What Causes Acne? Common Triggers To Look Out For

Last Updated: Mar 22, 2021

Why do so many people suffer with acne?

Why do some people get acne while others don’t?

How come some of us need every skincare product under the sun to look presentable while others have clear skin just by splashing some water over their face?

Where did we come from anyways? Why is life so unfair?

These are just some of the many questions people have been asking themselves throughout the ages. For something so widespread you’d think we would have learned by now what exactly causes acne.

Unfortunately, no one fully understands how or why acne forms. Although there are some good theories out there (genetics, poor diet, etc.) it doesn’t explain why some people get more severe forms of acne than others.

Luckily we do know what acne is associated with and by knowing what it’s associated with we can predict what will make us break out.

Hormones & Acne During Puberty

As you probably learned through firsthand experience sometime back in middle school, acne first rears its ugly head around the start of puberty.

What happens during puberty that causes acne to thrive?

Well, that is the period of your life when your body starts producing hormones on overdrive.

Androgenic hormones in particular like testosterone and DHT are increased during puberty and they cause your skin to produce more sebum (the proper term for the oily substance on your face). This goes for both guys and girls. Anyone with acne knows that oily skin is pretty much the best sign you’re about to break out within the next couple days. A greasy face clogs pores which lets the trapped bacteria grow inside making it the perfect environment for acne.

Estrogen also affects acne especially in& young women as most notice breakouts tends to come and go depending where they are along their monthly menstruation cycle. Low dose birth control pills can help control symptoms and are sometimes prescribed by doctors for this reason.

This is also evident during pregnancy which is yet another time women’s hormones become out of whack and acne tends to flare up. While it’s pretty hard to predict who will or won’t have to deal with acne during pregnancy, you should assume that if you struggled with acne before, you’ll struggle with it even more while pregnant.

So we can conclude from the fact that acne first starts appearing at the onset of puberty that it’s at the very least some kind of hormonal based disease — meaning it’s related to changes in these key hormones:

  1. Androgenic Hormones (Testosterone and DHT)
  2. Growth Hormone (Somatropin)
  3. Estrogen

We also know that these hormones are responsible for regulating the sebaceous glands in our skin which produce sebum. That’s part of the reason why pre-adolescents don’t have to deal with acne — they’re not yet producing the hormones giving the rest of us trouble.

More IGF-1, More Acne?

Further supplying evidence that acne is a hormonal disease, androgenic hormones are why bodybuilders who take steroids usually breakout once they start their cycle as they start injecting a massive amount of these hormones into their bodies.

And if you’re into bodybuilding you may want to reconsider taking that protein shake.

Whey contains IGF-1 (insulin like growth factor-1) and numerous studies have found it to be associated with increased cases of acne. Here’s one which found IGF-1 (and DHT an androgenic hormone) had a strong affect on acne in women. Men’s acne was also influenced by IGF-1 but too a lesser extent. IGF-1 encourages cell growth and scientists hypothesize that the increase in cells especially within pores combined with the oil your skin produces clogs them up and contributes to acne.

IGF-1 has also been found to raise insulin levels similar to the way foods with a high glycemic load do which are also sometimes blamed for causing acne.

The thing is, IGF-1 isn’t even necessarily bad for your skin which is why it doesn’t explain the whole story. Increasing IGF-1 also encourages your skin to start producing more collagen which is the underlying connective structure that keeps skin young and healthy. Less collagen = more older, wrinkly skin.

So what’s the deal? Is IGF-1 good or bad for your skin? More research needs to be done but it may not be the IGF-1 itself that’s responsible for the acne. It could be the fact that it raises the levels of androgenic hormones which then are what cause the acne.

By the way IGF-1 isn’t just found in whey protein. It can be increased by eating other dairy products and even certain spices like cinnamon.

We look into how dairy and other high glycemic foods can affect acne further below but if you’re trying to reach your daily protein requirement it might be best to start eating more real food and put the shakes down if your acne is acting up just to be safe.

How Stress Affects Acne

Have you ever broken out during finals week? Yes it sucks — are you supposed to worry about your grades or what’s going on with your skin?

Once again the connection between stress and acne isn’t quite clear. We know stress causes an inflammatory response within the body. Inflammation is marked by redness and swelling — two common characteristics of acne lesions.

Cortisol, the hormone released when the body experiences stress, has been found in higher amounts within men who have acne compared to men who don’t. Another study confirmed that women experience more breakouts during exam week compared to other weeks during the semester.

For many of us when stress is at its highest we’ll find ourselves breaking out.

This might be due to the fact that the skin cells which produce sebum also have receptors for stress hormones and this causes them to overproduce when you’re going through some rough times. More sebum increases the chances of clogged pores, thus increasing the chance the P. acnes bacteria gets trapped inside and acne begins forming. This is also why oily skin types usually struggle with acne more than dry and normal skin types.

Stress is a vicious cycle because no one wants acne but worrying about it only makes things worse.

And by the way, stress in this case doesn’t just mean psychological stress.

