Is eating beans triggering your acne?
At first glance, it seems like beans and legumes are loaded with dangerous antinutrients that damage your digestive system and trigger inflammatory acne.
But, as we’ll see shortly, these fears might be over-exaggerated.
There’s been a lot of discussion lately around the health benefits and drawbacks of legumes in the Paleo and “primal” diet community. Some health experts are quick to criticize legumes for their potentially harmful nutritional profile, while others say it’s no big deal.
So what’s the truth? Are beans behind your acne?
The Case Against Legumes
Legumes may cause acne due to high concentrations of lectins, phytic acid, and saponin, which can contribute to leaky gut syndrome and chronic inflammation. Legumes also contain FODMAPs, carbohydrates that can be difficult to digest.
Legumes Contain Antinutrients That Harm Your Digestive System
A healthy digestive system is absolutely critical for clear skin. If your gut isn’t healthy, chronic inflammation and even leaky gut syndrome can really wreak havoc on your skin and your overall health.
One of the easiest ways to really screw up your digestive system is by consuming foods rich in antinutrients, like lectins or phytic acid. These foods can penetrate the intestinal membrane and trigger inflammatory responses. This is a huge part of the reason why cutting out most grains is a key first step towards clear skin.
Pretty much every fruit, vegetable, grain and legume under the sun has antinutrients in it. Plants use antinutrients to protect themselves from being eaten and ensure survival. You can’t avoid all antinutrients, and you shouldn’t try. Instead, your strategy should be to limit consumption of the worst offenders and see how you handle certain foods.
This is the main gripe against legumes. Luckily, with proper cooking and preparation, the antinutrients found in legumes can be minimized.
Lectins are antinutrients that plants use to prevent predators from eating them – they’re designed to harm the digestive system of the animals (and humans) that eat them. We’ve evolved to be able to eat and tolerate a wide range of lectins, and in many cases, small doses of lectins don’t really do a lot of damage. Wheat germ agglutinin, a lectin particularly potent in wheat, rye, and barley, is one of the most damaging to our digestive system.
Lectins are not broken down like they should be during the digestive process. They stay in-tact and float down to the intestine, where they actually go through the intestinal lining fully in-tact. Once they’re in your bloodstream, your body sees them as a threat and sends out an inflammatory response as if the lectin were a harmful bacteria or a virus.
This process can lead to leaky gut syndrome and can be really harmful to our skin. As we know, chronic inflammation plays a huge role in whether or not pimples and acne form, and if we consistently consume high amounts of lectins it’s almost a guarantee that chronic inflammation will come into play somewhere.
Uncooked and unsoaked legumes contain high amounts of the lectin phytohemagglutinin, or PHA, which can cause digestive issues.
This high level of PHA is the solid argument against consuming legumes – however, as we’ll see shortly, most of the lectins found in legumes can be easily minimized with proper preparation, and not all legume lectins are as damaging or destructive as PHA.
Phytic acid is an antinutrient found in legumes that prevents you from properly absorbing nutrients like iron, zinc, calcium, manganese, copper, and magnesium.
This is particularly problematic for acne – manganese, magnesium, and especially zinc, are all critical for clear skin.
Phytic acid1https://academic.oup.com/jn/article/130/5/1378S/4686381 is the single largest dietary factor when it comes to how much zinc you actually your body actually absorbs.
In theory, this means that legumes (or any foods high in phytic acid) will actually reduce the nutritional value of pretty much everything else you eat with it.
So we should just totally avoid foods with phytic acid, right?
Well, not so fast – take a look at the chart below. Many “healthy” foods, including spinach and chard, are high in phytic acid.
“But I thought spinach was healthy!”
It is – don’t worry, phytic acid in moderation doesn’t pose a significant problem at all. In fact, it may prevent free radicals from forming, making it useful for fighting acne2https://www.ncbi.nlm.nih.gov/pubmed/9808648.
What this table ignores is that proper cooking and preparation can massively decrease the amount of phytic acid found in these foods. There are even compounds in your saliva that can break down the phytic acid before it enters the digestive system.
In the case of legumes, soaking at room temp for 18 hours can eliminate between 30 and 70% of the phytic acid.
Moral of the story: don’t stress trying to avoid phytic acid – with proper preparation and cooking you can eliminate most of them.
Saponins are soap-like molecules also found in legumes. They essentially “punch holes” in the membranes of the cells that make up the lining of our intestine, triggering an inflammatory response.
Consumption of high doses of saponins on a regular basis can lead to chronic inflammation or even leaky gut syndrome, which can cause pretty severe acne.
Just like phytic acid, not all beans are created equal in this regard:
The good news is that when consumed in moderation and on a semi-regular basis, saponins likely don’t pose a serious threat to your digestive system.
The bad news is that cooking doesn’t typically destroy saponins like it does lectins or phytic acid.
If you’re consuming Vegan or plant-based protein powder loaded with soy and find yourself breaking out, saponin is likely a huge part of the reason why. Check the ingredients on your protein powder and make sure soy isn’t a core staple in your diet.
