Diet doesn\u2019t cause acne. How often you\u2019ve heard that? For several decades now dermatologists have scoffed at suggestions that diet causes acne and insisted that it\u2019s just a myth. While they believed to be riding the high horse of science, in reality they\u2019ve been cruising with lowly donkey of dogmatism. And now the real myth comes back to bite them on the backside.<\/p>\n
Did you know that before the 1960s, dietary advice was part and parcel of acne therapy. Patients were asked to avoid sugary foods. Because studies as early as 1931 suggested that acne patients suffer from blood sugar problems.<\/p>\n
Then $(*@ hit the fan.<\/p>\n
1969 and 1971 saw publishing of two deeply flawed studies that to this day cause misery and suffering to acne patients.<\/p>\n
In 1969 Fullerton et al, conducted their now infamous chocolate acne study<\/a>. They gave 65 people either a daily candy bar with chocolate or a candy bar without chocolate (control). 4 weeks later they measured the difference in rates of acne, and found none. From this they concluded that chocolate doesn\u2019t cause acne.<\/p>\n This study is flawed on some many levels that I doubt even a 7th<\/sup> grade science teacher would accept it. Both of the candy bars were equally high in sugar, fat and calories. The control bar also had plenty of trans-fats, known to increase acne-causing inflammation<\/a>. All we can say from this study is that one candy bar didn\u2019t cause more acne than the other one.<\/p>\n In 1971 Anderson gave 27 university students, with self-reported dietary acne triggers, either chocolate, milk, roasted peanuts or cola for 1 week. He found no change in acne between the groups. Now, if the 1969 Fullerton et al study was bad, this one is beyond terrible. 1 week is nowhere nearly long enough (most diet-acne studies run for 12 weeks). He didn\u2019t in anyway take into account the other foods the students ate. In scientific terms this study is completely useless.<\/p>\n These two studies are the grand total of scientific evidence that dermatologists have when they say diet doesn\u2019t cause acne. As this 2010 review concludes.<\/p>\n The studies by Fulton et al and Anderson, although suffering from major design flaws, were sufficient to dissociate diet from acne in the minds of most dermatologists. Textbooks were revised to reflect this new academic consensus, and dermatologists took the stance that any mumblings about the association between diet and acne were unscientific and one of the many myths surrounding this ubiquitous disease.<\/p>\n Bowe WP, Joshi SS, Shalita AR. Let me be very clear about that. The notion that diet doesn\u2019t cause acne is not, and has never been, based on science. The fact that dermatologists still repeat it shows how badly out of date they are.<\/p>\n Let\u2019s see just how badly out of date they are.<\/p>\n In 2002 Dr. Lorein Cordain did his famous Kitavan study<\/a>. He studied two groups of native people living in Kitavan Islands in Papua New Guinea and Ache hunter-gatherers in Paraguay. He found zero incidence of acne among these native populations and concluded that acne is a disease of Western civilization.<\/p>\n Another review<\/a> mentions studies showing increased prevalence of acne when Canadian Inuits and Okinawans in Japan were introduced to Western foods.<\/p>\n In 2005 Adebamowo et al, tested the idea that milk causes acne<\/a>. More than 47\u2019000 nurses (data from Nurses Health Study 2) were asked about their high-school dietary intake and whether they had acne. The study found that those how drank the most milk had 22% higher risk of getting acne than those who drank the least milk. The risk was even higher (44%) for those who drank skim-milk.<\/p>\n This study has an obvious problem. Do you remember what you ate last week? Last month? Last year? Dietary recall is obviously less than perfect.<\/p>\n In 2008 the same authors followed up with better studies, a 2006 study with girls<\/a> and a 2008 study with boys<\/a>. In both cases they asked the participants to note down what they ate and followed them for 3 years. In both studies high milk intake increased risk of acne by about 20%.<\/p>\n Even a Nestle-sponsored review<\/a> found several ways milk and dairy products aggravate acne. The paper suggested that if Nestle wants to keep selling boatloads of milk, it better develop dairy products that don\u2019t cause so much acne.<\/p>\n Finally, an Italian study from 2012<\/a> also showed milk consumption increases the risk of acne.<\/p>\n These studies don\u2019t conclusively prove that milk causes acne, but they certainly suggest that drinking milk increases the risk of getting acne.<\/p>\n Several studies have looked at the effect of sugar and other high glycemic index (GI) carbohydrates on acne.<\/p>\n I\u2019m not going to bore you by going over all the studies individually. If you are interested, you can find the studies here<\/a>, here<\/a>, here<\/a>, here<\/a>, and here<\/a>. And don\u2019t forget about the Korean diet study I wrote about earlier<\/a>. Pretty much each of these studies took a group of acne patients and either asked them to eat a low glycemic load (LGL) or high glycemic load (HGL) diets. The LGL diets have more protein and focus on whole grains, fruits and other healthy carbohydrates. HGL diets are more normal Western diets that contain more white bread and pasta and other refined (white) carbohydrates.<\/p>\n Here\u2019s a summary of the results:<\/p>\n With the exception of one, all the studies showed that low glycemic load diets improve acne. In the one negative study both groups had similar total carbohydrate intake, I also wonder how well the teenagers actually stuck to the diet.<\/p>\n Regardless, the majority of the studies show that sugar and refined carbohydrates aggravate acne.<\/p>\n Malaysian study from 2012<\/a> compared diets of acne patients to those with healthy skin. They found that acne patients ate more refined carbohydrates, milk and ice cream. And an Italian study from 2012<\/a> found that adhering to Mediterranean diet protects against acne.<\/p>\n A 2009 review included a handy table that summarizes current diet-acne evidence.<\/p>\n
\nDiet and acne<\/a>.
\nJ Am Acad Dermatol. 2010 Jul;63(1):124-41. Epub 2010 Mar 24.<\/p><\/blockquote>\nStudies that link diet to acne<\/h2>\n
Milk and acne<\/h3>\n
Sugar and refined carbohydrates<\/h3>\n
\n
Other bits and pieces<\/h3>\n
Diet acne summary<\/h3>\n