Cow’s milk is often considered nature’s most wholesome food. But, is drinking milk from cows really healthy for you?

A growing body of scientific evidence continues to cast doubt on the belief that cow’s milk is healthy for human consumption. That is not to say that cow’s milk does not have its health benefits. Modest milk intake is a prime source of three important nutrients: calcium, potassium and vitamin D. These nutrients are important for building bone and keeping it strong. However, there isn’t enough evidence to support mainstream dairy industry claims that cow’s milk is specifically good for you and improves bone health.

“The only research that even begins to suggest that the consumption of dairy products might be helpful [in improving bone health and preventing osteoporosis] has been paid for by the National Dairy Council itself,” explains John Robbins, bestselling author of Voices of the Food RevolutionNo Happy Cows, Diet for a New America, and many other landmark works.

That there aren’t enough independent studies that support the claim that cow’s milk is good for you has not stopped the US Department of Agriculture’s My Plate initiative from recommending three cups a day of milk for everyone! The key consumer message the USDA gives is to switch to 1% or non-fat versions.

Surely you don’t need the government or any expert to tell you cow’s milk is not nature’s perfect food unless you are a calf. If you do need someone to tell you milk isn’t the perfect food, Harvard University’s food nutritionists provide alternative nutrition advice to the USDA’s food pyramid and specifically warn that milk isn’t an essential part of a healthy diet and may in fact pose health risks and contribute to a surprising number of problems.

Here are some of the key health concerns of cow’s milk you should be aware of.

1. Milk promotes bone health problems.

One of the most popular and mainstream beliefs about cow’s milk is that it promotes bone health and prevents osteoporosis and fractures. However, a good deal of newer evidence suggests that it does not help bones. One study of teenagers, for example, found that adult bone health was not related to the amount of milk or calcium consumed, but to the level of physical activity in earlier life. Walter Willett, MD, PhD, professor of epidemiology and head of the nutrition department at the Harvard School of Public Health, who is also one the most prominent critics of the USDA’s dietary guidelines, observes that in fact “countries in which almost no milk is consumed, such as many Asian countries, have low rates of fractures.”

Amy Lanou Ph.D., nutrition director for the Physicians Committee for Responsible Medicine in Washington, D.C., has also been quoted saying: “The countries with the highest rates of osteoporosis are the ones where people drink the most milk and have the most calcium in their diets. The connection between calcium consumption and bone health is actually very weak, and the connection between dairy consumption and bone health is almost nonexistent.”

2. Milk leads to increased cancer risk.

Dr. Willett’s chief worry, however, is that drinking too much milk increases cancer risk. “By now there’s quite a body of data showing a higher risk of fatal prostate cancer associated with milk,” he is quoted saying. “And though the evidence is somewhat mixed, we’ve still seen a slightly higher risk of ovarian cancer associated with drinking three or more servings of milk,” he adds. Corroborating Willett’s stance, Alison Stewart, editor of the Consumer Health Journal and the recipient of the 2005 Excellence in Women’s Health Research Journalism Award explains why milk leads to increased cancer risk:

“One reason milk consumption may lead to cancer risk is insulin-like growth factor, IGF-1 (not to be confused with bovine growth hormone, rBGH),” she says. “Milk contains IGF-1 for good reason: milk is designed for babies and IGF-1 helps us grow. IGF-1 affects growth, as well as other functions, and is normally found in our blood. Higher levels of IGF-1, however, appear to stimulate cancer cells.”

3. Milk promotes weight gain.

Contrary to what you might have heard, consuming large amounts of milk and dairy products may actually make you fatter. Can you honestly expect any different when the biochemical makeup of cow’s milk is designed to turn a 65-pound newborn calf into a 400-pound cow in one year? Milk has relatively high calorie levels. One cup of 2% milk, for example, has 138 calories. When you drink three cups a day you are adding 366 calories to your diet, which may have the opposite effect of reducing body weight. If you don’t exercise regularly, any extra calories you drink could be stored as body fat leading to weight gain.

4. Milk production leads to climate change.

UN study by the Food and Agricultural Organization (FAO) found that livestock production – which includes dairy farming – is one of the major causes of the world’s most pressing environmental problems, including air and water pollution, global warming and land degradation. Cows, in particular, account for putting out 18% of the world’s carbon dioxide, which is more greenhouse gas emissions than cars, planes and all other forms of transportation combined. Exploiting dairy cows before passing them on to the slaughterhouse after an average of four years (one-fifth their normal life expectancy) is not only morally disturbing, but also destructive because it involves harmful practices like deforestation and triggers offshoot environmental concerns like runoff.

Bottom line

Drinking a cold glass or two of cow’s milk is fine. However, you should know that you don’t have to drink milk to be healthy. In fact, you are much better off consuming less cow’s milk or completely switching to healthier milk alternatives like unsweetened almond milk, organic soy milk and rice milk.