One of the primary reasons I stopped consuming dairy was because I suffered from severe acne. Milk is well-known to adversely affect acne.[1,2,3,4,5,6,7,51] (Acne can also be a result of other poor dietary factors, not just dairy.) Personally, this is compelling enough evidence against dairy to restrict or eliminate its intake.

The evidence showing health detriments of dairy makes for a strong case against dairy consumption, with dairy potentially being one of the most harmful foods if consumed in excess (though it has tough competition in society’s generally unhealthy diet).

You may have heard about the latest of such studies (Milk intake and risk of mortality and fractures in women and men: cohort studies)[35] illustrating that high milk intake may be problematic to health, including even potentially accelerating aging. This is not the first case of milk consumption leading to bone problems, there’s a long history of concerns.

While dairy milk is touted to build strong bones, the evidence doesn’t support this claim (at least in women, more data is required for men[48,49,50]). Dairy is known to increase risk for prostate and ovarian cancers, and perhaps other cancers, infections and tumors.[7,8,9,10,11,37,41,42,43,44,45,46,47] Dairy increases incidence of diabetes.[12,13] Dairy may play a role in multiple sclerosis.[14] Dairy can elevate cholesterol.[15] Dairy can lead to Parkinson’s disease.[16] Dairy can contain hormones that adversely affect health.[17,18] A protein in dairy milk, casomorphin, is also linked with health detriments including sudden infant death syndrome.[19,20]

Dairy milk contains trans fat,[21] saturated fat and cholesterol,[22] intakes of which should be limited.[23,24] Milk can inhibit absorption of certain nutrients.[25,26,27]

Milk and mucus remains a controversial issue. Many people anecdotally report milk increasing mucus production, but this hasn’t been scientifically verified.[38,39] However, a theory has been proposed that mucus glands in the respiratory tract may respond to casomorphin from dairy milk, potentially stimulating the production and secretion of mucus in the respiratory glands.[28,40] At least in some people dairy milk is known and documented to increase mucus production or produce asthma-like symptoms.[28,39] It depends on the person, it depends on the milk, but the milk and mucus claim shouldn’t be dismissed entirely as an old wives’ tale.

However, moderate consumption of dairy milk in the form of an occasional glass is unlikely to cause much if any harm, but regular consumption shouldn’t be advised. While the USDA still endorses milk consumption[41] (which isn’t well-known to provide solid health recommendations due to the politics involved),[29] the Healthy Eating Plate & Healthy Eating Pyramid,[36] created by nutrition experts at Harvard School of Public Health and editors at Harvard Health Publications, suggests that dairy is not essential for diet and if consumed should be limited to one to two servings per day.

Milk is non-essential for good health so long as one ensures adequate calcium intake from whole or fortified foods.[30,31] There are many foods that have higher concentrations of calcium than dairy,[32] and there’s nothing particularly special about dairy when it comes to absorption.[33,34] Especially healthful sources of calcium include dark green leafy vegetables like bok choy, broccoli, collards, kale and mustard greens.

With all these potential risks, and with little benefit — and no benefits that cannot otherwise be obtained from more healthful foods — why consume dairy milk at all? There’s sufficient evidence to support the assertion that dairy milk is detrimental for human health and there’s no good evidence to suggest the necessity or benefit of adding dairy into a healthy diet.

In summary, dairy milk is not entirely bad, but caution should at the very least warrant its restriction if not elimination. While dairy milk is not exactly void of nutrition — it does contain some useful nutrients — it does come associated with a lot of unwanted and unhealthful baggage, and dairy is completely unnecessary for good health. Moderate consumption of one to two glasses per day may be safe to consume but may also adversely impact longevity and likely doesn’t provide additional health advantage over other healthful food sources. Based on the available evidence illustrating potential ill effects of dairy milk consumption, it may be advisable to further restrict dairy milk consumption to even less than the one to two glasses per day limit currently recommended by the Harvard School of Public Health. Some people may be able to tolerate dairy milk better than others, and some people obviously are allergic and should avoid completely. In any case, excess consumption should certainly be avoided; opposed to other healthful high-calcium foods like dark green leafy vegetables that do not require moderation or restriction.


