ACNE – THE ROLE OF DIET*
Acne is a common problem. Between 80%-90% of Australians will, at some time during their life, be affected by acne, and it can be very severe in up to 5% of all individuals. It is, of course, especially common in adolescents and young adults, at a time when the hormones are seeking a new balance. However it can occur at any age, from just after birth right through to middle age.
Severe acne is associated with low self-esteem, poor body image, social withdrawal and depression.
Acne vulgaris (common acne), or simply acne, is a common skin disease in humans, characterised by areas of skin with seborrhoea (scaly red skin), comedones (blackheads and whiteheads), papules (pinheads), pustules (pimples), nodules (large papules) and possibly scarring.
Acne affects mainly skin with the densest population of sebaceous follicles. These areas include the face, upper part of the chest and back. The lesions are caused by changes in the pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland.
The Cause of Acne
There are four major components of acne:
· Excessive production of oil by the skin
· Skin cells dividing excessively (hyper-proliferation)
Acne is caused by a blockage to the opening of the oil glands in the skin. These glands are called sebaceous glands and normally provide an oily substance called sebum, which is necessary to keep the skin supple and healthy. When there is excessive production of sebum and associated hyper-proliferation of the skin cells, the openings of the sebaceous glands become blocked or clogged with old dead skin cells. Usually these cells are simply shed from the surface of the skin, but if too much oil is being produced, the dead cells stick together and become trapped inside the opening of the gland. The blockage is sometimes visible. The outer-part of the blockage (near the surface of the skin) can become oxidised and become dark in colour, when it is called a blackhead. Sometimes the blockage is invisible and the collection of sebum under the skin appears as a small white lump or a whitehead.
If the blockage is tenacious the build up of sebum causes the gland to swell becoming pimples. These can rupture under the skin causing an inflamed red appearance. This inflammatory response attracts white cells to the area of damaged tissue. These are pustules, and are often infected with bacteria.
Sometimes the blockage is slightly deeper, causing the development of cysts below the skin. These may heal with significant destruction of the tissues, causing scarring. The scar is created by the wound trying to heal itself, resulting in the formation of scar tissue.
Enlargement of sebaceous glands and an increase in sebum production occur with increased androgen production, as occurs at and after puberty.
There is often a family history of acne, suggesting a possible genetic basis for the condition.
Acne is not an allergic disease.
Conventional Treatment of Acne
· General Skin Care.
General skin care should include regular washing with warm soapy water and avoidance of strongly fragranced or alcohol based skin care products. Products should be used that will not ‘clog pores’. These are described as ‘oil-free’ on the package.
· Topical Treatments
Topical treatments for acne include a wide variety of creams, lotions, gels and solutions composed of benzoyl peroxide, salicylic acid, alphahydroxy acids, antibiotics or retinoids (vitamin A derivatives).
A simple over-the-counter treatment for acne is benzoyl peroxide, which can be extremely effective in many people with mild acne. For effective treatment of both present and future acne, topical medications should be applied to the entire face or region where acne occurs.
Topical preparations have a mixture of beneficial effects on acne including anti-bacterial, anti-inflammatory and /or other anti-comedogenic properties.
· Oral Treatments
More resistant or severe acne will need the supervision of a professional such as a Dermatologist.
Oral antibiotics, such as the tetracyclines, are often effective. However, like topical preparations, they do not cure acne, and may need to be taken over a prolonged period of time. Antibiotics treat the associated infection but also cause thinning of the sebum.
Hormonal therapy may be used and is often effective in females with acne. Such therapy must be under the direction of the prescribing physician.
A daily intake of the vitamin A derivative isotretinoin, (marketed under a number of trade names including Roaccutane and Claravis) over a period of 4-6 months can lead to long-term resolution or reduction of acne. This product should only be considered as a last resort in severe acne, and must be supervised by a professional. Long term and often severe side effects can result. Isotretinoin is strictly controlled because of its effect on an unborn baby if taken during pregnancy.
The Role of Diet as a Cause of Acne and in the Treatment and Prevention of Acne
For years, doctors have proclaimed that diet has nothing to do with acne. This reflects the nutritional ignorance of physicians and their inexperience in treating disease with a diet that is nutrient-dense.
Does what we eat really affect acne?
In studies of diverse populations, individuals with acne commonly attribute the condition, or its exacerbation, to diet. Chocolate and oily or fatty foods, especially dairy, are implicated. However, reviews prior to 2007 concluded that diet plays no important role in acne and that the condition is primarily attributable to genetic predispositions and hormonal influences.
