In this blog, I explored the association between stress and acne. It got me thinking about if other supposed causes of acne have any scientific validity. It has been proposed before that eating unhealthy foods can cause an increase in the presence of acne. Therefore, I decided to investigate the link between someone’s diet and severity of acne.
In researching this topic, I came across this article, which details a meta-analysis of several studies exploring the relationship between diet and acne. Overall, the conclusions set forth in this article state that “compelling evidence exists that high glycemic-load diets may exacerbate acne,” and that “dairy ingestion appears to be weakly associated with acne.” However, nothing can be concluded about the link between acne and diets rich (or lacking) in nutrients such as omega-3 fatty acids, antioxidants, zinc, vitamin A, and dietary fiber. The article does mention a lack of randomized controlled experiments in the studies it reviewed, so therefore, we cannot define a causal link between the putative causal variable (diet) and the putative response variable (acne). In addition, it is possible that this meta-analysis fell victim to the file-drawer problem, in that it reviewed studies that found a link between high-glycemic diets and acne, but that there are several unpublished studies that found no such link, thereby causing researchers to overestimate the prevalence of this link.
More investigation led me to this study (PDF link here), which further explored the link between levels of glycemic-load in diets and acne. This controlled experiment involved an experimental group that received a low glycemic-load diet, while a control group received a diet high in “carbohydrate-dense foods.” To measure levels of acne, researchers recorded the number of acne lesions that participants had before and after the study. Overall, it was found that “total lesion counts had decreased more in the low-glycemic-load group than in the control group,” thus providing evidence consistent with the hypothesis that diets rich in glycemic foods might lead to increased acne. Being that this study was a controlled experiment, it provides us with stronger evidence than an observational study can. However, we must be wary of confounding variables, such as stress levels, weight, and ethnicity of participants, which could potentially be affecting these results.
Overall, we cannot definitively conclude that there is a link between someone’s diet and the prevalence of acne. However, there is evidence to suggest an association specifically between diets rich high glycemic-load foods (that being, foods that contain a lot of glucose, such as bread, pasta, and cereal: link here) and increased acne. Further studies must be done in order to identify what, if any, other types of foods might be causing acne. Generally, what all this means for us as a society is that we should aim for a diet low in foods containing lots of glucose, as it may help to reduce acne. Even if it doesn’t, there are lots of other health benefits that eating a diet like this can provide.
(As a side note, this blog is part of a three-part series in which I explore possible factors affecting of acne. You can find Part 1 here and Part 3 here).
I have always believed that food was a contributing factor to acne. Growing up I remember hearing that the more junk food i consume will make acne come about easier. Or if acne sprung upon me it was because i was eating unhealthy and had to change my diet. However, I was also aware that the amount of sleep and stress are major factors as well, not to mention genes for healthy skin. I was shocked when your research concluded that there was no scientific evidence between food and acne. Surprisingly, when I researched it myself i found similar conclusions; there is no scientific evidence or hard facts which prove food can cause acne.
On the other hand, in an article from webmd.com , Elizabeth Shimer Bowers states, “Whenever dermatologist Ellen Marmur, MD, eats chocolate, she breaks out two days later. Although she admits there is no hard science to explain why… more than one-third of people with acne see a connection between what they eat and their blemishes.” This just puzzles me because there are no facts that prove this, but they correspond with each other. Also, further in the article Marmur stated, ““Food is only about 25% of the picture when it comes to acne,” she says. The other 75% is influenced by hormones, stress, sleep levels, and where you live.” This shows clearly other factors go into acne, which is known, but also she said food is 25%. I am not sure what she means because there are no hard facts, but people know food does effect acne some how. Personally, I think his scenario can relate to what was discussed in class about prayer healing people. There was no answer from a scientific perspective, but there clearly was a relation. Maybe this is the same with food and acne, or the unhealthy food can increase the acnes bacteria which causes acne. Whatever it is, there should be a scientific reason and scientists should find a way to look further into it.