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Cow's milk may increase your risk of cancer, heart disease, and acne - here's what the research says and why most nutritionists still consider it healthy

Cow's milk may increase your risk of cancer, heart disease, and acne - here's what the research says and why most nutritionists still consider it healthy

Erin Heger,Samantha Cassetty

Milk is not bad for your health as it a good source of vitamins, minerals, and macronutrients like protein.
Research shows milk does not increase your risk of heart disease or increase blood lipid levels.
However, milk may increase the risk of hormone-related cancers like breast and prostate cancer as well as cause acne.

Although milk and dairy alternatives are on the rise, that doesn't mean they can't be part of a healthy diet. Here is what you need to know about the potential health risks and benefits of milk, and how much dairy you should eat each day.

The health benefits of milk

Milk contains many essential vitamins and minerals important to our health. The Dietary Guidelines for Americans recommends three servings of milk or other dairy foods to receive enough calcium, potassium, and vitamin D, which many people may not be getting enough of by consuming food alone, says Eshani Ewing, a registered dietitian with Orlando Health, a not-for-profit healthcare organization in Florida.

Here is a breakdown of the benefits of milk.

Milk is high in calcium

One cup of milk contains about 300 mg of calcium, which is about 30% of the general recommended daily value. This recommendation, however, varies by age and you need more calcium the older you get.

Adult men ages 19 to 70 need 1,000 mg of calcium/day and 1,200 mg/day after age 71.
Adult women ages 19 to 50 need 1,000 mg of calcium/day and 1,200 mg/day after age 51.

Calcium plays an essential role in bone health. Calcium is also important for:

Muscle contraction
Relaxation of blood vessels
Secretion of insulin, which controls blood sugar levels

Milk is high in Vitamin D

Milk is fortified with vitamin D and one cup of milk contains about 100 international units (IU) of vitamin D, which amounts to about 15% of your daily value. The recommended daily amount of vitamin D is 600 IU for children and adults younger than 70 and 800 IU for people over age 70.

Vitamin D is important to health because it:

Aids in the absorption of calcium and phosphorous, which protect against bone loss
Supports nerve and muscle function
Supports the immune system

Milk is a source of protein

One cup of milk contains about eight grams of protein. The recommended daily amount of protein varies by weight - 0.8 grams per kilogram of body weight is the minimum needed.

Proteins are essential for health and make up the building blocks for:

Bones
Muscles
Skin
Cartilage
Blood
Hormones

The health risks of milk

Dairy can be a valuable part of a well-rounded diet, but consuming too much milk may increase your risk of certain health conditions.

Milk may increase your risk of heart disease

When it comes to dairy products and heart disease, the research is mixed.

On the one hand, dairy products can be high in saturated fats, which can raise unhealthy blood lipid levels clogging arteries in the process and increasing your risk of heart disease. However, there is little evidence to support a link between consuming dairy and heart disease, says Ewing.

A 2012 study of people ages 45 to 84 years old found saturated fat from meat was associated with a higher risk of heart disease, whereas saturated fat from dairy correlated to a lower risk of heart disease. Another 2014 review found consumption of dairy did not exert negative effects on blood lipids.

That said, it's important to be aware of your total saturated fat intake from all sources if you have a family history of heart disease, says Amy Shapiro, a registered dietitian who works as a nutrition consultant in New York City.

The general guideline is for saturated fat to make up no more than 10% of your daily calories. The American Heart Association recommends limiting saturated fats even more to 6% of your daily calories.

Milk may increase your risk of certain cancers

Some scientists suspect the high-fat content and hormones in milk and dairy products may contribute to certain cancers, like breast cancer or prostate cancer.

A 2020 study found an increased risk of breast cancer among women who consumed cow's milk compared to women who consumed soy milk. Additionally, some other studies have found a potential link between dairy products and prostate cancer.

However more research is needed to determine how dairy products influence cancer, Ewing says.

"There is no strong evidence to suggest that drinking milk increases the risk of developing cancer," Ewing says. "It is key to consider an individual's overall eating pattern, as this is much more important to cancer risk than single nutrients."

Milk may cause you to break out

A 2005 study of adolescent women aged 14 to 18 found a positive association between total milk consumption and acne diagnosis.

Researchers suspect dairy products may increase certain hormones that contribute to sebum production, an oily waxy substance on skin that can cause acne. However, no randomized controlled trials have confirmed this link, and more research is needed.

"If someone thinks their acne is related to dairy intake, it may be worthwhile to limit dairy products to see if there are any beneficial changes," Ewing says. "Just make sure you are getting enough calcium and vitamin D from other sources."

No, milk is not bad for you

Milk can be an integral part of a nutritious diet, but how much and what kind you should drink depends on your medical history and health goals.

While there is no direct link between drinking milk and increased risk of heart disease, if you have a family history of heart disease, you may want to limit your saturated fat intake and talk with your doctor about alternatives to milk, Shapiro says.

For someone looking to lose weight, sticking to 1% to 2% milk or skim milk might be more useful than consuming whole milk, Ewing says.

Those with a milk allergy should opt for a non-dairy alternative, like almond, oat, or soy milk, Ewing says. Most non-dairy alternatives are also fortified with calcium and vitamin D, however, they may be low in protein so you'll need to make sure you are consuming other sources of protein like eggs, tofu, or meat.

Insider's takeaway

Some studies indicate milk may be associated with negative health outcomes, like heart disease or cancer, but more research is needed to draw definitive conclusions. When consumed in moderation, milk can be an essential part of a nutritious diet. If you are worried about the potential risks of drinking milk, talk with a healthcare professional about milk alternatives.