FOODS THAT CAUSE ACNE (35+ STUDIES): THE ULTIMATE GUIDE (2020)20 minute read

Do you suspect that food makes your acne worse?

Most acne sufferers do, and yet it’s easy to hear conflicting advice on what you should and shouldn’t eat. In this article, we’ll look at the best available research to determine which do contribute to acne—and we’ll cover how you can optimise your diet to help your skin.

Spoiler alert (and some excellent news!): an anti-acne diet doesn’t have to be a super restrictive one.

Contents

Does diet affect acne? A surprising history
Foods that cause acne—or do they?
Does dairy cause acne?
What to do about dairy and acne
Does sugar cause acne?
What to do about sugar and acne
Does chocolate cause acne
Do eggs cause acne?
Does peanut butter cause acne?
Takeaway points

 

Does diet affect acne? A surprising history

Have you ever wondered why your doctor doesn’t just give you a list of foods that cause acne? To understand why not, let’s go on a little journey back in time.

It’s the late 1800s, and a dermatologist has a new patient with acne. He cracks open his trusty textbook to see what to do, and reads that doctors before him found that diet plays a role in breakouts. He tells his patient to cut down on sugar and fat [1]. He doesn’t know why this helps, but he and his patient are happy to see some improvement.

The years roll on. Dermatologists in the 1930s learn that people with acne can’t process sugar properly [2], and some even suggest that cutting out specific carbohydrates can help [3]. Not all patients see improvements, but many do, and the diet-acne hypothesis remains strong.

Then we arrive in 1969. Two studies—one investigating chocolate [4], followed by another investigating chocolate, milk, roasted peanuts and fizzy drinks two years later [5]—find that diet does not affect acne at all. These studies are so influential that they shut down all diet-acne research for the next 40 years.

Those dusty textbooks from the 19th century are long forgotten, and a whole new generation of doctors learns that diet doesn’t affect acne.

 

Foods that cause acne—or do they?

Here’s the thing about science: it continually moves on. Unlike doctors from previous centuries, we now know that your hormones, your immune system and your gut bacteria are critical factors in the development of your acne [6].

And guess what influences those three factors? That’s right: your diet.

Modern researchers can now see that those seminal studies in 1969 and 1971 were deeply flawed [7], and the British Association of Dermatologists is once again referencing diet as a contributing factor in acne.

As you can see, it’s been quite the journey! And it’s still going on. More and more research is uncovering how and why dietary patterns affect acne. It’s far from a complete picture, but we can certainly glean enough to make a difference to your skin day-to-day.

So, without further ado, let’s look at the top five foods most commonly believed to cause acne:

1. Dairy
2. Sugar
3. Chocolate
4. Eggs
5. Peanut butter

If you want to know which of these do affect your acne—and which have been innocently accused—keep reading.

 

Does dairy cause acne?

The short story is that eating lots of dairy can contribute to acne. But not all types of dairy are equally acne-triggering, and not everyone will have a problem with dairy.

As you’ll learn with acne science, it’s all about nuance!

Let’s start with the basics: lots of large-scale studies suggest that plain old milk is the worst culprit. They knew this way back in 1949, when 1,925 patients kept food diaries and found that milk was the most common food implicated in acne flares [8].

More recently, in 2018, a meta-analysis (a study of studies) used fancy statistical analysis to work out that for every extra serving of whole milk and skimmed milk (about a cup), the risk of acne went up by 13% and 26% respectively [9].

That’s right—skimmed milk is worse for your skin than full-fat milk. That’s a finding that’s replicated in other studies too [10].

Now, when we get to other forms of dairy, things get a little hazy. One meta-analysis found that yoghurt and cheese are associated with acne [11], but another one found that yoghurt and cheese had no blame in acne at all [12]. Another study even found that fermented milk—otherwise known as kefir—even helps to improve acne [13].

Puzzling, right?

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The issue is that in these studies, researchers are observing large groups of people and trying to find patterns. That’s a useful starting point, but it wipes out the effect of individual variation. And that’s what’s important here: you just need to know whether dairy affects your acne.

For a whole bunch of genetic and epigenetic reasons, some people can tolerate dairy pretty well, while others are more sensitive to it. Let’s look at why:

Whey and casein sensitivity. These are the two major proteins in dairy [14]. If your immune system has decided that it doesn’t like these proteins, it can launch an inflammatory reaction that shows up on your face (or chest, or back…)[15].

