Does Soy Milk Cause Acne? A Dietitian Answers

Acne is a frustrating, inconvenient, often painful, and potentially embarrassing skin issue that affects many people even after their teenage years. Understandably, dietary strategies for attaining clear skin are highly sought after.

One of the most common suggestions online for preventing acne is to cut out dairy. If you’ve replaced dairy with soy milk and are still dealing with acne, you might be confused and wondering whether you’ve done something wrong.

So does soy milk cause acne? As a registered dietitian, I’ll discuss what we know about the relationship between nutrition and acne and whether soy consumption might play a role.

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What is acne?

Acne vulgaris is an inflammatory skin condition believed to be caused by a combination of factors including:

• Excessive sebum (oil) production
• Abnormal shedding of skin cells
• Alterations in the skin microbiome
• Inflammation

A person’s hormones, genetics, and diet may contribute to the development of acne¹. 

Acne vulgaris can vary in severity. Some people experience minor plugged hair follicles or the occasional pimple, while others struggle daily with painful, inflamed lesions.

It can be a distressing condition, so interest in the relationship between diet and acne is common. 

The relationship between diet and acne

Overall, there aren’t any specific foods that trigger acne in every individual. Some people may be more sensitive to certain foods than others, so it’s difficult to give blanket dietary advice that applies to everyone. 

What we do know when looking at the scientific evidence is that a Western-style diet has repeatedly been implicated as a significant factor in acne development. Western-style dietary patterns are high in calories, animal products, and added sugars and low in fruits, vegetables, whole grains, and omega-3 fats.

The reasons for this can be summed up in the following three sections.

Hormones

Hormones are chemical messengers that impact an astounding number of complex biochemical reactions in the body. When certain hormones are out of balance, acne is more likely.

Insulin is an incredibly helpful hormone, helping to maintain normal blood sugar levels and providing our bodies with the glucose (carbohydrates) needed to support a healthy metabolism.

However, chronically high levels of insulin can be a sign of insulin resistance. In insulin resistance, body cells don’t respond as well to insulin as they normally do. To counteract this, the pancreas produces more and more insulin over time. 

Insulin resistance is often associated with health conditions like:

• Pre-diabetes
• Type 2 diabetes
• Metabolic syndrome
• Polycystic ovary syndrome (PCOS)
• Non-alcoholic fatty liver disease

Insulin stimulates the production² of androgen hormones, such as testosterone, which are known to promote excessive sebum production and contribute to acne.

Insulin-like growth factor-1 (IGF-1) is a similar hormone that increases the production of androgens in the testes and ovaries. Milk increases levels of IGF-1 in the body and could be one reason why dairy consumption may exacerbate acne³ in Western countries.

Glycemic load

The “glycemic load” of a food refers to how quickly a typical serving size of that food causes a spike in blood sugar. Typically, foods with a high glycemic load that increase blood sugar quickly include:

• Highly sweetened/sugary foods (desserts, breakfast cereals, pastries, candy, sugar, honey, agave, jams)
• Sugar-sweetened beverages (soda, sweet tea, energy drinks)
• Fruit juice
• Refined grains (white rice, white bread, bagels, white flour)
• Rice milk

Western-style diets are high in these types of simple carbohydrates.

So what do high blood sugar spikes have to do with acne? It may be related to insulin. The higher your blood sugar spikes in a short period of time, the more insulin the pancreas has to release to help blood sugar move from the blood into the body’s cells where it can be used for energy.

And as we just learned, chronically high insulin can stimulate excessive sebum production and contribute to acne.

Interestingly, certain foods like reduced fat or skim milk can stimulate insulin production⁴ despite having a low or moderate glycemic load. 

Inflammation

The Western-style diet is pro-inflammatory⁵, promoting a state of chronic low-level inflammation in the body. 

This is due to a combination of dietary factors including low intakes of anti-inflammatory omega-3 fats and dietary fiber and excessive consumption of omega-6 fats, saturated fats, pro-carcinogenic processed meats⁶, and refined carbohydrates. 

Does soy milk cause acne?

Unfortunately, no studies have directly examined the relationship between soy milk and acne vulgaris. Based on the research we do have, however, soy products like soy milk that are rich in soy isoflavones may help improve acne symptoms.

A small 2015 randomized controlled trial⁷ tested the effects of soy isoflavone supplementation in women with acne. They found that 160 milligrams of soy isoflavones was enough to significantly reduce the number of acne lesions in these women. 

These researchers also did a follow-up study⁸ over 3 months with 40 women. Compared to the placebo group, women who took 160 milligrams of soy isoflavones had significantly fewer acne lesions and also had lower levels of dihydrotestosterone, an androgenic hormone. 

This led the authors to suggest that soy isoflavones may help improve acne vulgaris by reducing the production of these types of hormones.

Remember, however, that these are small studies and more research is needed to confirm these findings. 

Concerns about soy milk as a potential trigger for acne largely come from a misunderstanding of soy’s effects on reproductive hormones. Soy contains phytoestrogens, which are similar in structure to the mammalian estrogen produced by our bodies but can have very different effects based on the area of the body.

