiwis also contain many other beneficial nutrients such as vitamin A, folate, and a range of antioxidants which also protect and support growth. They can be consumed in a variety of ways and have two common varieties the “golden” and “green” kiwi which have slight differences in sweetness, both equally beneficial.