Dairy May Lower Cancer Risk

Dairy is a key part of dietary guidelines in many countries, and for good reason! It’s packed with high-quality protein, essential minerals like calcium and magnesium and vitamins such as B12 and A, making it a nutritional powerhouse.

Most dietary guidelines recommend two to three servings of dairy daily to keep our bodies fueled and healthy. Yet, many of us, at least in the United States, don’t quite hit that target. Research shows that dairy can help lower the risk of certain chronic diseases, and certain options can support gut health too.

A group of researchers aimed to explore the connections between dairy consumption and various health outcomes in adults by conducting a scoping review. This included looking at how dairy might affect heart health, different types of cancer, body composition, mortality, and other areas like type 2 diabetes, bone and joint health, and brain function. While there are plenty of systematic reviews on dairy and health, this scoping review looked at all types of dairy and their effects across a wide range of health outcomes, and the results were published in the European Journal of Clinical Nutrition.

How Was This Study Conducted?

To explore how dairy consumption affects health, researchers conducted a detailed review of existing studies. An expert designed the search strategy, focusing on two main themes: dairy consumption and its impact on health. 

The team used a pre-tested template to pull key information from the studies, such as the number of participants, study design, health outcomes and whether the results showed dairy having a positive, negative or neutral effect. Researchers identified 29 health outcomes related to diet, which were grouped into five main categories:

1. Heart and Blood Vessel Health: This includes conditions like heart disease, strokes (all types), high blood pressure and other cardiovascular issues.
2. Cancer: Various types of cancer were linked to diet, such as breast, colorectal, lung, stomach and prostate cancer, among others.
3. Body Weight and Composition: This covers issues like being overweight, obesity and weight gain.
4. Mortality: This includes overall death rates and deaths specifically related to heart and blood vessel diseases.
5. Other Issues: These include type 2 diabetes, bone health, joint problems (like arthritis) and cognitive health (brain function).

Some reports covered multiple health outcomes, so the total number of connections between diet and health is higher than the number of studies. Researchers then looked at how eating different types of dairy, like milk, cheese, yogurt and fermented dairy (e.g., yogurt, kefir), affects health. They analyzed 281 associations between dairy and health outcomes, such as heart health, cancer, body weight and diabetes.

Ultimately, this scoping review carefully mapped out the existing evidence on dairy consumption and its effects on a wide range of health outcomes, highlighting areas where more research is needed.

What Did The Study Find?

The study found interesting associations between consuming certain types of dairy and certain outcomes. But when it came to eating dairy of any kind, most studies found that eating any dairy reduced the risk of health concerns like heart disease, certain cancers (e.g., bladder, breast, colorectal), type 2 diabetes and obesity. Five studies linked dairy to higher risks of cancers like liver, ovarian, and prostate cancer.

When the researchers drilled down to evaluate how specific types of dairy are linked to certain outcomes, they found:

Milk 

Fifty-one studies looked into milk specifically, and from those studies and others, the researchers noted 13 positive associations between milk consumption and a reduced risk of certain health issues, including lower chances of developing oral, bladder and colorectal cancers. However, the majority of studies found no significant effect of milk on health outcomes.

Cheese

Cheese consumption showed promising results in 20 studies, many of which found it reduced the risk of health concerns like heart disease and even some cancers, including breast and colorectal cancer. On the other hand, 25 studies reported no effect of cheese on health outcomes. Only two studies linked cheese to an increased risk, specifically the risk of prostate cancer.

Yogurt

Yogurt stood out as particularly beneficial, with 25 studies showing it reduced the risk of health issues such as heart disease, type 2 diabetes and cancers like bladder, breast and colorectal cancer. But it’s important to note that another 25 studies found no effect of yogurt on health outcomes. Importantly, none of the studies linked yogurt consumption to an increased risk of any health problems.

Fermented Dairy

Fermented dairy products showed the most consistent benefits, and 13 studies delved specifically into fermented dairy. Across all studies, researchers noted that 13 findings supported a relationship between fermented dairy and a reduced risk of negative health outcomes, including heart disease, stroke and cancers like bladder and breast cancer. Additionally, four studies reported no effect, while only one study linked fermented dairy to an increased risk.

High vs. Low-Fat Dairy

Most of the 27 studies that looked at high vs. low fat dairy and certain outcomes focused on dairy as a whole, rather than just milk, and primarily examined how it affects heart health. They also explored links between dairy fat content and other health outcomes, such as certain cancers (breast, colorectal, ovarian and prostate), body weight, diabetes and mortality. And most studies found no difference in health risks between high-fat and low-fat dairy. In fact, both full-fat and reduced-fat dairy were often linked to better heart health. Only two studies found that full-fat milk was associated with a higher risk of heart problems. As for cancer, most studies found that full-fat dairy either had no effect or was linked to a lower risk of certain cancers.

While this study provides valuable insights into the relationship between dairy consumption and health, it does have some limitations. First, it relies on existing studies, which means the quality and design of those studies can affect the findings. For example, some studies may not account for other factors like overall diet, lifestyle or genetics that could influence health outcomes. Additionally, the results are based on associations, not cause-and-effect relationships, so we can’t say for sure that dairy directly causes the observed benefits or risks.  

How Does This Apply to Real Life?

This research highlights that including dairy in your diet can be a smart choice for supporting overall health. For example, yogurt and fermented dairy products consistently show benefits for heart health, type 2 diabetes and even reducing the risk of certain cancers. 

To include more dairy, try swapping your usual snack for a yogurt, adding milk to your morning coffee or cereal, or sprinkling some cheese on your salad or pasta. Even small changes like these can help you get closer to the recommended two or three servings of dairy a day. 

That said, it’s important to remember that your overall diet matters too; what you eat with your dairy is an important detail to focus on. For example, a yogurt parfait with fresh berries and nuts makes for a balanced snack, and a veggie-packed omelet with a sprinkle of cheese can be a nutritious meal. On the flip side, pairing dairy with high-sugar or heavily processed foods might offset some of its health benefits. The key is to think of dairy as part of a bigger picture for a well-rounded, balanced diet that supports your health in the long run.

Our Expert Take

This scoping review published in the European Journal of Clinical Nutrition sheds light on the relationship between dairy consumption and health, offering a broad overview of how different types of dairy may impact various health outcomes. The study found that dairy, particularly yogurt and fermented products, is often associated with reduced risks of heart disease, type 2 diabetes and certain cancers. Overall though, the overall findings suggest that dairy can play a positive role in a balanced diet.

For everyday life, this means that incorporating dairy into your diet can be a practical way to support your health, but it’s essential to do so thoughtfully. Focus on nutrient-rich options like yogurt, cheese and milk, and pair them with nutritious foods like fruits, vegetables and whole grains to support overall health.