The subject of acne and diet is quite controversial. Many people think that acne is related to diet, while dermatologists have insisted for years there is no link. But is that the actual, whole truth? What evidence were they resting their claims on? In this Medbook entry, I will review the literature about the link between diet and acne, and give some tips on what you can do to help heal your acne!
What to Eat for Acne
Today, millions of people suffer from acne (official term acne vulgaris). Both teenagers and adults are affected alike, and its forms take many shapes: surface bumps to deep, under-the-skin cystic acne. It costs our health system millions of dollars in appointments, medicines, and procedures, and its affects in sufferer’s lives can be long-lasting in the form of scars and pigmentation.
Most sufferers of acne are in the teenager age range, but adults of any age still suffer. Interestingly enough, adult sufferers past the age of 23 were more likely to be female, but a significant portion are still male, making it a disease that afflicts both sexes significantly.
Understanding how and why acne occurs is actually pretty complex. Basically, it occurs as the perfect storm of several different factors.
Where: the pilosebaceous units of the skin, chiefly the face, back, and chest.
When: when bacteria and sebum production increase (can be influenced by environment, hormones, etc). This is why it’s associated with puberty and teenage years, when hormones shift and change, though it can occur at around the menstrual cycles and in other times.
What: The bacteria P. acnes colonizes the sebaceous follicle. Together with the bacteria colonization, keratinocyte proliferation (the skin cells), sebum production, the follicle becomes inflamed, forming a “comedo” that forms into the acne lesion (a papule, pustule, cyst, etc).
What we thought before
Now that you under the basics of how acne happens, let’s take a brief dive into the science out there and our understanding today of the causes of acne. Previously, acne was thought to be largely genetic and hormone-driven, and completely unaffected by dietary or lifestyle factors. It was just something that happened to you, and changing your diet had negligible effect on your outcomes.
However, the articles most often cited by dermatological literature up until recently (as the tide begins to now shift and textbooks are being updated) were most often two studies that have recently been reviewed and thought to be weak in evidence and not applicable for modern society. These studies (by Anderson and Fulton, see below) were published in 1971 and 1969 — about 50 years ago! These studies not only are quite old to be basing the diet-has-no-effect stance on were also full of design flaws that make it so that we really cannot draw any conclusions about them. For full analysis see (Cordain, 2005).
Takeaway: the science of the previous century is dubious and controversial, but laid the foundation for the claim that diet has no effect on acne. New studies are emerging that cast doubt on this claim.
Some new stuff coming out
However, like I said before, the tide is now shifting. Multiple reviews have come out acknowledging the paucity of evidence that has previously existed and supported the previous consensus that diet and acne were not linked (see Davidovici, 2010).
In fact, new evidence supports the fact that diet can influence the factors we talked about above: the production of keratinocytes within the pilosebaceious units, androgen and thus sebum production, and the inflammatory reaction from P. acnes colonization. The literature supporting this is dense so I will only briefly review what is most relevant for this discussion. (If you don’t care to know the science supporting and just want to get to what you can do it about it, feel free to skip to below!)
Insulin and Glycemic Index
The best evidence thus far in the realm of diet and its link to acne surrounds one factor: high-GI diet may cause acne. “GI” is short for “glycemic index”, and this is a measurement that basically measures how high your blood sugar spikes after ingesting a certain food. High-GI foods are things like white flour products, white rice, candy, etc. Low-GI foods are things like vegetables, complex carbs, fish, berries, etc.
High-GI foods are being linked more and more in recent literature with acne production. The evidence includes the gold-standard: randomized controlled trials, not just reviews or prospective studies (see Smith, 2008). To summarize the many studies describing this link: high-GI foods may provoke acne, low-GI diets may help treat it.
The reason for this link between high-GI foods and acne is complex in its pathophysiology. Principally, high-GI foods are thought to cause increased production of insulin and insulin-like growth factor 1 (IGF-1). These hormones have been proven to lead to many of the pathological factors we talked about above (high androgen states, sebum, inflammation, etc.). High-sugar/high-GI diets lead to chronically elevated insulin and IGF-1 levels, and a decrease in something called IGFBP-3.
These two hormones have a wide variety of effects in the body, in the realm of acne pathophysiology. Basically, IGF-1 promotes basal keratinocytes (those skin cells involved in acne formation) production, whereas IGFBP-3 inhibits this process. Insulin and IGF-1 stimulate androgen production (which leads to sebum production), and decreased production of sex hormone binding globulin (SHBG), which functions to binds androgens in the blood and makes them unavailable for use. Thus, increased insulin and IGF-1 lead to decreased production of SHBG, which leads to less androgens being bound, and thus increased amounts available for use, leading to more sebum and its other effects. Insulin and IGF-1 not only increase androgen production which increases sebum, but they also directly stimulate sebum production. As a demonstration, on study found that directly injecting IGF-1 into women increased androgen production and acne formation (see Klinger, 1998).
