The Great Milk Debate: Does The Science Support Recent Claims?

Claim 1: Cow’s milk is full of protein and calcium

The article states that a 200 mL glass of milk contains 7 grams of protein and 130 milligrams of calcium. While this is true, these nutrients are not unique to cow’s milk. Soy milk, for instance, contains 6g of protein per 200 mL , with some higher protein varieties containing up to 10g of protein for the same amount. The article correctly points out that other varieties of plant-based milk, like almond or oat, contain much less protein compared with dairy or soy milk.

In terms of calcium, thanks to fortification, most plant-based milks contain almost around the same amount per glass compared with cow’s milk. The exception to this rule are organic products, as organic standards do not allow the addition of synthetic ingredients including vitamins and minerals.

The author did not touch on bioavailability of calcium across various milks, but did you know that most bioavailable sources of calcium are actually certain types of vegetables, including bok choy, brussel sprouts, and broccoli? They may not contain as much calcium as milk per portion, but their high absorption rate makes them worth considering. All the more reason to eat your greens!

The average adult (19+) requires 700mg of calcium and 45-55g of protein a day.

At the end of the day, whether you opt for plant-based or cow’s milk, both varieties can cover your nutritional needs.

Claim 2: Cow’s milk is a great source of B12

B12, which is important for energy metabolism, is almost exclusively found in animal-based foods.

Despite fortification, plant-based milks tend to contain less B12 than cow’s milk, which is a good source of it, as the article correctly states.

Nonetheless, for people who don’t want to reach for dairy drinks, B12 can also be found in nutritional yeast, shiitake mushrooms, algae products, or a variety of affordable supplements.

Claim 3: It boosts serotonin

The article cites a study claiming to link dairy milk consumption to reduced rates of anxiety and depression, however while the study is interesting, as pointed out by their expert, Rob Hobson, it cannot tell is the full story about causality. Click here to read our in-depth fact-check of the study in question. 

The article goes on to say that fatty acids in dairy milk can have a protective function in the brain as well as tryptophan, which is associated with serotonin production. There is some research that indicates a potential benefit to brain health from polyunsaturated fatty acids from cow’s milk, but the results remain controversial.

Tryptophan is an amino acid, which is a building block of protein and a precursor of serotonin. As such, it can be found in most sources of protein, including but not limited to milk. Nuts and seeds, for example, are a real powerhouse containing plenty of good fats, as well as tryptophan.
Furthermore, it’s important to note that the majority of the fats in dairy milk are saturated fats, which has been linked to increased cholesterol levels in the blood and can increase the risk of having a heart attack or stroke if consumed in excess. Plant-based alternatives on the other hand, generally contain much less saturated fat, making them a healthier choice for people trying to watch their saturated fat intake.

Claim 4: It helps to lower bowel cancer risk

Lastly, the claim that dairy consumption can reduce bowel cancer risk is true. A large-scale study published in Nature Communications showed that consuming 300mg of calcium daily could lower the risk of bowel cancer by 17%. Scientists concluded that this effect was driven for the most part by the additional calcium consumed, as opposed to specifically dairy products, meaning the same protective effect could also be achieved with calcium from other sources, including plant-based milks. 

The ‘best’ choice is individual

When taking nutrition advice from online sources, it is important to remember that the healthiest diet for each person is dependent on personal factors such as age, sex, activity level, food intolerances, or other health factors. 

A balanced diet, whether it includes animal-based foods or not, can meet nutritional requirements, and many of the benefits discussed above are not unique to cow’s milk. Whether cow’s milk is ‘best’ for our health, therefore, cannot be said universally.