Skincare Series Part I: Diet & Acne

Hi guys! Welcome to the first post in this Skincare Series! SO many of you have reached out asking about the connection between diet and acne, nutrition and general skin health, and about the products I use personally. I am so excited to share these posts with you guys, because this is a topic that really resonates with me. What you may not know, is that the reason I became interested in nutrition in the first place was in part due to my own struggles with acne from ages 22-24. 

While there is still a lot of research needed to be done in this area, I think the link between nutrition and skin health is undeniable. More and more dermatologists are seeing the connection between food and skin, and research continues to come out on this topic. To begin this Skincare Series, today’s post will cover Diet & Acne. Below I’ll outline where the research currently stands, providing links to some review articles if you’re interested in learning more.

Before I begin, I want to mention that as a dietitian I am by no means an expert in skin health. Based on current research, I can, however, help pinpoint certain foods that may be contributing, and suggest foods to include in your diet instead (PS – many of these foods are part of a general healthy diet anyway). If you are struggling with your skin, I would advise seeing a dermatologist; there are MANY contributing factors to skin health, and diet is only one of them!

Another important point to remember is that we are ALL different. Just because one person’s body might react to a food, doesn’t mean that yours will. Take the information below as a guideline, and as permission to experiment with what foods may be triggering your acne. A great idea is to keep a food journal, logging the foods you eat and the occurrence of acne. If you see a connection with some of the foods below, you can try eliminating them for a period of time to see if your acne improves.

DIET AND ACNE: THE HISTORY

The history behind the idea that diet can cause acne has been a controversial one. In the early 1900’s, researchers found a link between excessive carbohydrate consumption (particularly chocolate) and acne occurrence, which was then followed by studies showing a possible link between milk consumption and acne. In the 1960s, a handful of small studies were conducted that refuted the connection between diet and acne. These studies, however, were flawed in their design – they had small sample sizes, lasted for a short period of time (e.g. a week!), lacked control groups, were self-reported, etc. Because of these studies, the link between diet and acne was dismissed and not further investigated until about 40 years later. With advanced science and understanding of the pathogenesis of acne, new research is emerging that demonstrates a likely link between diet and acne occurrence. The primary food groups related to acne appear to be high glycemic index foods as well as some dairy products.

ACNE AND HIGH GLYCEMIC INDEX DIETS

Some of the strongest evidence relating diet and acne occurrence is with high-glycemic index diets. The Glycemic Index (GI) is essentially a measure of how particular foods can affect the amount of glucose (sugar) in the blood. High GI foods are those that are rapidly digested and absorbed into the bloodstream, causing a spike in blood sugar, which is then followed by a spike in insulin (the hormone that brings glucose out of our blood and into our cells to be used for energy).

Processed carbohydrate foods, such as cookies, cakes, white bread, etc. are often high on The Glycemic Index. Lower GI foods are the carbohydrates that are more slowly digested and absorbed, and therefore result in more gradual elevations in blood sugar. These foods include less processed, fiber-rich vegetables, whole grains, etc. Researchers have speculated that a high GI diet increases hyperinsulinemia (high insulin levels in the bloodstream), which may stimulate the release of a hormone called insulin-like growth factor-1 (IGF-1). IGF-1 is known to promote the production and secretion of sebum (the oil in our skin), the overproduction of which is a well-known factor in the pathogenesis of acne. Studies have additionally shown that individuals with acne have higher levels of IGF-1 than those without.

A 2014 review analyzing the current research on the role of high/low GI diets and acne occurrence demonstrates rather convincing evidence that a low GI diet may lead to an improvement in acne. Similarly, a 2013 review article published in the Journal of the Academy of Nutrition and Dietetics (by one of my past professors and her PhD student – yay!) suggests that a low-GI diet may be an approach to managing acne. Of course, the research on this is still evolving, BUT a low-GI diet is essentially one that is high in whole grains, fruits, vegetables, and low in processed foods. We know that these kinds of diets decrease the risk of obesity, cancer, diabetes, and other chronic diseases; thus, the health benefits of such a diet go way beyond reducing acne.

So how do we take this information and put it into practice? If you are someone who suffers from acne and finds yourself eating plenty of the high GI foods below, it may be worth trying to limit your consumption of these items. In place of these foods, try to choose lower GI food sources. Another tip I always like to give – combine your (ideally fiber-rich) carbohydrate sources with protein and/or fat. The fiber, fat, and protein help to slow the absorption of glucose into your blood as well. While this is pretty general healthy eating advice, you may find an improvement in acne occurrence over time. Please remember that “limit” doesn’t mean that you can never ever eat these foods again, just be mindful about it.

Foods to Limit: (High GI Foods)

• Cookies, cakes, candies, pretzels, soda crackers
• Soft drinks, soda, fruit juices
• White rice, instant rice
• White bread, white bagels
• Instant oats, cream of wheat
• Cereals like Corn Flakes, Rice Krispies, Fruit Loops, etc.
• Added sugars – check ingredient lists for words ending in -ose (glucose, sucrose, fructose, etc.), syrup, malt, cane juice, dextrose, etc.