FODMAPs are a collection of short-chain carbohydrates and sugar alcohols found in foods naturally or as food additives.
These carbohydrates can cause digestive issues, fatigue, lethargy, and poor concentration – legumes are included in this group along with many other fruits and vegetables, including apples, garlic, onions, bananas, and more.
While FODMAPs can pose a real problem for some people, particularly if you already have digestive issues, most people tolerate them just fine.
This is where self-experimentation comes into play – even with proper soaking and cooking, you might not be able to tolerate certain legumes.
Why beans and legumes might help acne
It may seem like the reasons to not eat legumes outweigh any potential positive benefits. How could something that punches holes in your gut possibly be healthy?
While legumes may contain large amounts of lectins and saponin, these antinutrients can be minimized through soaking and cooking. Furthermore, legumes contain several nutrients that help improve skin quality, including fiber, zinc, and manganese. Lastly, legumes are a low glycemic index carb source, meaning they don’t spike blood sugar levels and trigger high levels of insulin, a hormone linked to acne.
Proper Cooking and Soaking Minimizes Antinutrients
It’s unfair to look at legumes and say that they’re high in antinutrients, when in fact, after soaking and cooking, they’re really not.
You wouldn’t eat raw chicken breast and complain when your stomach hurts – the same is true for legumes.
Legumes have been consumed for thousands of years, and our ancestors went through great effort to ensure that the legumes they were eating were properly prepared – research shows we should do the same:
- Simply cooking legumes for as little as 15 minutes can wipe out most of the lectins they contain (R)
- Eating lectin-containing foods like legumes along with other foods can diminish the effects of lectins (R)
- Soaking legumes at room temp for 18 hours can eliminate upwards of 70% of the phytic acid content (R)
What this means is that while raw legumes might contain enough antinutrients to cause acne, it’s unlikely that moderate consumption of properly-prepared legumes will.
This is exactly the same case with nuts: they contain extremely high amounts of phytic acid, and some even contain lectins, however, with moderate consumption and proper soaking, they generally don’t pose any major problems when it comes to clear skin.
What this also means is that it’s essential that you buy high-quality, preferably organic legumes that you can soak – canned beans generally won’t do the trick here, and beans you get at a Mexican grill or restaurant likely haven’t been soaked and may still have high doses of antinutrients.
Bloating and gas after eating legumes are both good signs they weren’t prepared properly.
Quick Tip: How to soak and cook legumes
Soaking your legumes is simple: put them in an airtight container, fill it with filtered water, add a tablespoon or two of apple cider vinegar, and let it sit at room temp for 14-24 hours, changing the water out once or twice.
For cooking, it’s generally recommended to allow the water to reach a boil before adding the legumes, as opposed to bringing the water to a boil with the legumes already in the pot. Using this method you’ll destroy more of the phytic acid.
Legumes Are a Good Low Glycemic Index Carb Source
You’ve probably heard of the glycemic index, or GI before – it’s a number ranging from 1 to 100 that measures how fast a particular food raises your blood glucose/blood sugar levels.
As I discuss in this article, high glycemic index foods can be extremely problematic for people with acne – when you eat them your blood sugar levels rise immensely, and your body pumps out a hormone called insulin to help lower blood sugar. Chronically high insulin levels are one of the root causes of acne, and the main culprit is often a diet that’s high in refined carbohydrates, like bread, pasta, potatoes, and rice.
Legumes are a low glycemic index food, meaning they won’t spike your insulin levels.
This makes legumes an excellent source of carbs when compared to many other high-GI foods. Many people experience breakouts at after consuming high-GI foods, including “safe” starches like white rice and sweet potatoes. Legumes avoid this issue altogether and offer you slow-burning carb source without the blood sugar spike.
|Food||Glycemic Index||Glycemic Load||Insulin Response|
|Kidney Beans||28||7||Very Low|
There are numerous studies that support legumes being an ideal carb-choice for lowering insulin resistance:
- Eating a meal containing lentils led to less consumption of other carbs and lower blood sugar (R)
- Chickpeas have been shown to be more effective than other high-carb foods like wheat at reducing blood sugar (R)
- Overweight individuals consuming pea flour instead of wheat flour had much lower insulin resistance (R)
Many Legumes Are Loaded With Skin-Clearing Nutrients
Fiber is important for creating and cultivating a healthy digestive system. It feeds the gut flora, allows more nutrients to be absorbed during digestion, and takes potentially harmful bile out of the digestive system.
As we know, a healthy digestive system means healthy skin – and after cutting out grains, your diet may be lacking fiber. Why not use legumes to get there?
Legumes are rich in soluble and insoluble fiber, and a single serving often has more than 50% of the recommended daily value of fiber.
Getting enough zinc in a modern diet is really hard – the vast majority of the population is deficient in zinc, which is unfortunate because it’s absolutely vital for clear skin.
Zinc is arguably one of the most important minerals to consume for clear skin – it helps calm down the immune system, heal wounds faster, and transport vitamin A throughout the body.
Lentils and chickpeas (garbanzo beans) are excellent plant-based sources of zinc.
