Is Diary good or bad for you? and how does it effect your health?

There are many articles and research done on diary and it can be a topic which many have difference opinions on.

The answer isn't simple and the nutritional research can be complicated.

Like many other health (or the lack of it) comes from a complex interaction between many factors — our overall diets, our activities, our lifestyles, our environment, our genetics, our age, and so on.

With any type of food you consume, there is no “magic food” or “demon food” that will be the single factor determining your health, fitness, or body composition. Dairy is one small part of a much bigger picture.

In general, dairy consumption seems to help people lose fat, or maintain a healthy weight. Yogurt and cultured dairy seem to help the most.

This is probably due to:

  • the high-quality protein in dairy, which can be satiating (so we eat less overall)

  • nutrients such as calcium and magnesium

  • other unique compounds in yogurt and cultured dairy in particular, which may improve metabolic health, gut health, and other things that contribute to a healthy body composition

If you choose to eat dairy, it can be a helpful part of a fat loss or weight management program.

Dairy is especially helpful for folks looking to gain or maintain muscle mass.

It is a rich source of whey and casein, two very high-quality proteins. Both have been shown to be among the most effective proteins to promote muscular growth as they are incredibly rich in essential amino acids — the ones we can’t make and need to get from our diet.

Plus, dairy can be a good source of extra energy if we need additional calories to add mass or recover from hard workouts.

If you choose to eat dairy, it can be a helpful part of a muscle gain or athletic recovery program.

Bone health isn’t just about minerals; it’s also about getting enough protein and stimulating metabolic signals that tell bones to stay dense.

Dairy is a rich source of many nutrients that are important for bone health:

  • calcium

  • phosphorus

  • protein

  • magnesium

  • vitamin D

  • vitamin K2

The vast majority of the research over the past 40 years indicates that dairy consumption improves or maintains bone health, while helping to prevent or slow bone loss. This is especially true for people who are active and eat a generally healthy diet, as these elements work together to build and maintain a strong and healthy skeleton.

While dairy helps bone health, we don’t necessarily need it for bone health.

You can have a strong and healthy skeleton with or without dairy, so long as you ensure adequate intake of important bone nutrients (calcium, vitamin D, vitamin K2, protein, etc.) and provide a bone-building stimulus, like resistance training.

Conversely, you can have low bone density even with dairy intake, if you eat poorly in general and don’t exercise (or if there are other factors involved, such as hormonal issues).

In other words, dairy doesn’t have to be make-or-break for bone health. (See what we did there?)

In general, dairy consumption can help bone health. But you can get enough calcium and other bone-friendly nutrients without dairy.

Recent research indicates that there’s no significant association between the intake of dairy products and increased risk of cardiovascular disease (CVD) and stroke.

Often, dairy is associated with a slightly decreased risk (especially for stroke). That includes full-fat dairy, which in countries that regularly grass-feed their cows (such as Australia), is associated with a decreased risk of heart disease. This relationship is inconsistent in the US, however, likely due to different agricultural practices.

The fatty acid profile of dairy probably affects its behavior (and health effects) in our body. Since an animal’s diet dramatically influences its fatty acid content, and cultured/fermented dairy seems to behave differently than non-cultured, the relationship between CVD and dairy probably depends a lot on what animals were fed, and what type of dairy people eat.

If you are active and eat a well-balanced diet, moderate dairy consumption is unlikely to put you at risk for cardiovascular disease or stroke, and might decrease risk (depending what dairy you choose).

The recently-updated reports from the World Cancer Research Fund International and American Institute for Cancer Research provide the most comprehensive compilation of research on the associations between dairy foods, red meat, and processed meat and various cancers.

The conclusions provide further confidence that dairy products and milk are associated with a reduced risk of colorectal cancer and that high intakes of milk and dairy are not associated with increased risk of breast cancer. Previously, it was suggested that dairy intake was associated with breast cancer, so this is an interesting update.

Dairy intake also does not increase the risk of bladder cancer or gastric cancer, and is not associated with risk of pancreatic cancer, ovarian cancer, or lung cancer. They found the evidence for prostate cancer risk is inconsistent (which agrees with other evidence we’ve cited).

And it’s also important to note that even when dairy is associated with an increased risk of cancer, the overall calculated contribution from dairy to cancer risk is very small. Dairy is dwarfed by much larger contributors, such as smoking, obesity, alcohol, lack of activity and sun exposure.

Current research indicates that overall dairy intake does not pose increased risk of several types of cancer, but this is certainly an area where we need more research.

Some people simply can’t tolerate dairy. If you’re one of them, you might already know. But dairy allergies, intolerance, and sensitivities aren’t always so easy to identify.

Here’s what each one is, how to know if you have it, and what that means for you and dairy.

An allergy is defined by a particular immune response that is rather immediate.

If you’re having an allergic reaction to dairy, you’re most likely not going to feel it in only your digestive system, but also elsewhere: skin, respiratory system, mouth and throat, etc. Think: itching, swelling, hives, and potentially difficulty breathing.

If you’ve had a reaction like this to dairy, consult with a doctor to get allergy testing done. You can also try an elimination diet. Dairy allergies are most common in children, but can also occur in adults.

If you have a dairy allergy, you should avoid dairy.

Milk contains simple sugars such as galactose and lactose.

Some of us can digest these sugars well, some of us can’t.

In order to do so, we need to produce lactase and galactose-1-phosphate uridyltransferase, the enzymes that break down lactose and galactose, respectively. This depends on:

  • our genetic background;

  • our age (we’re more able to digest milk sugars when we’re younger);

  • our intestinal health or microbial environment; and

  • the friendly bacteria in the dairy products themselves (if they’re fermented).

If we can’t digest lactose properly, it passes intact into the large intestine. It then ferments, producing gas, bloating, stomach cramps, and diarrhea. Fun times.

If we can’t digest galactose properly, we may have a genetic disorder known as galactosemia. This is more serious, and newborn babies may be screened for it.

As biological organisms, humans have consistently evolved to meet the demands of their food environment, and many groups of people worldwide have independently evolved the ability to digest lactose (known as lactase persistence). In most cases, these populations (such as northern Europeans or East Africans) have traditionally been dairy farmers.

Some people who are lactose intolerant can, however:

  • digest non-cow dairy (such as goat milk);

  • digest fermented dairy (such as kefir);

  • digest low-lactose dairy (such as cheese); and/or

  • digest dairy if they take probiotics or lactase supplements.

There are also lactose-free dairy products available.

The best way to tell if you have lactose intolerance is to keep a detailed food log that tracks your symptoms, or try an elimination diet.

If you are lactose intolerant, you can experiment with different options to see what you can tolerate. If your symptoms are persistent, avoid dairy.

Some people are sensitive to dairy but lactose isn’t the problem. Instead, they may be intolerant or sensitive to something else in milk, like casein, whey, or other immunoglobulins (types of proteins) in milk.

When our immune system reacts to some component of milk, we can have digestive symptoms along with other food intolerance symptoms, such as inflammation, skin rashes and acne, irritated respiratory passages, and so forth.

The process for determining diary sensitivity and intolerance is the same as for lactose intolerance: Keep a detailed food log that tracks your symptoms, or try an elimination diet.

Ultimately, only you can decide if the occasional slice of pizza or bowl of ice cream is worth the potential digestive discomfort. Make the decision with your eyes wide open, aware of the tradeoffs, and based on your goals and values.

If you have another type of dairy sensitivity, you can experiment with different options to see what you can tolerate. If your symptoms are persistent, avoid dairy.

Bianca Peppas