The question: Can certain foods contribute to acne?
The answer: Foods aren't thought to cause acne, but studies strongly suggest that some can aggravate the condition. According to a review published last week in the Journal of the Academy of Nutrition and Dietetics, refined starchy foods and dairy products are leading culprits.
Acne is caused by the combination of too much sebum – an oily fluid secreted by glands in pores – and a buildup of dead skin cells. During adolescence rising levels of hormones, especially testosterone (present in males and females), are thought to trigger acne by creating a surplus of sebum.
Prior to the 1960s, dietary advice was a standard part of acne therapy. Patients were told to avoid eating too much carbohydrate and too many sugary foods because elevated blood sugar levels were implicated in acne. Turns out, there was merit to this theory.
Today, the most compelling evidence linking food to acne revolves around foods with a high glycemic index (GI) such as white bread, refined breakfast cereals, white rice, cookies, cake and sugary drinks. One well-designed study demonstrated a significant reduction in acne when people removed high glycemic foods from their diet. High GI foods cause blood glucose and insulin to spike, which in turn, is thought to trigger a hormonal response that leads to acne.
I advise anyone with acne to cut refined (white) and sugary foods from their diet. Foods with a low GI that don't spike glucose and insulin include sprouted whole grain breads, steel cut oats, 100-per-cent bran cereal, brown rice, quinoa, pasta, legumes, nuts, apples, oranges, berries, grapes and pears.
Dairy products have also been linked to acne. People who drink two or more servings of milk, particularly skim milk, each day are far more likely to have moderate or severe acne compared to those who drink less. Researchers speculate that certain components in milk – other than milk fat – may stimulate insulin and growth factors that increase testosterone.
If you plan to cut back on dairy to see if your acne improves, be sure to include other calcium-rich foods in your diet such as fortified non-dairy milks, almonds, firm tofu, cooked green vegetables, and canned salmon with the bones.
There is some evidence that chocolate may worsen acne, but the evidence isn't as strong as it is for high GI foods and milk. Being overweight is also thought to increase the risk of acne in males and females.
Foods rich in omega-3 fatty acids may actually help lessen acne. These special fats are thought to decrease inflammation in the skin and reduce certain hormones linked to acne formation. Good sources of omega-3 fats include salmon, trout, sardines, fish oil supplements, ground flaxseed, flax oil, chia seeds, walnuts and soybeans.
Leslie Beck, a registered dietitian, is the national director of nutrition at BodyScience Medical. She can be seen every Thursday at noon on CTV News Channel'sDirect (www.lesliebeck.com).
Click here to submit your questions. Our Health Experts will answer select questions, which could appear in The Globe and Mail and/or on The Globe and Mail web site. Your name will not be published if your question is chosen.
The content provided in The Globe and Mail's Ask a Health Expert centre is for information purposes only and is neither intended to be relied upon nor to be a substitute for professional medical advice, diagnosis or treatment.
Leslie Beck