Acne is a common and complex skin disease that affects individuals of all ages. Acne affects to some degree 85% of the population aged 11 to 30 years. Mild acne was defined as up to 10 lesions, moderate acne between 11 and 25 lesions, and severe acne as more than 25 lesions. It is not a life-threatening condition; however, it lasts for years and can cause physical and emotional scars. Despite this, acne may be a feature in many endocrine disorders, including polycystic ovary disease, Cushing syndrome, Congenital Adrenal Hyperplasia and acromegaly. Other nonendocrine diseases associated with acne include Apert syndrome, SAPHO syndrome, Behçet syndrome and PAPA syndrome. The overall knowledge about the causes, natural course, and therapy of acne is very low, not only among the general population but also among final year medical students and even among family physicians and nurses, where myths and misconception are still in practice.
Acne is a disease of the pilosebaceous unit [PSUs] which consists of sebaceous glands connected to hair follicle. These sebaceous glands produce an oily substance called sebum that normally empties onto the skin through the opening of the follicles. The pathology of acne is caused by four key factors: excess sebum production, hair follicular proliferation and plugging, Propionibacterium acnes (a normal anaerobic resident of the skin surface) colonization, and inflammation. Acne starts from the formation of hardened sebum, or the oily substance secreted to the skin through the sebaceous glands. This then will be permeated with acne-infecting bacteria, which in return will trigger the immune system to release white blood cells to obstruct the attack of the bacteria. As this happens, dead white blood cells and bacteria will accumulate in the hair follicles mixed with skin debris and dead skin particles. When the walls of this plugged follicle breaks down, it starts spilling everything like sebum, bacteria and shed skin cells, thereby leading to lesions and pimples also commonly known as zits. Acne lesions basically occur on the face, back, chest, neck and shoulders. Thus acne is a term for plugged pores [blackheads and whiteheads], pimples and even deeper lumps [cysts and nodules] that appear in different parts of the body.
Acne vulgaris is a leading skin disorder in irrespective of skin colour or age. Acne infantilis is the term used for acne that grows on newborn babies, on the other hand acne rosacea is related to middle-aged people. A recent practice survey conducted at the Skin of Colour Centre in New York City found acne to be the most common diagnosis in black and white patients. As a form of skin disease, the good news is that acne is not transmittable.
Although the exact cause of acne is still unknown, there are 3 main factors involved: hormonal, nutrition and environment. Some of the examples of these factors are listed here:
• Changing hormone levels in adolescent girls and adult women: One of the main factors include sudden burst of androgens that occur more during puberty leading to increased sebum production. The use of birth control pills can also cause outbreaks.
• Heredity or Genetics: Children usually have a tendency of getting acne from their parents and often get affected due to usage of drugs like androgens and lithium.
• Environmental: Irritants like pollution from industry or natural factors like high humidity, sun exposure, seasonal changes and climate can all precipitate an acne attack.
• Excess secretion of oil after using of skin products like moisturizers and cosmetics and certain types of makeup can also cause a breakout. Allergic reaction to components in cosmetic products can cause acne to erupt.
• Stress and anxiety. Stress may induce release of certain bioactive molecules that can enhance inflammation factors to be released. It is reported that the skin and the mind are linked.
A difference in the prevalence of acne between non-Westernized and fully modernized societies has been noted, and diet has been suspected to be the reason. This question regarding diet and acne is not a new issue and has been debated for many years. It was reported that acne was absent in the Inuit (Eskimo) population when they were still living and eating in their traditional manner. The prevalence of acne became similar to that in Western societies after their acculturation. Surveys of disease in some rural African villages in also reported far less acne than is found in the descendants of people in these areas who now live in the United Kingdom or the United States. More convincing is the study of schoolchildren from Purus Valley, a rural region in Brazil where of the 9955 children aged 6 to 16 years that were studied only 2.7% had acne.
Recently an analysis of 1200 Kitavan (Islanders of Papua New Guinea) individuals, including 300 aged 15 to 25 years, and 115 Ache (hunter-gatherers of Paraguay) individuals including 15 aged 15 to 25, found not a single case of acne of any grade. The diet of the Kitavan as well as the Ache includes mainly traditional foods that are locally cultivated hence the absence of acne in these societies is attributable to environmental factors, mainly local diets, which have a substantially lower glycemic index than the Western diet. This does not discard the hypothesis that an alternative explanation of the low prevalence of acne in these non-Westernized populations is that of genetic susceptibility to acne, especially given that the people in these isolated regions live in close-knit and closed communities.
Despite the debate, many westernised adolescents and their parents believe that food is a primary factor. A recent survey of adolescents found that as many as 62% to 72% believed that diet was a contributing factor in acne despite medical guidelines since the 1960s and 1970s that stated that diet plays no important role in acne, and that the condition is primarily attributed to genetic predisposition and hormonal influences. Recently, there has been a reappraisal of the diet and acne connection. The dietary components that have recently been revisited with regard to acne are dairy products, high-glycemic-index foods, fat intake, and fatty acid composition. Several studies have shown that higher levels of milk consumption were associated with acne risk. These studies, however, only suggest correlation but not causation and should be evaluated with caution. As the association was stronger with skimmed milk it suggested that it was not the fat content in milk that was the culprit. Researchers speculate that milk contains hormones and bioactive molecules, such as androgens, progesterone, and insulin growth factor-1 (IGF-1) or iodine all of which may have an acne-stimulating effect. The effect may be stimulated via a genetic pathway, involving FoxO1 transcription factor. This suggests that acne is certainly a disease with a genetic background and other factors induced by environmental growth factors in industrialized countries due to growth factor-mediated affects the genetics of acne. One study also links acne and cancer to the exogenous hormones in dairy products. More about the effects of these hormones are discussed in our book "Is Your Food Killing You?" Chocolate, oily or fatty foods, and foods with high sugar content have been repeatedly nominated as causing or exacerbating acne but no convincing evidence for such a link has been found either.
There are many other environmental pollutants besides added hormones and bioactive molecules deliberately added our foods that can cause acne. On rare occasions environmental pollution can result in a variant of acne called chloracne. Environmental acne results from various chemical exposures and the eruption may be mild or severe. One such example is the Yusho incident in Japan where ingestion of rice oil contaminated with polychlorinated biphenyls (PCBs), polychlorinated quarterphenyls and 2,3,4,7,8-pentachlorodibenzofuran caused acne like eruptions. Another similar incident occurred in Yucheng in Taiwan. In our book, "Is Your Food Killing You?" we discuss in more detail how these environmental pollutants enter the food chain.
Most mild case acne may be treated with over the counter acne medications. Standard therapeutic agents used in acne include oral antimicrobials, isotretinoin, and hormonal agents. The main limitation of current antibiotic treatment for acne is the rise of antibiotic resistance. Although isoretinoin therapy is very effective, it is associated with many potential side effects. These include dry skin, lips, and eyes, headache, decreased night vision, and more rarely, benign intracranial hypertension. It may also lead to an increase in liver enzymes and hypertriglyceridemia; the latter may potentially trigger acute pancreatitis. Additionally, isotretinoin is a highly teratogenic agent, especially if used within the first trimester of pregnancy.
Vitamins have been implicated to reduce the side effects of isotretinoin although this effect is controversial. Synthetic vitamins are widely used in cosmetics for the prevention and treatment of acne. It was reported that in 100 patients with acne (vs. matched controls), the systemic levels of vitamins A and E were much lower overall; also, the lower the levels of vitamins A and E, the more severe was the acne. It is likely that the blood levels of antioxidants are used up more readily in those with acne, because there is a greater demand to deal with free radicals that are produced during the stress to skin caused by acne. Several forms of vitamin C (ascorbic acid) are used in lotions, creams, serums, and patches. However, active L-ascorbic acid is such an excellent antioxidant that it is inherently unstable, turning brown as it is oxidized to dehydroascorbic acid when exposed to air. Therefore the shelf life of most formulations containing pure vitamin C is short. Vitamin D metabolites may be of importance for growth regulation and various other cellular functions in sebaceous glands making the sebaceous glands to be a promising target for therapy with vitamin D analogues. Omega-3 fatty acid is another supplement added to cosmetic products for the treatment of acne. An analysis of several cosmetic products containing omega-3 fatty acid supplements showed no conclusive evidence that these help in the treatment of acne.
Hormonal therapies used in acne include antiandrogens (androgen receptor-blockers) and agents designed to decrease the endogenous production of androgens by the ovary or adrenal gland, such as estrogens, combination oral contraceptives (OCs), low-dose glucocorticoids, or gonadotrophin-releasing hormone (GnRH) agonists. The use of OCs for acne is controversial because of their potential side effects. Knowing that you are not the only one inflicted with acne at some point in life or another helps as with a better understanding of acne, emerging drugs show potential for the future.
While the scientific research continues to be debated and reviewed, the best approach is to individualize an eating plan and focus on healthful dietary intake as diet seems to play a role indirectly in the management of acne. Continue to read up on acne research and help your fight against it.
Barrie has a keen interest in health and well being. If you want more on acne visit [http://acneandspots.com]
More on health and diet at [http://foodmythsbusted.com/blog]
By: Barrie McDowell
