You're Eating Too Much Dairy If This Happens To You

From a yogurt parfait for breakfast to a grilled cheese sandwich for dinner to a big glass of milk with some cookies for dessert, there are an almost endless number of ways to enjoy dairy. And Americans enjoy a lot of the stuff — about 653 pounds per person, according to 2019 data published by Statista.

But how much dairy should we be eating? The United States Department of Agriculture recommends all adults get three "cup equivalent" servings of dairy daily. Dairy is considered an essential food group because of the calcium it provides. "Cup equivalent" servings of dairy include 1 cup of milk or yogurt, 2 cups of cottage cheese, 1.5 ounces of hard cheese, or 1.5 cups of ice cream.

It can be tricky to discuss the consequences of overdoing it on dairy because it's such a large and diverse group of foods and beverages. Going wild on butter or ice cream won't affect your body in the same way that pigging out on yogurt might because these products are very different nutritionally. Whatever your dairy obsession, though, you should keep an eye out for these signs that prove you're eating too much.

A constant craving for more dairy

When it comes to your love of dairy, there may be a chemical explanation for why you're consuming more than you should.

Dr. Neal Barnard, a clinical researcher and author of "The Cheese Trap," explained that dairy products — particularly cheese — contain fragments of the protein casein known as casomorphins (via Forbes). Casomorphins are a type of natural opiate and function the same way as other opiates do in the body. According to Dr. Barnard, "these opiates attach to the same brain receptors that heroin and morphine attach to. They are not strong enough to get you arrested, but they are just strong enough to keep you coming back for more." While most dairy products, particularly cheese, milk, and yogurt, contain significant levels of the casein protein, dairy products that are almost entirely fat (such as cream and butter) have only trace amounts and thus may not be as addicting (via San Francisco Chronicle).

The irresistible quality of dairy was confirmed in a 2015 study published in PLOS One. This study analyzed the addictiveness of different foods based on participants' rankings and responses on the Yale Food Addiction Scale. Of the foods examined, cheese came in at number 10. Several processed foods containing dairy, however, scored even higher. Ice cream came in at number five, cheeseburgers were in the seventh spot, and pizza topped the list at number one.

Can too much dairy lead to weakened bones?

The primary reason dairy is included as a recommended food group comes down its calcium content (via USDA). According to the National Institutes of Health, calcium is essential for strong bones, and not consuming enough calcium is associated with lower bone density and greater risk for fractures. However, several studies suggest that consuming too many dairy products might actually be detrimental to our bone health.

In a study published in The British Medical Journal in 2014, researchers followed more than 100,000 Swedish individuals for approximately 20 years to see how diet affected health. They found that, among women at least, high intake of milk was actually associated with greater risk for fracture. The researchers urged caution when interpreting the results, however, because many factors may have impacted the results. Another study, this one published in 2014 in JAMA Pediatrics, concluded that "greater milk consumption during teenage years was not associated with a lower risk of hip fracture in older adults."

Unpleasant digestive symptoms

According to a 2013 paper published in the European Review for Medical and Pharmacological Sciences, roughly 75% of the world's population will become lactose intolerant at some point in their lives. This means that their bodies will no longer be able to produce enough lactase, the enzyme needed to break down and digest lactose, the sugar found in milk and other dairy products. The undigested lactose can cause a range of unpleasant symptoms, including abdominal pain and cramping, gas, bloating, and diarrhea. Severity of symptoms can vary significantly from person to person, depending on how much lactase an individual can produce and how much lactose they consume.

Lactose content varies among dairy products. A cup of milk has 12 to 13 grams of lactose, while an ounce of cheese can have 0 to 2 grams and a cup of buttermilk contains 9 grams. Yogurt contains between 5 to 10 grams per 6-ounce serving, but because yogurt is a fermented food, the friendly bacteria do the heavy lifting when it comes to breaking down the lactose (via the University of Virginia).