Unfortunately, legumes are also high in phytic acid, which binds to zinc and prevents it from being absorbed properly. Because of this, legumes aren’t the ideal source of zinc, but still better than many other plant-based alternatives.
For more information on foods high in zinc and supplements, see my Guide to Zinc for Acne.
Legumes are loaded with the skin-clearing mineral manganese – not to be confused with magnesium, another essential mineral for clear skin.
Manganese promotes a healthy immune system, helps prevent inflammation, and assists in the process of producing antioxidants that help prevent acne from forming in the first place.
Legumes are an excellent source of manganese – particularly chickpeas.
The best legumes to eat for acne
Just like any food group, balance is key when consuming legumes. While properly cooking and preparing legumes can minimize antinutrients, it doesn’t eliminate them. Binging on beans, or any other food for that matter isn’t a good strategy when it comes to clear skin.
With that being said, there are some legumes that have some pretty stellar nutritional profiles:
- Chickpeas (garbanzo beans) – Effective at reducing blood sugar (R). High in zinc, manganese, fiber.
- Lentils – Also effective at reducing blood sugar (R) and high in zinc, manganese, fiber, and thiamine.
Other beans and legumes are generally safe and have other effective health benefits. The only legumes that may cause acne-specific issues are soy and peanuts.
Legumes to avoid for acne
While most legumes are generally safe when prepared properly, there are still some that can be especially problematic for acne.
Take special caution with these legumes.
While soy is a little bit trickier to break down, and some people may tolerate it just fine, there are a few reasons it poses more problems than other legumes:
The Phytic Acid in Soy is Destructive and Resilient
Phytic acid, that nasty compound that makes it hard for our bodies to absorb essential nutrients, isn’t easily destroyed when found in soy. Even after sprouting, soaking, and cooking, much of the phytic acid in soy is still present (R).
This is especially problematic for acne – phytic acid makes it harder to absorb zinc and magnesium – two extremely essential nutrients for clear skin.
Soy Can Lead Hormonal Imbalances
There’s still a lot of debate about whether or not regular soy consumption has an effect on hormonal balance. The popular claim is that soy’s phytoestrogens bind to estrogen receptors and mimic your body’s naturally occurring estrogen without producing any of the benefits.
Scientific studies have found it hard to prove this (R), but if you’re struggling with hormonal acne cutting out soy may be a good strategy.
Yes, you heard that right, peanuts are in fact a legume. This includes peanut butter and any products that are heavily concentrated in peanuts.
They’re unique in that they have a few nutritional properties that you don’t get with many other legumes.
Peanuts are High In Omega-6 Fatty Acids
As I discuss in this article, your balance of omega fatty acids can make or break your chances at clear skin.
Omega-3 fatty acids are anti-inflammatory, while omega-6 fatty acids are pro-inflammatory. Too many omega-6 fatty acids can cause chronic inflammation – an overly-active immune system that can exacerbate acne by causing inflamed, angry, red pimples on the skin.
Peanut butter and peanuts are loaded with omega-6 fatty acids. A single tablespoon of peanut butter contains a whopping 2.5g of omega-6 fatty acids.
This makes peanuts extremely hard to stomach, even in moderation.
Peanut Lectins Aren’t Broken Down by Cooking and are Extremely Allergenic
Unlike many other legumes, peanut lectins are extremely resilient and aren’t broken down via cooking.
Worse yet is that peanut lectins are among the most allergenic, which can trigger even more inflammation.
The end result is that peanut lectins are much more like to damage your gut and immune system than other legumes.
See my full guide, The Best and Worst Nuts for Acne, for better alternatives to peanuts.
So far we’ve examined both the cases for and against legumes:
- The case against legumes: Legumes contain many of the same antinutrients found in wheat that harm your digestive system and can cause chronic inflammation
- The case for legumes: With proper preparation and cooking, many of these antinutrients can be eliminated. Furthermore, legumes are a good low-GI, nutrient-dense carb source
While legumes are generally safe, properly soaking (usually for around 24 hours in apple cider vinegar and water will do the trick) and cooking is essential when consuming legumes. Not all legumes are created equal: soy and peanuts may be especially problematic when it comes to acne.
If you tolerate legumes well, they may make a great low-GI carb source and a valuable asset in your journey towards clear skin. Just like all foods, they should be part of a balanced diet that contains plenty of other nutrient-rich food. All-and-all, they’re a much better source of carbs, fiber, and other nutrients than grains.
All science and research aside, it’s important to keep in mind that at the end of the day, YOU are the only one who can know if legumes can be incorporated into your diet. When in doubt, just experiment with them. Incorporate small amounts of legumes into your diet and see how you feel. Do you break out? Do you have gas or an upset stomach? Do you feel better when you have legumes in your diet?
Remember – you know your body much better than any health guru, diet, framework, or online blogger (including me!) – try out legumes and see what you think. They might just be the low-GI carb source you’ve been searching for.
As always, if you’re looking for a simple, easy, and free way to get started eating a diet optimized for clear skin, you can download the free GoodGlow Diet Blueprint. It has everything you need to get started eating an acne-free diet, all on one page.
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