Takeaway: a key factor to acne pathogenesis is high-insulin states, which you get by eating high-GI foods. Low-GI diets may be crucial to treating acne.
Role of Inflammation
Another point to touch on is the role of inflammation in acne and its relationship to diet. A portion of the pathophysiology behind acne is thought to be an inflammatory reaction produced by the presence of the bacteria we talked about above, P. acnes. Certain elements of this bacteria’s cell wall provoke our bodies to produce inflammatory substances called cytokines, such as IL-1 or IL-6. These cytokines have various effects linked to acne formation, such as the proliferation of basal keratinocytes.
One of the most important dietary factors associated with inflammation are PUFAs (poly unsaturated fatty acids, like omega-6 and omega-3, which we’ve all heard about). To recap, basically omega 3’s are anti-inflammatory, we want more of those and relatively less omega-6. The goal is to decrease the ratio of 6-to-3. Interestingly enough, in Western countries where acne is most predominant, the omega-6-to-3 ratio is about 10:1, whereas in non-Western countries the ratio is about 2-3:1! Whoa!
Ok, so first let’s understand what makes omega-3 so important. Basically, it has a bunch of effects, but it has been proven time and again to be anti-inflammatory and to decrease the expression of those inflammatory cytokines, which like we talked about, are implicated in the pathogenesis of acne. To demonstrate the relation of cytokines to acne, one study found that direct injection of a leukotriene-blocker (leukotrienes are some of those cytokines) reduced acne spots by 70% (see Zouboulis, 2001)!
Takeaway: a key component to acne is inflammation. The Western diet has a disproportionate amount of omega-6’s to 3’s. Increasing 3’s and decreasing inflammation may be a key factor to treating acne.
Dairy and acne
I will touch on another factor here briefly. Dairy is gaining popularity as a more-often recognized culprit of acne, specifically hormonal related acne (women, think around the jawline/chin, usually around time of menses). The associated of dairy with acne has traditionally been weak, but there are studies that link many of the dozens of hormones in dairy (including estrogens, progesterones, androgens, and more) to acne. These hormones exist in the milk regardless of fat content—skim, 2%, or whole milk—and regardless if it’s “raw”, “organic”, etc. There is a quite well known Nurse’s Health Study that examined 47-thousand nurses who drank milk in their youth and found that those who drank more milk had more severe acne.
Also, interestingly enough, to link dairy back to the GI-foods that we discussed above, though dairy products are considering relatively “low” GI, they were found in a 2001 study to evoke an insulin response similar to white bread! That means they increased production of insulin, which has all of the same downstream effects on acne and hormone production per above—and thus has the same potential to lead to the conditions that produce acne. Something to ponder!
Empirically, many patients nowadays are seen drastic improvements in acne by eliminating or reducing dairy from their diets, and I suspect that much more literature will be coming out on this topic in the future, hopefully in the form of randomized control trials.
Takeaway: dairy has a lot of hormones, even when organic, that are linked to acne.
What To eat for Acne
Alright, finally the part you were waiting for! Considering everything above—which, by the way, is truly only the tip of the iceberg on this topic, and only a crude summary—what should you eat for acne?
For now, let us save the topic of topical skincare for another day. I have a list of my favorite brands and products I’d be happy to share, but really those topical products really can only perfect the groundwork you lay with your diet.
As evidenced above, the main three things that you need to focus on for acne is:
High GI foods
Dairy and other hormone-containing foods (non-organic meat, etc)
So, it follows that you need to drastically reduce or eliminate these things. I am not saying you need to go vegan, but try going dairy-free and reducing your meat intake, buying organic and grass-fed when you are able to.
First, focus on what you need to eliminate.
Ditch white flour products
Crackers, cookies, cakes, breads, etc.
Ditch the sugar
Candy, sweets, desserts, pre-packaged sauces, ketchup
Eat as little as possible from a box.
Stick to whole foods - vegetables, whole grains, fruits, nuts, seeds. Rule of thumb - if it has a label with more than 5 ingredients, avoid!
Cut out dairy.
Cut out vegetable oils (and packaged foods that contain them).
Canola oil, soybean oil, grapeseed, etc. Switch to extra virgin olive oil and coconut oil.
Be careful with packaged foods! Many chips, cakes, baking mixes, and even “health” food like gluten-free breads, crackers, and sauces contain these.