Congestion, especially when you're already under the weather

If you're feeling extra congested, cutting back on dairy may have you breathing a little clearer. There's actually a lot of debate when it comes to whether or not dairy, particularly milk, causes increased or thickened mucus.

One 2005 paper published in the Journal of the American College of Nutrition found that among individuals with the common cold, "milk intake was not associated with increased nasal secretions, symptoms of cough, nose symptoms or congestion." But people who assumed milk would increase mucus production reported more respiratory symptoms after they drank milk. So even if dairy doesn't actually impact mucus production, it may change your subjective experience of a cold if you're a "believer." The paper's authors noted, however, that those with a true milk allergy can experience increased mucus production because of activation of their immune system after drinking milk.

A 2018 study published in The Laryngoscope found that participants on a dairy-free diet reported significantly less nasal congestion than those consuming dairy. It's important to note, however, that these were subjective evaluations and may not have corresponded to an objective increase in mucus production. Why would there be a discrepancy between how someone feels and what's actually happening? According to Verywell Health, one possibility is that "milk coats the mucus, making it feel thicker."

Breakouts

If you're overindulging on dairy, you may not be doing your skin any favors. The Mayo Clinic called out four underlying causes of acne: excess sebum (oil) production, inflammation, clogged hair follicles, and bacteria. Although dairy (or other food groups for that matter) doesn't directly cause acne, certain dietary factors may trigger or worsen a breakout in sensitive individuals.

However, it isn't clear why dairy products encourage acne flare-ups in some people. Healthline highlighted several theories, including a possible connection between the hormones given to dairy cows and our own delicate hormonal balance. The growth hormones naturally present in milk might also be to blame. A third possibility is that dairy, combined with refined carbohydrates, may increase insulin levels and make skin more prone to acne.

The fat content of the dairy you eat may even have an impact on your complexion. One 2014 report published in The Journal of Clinical and Aesthetic Dermatology noted that skim (nonfat) milk was more closely associated with acne than other full-fat dairy products.

An aged appearance

Hitting the dairy too hard may be prematurely aging your skin by causing inflammation. The problem, according to Dr. Frank Hu, a professor of epidemiology and nutrition at the Harvard T. H. Chan School of Public Health, is that researchers can't agree on whether or not milk and other dairy products are inflammatory (via Arthritis Foundation). For example, one 2015 study cited by the foundation concluded that dairy products cause low-grade inflammation. But a 2017 meta-analysis of 52 studies published in Critical Reviews in Food Science and Nutrition found that dairy typically has anti-inflammatory effects, except for those allergic to milk.

If dairy does cause inflammation, however, inflammation will contribute to older-looking skin. According to a 2018 paper published in the journal Cell Transplantation, inflammation is a major factor that can speed up the aging process. The paper's authors used the term "inflammaging" to describe the negative effects of inflammation on skin and other body systems.

Chronic inflammation triggers an overactive immune response that can cause long-term damage to the dermis (the second layer of skin, below the epidermis and above the hypodermis) and changes to the dermal extracellular matrix (the network of collagen that gives skin its structure and elasticity).

Achy joints

Eating a whole lot of dairy products like ice cream may make arthritis symptoms worse. In an interview with the Arthritis Foundation, Dr. Frank Hu acknowledged that there's conflicting research on the inflammatory effects of dairy, and part of that stems from the fact that dairy covers a wide variety of foods and beverages.

While there's plenty of evidence to suggest that yogurt reduces inflammation, the saturated fats present in many dairy products are generally considered inflammatory. But this means that low-fat dairy (such as skim milk) may have a drastically different impact on inflammation than full-fat options. Inflammatory responses will likely be more pronounced in individuals with a milk allergy or a sensitivity to casein, one of the proteins in milk. The research is mixed, but the Arthritis Foundation noted that, anecdotally, some people experience a reduction in arthritis symptoms when they cut out dairy.

Although we often think of arthritis as something we won't need to worry about until we're much older, 60% of the 54 million Americans with arthritis are of working age (18 to 64). In fact, arthritis is a leading cause of disability, and 8 million adults aren't able to work because of their arthritis (via the CDC).