Interestingly, cow’s milk casein seems to be the most problematic version. There’s a slightly different form of casein in sheep’s milk and goat’s milk, which is why some people who can’t deal with cow’s dairy find they’re okay with another form. They may also be fine with regular butter, as that naturally contains very little protein.

Whey is present in relatively small amounts in normal milk (it accounts for just one-fifth of the protein content [16]), but it’s found in large amounts in protein powders. Ever heard of ‘bodybuilding acne’? That’s often down to gym aficionados gulping down whey protein powder by the bucket load.

Mini interlude: don’t worry if this detail is confusing! We’ll talk about how you can find out if dairy is a problem for your skin in the next section.

Just before we do, let’s look at another reason why it can lead to breakouts:

Sensitivity to hormones. Despite what the fearmongers on the internet will tell you, your acne isn’t the direct result of the pus-hormone concoction found in cow’s milk. Yes, the natural hormones in milk can play a role, but the biggest effect is down to how milk makes your own hormones behave.

Certain substances in milk start a cascade of hormones and biochemical pathways that make your skin oilier and more acne-prone [17]. Some people are more susceptible to this than others (remember how I said this was nuanced!).

If sensitivity to hormones is the key reason you have a problem with dairy, you’re more likely to have a dose-response relationship with it. In other words, too much dairy leads to a breakout, while a little bit is okay.

So, what do you do with all this information?

What to do about dairy and acne

If you’ve been dealing with acne for a long time, you’ve probably learnt to be afraid of dairy. You may even avoid it at all costs. But it’s my experience—and the experience of many of my nutrition colleagues—that most people can find a happy balance with dairy if they wish to.

Let’s start with the bad news: to know if dairy is a problem for you, you need to cut it out of your diet entirely for a while. This means all milk, all butter, all, cheese, all ice-cream…you name it.

But the good news is that it doesn’t have to be a long while. One month would be ideal, but you can usually get a good idea of how it’s affecting you after just two weeks.

Observe your skin while you’re not eating it. Is it brighter? Clearer? Less sore? There’s no need to get obsessive, but it’s useful to watch for the feedback.

After two weeks (or a month), you need to test it by reintroducing dairy products. It’s best to do this in the order of less reactive to most reactive forms, so you can get a clear idea of what your body can handle. I’d recommend this order:

1. Butter
2. Fermented milk (kefir)
3. Hard cheese: Parmesan, Grana Padano, mature cheddar
4. Yoghurt
5. Soft cheese: cream cheese, Brie
6. Cream
7. Milk
8. Ice cream

Eat a decent serving of the dairy form in one day (e.g. a full glass of kefir) and then wait three days. If your skin doesn’t react, you can eat that food once more but keep an eye on portion size. If your skin does react, try and sheep or goat’s milk alternative and see if it makes a difference.

In an ideal world, you’d do this slowly and systematically, so you have time to evaluate each form of dairy thoroughly. But, hey, this is real life, and not all of us have time to wait three days between testing hard cheese and yoghurt.

Simply use it as an opportunity to become your own dairy and acne food detective. You may find that you’re okay with a bit of parmesan on your pasta, but a large latte makes your skin react. Experiment and see what works for you—after all, your diet can be as unique as you are.

Does sugar cause acne?

We’re on to the next biggie in the list. Let’s cut to the chase once more: eating too much sugar can contribute to acne. But once again, it’s not the sugar itself that’s causing breakouts—but how your hormones react to sugar.

To understand this, we need to revisit the biology you learned in school. This won’t take long, so bear with me!

Every time you eat carbohydrates or sugar, your body releases the hormone, insulin. This important hormone helps to get the sugar (glucose) in food out of your bloodstream and into your cells, where it’s needed most.

This mechanism is a normal bodily function. But eating too much sugar (glucose) can make your body release a lot of insulin—and this becomes problematic for your skin.

This is because excess insulin increases the production of androgens, a group of hormones which includes testosterone. Testosterone kicks your sebaceous glands into overdrive, which winds up making your skin more oily and more acne-prone [18].

Put more simply:

more sugar –> more insulin –> more androgens –> more testosterone –>more oil –> more acne

See the problem?

Most of the studies looking into sugar and acne have investigated glycaemic index and glycaemic load. These are just fancy terms to describe the effect a food has on your insulin: a higher glycaemic index or glycaemic load = more insulin released [19]. Based on what you learnt above, it’s hardly surprising that studies have found:

Traditional cultures which have very low-sugar/low-glycaemic-load diets often have no incidence of acne. This is true for the maize-munching Aché hunter-gatherers in South America and the whale blubber-eating Inuits in the Arctic [20, 21].