Foods to Include: (Low GI Foods)

• Sweet potatoes, yams, winter squash
• Beans, lentils, chickpeas
• Steel cut oats, rolled oats
• Whole wheat breads, whole wheat pastas, sourdough
• Whole grains such as brown or basmati rice, barley, bulgur, quinoa
• Popcorn
• Yogurt
• Fiber-rich fruits such as apples, berries, melons, pears, plums, etc.
• Meats, fish, poultry, cheese, nuts, seeds, soy products, and non-starchy vegetables

*Note: Some foods may appear high on GI lists, like watermelon or carrots, but they do not actually contain enough carbs per serving to raise blood sugar significantly. Another measurement, called the Glycemic Load (GL), has been developed to address this by factoring in serving sizes. This might sound confusing, but the bottom line is to go with less processed, fiber-rich whole foods, while avoiding added sugars.

DAIRY AND ACNE

I have had quite a few of you write to me asking if dairy specifically may be contributing to acne. Current research shows that you might be right! Interestingly, not all forms of dairy seem to be associated with acne development. A 2018 meta-analyses of 14 observational studies looking at the connection between dairy and acne found a positive relationship between total milk, whole milk, low-fat, and skim milk consumption and acne occurrence (this means that with greater intake of these products, there was a greater likelihood of acne development). Additionally, it was found that low-fat and skimmed milk had a stronger relationship with acne development than whole milk. Conversely, they did NOT find a significant association between yogurt and cheese consumption and acne occurrence.

The exact mechanisms linking milk consumption to acne remain to be confirmed. It is hypothesized that the milk proteins (casein and whey) stimulate the release of a hormone called insulin-like growth factor-1 (IGF-1), which, as mentioned above, may be involved in the development of acne. It is further thought that the fat-reducing process in making low-fat or skimmed milk raises the concentration of molecules responsible for the development of acne, which may explain why the whole fat versions have a weaker association with acne occurrence.

Why don’t we see the same relationship with cheese and yogurt consumption? It is thought that the fermentation process by probiotic bacteria present in these products lowers the level of IGF-1 in yogurt and cheese. Additionally, emerging research is showing a connection between the health of our gut and the health of our skin; thus the probiotics in these fermented products may have a protective effect on our skin health as well.

Similar to the high GI foods above, if you suffer from acne and regularly drink milk, consume ice cream, or whey protein powders and bars, you may benefit from limiting these foods for a period of time to see if your acne improves. Instead, try choosing items in the “foods to include list.” Do note that dairy is a primary source of protein, calcium, potassium, magnesium, and vitamins A and B12 in our diets; therefore, if you do choose to limit dairy, it’s important to consume other food sources of these key nutrients!

Foods to Limit:

• Milk and milk-based products (such as ice cream), especially skim and low-fat versions
• Protein bars and powders containing whey (be sure to check the ingredient list, and look for bars and powders made with plant-based proteins, and ideally no added sugars)

Foods to Include:

• Milk alternatives, such as soy, almond, hemp, coconut or flax milk (just make sure to get the UNSWEETENED version)
• Fermented dairy products, such as Greek yogurt, skyr, kefir, and cheese (again, choose plain, unsweetened/unflavored versions of these products)

This deliciously creamy pasta sauce doesn’t use any cream at all! The whole recipe is dairy-free, and I use whole grain pasta like brown rice or quinoa to make it a lower GI option too. Click pic for link to recipe!

DIET & ACNE: THE BOTTOM LINE

Like all topics in this ever-evolving world of nutrition science, more research is needed on the link between diet and acne. However, I think it’s safe to say that the mindset behind diet and acne has changed, and more and more dermatologists are recognizing a link between the two. As I mentioned before, the information here does not substitute the advice of a dermatologist, but rather may help you identify potential triggers to your acne. Not everyone’s skin will react the same way to these foods (some people can eat them regularly and have no acne at all), but possibly it could help you! 

I hope you guys find this post insightful. Next up in this Skincare Series, we’ll delve into the research covering nutrition and overall skin health, touching on fats, antioxidants, collagen, etc. Stay tuned!

REFERENCES

1. J Burris, W Rietkerk, K Woolf. Acne: the role of medical nutrition therapy. Journal of the Academy of Nutrition and Dietetics. 2013;113:416-430.
2. WP Bowe, SS Joshi, AR Shalita. Diet and acne. Journal of The American Academy of Dermatology. 2010;63(1):124-141.
3. SN Mahmood and WP Bowe. Diet and acne update: carbohydrates emerge as the main culprit. Journal of Drugs in Dermatology. 2014;13(4):428-435.
4. M Aghasi, M Golzarand, S Shab-Bidar, et al. Dairy intake and acne development: a meta-analysis of observational studies. Clinical Nutrition. 2018. https://doi.org/10.1016/j.clnu.2018.04.015

PS. If you’re interested in learning more about diet, the microbiome, and skin, check out Dr. Whitney Bowe’s book The Beauty of Dirty Skin. This post is in no way affiliated with her, but I did have the chance to watch her speak. She is one of the dermatologists leading the research between these topics and the science is fascinating!