Physical stress from too little sleep, not enough exercise, and even smoking* probably won’t cause acne directly but can encourage its growth indirectly as these activities are physically taxing on your body. In fact, an interesting study from 2009 found smoking cigarettes in a sample of 1046 women was strongly correlated with non-inflammatory types of acne (meaning comedones like whiteheads and blackheads). Note that the overall research linking cigarettes to acne is conflicting as some studies haven’t found any correlation.

This is the mind-body connection. If you neglect your body, your mind will suffer and vice versa. Neglecting your body for long enough will eventually lead to psychological stress — kick starting cortisol which then leads to more sebum, more clogged pores, and more acne.

Deep breaths and positive thoughts people.

Diet & Acne

Like any of the other factors we talked about above, the exact role diet plays in causing acne is up for debate but it makes that it would be at least partly responsible.

We do know for a fact that the food you eat impacts the health and appearance of your skin. We’ve said it plenty of times before — proper nutrition is the foundation of every great skincare routine. We even have an entire guide going over exactly what you should and shouldn’t be eating for better skin.

Anyways, right now we’re only talking food as it relates to causing acne, not what to eat for prevention. We’ll cover what foods you should be eating to prevent acne in the next part of this guide (you can also check out the skin nutrition guide we linked to above).

So we mentioned earlier two important types of foods to look out for in regards to diet:

  • Foods with a high glycemic load.
  • >Dairy products.

Both have shown to be correlated with acne in studies.

Dairy is problematic for so many people not just because it contains IGF-1 but also because it’s filled with other precursors to androgenic hormones. Since these are hypothesized to increase the amount of sebum your skin produces, many people have tried cutting dairy out of their diets — and with success. This simple act alone often improves acne symptoms and stops break out without even having to use other treatments.

Foods that rank high on the glycemic index are also potentially problematic although for slightly different reasons. These foods raise your blood sugar levels higher than foods that rank low on the index. Research regarding foods with a high glycemic load (these are sugary foods usually high in carbs) is still inconclusive though as studies haven’t been able to pinpoint whether the people eating foods low on the glycemic index benefited more from having less sugar spikes or from the ensuing weight loss that occurred.

Glycemic Index Skin

Yes calorie restriction and losing weight can improve acne symptoms. Sustaining a low calorie diet, and we’re talking about starvation level here, for multiple days in a row almost completely halts sebum production and reduces acne symptoms. Eating high calorie diets increase the production of androgenic and growth hormones causing the skin to increase oil production and… well you know the rest.

No matter which theory holds true, we can all agree that cutting down on sodas, juices, pastas, breads, and other sugary drinks could be of benefit to people if not for improved acne symptoms then at least for the fact they’ll help keep our weight under control and our bodies sensitive to insulin which has its own benefits.

Here’s some more “food for thought” in regards to what triggers acne to grow.

Does Chocolate Cause Acne?

Research is inconclusive on whether chocolate causes acne. Common advice from doctors and scientists in the early 20th century and medical studies warned people to stay away from chocolate to avoid acne problems although this was challenged when two semi-recent studies released in 1969 and 1971 found no correlation between acne and chocolate intake.

Chocolate, particularly milk chocolate, is sugary and raises insulin levels similar to other foods high on the glycemic index. If insulin spikes really are to blame for increased sebum production by the skin then chocolate could theoretically be responsible for encouraging acne to thrive.

On the other hand, chocolate also contains antioxidants which may help in improving acne symptoms. Antioxidants fight inflammation and it isn’t a stretch to conclude that the inflammatory types of acne like cysts, nodules, pustules and papules can be fought by eating more antioxidants.

The jury’s out and we won’t tell you not to eat a chocolate if you really want to. If it’s dark chocolate (less sugar and more antioxidants than milk chocolate) and only an occasional indulgence you should be fine.

Greasy Foods

The connection between greasy and fatty foods like pizza and fries is often made to acne mostly because acne itself is often greasy looking on the surface of skin.

It’s true that dietary fat is used to produce sebum. But we suspect the problem with these foods might be related to the fact that pizza contains cheese and thus people experience the potentially negative downsides to increased IGF-1 levels. Fries also aren’t the healthiest foods around and can contain unhealthy fats which cause negative health effects.

Whether these effects eventually cause an increased occurrence of acne is up for debate as the potential link between high fat diets and acne hasn’t been well researched. Healthy fats are an important part of any diet but limiting your consumption of saturated and especially trans fats might be of benefit.

We also want to remind people that if you consistently find yourself breaking out after eating a particular food, try going without it for a month to see if your skin improves. There may be something you’re eating that your skin just can’t handle and it triggers acne. Only by methodically cutting out foods from your diet will you find out what is or isn’t responsible for breaking you out.


We can conclude with this:

Acne seems to be a predominately hormonal and inflammatory based disease. Genetics definitely play some role but you have quite a bit of control over the food you eat, your lifestyle choices like choosing not to smoke, the way you handle stress and even to a lesser extent your hormones which are affected by the food you eat and the amount.

So the next logical question to ask is “What can I do about it?” Check out these tips for preventing acne next.

Featured Image by Thirteen of Clubs // Cropped & Filtered Original
| Last Updated: Mar 22, 2021