Can you drink too much milk

Can you drink too much milk?

Pawel Malczewski
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Short summary

We all have a different limit of how much milk and other dairy products we can handle per day. It depends on various factors, such as the level of lactose intolerance, gender or the presence of certain diseases.

This article discusses the daily intake limits for specific risk groups and restrictions due to lactose intolerance. For a quick answer click here.

Explanation

Current dairy intake recommendations

Current recommendations for adults of dairy product intake are not consensual. However, on average, all agree to be in the range of 2.5-3 servings daily. Here are some examples:

USDA (Choose my plate): 3 servings (1)USDA. United States Department of Agriculture. All about the dairy group. Available here.
Health Canada: 2-3 servings (2)Health Canada. How Many Food Guide Servings of Milk and Alternatives Do I Need? Available here.
Nutrition Australia: 2.5 servings (3)Nutrition Australia. Serves of dairy. Available here.
American Heart Association: 2-3 servings (4)American Heart Association. Suggested Servings from Each Food Group. Available here.
Australian Government: 2.5 servings for younger adults, 3.5-4 servings for adults over 50 years of age. (5)Australian Government. National health and medical research council. