By Jill Coleman
We can no longer blame it on adolescent hormones. In the United States, not only do up to 95% of teens experience some degree of facial acne, but more and more adults are also suffering from chronic acne, and for some it is crippling.
The conventional notion that acne is purely an issue of facial cleanliness and attention to clean linens is an oversimplification. In fact, more research is emerging that identify the traditional American diet as the culprit. Acne development starts in the gut, not solely on the skin. Loren Cordain wrote a great book about this called “The Dietary Cure for Acne” and this article touches upon many concepts from his book. Highly recommend!
In a general sense, several factors can influence acne development from gender to genetics to hygiene to certain conditions relating to hormonal imbalances such as polycystic ovarian syndrome (PCOS) or diabetes. Food influences acne by affecting hormones like insulin, testosterone, estrogen, and other chemical messengers that induce cascades of reactions that can lead to the development of acne.
Normal skin cell formation versus acne pathology
The normal life cycle of the skin cells involves cellular formation, cellular movement toward the more superficial layers of the skin, programmed cell death (apoptosis) and a final sloughing off. The whole cycle called desquamation takes about one month.
In the case of acne, apoptosis is delayed and cells do not slough off easily, resulting in an ultimate blockage and cutting off of oxygen to the pore. Cells remain adhesive, not breaking down as expected, which creates a thick, scaly layer of cells, known as hyperkeratinization.
Under normal circumstances, the adjacent sebaceous gland produces sebum, an oil and wax mixture produced to hydrate the skin and prevent dehydration. Overproduction of sebum and the enlargement of the sebaceous glands contribute to acne formation also.
Once oxygen is cut off in the pore due to pore blockage, the normal bacteria that healthfully sit on the skin’s surface, will instead colonize the blocked pore, and thrive in the now anaerobic environment, which brings in additional pro-inflammatory immune cells. And if inflammation is severe enough, the underlying hair follicle can rupture and damage the surrounding tissue, presenting as redness and swelling on the skin’s surface. Deeper damage can present as a cyst, with the potential for scarring.
Role of hormones
Now that we understand a little more about how acne develops, we can take a look at how food affects the key hormonal players to either promote or hinder acne development.
The hormone testosterone plays a role, as increased levels of the hormone also increases growth of acne and can lead to excessive sebum production. It is not, however, the absolute amount of testosterone circulating in the blood, but instead the rate at which testosterone is converted to its more active form, dihydrotestosterone (DHT).
The enzyme 5-alpha-reductase, existing in the skin, is responsible for this conversion, and people who have higher enzymatic activity of this enzyme also have greater acne development. A high protein diet has been shown to slow the activity of this enzyme.
In addition, newer resources cite insulin’s role in acne development via two hormones: insulin-like growth factor binding protein 3 (IGFBP-3) and insulin-like growth factor 1 (IGF-1).
Both of these growth factors are impacted by insulin to affect the development of acne, and each play a specific role in the pathogenesis. IGFBP-3 increases the rate of apoptosis, while IGF-1 stimulates cell growth and proliferation. Insulin decreases IGFBP-3’s availability to the cells; an undesirable outcome since apoptosis is needed to maintain normal rates of sloughing off; while insulin increases IGF-1, further exacerbating the hyper-keratinization problem leading to a blocked pore.
It is important to understand the pathogenesis of chronic acne, as well as the key metabolic players like testosterone and insulin, to be able to treat the condition through food elimination and dietary manipulation.
Seventy-percent of the standard American diet consists of a combination of refined oils, refined sugars, grains and dairy. Insulin release is higher when consuming refined sugars, grains and even the low-glycemic diary, which is still insulinigenic. Thus, it is advisable to avoid all processed, refined grains and cereals, refined sugars, and all dairy (cheese, milk, whey, etc) to control insulin release.
A study published in the Journal of the American Academy of Dermatology (Smith, et al. 2007) concluded that acne sufferers who undergo a low-GI diet have significantly reduced lesion incidence versus a group undergoing a high-GI “traditional” diet.
And more recently, a study published in the journal Molecular Nutrition & Food Research (Smith et al., 2008) showed that a low glycemic load diet significantly reduced biochemical markers for acne development (such as insulin, sex hormone binding globulin, IGF-1, etc) in as little as 7 days on a low GL diet.
Systemically pro-inflammatory foods like fatty meats, refined vegetable oils and alcohol will affect the inflammation associated with acne also, and should be limited. Choose foods that contain higher relative amounts of omega-3 to omega-6 unsaturated fatty acids, like walnuts, flaxseed, and Wild Alaskan salmon to reduce inflammation further. Supplementing with a high potency omega-3 supplement is a good idea.
Another food component that could impact acne development is lectin, made up of protein or a combination of proteins and carbohydrates and are found frequently in grains, beans and legumes. Although many believe these food components are minimally absorbed, they are, in fact, absorbed in the gut via EGF receptors. In the blood stream, they can bind to certain enzymes that hinder the breakdown of connections between skin cells, increasing cellular adhesion, hinders sloughing off, and blocks the pore. Thus, it may be advisable to avoid the legume/nut family (except for walnuts).
To lower your risk of developing chronic acne or improve current acne, your nutrition plan should include the following:
- High amounts of low glycemic index fruits and vegetables
- Organic poultry and lean beef (grass-fed is better since it is higher in omega-3s)
- Lean cuts of pork and eggs (mostly whites, though 1-2 yolks/day is okay)
- Wild salmon and white fish
- Walnuts and olive, avocado and canola oils
- Grain products on the whole should be avoided, though for extremely active individuals, small portions of lower GI carbs like oat bran and yams can be eaten in moderation