  1. Diet and acne: a review of the evidence
  2. Milk consumption and acne in adolescent girls
  3. Milk consumption and acne in teenaged boys
  4. High school dietary dairy intake and teenage acne
  5. Milk consumption: aggravating factor of acne and promoter of chronic diseases of Western societies
  6. Evidence for acne-promoting effects of milk and other insulinotropic dairy products
  7. Acne, dairy and cancer: The 5alpha-P link
  8. Should dairy be recommended as part of a healthy vegetarian diet?
  9. Diet, insulin-like growth factor-1 and cancer risk
  10. The impact of cow’s milk-mediated mTORC1-signaling in the initiation and progression of prostate cancer
  11. Inhibition of aflatoxin B1-induced gamma-glutamyltranspeptid
  12. Relationship between cows’ milk consumption and incidence of IDDM
  13. Risk Factors and Primary Prevention Trials for Type 1 Diabetes
  14. Correlation between milk and dairy product consumption and multiple sclerosis prevalence: a worldwide study
  15. Effect of two types of soy milk and dairy milk on plasma lipids in hypercholesterolemic adults: a randomized trial
  16. Meeting report: consensus statement-Parkinson’s disease and the environment: collaborative on health and the environment and Parkinson’s Action Network (CHE PAN) conference 26-28 June 2007
  17. Exposure to exogenous estrogen through intake of commercial milk produced from pregnant cows
  18. Consumption of animal products, their nutrient components and postmenopausal circulating steroid hormone concentrations
  19. Cow’s-milk-induced infant apnoea with increased serum content of bovine casomorphin
  20. Relation of beta-casomorphin to apnea in sudden infant death syndrome
  21. TRANSforming the Food Supply
  22. Milk, whole, 3.25% milkfat
  23. Tolerable upper intake levels for trans fat, saturated fat, and cholestoral
  24. Trans Fatty Acids and Cardiovascular Disease
  25. Addition of milk prevents vascular protective effects of tea
  26. Does adding milk remove the benefits of your daily cuppa?
  27. Antioxidant activity of blueberry fruit is impaired by association with milk
  28. Does milk increase mucus production?
  29. Saving U.S. dietary advice from conflicts of interest
  30. Veganism, bone mineral density, and body composition: a study in Buddhist nuns
  31. Comparative fracture risk in vegetarians and nonvegetarians in EPIC-Oxford
  32. Foods highest in Calcium
  33. Calcium absorption in Australian osteopenic post-menopausal women
  34. The impact of dietary protein on calcium absorption and kinetic measures of bone turnover in women
  35. Milk intake and risk of mortality and fractures in women and men: cohort studies
  36. Healthy Eating Plate & Healthy Eating Pyramid
  37. A milk protein, casein, as a proliferation promoting factor in prostate cancer cells
  38. Relationship between milk intake and mucus production in adult volunteers challenged with rhinovirus-2
  39. Milk consumption does not lead to mucus production or occurrence of asthma
  40. beta-Casomorphin-7 regulates the secretion and expression of gastrointestinal mucins through a mu-opiod pathway
  41. What Is Dairy? – Food Groups – – USDA
  42. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies
  43. Milk stimulates growth of prostate cancer cells in culture
  44. The experience of Japan as a clue to the etiology of breast and ovarian cancers
  45. Incidence and mortality of testicular and prostatic cancers in relation to world dietary practices
  46. Milk consumption is a risk factor for prostate cancer: meta-analysis of case-control studies
  47. Milk consumption is a risk factor for prostate cancer in Western countries: evidence from cohort studies
  48. Milk Intake in Early Life and Risk of Advanced Prostate Cancer
  49. Milk intake and risk of hip fracture in men and women
  50. Milk consumption during teenage years and risk of hip fractures in older adults
  51. Early-Life Milk and Late-Life Fracture—Reply
  52. Nutrition and acne
  • Updated 3 years ago
Robert Roose

Robert is a nutrition advocate focused on optimal health and longevity.