dairy, lactose


Dietitians weigh in on the pros and cons of the controversial food group.

Whether cow's milk deserves a place in your diet might be one of the most debated questions in the field of nutrition. The short answer is: It depends. Here’s what we know about the benefits and drawbacks.

Pro: It’s packed with protein.

Cow’s milk contains eight grams of protein per eight ounces, while unsweetened soy milk contains about four grams. Almond milk contains a little over six grams, and hemp milk has roughly three grams of protein per serving. Nut-based, non-dairy milks also contain less of other important nutrients such as potassium and riboflavin.

“Milk is an excellent source of calcium and vitamin D, nutrients most Americans lack,” says Torey Armul, RD, a Chicago-based dietitian and spokesperson for the Academy of Nutrition and Dietetics.

Con: It can aggravate gluten insensitivities.

The dairy protein casein is structurally similar to gluten, the protein in grain. So people with gluten sensitivities might have problems with casein and dairy as well, says Terry Wahls, MD, a clinical professor of medicine at the University of Iowa. If gluten is an issue for you, it's likely you'll also have excessive inflammation in response to casein, she says. 

Pro: It boosts post-workout recovery.

A glass of cow's milk after a strength-training session is a quick and easy way to build muscle, research suggests. Another study found that it might help to curb appetite after exercise: Researchers at Northumbria University in the U.K. found that women who drank 2 1/2 cups of skim milk after 30 minutes of moderate to vigorous cycling ate significantly less during lunch an hour later compared with women who drank the same amount of orange juice. Researchers attributed this to the dairy, though it could also be due to the sugar-protein combo.

Con: Most us of are intolerant to lactose.

Globally, approximately 65 percent of people are lactose intolerant, which is why you might notice milk can upset your stomach. It's a relatively new food for humans, first appearing in the human diet around 8,000 years ago, Wahls says, noting, “I think the evolutionary evidence is clear that dairy is not critical for health.” If you’re thinking of going non-dairy, consider unsweetened soy milk, which has around the same amount of protein as cow's milk.