– Swapping to a low-glycaemic-load diet can reduce acne. A randomized controlled trial (the gold standard of research) looked at 43 male acne patients and found that those who ate a low-glycaemic-load diet had fewer pimples after just 12 weeks [22].

– Low-glycaemic-load diets can change the composition of your sebum (natural facial oil) so that it’s less likely to cause acne [23]. Low-glycaemic-load diets can even shrink your pores [24]. How cool is that?

What to do about sugar and acne

When you understand the sugar-insulin-acne connection, you can see that for clear skin, managing your insulin response is just as important as reducing your overall sugar intake

This is what’s known as ‘balancing your blood sugar’, and it’s simple to do. Here are some general principles:

1. Opt for complex carbohydrates over white, refined ones. This means choosing a hearty, seeded bread over a white bagel. It means opting for sweet potatoes over French fries. Need more examples? Here you go:

You get the picture. Complex carbohydrates are rich in fibre and digested slowly, which means they release their glucose into your bloodstream more gradually—giving you a healthy insulin response and happier skin.

2. Eat protein and healthy fats with every meal or snack. These also take longer to digest, which means they further reduce the glycaemic load of your food. Not sure what proteins and healthy fats are? Here’s another handy table for you:


Again, this is easy when you get in the habit. Add nut butter to apple slices, drizzle olive oil on your salads and sprinkle seeds into your porridge. You’ll find that you stay fuller for longer too.

3. Be mindful of hidden sources of sugar. You know that it’s not a good idea to drink gallons of coke, but have you considered how much sugar is in your glass of orange juice? Condiments (even savoury ones) are often full of sugar too. Ketchup, for example, contains almost a teaspoon of sugar per single serving.

 Get into the habit of checking ingredients labels. As a rule of thumb, anything that has more than 5–10g sugar per serving is worth reconsidering. Cutting down on your added sugar intake will not only help your skin, but it will also help your health as a whole.

One final note before we move on: don’t be afraid of fresh, whole fruit. Yes, it contains sugar, but it also contains lots of fibre, vitamins, minerals and phytonutrients that are good for your skin. In fact, many fruits are a mainstay of low-glycaemic-load diet [25].

Does chocolate cause acne?

There’s no robust evidence that pure chocolate causes acne [26]. Remember those early studies that shut down acne-nutrition research for 40 years? Yes, they were flawed, but they also found that chocolate had no impact on acne.

So why the deep-rooted belief that chocolate causes acne?

Well, it’s probably because of the way most people consume chocolate. When was the last time you opted for a bar of 100% chocolate? Most people choose sweet, creamy milk chocolate—which contains the milk and sugar that are more strongly associated with acne.

And yet, as with all research into food and acne, there’s nuance. Another study did look at the effect of pure chocolate by asking 25 acne-prone male patients to eat 25g of 99% dark chocolate daily for four weeks. After two weeks, their acne got worse [27].

There are a few issues with this study, though—namely the small number of subjects studied, the fact that they were all male, and that there was no control group for comparison. It’s certainly not enough to suggest that pure chocolate worsens in acne in everyone. It’s not something I’ve observed clinically either.

If you’re curious, experiment and see what works for you. Remember: your diet is your own.

 

Do eggs cause acne?

Let’s get straight to the point again: there’s very little evidence to suggest that eggs cause acne. One case-control study did find a link between egg consumption and acne, but this isn’t a finding that’s been replicated elsewhere [28].

And yet more than 1,000 people google ‘Do eggs cause acne?’ every month. Clearly, people have their suspicions.

To understand what’s happening here, let’s consider inflammation. The old view of acne what that breakouts led to inflammation, but newer research suggests that inflammation can actually precede acne [29]. In other words, if you’re a little bit inflamed, you’re more likely to get pimples.

But what has all this got to do with eggs, you’re wondering?

Well, a source of chronic, low-grade inflammation in the body in food sensitivities. This is because much of your immune system clusters around your gut. If you’re eating something your body doesn’t agree with, your immune cells are ideally placed to react with an inflammatory cascade [30]. This inflammation can then exacerbate acne [31].

