Anyone who grew up in the heyday of the popular "Got Milk?" ad campaign, in which many high profile athletes touted the benefits of the bovine beverage, might be surprised to know that a growing number of today's players are ditching dairy altogether.
Why are so many stars calling it quits on milk and its derivatives? And are they right to do so? Let's take a look at their reasoning.
What is a Dairy Product?
First, let's define the word "dairy." A dairy product is any food produced from the milk of mammals. Dairy products can be made with milk from a variety of animals, including goat, sheep and buffalo. But inside the United States, dairy products are closely associated with cow's milk. According to Dairy Management, Inc., cow's milk accounted for nearly 95 percent of all American milk consumption in 2014.
Though cow's milk and the products it is used to produce are still a gigantic industry in the U.S., overall dairy consumption is on the decline. U.S. cow milk sales tallied under 6 billion gallons in 2012, the lowest total in decades. Meanwhile, non-dairy alternatives such as almond milk have exploded in popularity.
But Isn't Milk Healthy?
Based on its nutritional profile, cow's milk looks like a fairly nutritious beverage. One serving of whole cow's milk contains 103 calories, 2.4 grams of fat, 1.5 grams of saturated fats, 12 grams of carbohydrates, 107 mg of sodium, 13 grams of sugar, 8 grams of protein, 366 mg of potassium and 30 percent of your daily calcium. Skim milk is lower in fat, but a growing amount of research is finding whole milk might be the better overall option because the fats it contains deliver beneficial health properties. (That fat also helps promote satiety, helping you feel fuller, longer.)
"The fat content of milk is where many of its nutrients are located, such as vitamin A, vitamin K2 and omega-3 fatty acids. When you remove the fat to create skim milk, you're removing a lot of those nutrients as well," says Brian St. Pierre, a dietitian at Precision Nutrition.
Since milk has high levels of beneficial nutrients such as healthy fats, protein, potassium and calcium, why are so many athletes moving away from dairy products? For some, the answer lies in how their body digests lactose.
What is Lactose Intolerance?
According to the Mayo Clinic, lactose intolerance refers to a state where one is "unable to fully digest the sugar [lactose] in milk." Lactose is the main sugar found in cow's milk. Any product made with cow's milk contains lactose unless it undergoes a special process to remove the sugar. If so, the product will be marked as lactose-free.
The most common cause of lactose intolerance is a condition known as primary lactase deficiency. Lactase is an enzyme produced in the small intestine that is crucial for breaking down lactose into glucose and galactose, two simple, digestible sugars. People with primary lactase deficiency experience a decrease in lactase production over time, often beginning at about 2 years old.
A deficiency of lactase can cause what is known as "lactose malabsorption," where undigested lactose passes into the colon, where it is broken down by bacteria, creating fluid and gas. This leads to the symptoms commonly associated with lactose intolerance—abdominal bloating, diarrhea, gas and nausea. The amount of lactose someone with lactose intolerance can tolerate before experiencing symptoms varies greatly, depending on the individual and the type of dairy product they're consuming.
"About 40 to 60 percent of all adults are unable to tolerate the lactose sugar in [cow] milk, often causing some not-so-fun gastrointestinal issues," says St. Pierre.
In fact, lactose intolerance is so prevalent worldwide that it's considered the normal state for most adults and not an actual disease condition. However, people with European ancestry have been found to have an abnormally high tolerance for lactose.
"Those from European countries have evolved to handle dairy better than those coming from countries in Africa and Asia," says Ryan Andrews, also of Precision Nutrition. The ability to digest cow's milk into adulthood is known as lactase persistence, and it likely traces back to a genetic mutation which appeared in European dairy farmers over 7,000 years ago.
A few tests can be used to determine whether an individual is lactose intolerant. The aptly named "lactose intolerance test" gauges the body's reaction to a high-lactose liquid via blood testing two hours after consumption. If your levels of glucose don't rise, that's a sign your body isn't properly digesting and absorbing lactose. There's also the "hydrogen breath test," which requires you to drink a high-lactose liquid, then have the amount of hydrogen in your breath monitored. If your body doesn't digest lactose, it will ferment in your colon and release hydrogen and other gases. If larger than normal amounts of hydrogen appear in your breath when tested, that's a sign you aren't fully digesting lactose.
