Does milk cause heart attacks and cancer?

Question

Who can debunk or prove the claim: "Milk is dangerous for your health, because of heart attacks and higher risks of cancer."

What about curd?

Answer 1

Cancer

There is a study by Dr Ganmaa Davaasambuu et al at Harvard dated 2002 which links hormones in milk with increased risk of certain cancers.

Among the food items examined, milk (1961-90) was most closely correlated with prostate cancer incidence (r = 0.711), followed by meat (0.642) and coffee (0.606)

Dr Davaasambuu's study cites Davies TW, Palmer CR, Ruja E, et al. Adolescent milk, dairy product and fruit consumption and testicular cancer. Br J Cancer 1996;74:657-60.

Heart disease

Milk is a source of cholesterol which is said to come in two forms: high density lipoproteins (HDL), which help reduce your risk of stroke & heart disease and low density lipoproteins (LDL) which is deposited in arteries and increases risk of heart disease. It is recommended that you consume no more than 300g of cholesterol per day (about 9 cups of milk).

There's a relevant listing of studies at pro-Con

Health Benefits of Milk

In 2001 the BBC reported

[A] Bristol University study revealed that even drinking full fat milk, more common a couple of decades ago, was not linked to an increase in deaths from coronary heart disease. In fact heart disease death rates among regular milk drinkers were even found to be lower.

The 25-year study of 5,700 Scottish men found that heart disease death rates among men drinking more than a third of a pint of milk each day were 8% lower than those who drank less.

Deaths from cancer and strokes were 10% lower among the regular milk drinkers.

The research team said the benefits of milk could be linked to its high calcium levels and that this might counteract the adverse effects of the saturated fat content of milk.

As Oddthinking noted in a comment: "dairy (low-fat, in moderation) or calcium-fortified soy milk is actually recommended by, for example, EatWell and MyPlate guidelines."

Conclusion

There seems to be no evidence that avoiding milk altogether is warranted.

Answer 2

The Harvard School of Public Health says this about milk. http://www.hsph.harvard.edu/nutritionsource/calcium-full-story/

Regarding heart disease: "Many dairy products are high in saturated fats, and a high saturated fat intake is a risk factor for heart disease." About low-fat dairy products, it says, "Strangely, it’s often the same people who purchase these higher fat products [butter, ice cream] who also purchase the low-fat dairy products, so it’s not clear that they’re making great strides in cutting back on their saturated fat consumption."

Regarding cancer: "A diet high in calcium has been implicated as a probable risk factor for prostate cancer." "High levels of galactose, a sugar released by the digestion of lactose in milk, have been studied as possibly damaging to the ovaries and leading to ovarian cancer." "At moderate levels, though, consumption of calcium and dairy products has benefits beyond bone health, including possibly lowering the risk of high blood pressure and colon cancer. While the blood pressure benefits appear fairly small, the protection against colon cancer seems somewhat larger, and most of the latter benefit comes from having just one or maybe two glasses of milk per day in addition to what we get from other foods in our diet. Getting more than this doesn’t seem to lower risk further."

Bottom line: High intake of calcium in general possibly lowers the risk of colon cancer but raises the risk of prostate cancer. Lactose in general possibly raises the risk of ovarian cancer. Saturated fat in milk is a risk factor for heart disease. That risk is reduced by substituting low-fat dairy products, as long as one doesn't compensate by consuming more high-fat dairy products.