Eggs are a common food sensitivity [32], so it could be that people who suspect eggs trigger their acne have an undetected egg sensitivity. The confusing thing is that it’s possible to have a food sensitivity without digestive symptoms, so the only way you could know for sure is to eliminate eggs for a while and see if your skin improves. Head back up to the ‘What to do about dairy’ section to see how to eliminate and re-test a food.

This connection is part of a much bigger topic in acne and dermatology research: the gut-skin axis. More and more research is showing that the health of our guts (and particularly our gut bacteria) directly affects the health of our skin [33]. For an introduction on how to support your gut health for clear skin, head over to Gut Bacteria and Acne: What’s the link?

 

Does peanut butter cause acne?

Unless you know you react to peanuts, it’s unlikely that peanut butter is a significant driver of your acne. It’s similar to eggs in that way.

The belief that peanut butter is linked to acne likely stems from the fact that it’s high in omega-6 fatty acids. These are essential fats (a.k.a. you need to eat them), but too many can have a pro-inflammatory effect in the body [34]. As you learnt above, inflammation is bad news for acne.

It’s unlikely that you’re eating too many omega-6 fats from peanut butter alone—you’d have to guzzle jars of the stuff daily. What is more likely is that you’re overconsuming other sources of omega-6 fats—such as processed seed and vegetable oils—as most people in the Western world do [35]. This is why greasy foods, fried in these oils, are often linked to acne too.

The good news is that another type of essential fat, omega-3 fatty acids, have an anti-inflammatory effect in the body [36]. Eating omega-6 and omega-3 fatty acids in a ratio of 4:1 could help to quell inflammation, but most people eat them closer to a ratio of 16:1. That means you may be eating 16 times as many pro-inflammatory fats as anti-inflammatory fats [37].

Confused? Don’t be. Rather than worry about peanut butter specifically, all you need to do is up your intake of omega-3-rich foods, and decrease your intake of omega-6-rich foods. Common sources are listed below:

If you’re more of a visual person, check out the graph below. A good rule of thumb is to avoid eating too many of the oils that have long blue bars:

Composition of dietary fats graph

You may be thinking, ‘What on earth is soybean oil?! I don’t put that on anything!’. You probably don’t—but food manufacturers do. Get into the habit of checking ingredients labels. You may be surprised at how often you’re eating these omega-6-rich oils.

If you need any more convincing, one study found that teenagers who ate more fish had less acne [38]. Bottom line? If you want to help your acne, spend less time worrying about peanut butter and more time eating oily fish.

 

Takeaway points

 As you can see, there’s not a single food that causes acne in everyone—but some foods can trigger acne in susceptible people. Here’s what we know:

Cow’s dairy has been linked to acne in some people. The most problematic form seems to be skimmed milk, followed by other types of milk. Yoghurt and cheese seem less likely to trigger acne.

– If you want to know if dairy is an issue for you, cut it out of your diet entirely for at least two weeks. Reintroduce it slowly and monitor your skin’s reaction. You may find that you tolerate goat’s dairy or sheep’s dairy better.

– Eating too much sugar has been linked to acne. To help clear your skin, cut down on sugary foods and drinks. Focus on eating protein, healthy fats and complex carbohydrates instead.

– There’s no robust evidence that chocolate causes acne. Eating lots of milk chocolate may exacerbate acne, though, because it contains milk powder and sugar.

Eggs are unlikely to cause acne unless you have a specific sensitivity to eggs. You can try eliminating eggs for a while to see if it makes a difference to your skin.

Peanut butter is also unlikely to cause acne unless you have a peanut sensitivity. Peanut butter is rich in pro-inflammatory omega-6 fatty acids, but you can balance this by eating more anti-inflammatory omega-3 fatty acids (primarily found in oily fish).

Your gut health not only affects how you react to food, but it also plays a role in your skin health. You can read more about this in Gut Bacteria and Acne: What’s the link?

Acne can cause a lot of food fear. Although food does play a role, it’s unlikely that it’s the only driver of your skin condition. Believe it or not, you can indulge in ice-cream and cake from time to time and have clear skin.

Use the above as guidelines to work out what’s best for you. For healthy skin and a happy mind, the goal is always to make your diet as diverse as possible.

Want to learn more? Get your copy of my book, The Happy Skin Solution.

For easy, acne-friendly recipes, download your copy of the Clear Skin Meal Plan.

Nutritional Therapist Fiona Lawson

Fiona Lawson is a former national magazine editor turned registered nutritionist and acne specialist. She holds a BANT-registered qualification in Nutritional Therapy, and she is currently working towards her MSc in Nutritional Medicine.

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