Q) My 26-year-old daughter has acne vulgaris. She eats well, uses only natural products on her face, exercises and generally feels she's doing all she can to be fit and healthy. Her acne continues, though. Her GP suggested a light box-not the type used for SAD, but one that uses red and blue light waves. Would this be any good?-P.S., via e-mail
A) Acne is usually thought of as a transient condition of adolescence. But, in fact, over 50 per cent of women and 40 per cent of men have facial acne past the age of 25. So your daughter is not alone. It's also true that adult acne is four times more likely to persist in women than in men.
The first question to ask is whether your daughter has really explored all the possible reasons for her acne.
You mention diet. In the past, doctors have tended to disregard any diet- acne connection, but the idea is now beginning to gain some ground. Observations made in non-Western-ized populations show a low incidence of acne.
Indeed, exposure to the usual Western diet appears to stimulate acne: for example, native cultures in Paraguay and Papua New Guinea are no longer acne-free after having shifted to a Western diet (Arch Dermatol, 2002; 138: 1584-90).
Earlier this year, refined carbo-hydrates were fingered as the possible culprits. A clinical trial tested a group of acne sufferers, and put half of them on a diet low in refined carbohydrates, leaving the rest to carry on eating as usual. After 12 weeks, those who ate less-refined carbs had significantly less acne-and lost weight, too (Am J Clin Nutr, 2007; 86: 107-15).
Another dietary factor may be dairy. The prestigious Harvard School of Public Health recently reported a small increased risk of acne among adolescent girls who drink milk-whether full-cream, low-fat or skimmed (J Am Acad Dermatol, 2005; 52: 207-14). There's a similarly low but significant extra risk of acne if you have Candida infection (Mycoses, 1995; 38 Suppl 1: 7-13).
Conventional treatments for acne are, to say the least, unsatisfactory. Isotretinoin is the best known, but comes with major side-effects, in par-ticular, birth defects. So no woman of childbearing age should go near it. Another long-standing treatment is benzoyl peroxide, a crude therapy that simply peels off the top layersof skin; it is also potentially carcino-genic. Antibiotics, both applied tothe skin and in pill form, are claimed to be effective, but quickly become resistant-and the side-effects are substantial.
However, alternative treatments are also few and far between. Some acne sufferers find supplements of blackcurrant seed and evening prim-rose oil helpful, but there's no clinical evidence to support their use. There are data, though, supporting the effectiveness of herbal Ayurvedic formulations (J Ethnopharmacol, 2001; 78: 99-102). Also, when Japanese doctors tested homeopathy on a wide rangeof chronic skin conditions, including acne, they found a more than 50-per-cent improvement in up to 88 per cent of patients (Complement Ther Med, 2007; 15: 115-20).
The drug-free treatment that's getting everyone excited is light-blue light, red light, even laser light. These treatments are collectively known as 'photodynamic therapy' and, in the last few years, a flurry of clinical trials have tested their effectiveness (see box below).
Throwing light on acne
One of the first tests of photodynamic therapy (PDT) used a 585-nm pulsed-dye laser. Ten patients with acne scarring received the treatment, and all showed "cosmetic improvement" in the depth of their facial scars. The therapy is thought to stimulate the production of collagen in the skin (Dermatol Surg, 2002; 28: 942-5).
More recently, doctors at Yale University obtained even better results with the same technology, achieving "complete clearance [of acne] in 100 per cent of patients". The trick was to first prepare the skin with a chemical compound to increase its sensitivity to light. The acne clearance lasted at least six months after only three treatments in most cases (J Drugs Dermatol, 2006; 5: 45-55). No side-effects were reported, although this particular laser technology has caused blistering when used for skin problems such as port-wine stains (J Invest Dermatol, 1995; 104: 798-802).
Potentially less hazardous is light treatment using high-intensity narrow-band blue light. Although less powerful than a laser, it was effective in a double-blind clinical trial by Israeli doctors, who found that it produced "a significant reduction of 59-67 per cent of inflammatory acne lesions after only eight treatments of 8-15 minutes". The benefits were maintained for at least eight weeks. How does it work? Intense blue light destroys acne bacteria in the lab, so this is how it's believed to work on skin (J Cosmet Laser Ther, 2003; 5: 111-7). The device tested was ClearLight(R), a 50-kg piece of kit only available from a cosmetician (see www.curelight.com).
Portable light-therapy kits are available, however, and have been tested by dermatologists at London's Hammersmith Hospital. They found that the best uses blue-red light, which works "probably by combining antibacterial and anti-inflammatory action". Called BeautySkin (lb199.99 plus lb15.00 p&p from www.acne-advice.com), its final average acne clearing was 58 per cent-but a solo blue-light kit wasn't far behind in efficacy (Br J Dermatol, 2000; 142: 973-8)