At first glance, it seems like beans and legumes are loaded with dangerous anti-nutrients that damage your digestive system and trigger inflammatory acne.
But, as we’ll see shortly, these fears might be over-exaggerated.
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
Lectins are antinutrients that plants use to prevent predators from eating them – they’re designedto 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
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 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.
Saponin
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
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
White bread
75
34.7
High
Corn chips
63
39.9
High
White rice
79
40
High
Sweet Potato
61
14.8
Moderate
Chickpeas
28
8
Very Low
Kidney Beans
28
7
Very Low
Lentils
26
6
Very Low
Lima Beans
32
10
Low
Black Beans
42
13
Moderate
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
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.
Zinc
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.
Manganese
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.
Food
Fiber
Zinc
Manganese
Chickpeas
12.5g
2.51mg
1.69mg
Lentils
15.6g
2.51mg
0.98mg
Peas
8.8g
1.64mg
0.72mg
Kidney Beans
13.6g
1.60mg
0.76mg
Black beans
15.0g
1.93mg
0.76mg
Pinto beans
15.4g
1.68mg
0.77mg
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.
Soy
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 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.
Peanuts
Yes, you heard that right, peanuts are in fact a legume. This includes peanut butter and any products that are heavily concentrated in peanuts.
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.
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 Click Me!GoodGlow Diet Blueprint. It has everything you need to get started eating an acne-free diet, all on one page.
Frequently Asked Questions
Do canned beans contain lectins?
No canned beans are not high in lectins because they come pre-cooked. Additionally, lectins are water-soluble so washing the beans off with water should remove the majority of the lectins remaining in the beans.
Do chickpeas cause inflammation?
No, chickpeas are anti-inflammatory and nutrient-dense. Chickpeas contain protein, fiber, and lots of antioxidants that help reduce inflammation.
Need more help? Ask our team!
I’ve helped over 2,500 people clear their acne naturally. If you cannot easily find an answer to your question on the website, please reach out to me by email ([email protected]) or send me a message on Instagram or Twitter. I will reply within 24 hours.
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Hi I’m Sam Wood. I’m the chief editor, lead acne expert, and health coach behind GoodGlow. I’m also an author of one of the top selling acne books on Amazon, a husband, father of two, and a pretty good cook!
I’m so glad you found GoodGlow and hope the information I have spent the last 10 years cultivating will help you clear your skin and improve your overall health.
I began experiencing acne breakotus as a sophomore in high school, but unlike most of my friends, my acne actually got worse as I got into my 20s. I exercised regularly, ate healthy (or so I thought) and spent hundreds of dollars a month on high end skincare products and supplements to help clear my skin. Despite these measures my acne breakouts and scarring only got worse as the years wore on.
This greatly wore on my self confidence and mental health. Simple things like taking pictures or going out with a large group made me feel self conscious. So I avoided these situations whenever I could help it.
As a last ditch effort I decided to try an extremely restrictive diet recommended by a close friend with an autoimmune disease. After following this diet for about two months my skin started to clear for the first time in over 8 years. The good news is that this restrictive diet is not actually necessary for 99% of people to permanently clear their skin, and over the course of a few months I was able to add back about 90% of my “normal diet”.
After clearing my skin I spent the next 4 years self experimenting on myself with different diets, supplements, skincare products to try and find a pattern for what was triggering my acne breakouts. I even tried different meditation, ice baths, and accupuncture to try and isolate the root cause of the breakouts.
In the end I realized that an extremely restrictive diet was not necessary for clear skin. The most important thing to do is to avoid inflammatory foods in your diet. Some common examples of this are fried foods, alcohol, sugar, and dairy.
Most impoirtantly I stopped reading trendy websites for skincare advice and began reading medical journals authored by dermatologists and nutritionists. Although the information in the articles was great the information was not easily understandable to most readers (including me). I spent hours dissecting individual posts and looking up terms I did not understand. Over the next 6 months I gradually began to understand these journals and started self experiemting some of the research on myself.
After experiencing quite a bit of success personally, I started sharing my research on forums and with close friends struggling with acne. When I shared the research it was in easy to understand, plain English. Everyone I talked to loved what I had to say and kept asking more and more questions. So I decided to start a blog so I could just send someone a link when they asked a question instead of rewriting something I had sent 100 times before 😅
While the same directional principles apply to everyone, acne is very personal and should be treated on an individual basis. That’s ultimately why I created GoodGlow. To help everyone reverse engineer the root cause of their acne and clear their skin permanently.
To date I’ve helped over 2,500 people clear their skin using a natural, holistic approach. If you are unable to find an answer to your question in any of the articles my team has written please reach out and I will do my best to guide you to the proper information and resources so you can make a thoughtful, informed decision. Read more of Sam's articles.
do refried beans count as harmful as well?