Evidence consistently shows that soy phytoestrogens don’t have negative health effects. They, along with soy protein, also have no impact on male reproductive hormones like androgens⁹, so it’s unlikely that soy triggers acne in most people.

So far, there isn’t any evidence to suggest that soy milk causes acne. Sweetened soy milk may be more likely to trigger acne if your skin is particularly sensitive to sugar. However, I still wouldn’t expect it to be an issue for most people since even sweetened soy milk contains protein and healthy unsaturated fat, both of which help to reduce glycemic load. 

Dietary strategies to help manage acne

Thankfully, some dietary strategies can help manage breakouts. Individual responses to different foods can vary, of course, so some strategies may be more helpful than others for certain people. 

Of course, dietary strategies will be most effective when combined with an effective skincare routine and treatment from a board-certified dermatologist, especially in the most severe cases of acne. 

1. Choose a protein-rich non-dairy milk

Research shows that dairy may be an acne trigger, especially for people living in Westernized countries. I’ve experienced this personally — after cutting dairy out of my diet before I ever went vegan, I noticed a significant improvement in my acne-prone skin.

Of course, dairy isn’t a trigger for everyone. But for those affected by it, choosing a protein-rich non-dairy milk like soy milk or pea milk can make a big difference.

2. Reduce the glycemic load of your meals 

Try the following strategies to reduce the glycemic load of your diet:

• Limit sugar-sweetened beverages like soda, sweet tea, energy drinks, and sports drinks (unless you’re drinking the latter to support physical activity or sports)
• Choose whole plant foods rich in dietary fiber
• Include sources of protein, healthy fats, and complex carbohydrates at meals
• Use caloric sweeteners like sugar, agave, and maple syrup sparingly
• Choose protein-rich soy or pea milk as your go-to non-dairy milk

3. Add omega-3s

Eating more foods rich in anti-inflammatory omega-3 fats may also help. Try adding one or two of the following to your diet:

• Walnuts
• Ground flaxseeds
• Chia seeds
• Flaxseed oil
• Canola oil
• Algae-based DHA/EPA omega-3 supplements

4. Choose healthier fats

Research¹⁰ has shown that eating heart-healthy monounsaturated and polyunsaturated fats in place of saturated fat from animal foods may help fight insulin resistance. 

Saturated fats can also worsen skin inflammation¹¹ and increase sebum production, supporting the development of acne.

Fortunately, following a plant-based diet that includes plenty of healthy vegan fats from nuts, seeds, avocados/avocado oil, olives/olive oil, and canola oil is a good way to reduce your saturated fat intake — as long as you moderate your consumption of foods made with or cooked in coconut and palm oils.

RELATED: Is Canola Oil Vegan? Is It Healthy?

5. Eat more fiber 

Practically, eating more fiber means eating more minimally processed plant-based foods like fruits, vegetables, whole grains, beans, nuts, and seeds. Fiber feeds healthy gut bacteria, helping them produce anti-inflammatory compounds that reduce inflammation in the gut¹².

Fiber also helps reduce the glycemic load of a meal by slowing down how quickly carbohydrates are absorbed into the bloodstream. 

6. Get your vitamin D levels tested

Vitamin D deficiency may be a factor in the development of acne. A 2016 study¹³ found that people with acne were more likely to have a vitamin D deficiency than people without acne and that vitamin D supplementation helped improve acne in people who were deficient.

I recommend vegans choose vitamin D-fortified non-dairy milk (like soy milk) to help prevent vitamin D deficiency.

RELATED: The Most Helpful Blood Tests for Vegans

Summary

Currently, there’s no evidence to suggest that soy milk causes acne. In fact, soy milk could help reduce acne in people for whom dairy milk is a trigger. 

Soy contains anti-inflammatory phytoestrogens, which, despite misinformation prevalent on the internet, haven’t been shown to negatively impact the skin.

Soy milk is high in protein and contains healthy unsaturated fats, making it helpful for reducing the glycemic load of your diet. When fortified, it’s also a helpful source of skin-friendly vitamin D. If your skin is sensitive to sugar, you may want to choose an unsweetened variety.

If you’re interested in learning how to choose the most nutritious plant-based milk, check out A Vegan Dietitian’s Guide to Non-Dairy Milk.

The scientific information in this article was accurate at the time of publishing but may change over time as new research becomes available.

References

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9. Reed KE, Camargo J, Hamilton-Reeves J, Kurzer M, Messina M. Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies. Reprod Toxicol. 2021;100:60-67. doi:10.1016/j.reprotox.2020.12.019
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11. Podgórska A, Puścion-Jakubik A, Markiewicz-Żukowska R, Gromkowska-Kępka KJ, Socha K. Acne Vulgaris and Intake of Selected Dietary Nutrients-A Summary of Information. Healthcare (Basel). 2021;9(6):668. Published 2021 Jun 3. doi:10.3390/healthcare9060668
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13. Lim SK, Ha JM, Lee YH, et al. Comparison of Vitamin D Levels in Patients with and without Acne: A Case-Control Study Combined with a Randomized Controlled Trial. PLoS One. 2016;11(8):e0161162. Published 2016 Aug 25. doi:10.1371/journal.pone.0161162