More recently, well-designed, controlled, prospective studies have supported the association between specific dietary factors and acne. The published literature looking at the association between diet and acne was critically examined by Dr E. H. Spencer and her co-workers at the Department of Medicine, George Washington University School of Medicine, Washington DC. Their article Diet and acne: a review of the evidence was published in the International Journal of Dermatology in 2009 (48, 339-347). They stated in the conclusion:
“Evidence suggests that components of Western diets, particularly dairy products, may be associated with acne. The hormonal effects of dietary components, such as glycaemic index levels or fat or fibre intake, may mediate the effect of diet on acne risk.
Until 2005, cross-sectional, cohort, and clinical intervention studies designed to address the relationship between diet and acne typically failed to incorporate adequate controls, objective measures, and appropriate statistical analyses. Well-designed prospective studies published since 2005 have elucidated the mechanisms whereby particular foods and dietary constituents may influence acne risk and severity.”
Acne typically results from excessive sebum production, which causes follicular cells to hyper-proliferate and block the follicle opening, as described above. Bacteria can then colonise in the follicle, and an immune response results in inflammation. Sebum production may be influenced by androgens and hormonal mediators, such as SHBG and IGF- 1 all of which may be influenced by the following dietary factors.
· Dairy Products
Early population-based studies showed that areas with minimal consumption of dairy products had very low acne prevalence. More recently, three large studies reported a positive association between milk intake and acne. Adebamowo et al., in three separate published studies, showed that higher levels of milk consumption were associated with a 20% or greater increase in acne in adolescent girls (2006) and similar findings in teenage boys (2008). This association held true for whole milk as well as skim milk Furthermore in the Nurses Health Study, those who consumed high amounts of dairy products during high school (based on later recall) showed a greater prevalence of severe acne than those with less frequent consumption (2005).
In recent observational studies, skimmed milk was consistently associated with acne, suggesting that the fat content of milk does not appear to affect its acne-causing ability. Some authors have reported that the hormones in milk such as IGF-1, 5alpha-reduced steroids and alpha-lactalbumin, may survive milk processing and affect the proteaceous unit. Milk consumption also increases IGF-1 production.
Hormonal influences that affect insulin-like growth factor 1 (IGF-1) levels are a key to the development of acne. Elevated IGF-1 levels lead to changes in gene expression that cause inflammation, hormonal changes, increased oil production and the development of acne lesions. Protein intake is the major factor that determines circulating IGF-1 levels, especially protein from dairy products.
· Foods with a High Glycaemic Index
The glycaemic index (GI) is a measure of the effect of a certain food on blood glucose levels. High GI foods like refined carbohydrates produce spikes in blood glucose, leading to excessive insulin levels in the blood (hyper-insulinaemia), which contributes to diabetes, heart disease and several cancers. Hyper-insulinaemia not only promotes inflammation, but also raises IGF-1 levels, further contributing to acne. Several studies have shown that a low GI diet leads to an improvement in acne, and a decrease in IGF-1 and skin oil production.
· Fat Intake
Diets high in saturated fat increase the concentration of IGF-1.
Low-fat, high-fibre diets tend to decrease the concentration of IGF-1 and androgens.
Omega-6 fats are precursors to pro-inflammatory mediators and have been associated with the development of inflammatory acne. In contrast, high levels of omega-3 fatty acids have been shown to decrease inflammatory factors, and may reduce acne risk by decreasing IGF-1 levels. The ratio of omega-6 to omega-3 fatty acids in Western diets is at least 10:1, and often as high as 30:1. Studies have suggested that inflammatory markers increase as this ratio increases. Ideally, the ration of omega-6 to omega-3 fatty acids in our diet should be radically different to currently, it should be in the realm of 3:1. The perfect, unattainable, would be 1:1.
· Protective Micronutrients
Blood levels of zinc, carotenoids and vitamin E are known to be lower in acne sufferers compared to those without acne, suggesting that maintaining micronutrient adequacy may help prevent acne. Vitamin D and sunlight exposure are also protective against acne.
A dominantly plant based diet is the ideal way to ensure optimal levels of micronutrients (see my March 2009 newsletter Foods for Health).
While acne is not a fatal condition, in severe cases it can have significant psychological consequences as the result of low self-esteem, poor body image, social withdrawal, depression and even suicidal intent. This is stress to the individual. Research has shown that increased acne severity is significantly associated with increased stress levels. Acne can cause stress and thus perpetuate itself to some extent.
Many different treatments exist for the treatment of acne. An appropriate diet, as outlined above, may be sufficient to control this condition. Even if some form of treatment is also required, diet should be an integral part of the overall management.
*Copyright 2011: The Huntly Centre.
Disclaimer: All material in the huntlycentre.com.au website is provided for informational or educational purposes only. Consult a health professional regarding the applicability of any opinions or recommendations expressed herein, with respect to your symptoms or medical condition.
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