Cow's milk is a daily, staple food for many people and has been for millennia. While it's still a popular food, recent studies suggest that milk may have harmful effects on the body. Other research, however, points out the health benefits of dairy.
So, what’s the truth? Read on to learn about the pros and cons of milk, as well as some alternatives you may want to consider if you can't tolerate milk or choose not to drink it.
Nutrients in milk
Milk is considered a whole food and provides 18 out of 22 essential nutrients. It contains more calcium, magnesium, phosphorus, potassium, zinc, and protein per calorie than any other food in a typical diet:
Nutrient
Amount per 244 g
Percentage of Recommended Daily Amount (RDA)
Calcium
276 mg
28%
Folate
12 mcg
3%
Magnesium
24 mg
7%
Phosphorus
205 mg
24%
Potassium
322 mg
10%
Vitamin A
112 mcg
15%
Vitamin B-12
1.10 mcg
18%
Zinc
0.90 mg
11%
Protein
6 to 7 g (casein and whey)
14%
Milk also provides iron, selenium, vitamin B-6, vitamin E, vitamin K, niacin, thiamin, and riboflavin.
Fat content varies. Whole milk contains more fats than other types:
saturated fats: 4.5 grams
unsaturated fats: 2.5 grams
cholesterol: 24 milligrams
Benefits of milk
Appetite control
Drinking milk hasn't been linked to weight gain or obesity. While dairy is also not associated with weight loss, it may help curb appetite. A 2013 study showed that dairy helped individuals feel fuller and reduced how much fat they ate overall.
Bone development
Milk helps to improve weight and bone density in children. It also reduces the risk of childhood fractures. Research shows that pregnant women who ate plenty of dairy- and calcium-rich foods had babies with better bone growth and mass.
Additionally, adding more dairy to the diet of preteen girls was found to be better for bone health than giving them calcium supplements. Milk also provides proteins that are necessary to build and maintain healthy bones, teeth, and muscle. A liter of milk provides up to 35 grams of casein and whey proteins.
Bone and dental health
A glass of milk contains almost 30 percent of the daily requirement of calcium for adults. Milk also contains potassium and magnesium. These minerals are important for healthy bones and teeth.
Dairy provides almost 50 percent of the calcium in a typical diet. Dairy products are also the main source of how people get their daily intake of calcium worldwide.
Most milk has added vitamin D. A glass of fortified milk contains almost 30 percent of the recommended daily amount. Vitamin D is needed to balance calcium and phosphorus in the body.
Milk may also help to prevent cavities. Research showed that getting more dairy, calcium, and vitamin D helped to reduce dental plaque in older adults.
Diabetes prevention
Type 2 diabetes impacts how your body burns food for energy. Diabetes can also increase your risk of heart disease, stroke, and kidney disease. Several studies found that whey protein in milk may help to prevent type 2 diabetes in adults. This may be because milk proteins improve your blood sugar balance.
Heart health
Milk fat may help raise levels of good cholesterol called HDL, which helps to prevent heart disease and stroke.
Additionally, milk is a good source of potassium. This mineral helps to balance blood pressure.
Cows that are pastured or grass-fed make milk with more omega-3 fatty acids and conjugated linoleic acid. These fats help to protect heart and blood vessel health.
Negative side effects of milk
Acne
A study found that teenagers with acne drank higher amounts of low-fat or skim milk. Adult acne may also be triggered by dairy. Other studies linked this skin condition to skim and low-fat milk, but not to whole milk or cheese. This may be due to carbohydrates and whey protein in milk.
Other skin conditions
Eczema is worsened by some foods, including milk and dairy.
A study found that pregnant and breastfeeding mothers who added milk and a probiotic to their diet reduced their child's risk of eczema and other food-related allergic reactions. Dairy may also be a trigger food for some adults with rosacea.
Allergies
More than 5 percent of children have a milk allergy. It can cause skin reactions, such as eczema, and gut symptoms like colic, constipation, and diarrhea. Other serious reactions include:
anaphylaxis
wheezing
difficulty breathing
bloody stool
Children may grow out of a milk allergy. Adults can also develop a milk allergy. Antibiotics given to dairy cows may also be linked to milk allergies.
Bone fractures
Drinking three or more glasses of milk a day may increase the risk of bone fractures in women. Research found that this may be due to sugars called lactose and galactose in milk.
Another study showed that bone fractures in elderly adults due to osteoporosis are highest in areas that consume more dairy, animal protein, and calcium.
Cancers
Excess calcium from milk and other foods may increase the risk of prostate cancer. Milk sugars may be linked to a slightly higher risk of ovarian cancer.
Milk from cows given growth hormones contains higher levels of a chemical that may increase the risk of some cancers. More studies are needed on the long-term effects of these hormones and on antibiotics given to dairy cows.
Lactose intolerance
Cow's milk has a higher amount of lactose than milk from other animals. Up to 75 percent of the world's population has some form of lactose intolerance. Most people with this condition can safely add small amounts dairy to their diet.
The takeaway
Milk is naturally packed with essential nutrients in a convenient and accessible form. Drinking milk is particularly important for children and may help you and your child maintain good health.
Milk nutrition varies. Milk from grass-fed or pastured cows provides more beneficial fats and higher amounts of some vitamins.
More research is needed on the amount of milk that is most beneficial and the effects of antibiotics and artificial hormones given to dairy cows.
It's best to choose organic milk from cows that are free of growth hormones. Milk alternatives can also be part of a healthy, balanced diet.