Your eyes might be the window to your soul but your skin is the open door to your age. A bright, supple skin is a communication to the world that here is a healthy person.

There is also evidence your diet directly affects the health and appearance of your skin. Even small increases in fruit and vegetable consumption lead to visible improvements in skin colour and this applies across all cultures.

The effect is probably due to carotenoids and other pigments found in fruit and vegetables causing a heightened “golden” hue to the skin. Research has even shown that people who eat a lot of foods high in carotenoids are consistently rated as more attractive than people with fewer carotenoids in their diet. To keep your skin as healthy and glowing as it can be, here are few specific skin-friendly foods to focus on.

Strawberries

Berries of all sorts are very healthy foods. The key benefit of berries is their antioxidant content; indeed, strawberries are such powerful antioxidants that NASA looked at using strawberry extract to protect its astronauts against the effects of radiation once beyond the protective shell of the Earth’s atmosphere.

Strawberries, like all berries, are an excellent source of antioxidant polyphenols. Strawberries also contain a range of nutrients such as vitamin C, manganese, magnesium, B vitamins and potassium but it is the powerful polyphenols that have been shown in recent times to be mighty healthy.

The all-round antioxidant qualities of tomatoes make them very useful to protect your skin against oxidative damage.

Sun exposure is a leading cause of skin damage and therefore ageing. You might think of enjoying some chilled strawberries on a hot day but not think of those delicious strawberries as sun protection. However, research suggests they very well could be.

Researchers from Spain and Italy prepared human skin-cell cultures and added strawberry extracts to the cultures at concentrations of 0.05mg/mL, 0.25mg/mL and 0.5mg/mL. These skin cells were then exposed to UV light equivalent to 90 minutes of midday summer sun on the French Riviera.

When the strawberry-protected cells were compared to cells that had no strawberry but an equal UV exposure, results showed that cells immersed in strawberry extract survived better and had reduced DNA damage. The protection also increased as the concentration increased, 0.5mg/mL extracts giving the best protection.

The antioxidant anthocyanin compounds from strawberries have anti-inflammatory and enzyme-modifying effects that reduce the chances of developing skin cancer and skin damage.

Tomatoes

Tomatoes when fully ripe are packed with nutrition. They contain lots of vitamin C, carotenes and potassium. A fully ripe tomato contains up to four times more beta-Carotene than green tomatoes.

Lycopene is a carotenoid related to beta-Carotene and found in high concentration in tomatoes. In recent times it is lycopene that has been gaining a lot of attention for its healing potential but it’s by no means the end of tomato’s nutritional bonanza. Tomatoes also provide fatty acid derivatives (including 9-oxo-octadecadienoic acid) and vitamin A as well as bone-healthy vitamin K. They are also a source of vitamin B₆, folate and fibre.

The all-round antioxidant qualities of tomatoes make them very useful to protect your skin against oxidative damage. There is evidence that tomatoes, and especially lycopene, can reduce skin reddening after sun exposure and help retain moisture in skin in air-conditioned environments.

In an interesting study done at Newcastle University in the UK, researchers compared the skin of 20 women, half of whom were given five tablespoons (55g) of standard tomato paste with 10g of olive oil every day for 12 weeks. The effects on their skin were compared with the remaining volunteers, aged between 21 and 47, eating just olive oil for the same length of time.

The volunteers were exposed to UV rays found in sunlight at the beginning and end of the trial. Among those eating tomato paste, researchers found significant improvement in the skin’s ability to protect itself against UV.

Compared with the other women, the tomato-eating group had 33 per cent more protection against sunburn in the form of less redness. The researchers calculated the protection offered by the tomato paste to be equivalent to a sunscreen with a sun protection factor (SPF) of 1.3.

Skin samples taken from groups before and after trial showed an increase in levels of procollagen, a molecule that gives skin its structure and loss of which leads to skin ageing and lack of elasticity. There was also less damage to mitochondrial DNA in the skin, which is also believed to be linked to skin ageing.

Cucumbers

Cucumber does not have the healing reputation of more celebrity vegetables like broccoli but it is actually a very healthy food. While it is refreshing due to its high water content there are still plenty of valuable nutrients in your humble cucumber.

Cukes are a valuable source of conventional antioxidant nutrients including vitamin C, beta-Carotene and manganese. In addition, cucumbers contain numerous flavonoid antioxidants including quercetin, apigenin, luteolin and kaempferol. In animal studies, fresh extracts from cucumber have been shown to provide specific antioxidant benefits and reduce inflammation.

The skin of cucumber is actually an excellent source of the mineral silica which contributes to the strength of connective tissues in your body.

The added bonus as far as your skin goes is that the skin of a cucumber is actually an excellent source of the mineral silica, which contributes to the strength of connective tissues in your body. This connective tissue is the structure that provides a framework for your body and includes muscles, tendons, ligaments, cartilage and bone.

Juice of cucumber, including the cucumber skin, is often recommended to improve the health and appearance of human skin since connective tissue like collagen is necessary to give skin its structure. This is why you may see someone with cucumber rings resting over their eyes.

Whether the silica is absorbed through the skin in great enough quantity to be of any benefit remains to be proved. You are far better to eat your cucumbers skin and all, thus receiving an antioxidant and silica boost that will be great for your skin.

