Nowadays, a healthy way of living is strongly associated with healthy food. A healthy diet considers the intake of a variety of nutrient rich food. The human body needs different nutrients to support overall health. Consumers are increasingly choosing nutrient-dense food – food high in fibers, healthy oils, high in proteins, vitamins, minerals, numerous antioxidants. The healthy diet is progressively including a variety of nutritious foods, like vegetables, fruits, seeds, nuts, and lean proteins.
The awareness is growing that a diet rich in macronutrients and micronutrients has a crucial role in health. A balanced diet of body friendly nutrients boosts the immune system, prevents diet-related diseases, and contributes to a good mood.
The same appeal is reflected in cosmetic products. Consumers believe that what is healthy for the body is also beneficial for the skin. Therefore, consumers expect that products containing ingredients derived from food will bring the beneficial advantage to a cosmetic product. Skin care products will influence skin metabolism, improve skin condition, and reduce signs of ageing.
The cosmetics industry is developing new skin care products to meet this new market demand. Natural food ingredients with proven effectiveness are incorporated into the products, but innovative ones are also sought after.
The list of foods from which such effective ingredients can be sourced is getting longer.
Table 1: Plant based oils
| Oils / Triglycerides | Source |
| Coconut oil | Seeds of Cocos nucifera |
| Avocado oil | Dehydrated fruit of avocado (Persea gratissima) |
| Sunflower seed oil | Seeds of sunflower (Helianthus annus L.) |
| Apricot kernel oil | Kernel of Prunus armeniaca |
| Cocoa butter | Cocoa bean (Theobroma cocoa L.) |
| Mango butter | Mango seed (Mangifera indica) |
| Papaya seed oil | Plant Carica papaya |
| Wheat germ oil | Extraction of wheat germ (Triticum vulgare) |
| Olive oil | Olives (Olea europaea) |
| Grape seed oil | Grapes (Vitis vinifera) |
| Sesame oil | Sesame (Sesamum indicum) |
| Almond oil | Almond (Prunus amygdalus ) |
| Walnut oil | Walnut (Juglans regia) |
| Black current seed oil | Fruit seed Ribes nigrum |
| Rasperry seed oil | Fruit seed Rubus idaeus |
| Linsees oil | Flax (Linnum usitatissimum) |
| Neem oil | Neem seed (Melia azadirachta) |
Natural ingredients are derived from different parts of plants, vegetables, fruits, and grains. The most common form of ingredients are oils, and the table below presents the most used oils and their sources. Natural ingredients derived for food provide important functions as antioxidants and moisturizing agents: emollients, occlusives and humectants. They serve multiple benefits to the skin.
Ingredients rich in antioxidants
The main role of antioxidants in skin care products is to prevent damage to the skin caused by free radicals.
Some of the biological processes that take place in the body result in the formation of free radicals. These are chemical species that have at least one unpaired electron, which makes them very unstable, but also reactive. To become stable, these molecules need to pair with one electron and find it in another molecule. This process is called an oxidative reaction.
Now the second molecule is lacking an electron, it becomes a free radical and looks for a new molecule to provide the electron it needs. This way a chain reaction is started.
In addition, numerous highly reactive free radicals, obtained from molecular oxygen, are reactive oxygen species (ROS). Basically, ROS are by-products of body’s aerobic metabolism. ROS react with proteins, lipids, and nucleic acids, in the form of their degradation and thus cause cell damage.
When the generation of ROS and other free radicals highly increase, due to the influence of internal factors, as body physiological reactions, and external environmental factors, as pollution, UV irradiation, climate and smoking, a phenomenon known as oxidative stress is occurring. The body cannot protect cells from these reactive products anymore. Cell damage begins to appear. Oxidative stress also affects the reduction of collagen and elastin production and accelerates the aging process of the skin, such as formation of wrinkles, skin dryness, and loss of skin tone.
The human body can mitigate the damage caused by these reactions with the help of molecules with antioxidant activity. Antioxidants are molecules that fight and neutralize free radicals, as scavengers, stopping the oxidative chain reaction before vital compounds are damaged. They protect cells from oxidative damage and reduce the effects it causes.
Moisturizing agents
The low water content of the skin is the main cause of skin ageing and skin dryness. The most visible signs are the dull look, uneven tone, and fine wrinkles. More difficult forms of skin dryness are scaly skin, flakes, redness, and irritation. Retention of water in the stratum corneum, the outermost layer of the skin, is essential for adequate moisturization of the skin.
This can be achieved by preventing the evaporation of water from the skin using occlusive ingredients, using emollients to keep water under protective film or by keeping the integrity of the skin barrier.
Emollients form a film on your skin’s outer layer with a dual role. The first role is as a protective film to prevent the loss of moisture. The second role is to soften skin by soothing dry and irritating parts of skin. Natural emollients from food sources are derived from vegetable oils and various plant extracts. Plant derived emollients are extracted from plant leaves, plant seeds, ground fruit or nuts.
Occlusives form a thick and greasy layer on your skin. Their function is to prevent water loss and to keep it at the current level. Occlusives do not increase the moisture, but they form an effective barrier to retain existing water.
Humectants provide moisturization by drawing water from deeper layers and from the air and by locking the water in the stratum corneum. Humectants increase the moisture level.
Table 2: Moisturizing agents used in skin care
| Actives | Function on the skin | Food ingredients |
| Emollients | Hydration due to protective film formationSoothing | Coconut Almond Avocado Argan Olive Borage Primrose Castor bean Palm Sunflower Raspberry |
| Occlusives | Hydration due to formation of a protective layer on the surface of skin and create a barrier to prevent moisture loss | Coconut oil Olive oil Jojoba oil Almond oil |
| Humectants | Hydration by drawing water, attracting water and bind it | Sorbitol Glycerol Honey |
Food ingredients and their activity in cosmetic products
- Carotenoids
Carotenoids are the most potent single oxygen radical scavengers, as they have the ability to absorb their excess energy. Carotenoids are beta-carotene, lycopene, lutein and zeaxanthin. Lutein has the highest antioxydant activity. Caroteniod provide excellent protection from skin damaging free radicals. In addition, they prevent degradation of collagen and elastin. They also maintain skin density and firmness.