Heartburn

According to the American College of Gastroenterology, more than 60 million Americans get heartburn at least once per month (via The Washington Post). Heartburn is a symptom of both acid reflux, "a common medical condition that can range in severity from mild to serious, and  gastroesophageal reflux disease (GERD), "a chronic, more severe form of acid reflux" (via Healthline).

Frequent heartburn is uncomfortable and can have serious consequences if untreated, included esophageal cancer, per Healthline. While milk is a common folk remedy for heartburn, dairy can actually make acid reflux worse. As the World Gastroenterology Organization explained, milk may temporarily "buffer" stomach acid, causing a reduction in symptoms, but on a longer timeline the fat and other nutrients in dairy stimulate the stomach to produce even more acid, making heartburn worse. This connection between dairy's fat content and acid reflux was confirmed in a 2010 study published in the Korean Journal of Gastroenterology. After examining 35 common beverages, the researchers concluded that full-fat milk was more likely to trigger heartburn than low-fat milk.

Johns Hopkins Medicine explained that "foods commonly known to be heartburn triggers cause the esophageal sphincter to relax and delay the digestive process, letting food sit in the stomach longer."

Worsening sleep apnea

Eating a lot of dairy, especially at dinnertime, may make it more difficult for you to get a good night's sleep. A study published in the American Journal of Lifestyle Medicine in 2018 examined how different dietary factors affected the severity of obstructive sleep apnea (OSA) among 104 participants with the condition. The study's authors found that "eating greater than 2 servings of dairy daily was associated with worsening severity of OSA." It's important to note, however, that the researchers did not distinguish between different types of dairy products.

According to the Mayo Clinic, sleep apnea is a condition in which breathing stops and starts as someone sleeps. OSA, in which the throat muscles relax and close off the airway, is the most common form. Deprived of oxygen, individuals with OSA will partially wake five to 30 times every hour, leading to very poor sleep quality and daytime tiredness.

OSA is a serious issue that also increases your risk for a number of other conditions, including type 2 diabetes, metabolic syndrome, high blood pressure, and heart attack. The American Sleep Apnea Association estimates that 22 million Americans have sleep apnea, but 80% of moderate and severe cases go undiagnosed.

Migraines

According to the Migraine Research Foundation, 12% of Americans get migraines. If you're one of them and have been experiencing an uptick in episodes, it may be a sign you're consuming too much histamine-rich dairy. Histamine is a chemical produced by the body and found in some foods that triggers the release of stomach acid to aid digestion and is part of the body's immune response.

The enzyme diamine oxidase (DAO) breaks down histamine, but some people either have a DAO deficiency or have an imbalance in their gut bacteria that leads to a buildup of more histamine than their DAO levels can handle. These people have a histamine intolerance and, when histamine levels get too high, it can cause a number of symptoms, including migraines and headaches. Aged cheeses and fermented dairy products such as yogurt are particularly high in histamine (via Healthline).

Aged cheeses can also trigger migraines because of their high tyramine content. According to WebMD, tyramine is a substance known as a monoamine and is found in aged and fermented foods. Our bodies produce the enzyme monoamine oxidase (MAO) to help break down tyramine. But for those who don't produce enough MAO or who are on a type of antidepressant known as a monoamine oxidase inhibitor (MAOI), tyramine can build up in the system. How exactly it causes migraines is unknown, but tyramine may trigger production of too much norepinephrine, which in turn can cause changes in the brain that lead to migraines.

Can you attribute your depression to your ice cream habit?

If you're regularly feeling down in the dumps and you can't figure out why, your dairy habit could be to blame. A 2010 study published in the Asia Pacific Journal of Clinical Nutrition concluded that "low fat dairy may have beneficial effects on social functioning, stress and memory, while whole fat dairy may be associated with poorer psychological well-being." The authors found that higher intake of whole-fat dairy products was associated with "increased depression, anxiety, stress, cognitive failures, poorer memory functioning and general health."