Reduce consumption of meat, and when you do eat meat, buy organic and grass-fed.
All of these things above are things that either raise your blood sugar (remember that glycemic index we talked about), provoking insulin release and IGF-1 and all its nasty effects, or worsen inflammation in the body like those omega-6 containing vegetable oils.
what to eat instead
vegetables (greens, greens, greens!), fruits, whole grains, nuts, seeds, beans & legumes
walnuts, chia seeds, wild caught salmon, flaxseeds
Switch to organic meat and wild-caught fish.
Salmon, cod, organic chicken, eggs. Skip the red meat!
chia & flaxseeds
green tea, matcha
A word on supplements
I am a little wary when it comes to the realm of supplements. Currently, I take turmeric intermittently, but other than that, I take only a multivitamin. Some functional medicine doctors, like Dr. Hyman, recommend certain supplements for hormonal control, like evening primrose. I’ve read about a lot of people who have had success with this particular supplement. I’ve also heard of people taking supplements like this one, that have a blend of vitamins and other things that “support hormonal balance”. This works for many people, I am sure, but I strongly advise caution with these supplements. They are not FDA-regulated, and their contents can be very dubious, depending on the integrity and transparency of the company. Sometimes, supplements, when tested in laboratories, contain none of the ingredients they say they do—and other times, they were found to contain entirely different ingredients! Beware, do your research on the company, and don’t trust the “fantastic” 5-star reviews!
If you do want to “supplement”, I suggest going with turmeric or curcumin, and/or a green powder. I do a dose of Amazing Grass every day in water, for an extra boost of anti-inflammatory and antioxidant greens, and it has made a world of difference to me.
Ok, so we’ve covered the food! I have few more non-food related tips that may help you.
First off, acne has been linked to times of increased stress. So, do things that decrease your stress! This could be meditation, mindfulness, yoga, or any number of practices.
Second, exercise on a daily basis. That is, do not miss a single day. I am not saying you should run a 10k every day, but you need to get in 30 minutes of exercise per day at a minimum - whether that’s walking, running, cycling, HIIT, weight training, or whatever group class you like. You need to do something - the benefits of exercise to your hormone profile is more than I can cover in this article, but it has proven to be immensely beneficial in many ways, and will make a drastic improvement to your health, including acne. I promise you have time for it; I’m currently doing 80 hour work weeks, and I do at least 30-45min every day myself. It’s totally possible!
Third, see a dermatologist. Yes, change your diet. Yes, exercise and and meditate and control your stress. But also see a dermatologist to make sure they have no further recommendations for topical treatments, for potential scarring issues, or any advice they can offer you. They may put you on a medication for a short while (if you like, they will not force you), while you get your diet under control, which can help control your breakouts and the resultant scarring! Also, rarely, severe or rapid-onset acne can be a sign of an underlying illness so it can’t hurt to check it out!
Control your stress
Meditate or mindfulness on a daily basis. I currently use Headspace for at least 5-10 min every day. There is also Deepak Chopra and the Calm app, or any number of free online meditations.
Not too intense. Do something you enjoy and will do on a daily basis, but make sure it gets your heart rate up a good bit! Aim for >30min every day. Every day.
See a dermatologist at least once for recommendations.
They may have good advice to offer you while you are sorting out your diet. You would be amazed - these are some of the smartest docs out there!
The science on acne is confusing and ever-evolving. What is becoming more and more clear is that it is largely a disease of modern Western culture, with our Western and Americanized diets full of processed and additive- and sugar-containing foods. Tackling this problem on a personal level can be quite daunting, but it can be done if drastic changes are made in your life. Simply eating less candy will not provoke a change. You need to make bigger changes to see bigger results, simply put. But when you do, the work required will be worth it—and the benefits of changing your diet will extend far beyond the realm of your skin!
Eat whole foods.
Skip processed and refined foods, chiefly sugar- and flour-containing products.
Focus on anti-inflammatory foods: turmeric, leafy greens and all vegetables, walnuts, berries
Get your mind right. Meditate and control your stress.
Exercise every day, at least 30 minutes.
Whew! You made it to the end! I will be updating this article as I hear of new literature coming out on this topic, so keep checking back to this link for updates!
This is an entry into my Medbook, an encyclopedia with functional and holistic medicine science and recommendation for common disease. The goal of Medbook to create one entry for each condition, creating a one-stop-shop for all you need to know about specific conditions and things you can do as an empowered person to take control of your health! This advice is not a replacement for the advice of a licensed medical professional, and is not aimed to diagnose, treat, or cure.
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