- Oats
The oat (Avena sativa) is a cereal grain, rich in lipids, proteins, vitamins E, B3 and B5. Oats also contain beta-glucan, as a long-chain carbohydrate. The numerous nutritious ingredients contained in oats strengthen the skin’s barrier, sooth and moisturize skin. Products with oats are protective against external influence and are very effective moisturizers. Oat is a helpful active ingredient for symptoms of very dry skin, like roughness and scalling.
- Green tea extract
Cosmetic products enriched with green tea extract primarily help reduce the signs of aging, the appearance of wrinkles and fine lines, soothes redness and repairs damage, decrease puffiness, and diminish the appearance of dark circles, reduces the appearance of cellulite. Green tea extract contains polyphenols, caffeine and catechin derivatives.
It gained cosmetic importance due to its prolonged moisturizing effect and influence on skin appearance factors, improving the complexion tone, texture, and resilience. Products with green tea extract also stimulate circulation and regulate sebum production.
- Aloe vera
Gel from leaves of plant aloe vera are rich source of vitamins A, C, E and B12, amino acids, polysaccharides, phytosterols, minerals like zinc and magnesium. Providing an antioxidant effect and preventing trans-epidermal water loss, it slows down the aging process of the skin. As aloe vera contains large amounts of water, it strongly hydrates and soothes the skin. It gives a cooling effect on sunburns and rashes, and it helps soothing itchiness or irritation.
Aloe vera is suitable for acne-prone skin, as well as for oily skin, as it helps minimize enlarged pores.
- Berries
Strawberries, blueberries, raspberries, blackberries, and acai berries are well-known as superfoods. Fatty acids in berries attract and bind the water in the skin and thus helps to regulate the moisture. In addition, berries are high in vitamin C and antioxidant phenols and flavonoids. They contain vitamins A and E as well. All these nutrients make berries the ideal ingredient for protection of skin damage, promoting cell repair and rejuvenation of the skin.
- Avocado oil
Avocado oil contains exceptional nutrients for the skin. It has a particularly high content of vitamins A, E, D, C and B complex and therefore has a very strong antioxidant activity. Furthermore, it contains essential fatty acids, particularly high concentration of monounsaturated fat, then sterols, phytosterols and carotenoids. The rich composition of avocado oil provides moisturization to skin, protection, restores and soothes the skin. It is a suitable ingredient for anti-aging products, reduces wrinkles and improves skin texture.
- Coconut oil
Coconut oil is one of the most used oils in cosmetic products. It contains saturated fatty acids, such as myristic, palmitic and lauric, Due to such content, it possesses oxidative stability, and it is used in a variety of different cosmetics products. Coconut oil is considered an effective moisturizer and emollient especially for dry skin, as it has water-retention properties. As an occlusive ingredient, it forms film on the top of the skin and keeps moisture underneath, soothing the skin. In addition, it improves skin elasticity, improves uneven skin tone, and softens skin. It also provides low UV protection.
- Olive oil
Olive oil is rich in vitamins A, D, K, and E, oleic acid, beta carotene, polyphenols, essential fatty acids, in particular alpha-linoleic acid. In addition, it contains a strong antioxidant squalene. Skincare products with olive oil are used to hydrate and nourish the skin, to prevent moisture loss and keep the skin soft. They help to prevent premature skin ageing.
- Almond oil
The nourishing oil contains a high level of fatty acids, which supports barrier function of skin. It helps restore and maintain skin barrier function. Almond oil also contains vitamins A, B1, B2, B6, D and significant amount of vitamin E. With such strong antioxidant activity, it is effective against oxidative stress. High content of linoleic acid makes almond oil suitable for dry skin and very dry skin conditions. Almond oil acts as an emollient and as an occlusive agent. It can help reduce symptoms of skin irritation and improve damage from UV exposure. Almond oil is one of the most used emollients for skin care products.
- Grape seed oil
Grape seed oil is extremely rich in powerful antioxidants. It contains resveratrol and polyphenolic compounds (proanthocyanidis and procyanidis), as free-radical scavengers and inhibitors of ROS. They can improve skin tone and provide protection against UV rays. In addition, it contains omega fatty acids, vitamins E and F, and vitamin C. Skin products with grape seed oil can improve skin’s appearance, soften the skin, and improve its elasticity.
Grape seed oil is an excellent compound for the anti-ageing cosmetic product, as it fortifies the skin’s barrier, helps reduce fine lines and wrinkles and boosts collagen production.
- Jojoba oil
Jojoba oil helps repairing the skin lipid barrier, reduce trans-epidermal water loss. The structure of jojoba oil is like skin’s sebum and, therefore, it helps control sebum production. Jojoba oil is rich in flavonoids and vitamin E, antioxidants that defend skin against oxidative stress. It is also a source of B-complex vitamins. Jojoba oil has a protective and caring function in a skin care product, as it hydrates and softens dry skin, restores its elasticity and radiance.
Food ingredients are great molecules for skin care. They should primarily be considered as conditioning agents, as they support proper functioning mechanism of the skin, like nourishing and protection of the skin, prevention of moisture loss, improvement of skin elasticity. Food ingredients have a great role as anti-ageing agents and agent to improve the condition of dry skin. Further benefits are connected to a healthy look of the skin.
References:
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