It's important to note, however, that this group of dairy products included things like ice cream, which is pretty different from a glass of whole milk, nutritionally speaking. In addition to the impact of fat, the proteins in dairy may also play a role in our psychological wellness. In an interview with The Sun, nutritional therapist Kay Ali noted that "for some people, casein — a protein found in dairy products — has been associated with inflammation in the brain and depression" (via New York Post).

However, not all experts agree. In an interview with The Seattle Times, registered dietitian Susan Kleiner said that the whey protein in milk can "reduce physical responses to stress, improve mood, and enhance memory."

Too much dairy and high cholesterol: Are they related?

The American Health Association (AHA) advises that eating excess amounts of saturated fat increases cholesterol levels, particularly LDL ("bad") cholesterol, which in turn raises your risk for heart disease and stroke. The AHA recommends limiting saturated fat intake to 5 to 6% of total calories. On a 2,000-calorie diet, that's about 13 grams. 

Unfortunately for dairy lovers, cream, butter, and cheese are all high in saturated fat, as are any dairy products containing whole or 2% milk. Cream, for instance, contains almost 15 grams of saturated fat per 3.5-ounce serving, while the same serving size of cream cheese contains nearly 30 grams (via the FrieslandCampina Institute).

Still, not all experts agree with the conventional wisdom that saturated fat in dairy increases cholesterol and, therefore, risk for heart disease. One study, published in 2015 in Food and Nutrition Research, found that "cholesterol levels did not increase after high intake of 27% fat Gouda-type cheese over 8 weeks' intervention." A meta-analysis published in The American Journal of Clinical Nutrition in 2016 concluded that "dairy fat intake was not significantly related to risk of total CVD [cardiovascular disease]."

High blood pressure

The 2020–2025 Dietary Guidelines for Americans recommends that adults limit their sodium intake to no more than 2,300 milligrams a day because eating too much salt can lead to high blood pressure. The average American, however, consumes about 3,400 milligrams daily — almost 150% of the recommended amount (via the FDA).

While many dairy products contain only modest amounts of sodium, some cheeses can pack a real punch of salt. According to Healthline, Swiss and brie each contain 170 milligrams of sodium per ounce. Gouda and cheddar both have about 200 milligrams per ounce, while feta has 360 milligrams. Highly processed cheeses, like American cheese, can contains as much as 400 milligrams of sodium per ounce (via Everyday Health). Buttermilk and cottage cheese are two other dairy products surprisingly high in sodium.

High blood pressure — defined as a systolic pressure of 130 mmHg or higher or a diastolic pressure of 80 mmHg or higher — is a big problem in the United States. About 45% of American adults have high blood pressure, and only one in four has their condition under control. Having high blood pressure increases your risk for heart disease and stroke, both of which are leading causes of death in the United States (via the CDC).

Breast cancer

Roughly one in eight women will be diagnosed with breast cancer at some time in her life, and the disease is expected to claim the lives of more than 40,000 men and women in the United States in 2021. It's the second most diagnosed cancer, behind skin cancer (via BreastCancer.org). Because it's so common, researchers have worked hard to try to determine which dietary and lifestyle factors may increase or decrease a person's chances of having breast cancer.

One study published in the in the International Journal of Epidemiology in 2020 found something particularly  interesting about. "Consuming as little as 1/4 to 1/3 cup of dairy milk per day was associated with an increased risk of breast cancer of 30%," Gary E. Fraser, the paper's lead author, told Loma Linda University Health. "By drinking up to one cup per day, the associated risk went up to 50%, and for those drinking two to three cups per day, the risk increased further to 70% to 80%."

study published in Current Developments in Nutrition in 2017, researchers found that regular yogurt consumption reduced breast cancer risk, while high intake of American, cheddar, and cream cheese was associated with a "marginally significant" increase in risk. Milk appeared to increase risk for non-estrogen-driven breast cancer.