Avocadoes

Avocadoes are rich in monounsaturated fat and can assist supporting the right fat profile in your skin. You can use avocado oil on your skin as a moisturiser, though it does more than moisturise. Avocado oil may also protect skin from sun damage.

According to a study published in the journal Archives of Dermatological Research, applying avocado oil to your skin prior to sun exposure reduces sunburns and inflammation. You still need to apply sunscreen and shouldn’t spend too long in the sun but this attests to avocado’s skin protective effects when used on the skin.

Instead of just lathering on avocado oil, though, you should eat avocadoes and get all the benefits that avocadoes have to offer your skin as it ages.

As well as their fat content, avocadoes are a great source of both insoluble and soluble fibre. The former keeps you regular while the latter helps control appetite by making you feel fuller longer.

However, when it comes to your skin, the real power of avocadoes is vitamin E. This nutrient is the key to improving your skin’s health. As a fat-soluble antioxidant, vitamin E is ideally suited to protecting the fats of your skin against oxidative free radical damage.

The other great thing about avocado is that it is an excellent source of carotenoids. We tend to think about carotenoids as most concentrated in bright orange or red vegetables like carrots or tomatoes. While these vegetables are fantastic sources of carotenoids, despite the dark green skin and largely greenish inner pulp of avocado it is now known to contain a spectacular array of carotenoids.

Researchers believe that avocado’s amazing carotenoid diversity is a key factor in its anti-inflammatory properties. The list of carotenoids found in avocado include well-known carotenoids like beta-Carotene, alpha-Carotene and lutein but also many lesser known carotenoids including Neochrome, neoxanthin, beta-cryptoxanthin, zeaxanthin and violaxanthin.

To return to where we began with avocado, one of the criticisms of avocado has been that it is too high in fat (about 85 per cent of its calories come from fat). As we have said, these fats are largely monounsaturated but there is more to it than that. Avocadoes also contain phytosterols that account for a major portion of avocado fats. These phytosterols include beta-Sitosterol, campesterol and stigmasterol and they help keep inflammation under control. The anti-inflammatory benefits of these avocado fats are particularly well documented in problems associated with arthritis.

Then there are avocado’s polyhydroxylated fatty alcohols (PFAs). PFAs are widely present in ocean plants but fairly unique among land plants. Like avocado’s phytosterols, its PFAs also provide anti-inflammatory benefits.

Lastly, avocado contains high amounts of a monounsaturated fatty acid called oleic acid — more than half its fat content. Oleic acid helps the digestive tract form transport molecules for fat that can increase absorption of fat-soluble nutrients like carotenoids. As a monounsaturated fatty acid, it has also been shown to help lower your risk of heart disease.

This last action of oleic acid in your digestive tract also brings up of another point, which is that the health of your skin is heavily dependent on the health of your digestive tract.

Fermented foods

The health of your digestion is so closely linked to the healthy ageing of your skin because your skin is an organ of elimination, as is your digestive tract. If things aren’t going well in your digestion then your skin will be dealing with an excess toxic load as well as an array of other harmful substances that would not be there if digestion was healthy.

Perhaps central to your digestive health is the bacteria present in your gut (your microbiome). Unfortunately, most of us are inadvertently killing all of the good bacteria we need in our systems through processed foods, antibiotics, stress and chlorinated water. This is deadly because we are also not replenishing our bodies with the probiotics we need to live a happy, healthy life.

So many of the health concerns we face today are caused by an unhealthy microbiome. Most physical and mental disease originates in the digestive system. This includes disorders such as acne, depression, asthma, autism, food allergies and digestive disorders.

Once you heal your digestive system by balancing your microbiome, many disease symptoms will often disappear. In simple terms, the health of your digestive system depends on having the right bacteria in the right balance and in turn your overall health heavily depends on the health of your digestion. So a healthy microbiome is central to how your skin will age.

Ancient cultures all around the world consumed fermented food and beverages at almost every meal. These fermented foods contain enzymes and beneficial bacteria from lacto-fermented vegetables, fruits, beverages, raw dairy products and condiments. In modern times, fermented foods are rarely seen around the dinner table. We are no longer getting the live probiotics and enzymes from our food that our bodies so desperately need.

Before refrigeration, cultures would preserve their vegetables and dairy through lacto-fermentation, which increases the nutritional content of the product dramatically. When food goes through the fermentation process it begins to produce beneficial bacteria such as Lactobacilli, along with other strains, that sustain the health of your entire body. Without enough of these healthy bacteria in your body you begin to experience symptoms that range throughout the body but often begin with your skin.

With the right equipment you can ferment many foods including cabbage, carrots, beets and more. That cabbage sitting in the fridge can be turned into sauerkraut. You don’t have to ferment your own food, of course — the growing awareness around the need for fermented foods means that many are being made by ethical artisanal producers. You can also consume pre-fermented foods like miso and tempeh.

When you begin to eat fermented food on a daily basis you are providing the nutritional basis for a thriving and healthy bacterial ecosystem in your gut. Getting the bacteria in your digestive tract right means your skin will age as well as possible.

Incorporate these foods suggested here into your daily meal planning and you can be comfortable in your skin for life.