Which foods should be prioritised to slow down skin ageing?

Throughout life, the body's cells are subjected to oxidative stress. This refers to the generation of highly reactive molecules known as free radicals. These are ubiquitous in the process of cellular metabolism and can interact with DNA, proteins, and polyunsaturated fatty acids in the body, causing DNA chain breaks and oxidative damage, protein-protein cross-links, protein-DNA cross-links, and oxidation of lipid metabolism. All these alterations are the primary internal causes of ageing and skin dysfunctions.

This observation has led to a medical revolution that has emphasised the role of antioxidants and free radical scavengers in the prevention and management of skin ageing. As in vivo oxidation ultimately leads to the ageing of the organism, exogenous antioxidant supplements, of which diet is a significant source, have become a research topic for several years now.

Thus, to limit skin ageing, it is recommended to consume foods rich in antioxidant compounds such as certain vitamins (vitamins A, C and E), polyphenols, carotenoids, bioflavonoids and trace elements (zinc, manganese or selenium).

Theindex ORAC (Oxygen Radical Absorbance Capacity) measures the free radical absorption capacity per 100 grams of food. The higher the ORAC index, the more quantitatively the food possesses antioxidant properties. The federal government estimates that Americans consume 4,000 to 5,000 ORAC units per day, equivalent to 2 ½ servings of fruits/vegetables. However, research estimates that people need 12,000 to 13,000 ORAC units to effectively eliminate free radicals!

According to this index, here are the foods richest in antioxidants that should be consumed very regularly to slow down skin ageing.

1. Clove

2. Oregano

3. The acai berries

4. Cocoa (powder, unsweetened)

5. Dark chocolate (> 70% cocoa)

6. The powdered curry

7. Turmeric

8. The cooked artichoke

9. Pomegranates

10. The apple (Granny Smith)

11. Cooked broccoli

Furthermore, the lycopene, a red liposoluble pigment belonging to the carotenoid family, is an excellent anti-wrinkle compound. In a study published in 2008 in the "European Journal of Pharmaceutics and Biopharmaceutics", researchers discovered that out of the 20 people studied, those with high skin concentrations of lycopene had smoother skin. Consuming more lycopene can also protect the skin from sunburn. This pigment is primarily found in the tomato, the watermelon, pink grapefruit and papaya.

Lipids form a significant part of the skin and are closely linked to the function of the epidermal barrier, the structure of membranes, the balance of the internal environment, and the repair of damage. Skin ageing is accompanied by a decrease in fat content, primarily due to a reduction in the skin cells' ability to synthesise and secrete lipids. Moreover, the amount of dietary lipids consumed is closely related to the lipid composition of the body and skin tissues, and an insufficient intake of essential fatty acids or abnormal fat metabolism leads to severe skin diseases. Polyunsaturated omega-3 and omega-6 fatty acids play an important role as human skin barriers, and also have certain effects in the prevention and treatment of skin inflammation. In mice, a study has shown that oral olive oil can reduce skin ageing induced by chronic psychological stress by acting on the NF-B NRF2 pathway. Also in mice, it has been demonstrated that 7-MEGATM 500 (a product containing more than 50% palmitoleic omega-7 acid present in fish oil) alleviates the oxidative stress of the skin induced by UV-B rays, inflammation, ageing, and promotes skin regeneration.

Further studies have shown that fermented fish oil protects skin ageing by inhibiting free radicals induced by fine particles, blocking the pathway of the Mitogen-Activated Protein Kinase/Activator Protein 1 (MAPK/AP-1).

In summary, numerous scientists have proven the effect of dietary fatty acids such as omega-3, omega-6, and omega-7 on skin ageing.

Which foods rich in "good fats" should we consume?

Avocados, nuts (almonds, walnuts, hazelnuts...), seeds, oily fish (salmon, sardines, herring, trout...), sunflower oil, olive oil, sesame oil, linseed oil, rapeseed oil, and margarines made from vegetable oil.

Beware, not all fatty acids are beneficial in our diet. Those referred to as saturated are generally best avoided. They can be found in fatty meats and processed meats, animal fats, dairy products high in fat (butter, cream, whole milk...), palm oil, coconut oil, many processed foods, and most fried foods.

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• WILLIAMSON G. & al. Skin bioavailability of dietary vitamin E, carotenoids, polyphenols, vitamin C, zinc and selenium. British Journal of Nutrition (2006).

• FRIGOLA A. & al. ORAC and TEAC assays comparison to measure the antioxidant capacity of food products. Food Chemistry (2009).

• SHAW G. Is your diet aging you?Simple strategies to keep you young, inside and out (2014).

• SOYUN C. The role of functional foods in cutaneous anti-aging, Journal of Lifestyle Medicine (2014).

• CHANGWEI CAO & al. Diet and skin aging — from the perspective of food nutrition. Nutrients (2020).