In a society obsessed with appearances, acne often influences a person's quality of life, leading to social withdrawal, anxiety, and sometimes depression. Treatment of the skin problem is therefore essential, and new research suggests that diet could play a bigger part than was thought.
A recent study published in the Journal of the Academy of Nutrition and Dietetics has determined that there is increasing evidence of a connection between diet and acne, particularly from high glycemic load diets and dairy products, and that medical nutrition therapy (MNT) can play a role in acne treatment.
Since the late 1800s, research has linked diet to this common disease, identifying chocolate, sugar, and fat as particular culprits. But in the 1960s, studies began to refute the link between diet and acne.
"Recently, dermatologists and registered dietitians have revisited the diet-acne relationship and become increasingly interested in the role of medical nutritional therapy in acne treatment," says one of the study authors, dietitian Jennifer Burris of the Department of Nutrition, Food Studies, and Public Health at New York University.
Her team culled information from studies between 1960 and 2012 that investigated diet and acne. Acne occurs when hair follicles get plugged with oil and dead skin cells, creating an environment for bacteria to thrive. They may appear in the form of whiteheads, blackheads or pimples.
Diet aside, the condition can be triggered or aggravated by many factors: a family history of acne, hormonal changes, certain medications, stress, sweatiness, certain cosmetics and skincare products, improper cleansing methods, and aesthetic treatments.
In Hong Kong, acne affects 80 per cent of adolescents and young adults aged 11 to 30 years. "Developed countries have more acne sufferers, as often more development leads to increased ingestion of refined carbohydrates," says Dr Suseela Narra, a dermatologist at Narra Dermatology and Aesthetics in Washington.
The US alone has 17 million acne sufferers.
"I advise my patients to avoid processed foods and refined carbohydrates, including white bread, white pasta and white rice, as well as anything that is pre-packaged," Narra adds.
"I tell them to concentrate on eating whole fruits, vegetables, whole grains, and good fats like avocados and olive oil. They often see improvement after reducing sugar and refined food consumption. I have to say dietary control has more of an effect on mild to moderate acne than on severe acne."
The Glycemic Index is a scale from 0 to 100 that ranks carbohydrate-rich foods by how much they raise blood glucose levels. Pure glucose serves as a reference point with a GI of 100.
High GI foods (70 or more) include white bread, baked potato and pretzels. Low GI foods include pumpernickel, yam and legumes.
High GI foods increase insulin levels, causing the stimulation of sebaceous glands, which then produce increased sebum, resulting in the clogging of pores and acne. In general, high fibre foods tend to have a relatively lower GI.
Dairy's contribution to acne is controversial. The hormones in dairy products are thought to stimulate sebaceous glands, much like our endogenous hormones do. Some studies show more of a connection between acne and skim milk than with whole milk.
If you avoid dairy, Karen Chong, registered dietitian at Matilda International Hospital, cautions that it is important to replace the calcium from other high calcium food sources such as dark green leafy vegetables, calcium fortified soy products such as tofu, calcium fortified orange juice, almonds, beans, and sardines with edible bone.
Hippocrates said, "Let food be your medicine and let medicine be your food."
Skin is constantly under construction and needs nutrients to repair and rebuild.
Charmain Tan, a registered dietitian at Seventeen Nutrition Consultants, suggests eating a well-balanced diet rich in fruits, vegetables, fish rich in omega-3, and low GI foods.
A healthy diet might keep blood sugar steady and fight inflammation and oxidative damage that link to skin problems. "Maintain a food diary and regularly review it to pin down what sort of foods are giving you skin problems," Tan suggests.
Medical reviews so far contain very little objective data, and studies have been inconclusive on the relation between diet and acne, says Dr Georgia Lee, aesthetics physician and pioneer of DrGL skincare products in Singapore. This is due to methodological limitations, such as small sample size, lack of appropriate controls, incomplete reported results or failure to clearly define the changes in acne.
But Lee believes there is a link between diet and acne, "as many dietary factors influence a variety of hormones and growth factors, which in turn influence sebaceous gland biology and production of sebum.
"I find that acne associated with seborrhoeic dermatitis seems to do very well with a low glycemic, minimal bread and alcohol diet. Abstinence, if adhered to, should lead to the condition improving in three months."
To keep zits at bay involves learning how to manage stress, reduce caffeine, alcohol, unhealthy fats and sugar, drink more water and engage in regular exercise.
The dermatologists' arsenal of anti-acne medications - benzoyl peroxide, antibiotics and Accutane - hasn't expanded in decades.
Recent studies have suggested other treatment possibilities, from viruses present on human skin, to herbal tinctures of thyme, marigold and myrrh.
Burris and colleagues say the medical community should not dismiss the possibility of diet therapy as an adjunct treatment for acne.
"At this time, the best approach is to address each acne patient individually, carefully considering the possibility of dietary counselling," she says.