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Is Dairy Dangerous? We Dive Into The Science 

Emma Rose
Author: Medical reviewer:
Updated on March 16, 2020
Emma Rose
Contributing writer
By Emma Rose
Contributing writer
Emma Rose is a freelance journalist and writer for mindbodygreen. She received a BS in Biology with a Minor in Nutrition Sciences from the University of Washington, and has previously written for Bulletproof.
Bindiya Gandhi, M.D.
Medical review by
Bindiya Gandhi, M.D.
Dr. Bindiya Gandhi is an American Board Family Medicine–certified physician who completed her family medicine training at Georgia Regents University/Medical College of Georgia.

Dairy is a confusing topic in the health world, and it can be difficult to find the “correct” path in a sea of contradictory advice. But is dairy dangerous? While there are risks and benefits, the truth is that dairy works for some bodies, but not for all. To one person, dairy could mean breakouts, bloating, or other symptoms of intolerance, but for another, it could be a valuable source of bone-building minerals and fat-soluble vitamins.

Read on for the pros and cons of dairy in your diet. Below, we’ll explore different types of dairy, factors to look for in order to add the most benefits to your diet, and helpful tools to learn if dairy is right for you.

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Health concerns with dairy.

Dairy is a major staple in the western diet, yet it’s also one of the most commonly experienced food sensitivities. While the human body is designed to digest mother’s milk at infancy, that ability is often short-lived. For some humans, as we age, our body loses its ability to digest lactose, the prevalent sugar in milk. This is called lactose intolerance, and it affects about 65% of adults worldwide.

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Lactose intolerance.

With lactose intolerance, your body stops producing enough lactase, which is the enzyme needed to break down the lactose sugars in milk. When your body is unable to break down those lactose sugars, that’s what causes the discomfort you may feel.

You’re not alone. Approximately 65% of adults are genetically lactose intolerant, rising to 70-100% for folks of east asian descent. Lactose intolerance can also develop after damage to the small intestine, such as Crohn's disease or Celiac disease. 

If you are lactose intolerant, you’re likely familiar with symptoms like bloating, gas, diarrhea or discomfort after eating dairy. However, different proteins in milk can cause different problems. According to Megan Fahey, M.S., R.D., CDN., the two main proteins found in milk are casein and whey, and the casein is made up of 2 main genetic types: A1 and A2. 

“When the A1 protein is digested, it produces a peptide called beta-casomorphin-7 (BCM-7), which has been linked with symptoms of stomach discomfort similar to those classically associated with lactose intolerance,” she says. 

Dairy allergies.

That said, A dairy allergy is different from lactose intolerance, as a dairy allergy is an immune allergic reaction to casein or whey. This allergy can show up in the same ways as other food allergies, ranging from hives, itching and swelling, to the more severe anaphylaxis. 

To put it simply: Lactose intolerance involves the digestive system, while a dairy allergy involves the immune system, even though both can lead to similar feelings of stomach discomfort.

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What about dairy and acne? 

Maybe you’ve heard of a celebrity or friend who cleared their skin for good by cutting out milk. One study even analyzed the results from 14 different studies on dairy and skin, found that higher dairy intake may contribute to acne in children and young adults1. That said, it’s not exactly clear if dairy itself is the culprit. Some scientists believe that acne may be triggered by excess hormones and growth factors2, which are especially high in non-organic milk products.

How to know if you’re sensitive to dairy. 

Well, you are what you eat, and the best advice often comes from simply listening to your body. A useful tool for detecting lactose intolerance, milk allergies, or any other food sensitivity is called an “elimination diet.” This involves removing the food in question from your diet for 2 weeks to a month, then re-introducing it to help you understand your body’s response. If adding this food causes negative symptoms, it’s probably best to avoid it. 

While experimenting and listening to your body may be enough to determine a lactose intolerance or sensitivity, a doctor can also perform a breath or blood test to test your body's ability to break down lactose sugars. Even mild allergies can be detected by a blood or skin test, performed by an allergist or doctor. Food sensitivity testing might be more helpful for some people than an elimination diet, as you can clearly see what you’re sensitive to on paper (which might make you more likely to adhere to it).