For an athlete with a genuine lactose intolerance, the benefits of avoiding dairy are obvious. With no nasty gastrointestinal issues to worry about, of course they're going to feel better.
Why Might An Athlete Who Isn't Lactose Intolerant Feel Better After Cutting Out Dairy?
Many athletes and people in general have reported feeling better after dropping dairy, despite the fact they don't suffer from lactose intolerance. There are a few reasons why this might be the case.
First, although it's highly unlikely, they could have a milk allergy. According to the American College of Allergy, Asthma and Immunology, milk allergies occur in 2 to 3 percent of children younger than 3, but 80 percent of those affected outgrow it before they turn 16. Unlike lactose intolerance, people allergic to milk have an adverse immune reaction to one or more constituents of the milk of an animal outside of lactose.
Second, for those who don't suffer from lactose intolerance or a milk allergy, dairy could be slowing them down due to the presence of A1 casein, a phosphoprotein found in much of the cow's milk produced in the U.S. According to Kamal Patel, director of research for the health and nutrition website Examine.com, recent studies on mice suggest A1 casein could cause inflammation in the gut.
An inflamed gut can lead to something called "leaky gut syndrome." When the gut wall gets irritated or inflamed, it loses its selective permeability. A healthy gut allows only specific beneficial things—like vitamins and amino acids—to escape through the gut wall and into the bloodstream. A leaky gut loses this ability, often letting harmful things like undigested food particles, toxins and microbes escape from the gut and enter the bloodstream. That can throw the immune system out of whack and lead to a host of issues.
Third, an athlete might feel better after dropping dairy due to dietary displacement. When you eliminate dairy from your diet, you have to replace their calories and nutrients with other foods. If the foods you add are nutritionally superior to what you ate before, you will feel the benefits of a better diet.
"If someone starts eating a bit less cheese, yogurt and milk and replaces those with veggies, fruits, beans, whole grains, nuts and seeds, they could be doing their body good by getting nutrients most dairy products don't provide," Andrews says.
Dietary displacement is why many people feel better on a gluten-free diet, even if they don't have celiac disease or an actual gluten sensitivity. It's not because their body is devoid of gluten; it's because they're now eating fewer highly-processed foods and more fruits and veggies.
I'm not lactose intolerant but I'd like to see how I feel without dairy. What should I do?
If you're interested in seeing how you feel without dairy, Andrews suggests first cutting out dairy at certain times and seeing how you feel.
"If someone drinks a whey protein shake with whole milk for breakfast each day and gets congested, try a non-dairy breakfast instead and take note of how you respond," Andrews says. This can be a good way of gauging dairy's effects on you without cutting it out entirely.
If you do decide to go dairy-free, you can choose from several smart replacement foods to ensure you're still getting the necessary nutrients.
"Dairy is highly advertised and promoted in North America, so a lot of people think it's mandatory to consume. The idea of not consuming it can be a bit scary for some people at first, but it's important to remember that not everyone across the world is consuming dairy every day, and it's not an essential food to consume," Andrews says. You can replace the nutrients lost by ditching dairy fairly easily. "Foods to include more of when cutting out dairy should include beans, greens, nuts and seeds to make up the missing protein and minerals."
For those who want to consume dairy, Andrews suggests seeking out organic products made with milk from grass-fed, pasture-raised animals whenever possible. Check the Cornucopia Institute Scorecard to compare the various conditions under which different brands of cow milk are produced. The card scores each brand based on factors such as hormones and antibiotics used on the cows, health and longevity of the cows, and grazing and open land provided for the cows. All of those factors can impact the nutritional makeup of the milk the cows produce.
Of course, it's also wise to opt for more nutritious (and less processed) dairy options like plain yogurt and kefir over ice cream and mozzarella sticks.
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