Chocolate milk seems to be a good recovery drink, although you should drink it in moderation - it's rich in sugar and fat, and may increase ovarian cancer risk.
Finding good information on chocolate milk is no easy task. Google delivers forceful agenda-driven arguments both for and against. There's milk boosterism from the dairy industry, of course - their message should be considered carefully, as they have a financial stake in people drinking chocolate milk. There's also a healthy serving of hardline anti-milk hucksterism from alternative medicine blogs, paleo diet evangelists, and cranks claiming that cutting out the milk protein casein can cure autism.
First, the arguments from the pro-dairy crowd: chocolate milk, despite high sugar content, can protect against cavities. That's reasonably well supported in the research - chocolate milk is an important source of calcium, which helps to protect teeth, and there's some evidence that it replaces more sugary drinks in the diet. You should still check the labels on chocolate milk to ensure that you're picking a brand with relatively low added sugar. Remember also to consider dietary sugar in context; consume too much overall, and you up your risk of a wide range of health problems.
There's also good evidence that chocolate milk is an effective post-workout recovery drink - especially after endurance sports like running, swimming, or cycling. There's water, so it helps to replenish what you've sweated out; chocolate milk has a 4:1 carbohydrate to protein ratio, which is ideal for the helping your muscles to re-up on stored energy. There's not a huge body of research behind the notion of chocolate milk as a recovery drink, and the idea has been aggressively promoted by the dairy industry, but the science so far supports it.
What the science doesn't support is the notion that casein, the protein component in chocolate milk, is the cause of "recurrent childhood ear infections, eczema, chronic bronchitis, asthma, and sinus conditions." That's the claim made by livingtraditionally.com - a hotbed of misinformation, pseudoscience, and fear-mongering. Anya Vien, who runs the site, claims also that casein contributes to or causes autism; that's not true. She supports the theory that rBGH can cause a whole rash of disorders and problems in humans; while it's not great for cows, there's little to no evidence to support that claim, as we've laid out in a separate post.
She also claims that milk blocks calcium absorption and actually drains calcium from the bones by increasing the body's "metabolic acidity;" there's no such thing as metabolic acidity - that's not how acids and bases work in the body - and the majority of research still says that drinking milk fortifies bones, provides calcium, and lowers risk of osteoporosis.
She supports the calcium-draining claim with an as-yet unexplained paradox that actually is borne out in the data - that countries with lower dairy consumption have correspondingly lower rates of osteoporosis. That much seems to be true, although the scientific literature has not yet proven or disproven that average national milk consumption is causal rather than simply correlated; we don't know why this is the case, or that milk is behind it, since a wealth of other research indicates that milk consumption fights osteoporosis.
There are some real concerns with chocolate milk: it's rich in saturated fats and cholesterol, which should be limited and properly balanced in your diet - otherwise, you up your risk of diabetes, heart disease, and other problems. Most adults can't break down lactose and will experience discomfort if they drink it. The Swedes have found that excessive milk consumption can up cancer risk in cohort studies. Finally, the dairy industry uses a lot of antibiotics on their cows - that contributes to antibiotic resistance, which is bad for all of us.
- Chocolate milk has more sugar than regular milk. Watch your sugar intake, as too much can cause a range of health problems.
- Chocolate milk is rich in saturated fat and cholesterol - they can cause problems in excess, so watch your intake
- Too much milk may increase your risk of prostate cancer
- The dairy industry uses antibiotics heavily, which contributes to antibiotic resistance
- Most adults can't break down lactose and may experience indigestion when drinking milk
- Some adults can't break down casein, the protein found in milk, and a smaller set are allergic to it