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Are there any health benefits of dairy?

For those not intolerant of dairy, several studies suggest that dairy intake may actually be linked to 3reducing3 inflammation3 in the body. Dairy products (especially full-fat dairy) can be an excellent source of fat-soluble nutrients like Vitamins A, D, E and K. 

And let’s not forget dairy’s original claim to fame: Calcium. While there are plenty of non-dairy sources for calcium, dairy products are a great source of bone-building minerals. Calcium is important both as children’s bones develop, and to prevent bone loss or accidental fractures4 as we age.

Fermented dairy products like yogurts, kefir and cheese are also an accessible way to incorporate more gut-healthy probiotics in your diet. While the diverse array of bacteria used can make it difficult to study fermented dairy as a whole, some studies do show that populations who consume more fermented dairy also tend to have lower risks of cardiovascular diseases5.

Types of dairy—do they matter?

Different types of dairy have different health impacts. Here’s exactly what to look for in certain dairy products in order to find the source that may work best for you (if any).

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What about butter? 

Butter contains mainly fat, with very little sugars or protein. Because lactose and protein are the most irritating compounds in dairy, many milk-sensitive people can still enjoy both butter and ghee--although, there is debate on whether or not this high fat content leads to an increase in total cholesterol.

Whole milk or skim milk?

Whole milk contains the full amount of fat, whereas skim milk is fat-free. While you might think a fat-free skim milk is the way to go, keep in mind that many of the beneficial nutrients in milk (such as vitamins A, D, E and K) are fat soluble nutrients and are naturally contained in full-fat products.

Organic vs non-organic.

Non-organic milk has the potential to contain harmful agents such as pesticides and growth hormones. A recent study found that conventional (non-organic) milks tested positive for pesticides, added hormones and growth factors, and even illegal levels of antibiotics6. That said, buying organic when possible can help you reduce your exposure to these toxins. 

Grass-fed dairy.

Though often more expensive, dairy from grass-fed cattle is considered healthier, as it can contain a higher nutrient content. Grass-fed cows tend to produce higher levels of omega-3 fatty acids, less omega-6 fatty acids, and more conjugated linoleic acid (CLA) than conventional dairy cows. (Hello heart health!) Plus, the environmental impact7 of grass-fed dairy is far less than dairy from grain-based feedlot operations.

Fermented dairy.

Fermented dairy contains probiotics, which we know can have significant benefits on our gut health. That said, for many dairy-sensitive people, fermented dairy products such as yogurts or cheeses may be easier to digest8, plus pack a beneficial dose of live probiotics. Fermented dairy products may also be linked to lower risk of CVD5. However, you should still experiment to see how fermented dairy makes your body feel and avoid products packed full of sugars or artificial flavors.

A1 vs A2 casein.

A1 and A2 casein are different variations of dairy’s main protein. While this type isn’t as well known in the US, studies support that A2 casein may be less irritating than A1 casein. That said, some people with milk intolerances are more able to tolerate A2 products.

Goat’s milk vs cow’s milk.

Goat’s milk is another dairy option, and may be easier to digest than conventional cows milk. While most cows produce A1 casein, goat dairy contains primarily A2 casein9, and is lower in lactose than cow’s milk.

“Most modern European-type cattle produce milk containing A1 beta-casein,” says Fahey. “When working with clients to eliminate A1 beta-casein, I recommend incorporating goat, sheep, and buffalo milk for improved tolerance of a dairy-inclusive diet.”

However, it’s important to note that some people will still be sensitive to goats milk if they have a general casein intolerance, so be mindful of what works best for your body! 

The bottom line with dairy.  

Like so many aspects of our diets, what works for someone else might not work for you, and your body is the best judge of how you tolerate dairy. While dairy can be delicious and beneficial to some folks, it’s not a necessary part of your diet.

If you opt not to consume dairy, for health or other reasons, check out this guide to the best plant-based milk alternatives to simplify going dairy-free.