This meme, and many similar ones, have been floating around some health food, “wellness” and vegan circles. It claims that there are millions of pus cells in milk along with toxic proteins, and is responsible for a litany of health problems. Is this true? What does the science say about this?

“Pus Cells”

The meme claims that there are millions of “pus cells” in our milk, but what does this mean? The reality is there is no such thing as a “pus cell”. What’s likely meant by this is the somatic cell count (SCC) found in milk. These can include several different types of cells, like skin cells that naturally slough off into the milk, but are primarily white blood cells.

Even perfectly healthy cows have these cells in their milk, at SCCs of around 100,000 cells/mL (roughly 35.5 million cells/12 oz. glass). Higher amounts may result with infections of the udder, known as mastitis, as these cows have more white blood cells to fight the infection. Mastitis is similarly found in human breastfeeding, where mothers often get tenderness and pain resulting from infection.

The USDA sets the SCC legal limit at 750,000/mL (266 million cells per 12 oz. glass), but most cows have much less. Their recent 2014 study found the average was 229,000/mL (81 million per glass), and the vast majority of producers had less than 400,000. Goat milk, which is often thought of as healthier, has a much higher SCC limit of 1.5 million/mL. This is due to the differences in the way they produce milk, and has little to do with the health of the product, although a hysterical meme could claim that goat’s milk has double the “pus cells” of cow’s milk.

While it sounds like having 80 million somatic cells in a glass is a lot, remember that there are about 5 billion cells in just 1 mL of blood. A glass of blood (like the meme gruesomely portrays) would consist of 1.78 trillion cells, meaning the average American cow’s milk consists of less than .005% (5 thousandths of a percent) of somatic cells.

While the thought of having even this little amount might repulse some, this sort of thing could be said of anything we eat. Foreign bacteria and cells are found in all of our food, but at low doses it’s generally not a health issue. For example, fresh fruits and vegetables harbor large and diverse populations of bacteria (mostly harmless).

Additionally, there is a strong incentive for dairy farmers to reduce mastitis in their herds, as it’s extremely costly. There are many ways to treat and control these infections, and ironically larger herds have lower SCC counts than smaller farms, as they are more modern and better managed. The business reality is that cows with mastitis produce less milk, and are economically undesirable.

Is Casein Toxic?

Casein is the primary protein found in milk. This meme’s claim that casein is toxic is bizarre, considering it’s found in all mammal’s milk. It would be strange that the protein at the root of all of our development was toxic. Fortunately, this isn’t the case. Far from being toxic, casein is the highest quality protein for human consumption, based on its amino acid profile and digestibility.

The notion that casein leeches or inhibits calcium is also inaccurate. Casein proteins are the way the mother gets calcium into the body of a growing mammal to allow bone growth. Calcium is attached to the casein proteins (there are 4 major ones) through a phosphate group on an amino acid called serine.

Whether or not milk and casein should be included in an ideal diet is a complicated nutritional question that scientists disagree on. There are those like Dr. Colin Campbell who advocate vegan diets and claim the research shows casein proteins are harmful and carcinogenic. However, there are convincing rebuttals of this, and many other studies and doctors that disagree. A recent meta-analysis showed that dairy intake has no significant impact on increased cancer mortality risk. Low dairy intake may even reduce relative risks to cancer (although whole milk was associated with prostate cancer mortality in men).

While the health benefits or drawbacks of milk are up for some debate, calling casein toxic appears unfounded. Just look at the Maasai tribe in Kenya and Tanzania, who consume extremely high quantities of milk. Traditionally, this tribe (particularly the men) consumed almost exclusively cow’s milk and blood, yet showed low rates of most lifestyle diseases. While some would argue that this isn’t your average supermarket milk, or that it’s due to their prolific walking and exercise, the fact remains they consume more casein than almost anyone on the planet and they’ve been healthy for generations.

Is Milk Responsible for Diseases and Ailments?

This meme claims that milk is responsible for everything from acne to Multiple Sclerosis. Some of these ailments could be legitimately caused or exacerbated by milk for those with allergies or lactose intolerance. As a consequence, those people probably shouldn’t consume milk! But, the harmful effects are certainly not true for everyone.

Studies show there is no evidence linking milk to asthma, and this seems to be a well-debunked myth.

The assertion milk is responsible for tooth decay is also misleading, as research shows dairy actually helps prevent tooth decay. Just as long as it isn’t flavored milk with added sugar.

As far as MS, there is evidence that increased milk consumption is correlated with the disease, although the link is diminished with cream and butter and disappears with cheese.

As noted above, milk is associated with increases in certain cancers, but a meta-analysis found it wasn’t associated with an overall cancer increase.

If we look at other common foods, there is also evidence linking the proteins in wheat to chronic health conditions like MS, asthma, arthritis and lupus. Or evidence linking soy to endocrine disruption. Or nut and gluten allergies that cause all sorts of health issues. Pick almost any food, and there’s probably evidence that it’s associated or related to certain conditions in people. Without context, one could use misleading scare tactics for practically anything.

After all, the UN lists over 900 substances and finds only one to be definitely non-carcinogenic. This is caprolactam, a substance used in nylon production, which while non cancer causing isn’t exactly pleasant. Even short-term exposure to this substance can cause burning of the eyes and throat, headaches and confusion.

Conclusion

Pretty much everything shown in this meme is false or misleading. There is no such thing as a “pus cell”, and normal amounts of somatic cells in milk are not inherently harmful. Casein is not toxic, in fact it’s one of the best (if not the best) forms of protein. While those suffering from milk allergies or lactose intolerance might be harmed by consuming milk, there is little to no evidence that it is a danger or significantly associated with most diseases.