Does eating collagen get under your skin?
Pig trotters in sweet vinegar is a traditional dish loved by many Chinese. Aside from its rich flavour, the dish is popular for another reason: the trotters contain very little meat and fat, but plenty of collagen.
Those obsessed with looking forever young have gone from having collagen injected and slathered on skin, to eating it to keep age at bay. Collagen, a fibrous protein that connects and supports tissues in the body, is found naturally in trotters, shark's fin, and chicken and fish skin. But these days, thanks to a craze originating in Japan, it's being added to all kinds of food - from marshmallows and jam to ramen and soft drinks.
Collagen makes up about one quarter of the body's protein and occurs naturally in humans and animals. Derived from the Greek words 'kolla' (glue) and 'gennao' (to produce), collagen is needed for healthy skin, bones, organs and connective tissue. Collagen production decreases naturally with age. It is also affected by free radicals formed through sun exposure, pollution, smoking, stress and alcohol use.
Its reduction is most obvious in the skin. 'Healthy collagen fibres act as little springs inside the skin, giving it elasticity, suppleness and firmness,' says Dr Tinny Ho, a dermatologist at SkinCentral. 'Loss of collagen causes wrinkles, sagging and a thin, crepey look to the skin.'
Secretary Paulina Chan, 30, swears by collagen supplements. Chan downs a collagen drink once a day in a bid to keep her face wrinkle-free. 'I think it has made my skin more radiant, and I have fewer pimples. People tend to think I'm younger than I really am,' she says.
Eating collagen may help the overall formation of collagen in the body, according to a paper published in the Archives of Dermatological Research in 2008. Research published a year later by Tokyo University suggested that eating collagen could reverse the effects of sun-related skin ageing.
Other experts, however, are not convinced. The British Skin Foundation asserts that there is no evidence to show that eating collagen is beneficial for the skin in any way. 'Very few oral supplements have good published studies to prove their effectiveness,' Ho says. 'In general, dermatologists do not regard oral supplements as an effective way of boosting the collagen in the skin.'
There is actually no way for collagen to be transported directly to the skin when it is eaten, as it is broken down during digestion into amino acids just like any other protein. These amino acids are then used to produce different kinds of protein needed for muscle and cartilage growth, healthy hair and nails, haemoglobin production and other processes in the body.
'Any perceived improvement in skin condition is more likely to be because of a placebo feel-good effect and increased amount of water intake due to consumption of the product,' says Sally Poon, a registered dietitian.
The protective nature of skin also means that collagen creams don't work, either. Although skin is porous to allow perspiration to take place, it also prevents microorganisms from invading the body. To be able to enter the epidermis - the outermost layer of skin - a substance must have a molecular weight of less than 3,000. Most collagen molecules used in cosmetic creams and lotions have a molecular weight of 300,000.
'Collagen creams are not really useful for increasing collagen in the skin. They can be good moisturisers, at best,' Ho says. She adds that effective products should stimulate collagen production within the skin, rather than contain collagen per se. 'Many skincare ingredients such as retinols, glycolic acids and certain peptides have been proven to have this collagen-boosting effect,' she says. However, they can cause skin irritation and are found in higher, effective concentrations mainly in products that require a dermatologist's prescription.
Prevention appears better than cure when it comes to collagen loss. In particular, sun exposure can cause a lot of damage to the collagen structures within the skin. 'UV, along with pollution and lifestyle habits such as smoking and stress, cause the formation of free radicals in the skin, which affects the skin's ability to repair itself and produce new collagen,' Ho explains. 'I would strongly suggest the proper use of a good sunscreen with UVA and UVB protection on a daily basis and the use of good antioxidant skincare products to counteract the damaging effects of free radicals.'
Poon suggests that those concerned with healthy skin should simply focus on eating healthily, instead of eating collagen. 'In general, people in Hong Kong do not have a protein deficiency problem. Adhering to a balanced diet is the best way to obtain suitable amounts and types of proteins and all other nutrients,' she says.
A 2001 Swedish study found that eating more vegetables, olive oil, mono-unsaturated fat and legumes, and eating less milk and dairy products, butter, margarine and sugar resulted in less skin wrinkling, even with sun exposure.
