According to Dr. Jeannette Graf, a dermatologist from Great Neck, NY and author of Stop Aging, Start Living: The Revolutionary 2-Week pH Diet, the pH of the food you consume and products you use affect the state of your skin. As Graf states in the January 2007 Elle: “Reducing exposure to chemicals can definitely help stabilize skin and hair pH.” Although some experts agree with Graf’s alkaline theory, some also believe the skin should be kept at a slightly acidic pH, as stated by Danny Siegenthaler, a doctor of traditional Chinese medicine and co-creator of Natural Skin Care Products by Wildcrafted Herbal Products: “Maintaining a slightly acidic pH of around 5.5 is critical.”
If these contrasting opinions seem confusing, it’s no wonder — a Google search for “skin ideal pH” results in just as many statements for the acidic (under 7) as the alkaline (over 7)!
What support is there for each pH theory?
According to Dr. Graf, the skin should be kept at a pH slightly higher (more alkaline) than 7 (neutral pH) because most of the foods consumed by Americans result in acidity, including meat, sugar, alcohol, and processed foods. As Graf tells Elle, “They’re converted into acids in the bloodstream…the slightly acidic epidermis becomes superacidic, and your complexion suffers.” Graf‘s opinion is further supported by homeopath Heather Osler, who states in this article that “80 to 90 percent of the average American’s diet contains acidifying foods.” and Graf adds further that “three servings of a healthy, alkaline food for every soft drink will help keep pH in line.”
Unfortunately, this does not seem to be a universal opinion, as Siegenthaler elaborates here: “With increasing age…the skin’s pH becomes [less acidic], and thus more susceptible to bacterial growth. This reduced acidity kills fewer bacteria than before, leaving the skin susceptible to bacterial growth and infections. The skin weakens as a result and begins developing problems with increasing age.” Further, according to Elle, the Charme Skincare System that shifts the pH of water to the acidic range is used in West Hollywood, as Nile Institute Spa owner Nina Curtis says, “The restructured water is great for killing bacteria post-extractions.” Houston dermatologist Dr. Alpesh Desai agrees: “Acidic water creates a hostile environment for bacteria.”
What happens when skin pH is out-of-balance?
Both camps — those in favor of the slightly acidic and slightly basic skin pH — feel that skin pH plays a role in the attainment and maintenance of a clear complexion.
What is too acidic — or basic — to eat?
According to Dr. Graf and other nutritional experts, including a holistic expert in this article, the digestion of meat, sugar, alcohol, and processed foods can take pH to an unfavorably acidic level.
What is too acidic — or basic — to use on my face?
This is interesting, because acidic solutions of alpha hydroxy acids, such as glycolic acid and lactic acid, as well as vitamin C as L-ascorbic acid (amongst others) have many beneficial effects when topically applied the skin, despite their acidic pH. On the contrary, (including while some [basic] alcohols are beneficial and hydrating for most skin (cetyl alcohol, cetearyl alcohol, cetostearyl alcohol, cetyl alcohol 40, C12-15 alcohols, stearyl alcohol and lanolin alcohol), certain low-molecular weight alcohols are not (like methanol, ethanol, and SD alcohol 40, amongst others). As such, there does not seem to be a definitive answer to the skin pH question insofar as what is acceptable and unacceptable to topically apply to your skin.
Does independent scientific research support either theory?
There is a small amount of research on skin pH available. One independent study from 1994 by Dikstein and Zlotogorski here suggests that skin pH only varies slightly amongst Caucasian skin, and is slightly more alkaline in Indian skin. There is also a documented pH gradient present in all skins, as resolved by fluorescence imaging in this 2002 study in the Biophysical Journal. In Dr. Graf’s Stop Aging… book, detailed stories of patients who experienced brightened complexions and improved skin tone and appearance after adopting the suggested alkaline diet and skincare regime are provided.
Overall, however, it would seem that more independent scientific research needs to be done to determine the exact degree of variance in skin pH and its effects.
In summary?
The information on how pH affects the skin is vast, and unfortunately, contradictory at this time. It seems that the best option is to eat healthfully (which usually means a reduction in red meat, white sugars, alcohol, and processed foods anyway) and to use skin care products with well-documented ingredients that are specifically recommended for you by a dermatologist. Although it would be nice to have an all-encompassing theory like the pH theory for the skin, I doubt one can be universally adopted until further research is done.
P.S.: If you have additional scientific information on how pH affects the skin (preferably scholarly and not affiliated with a product), please feel free to contact me! I will update the blog with more verifiable information as it becomes available.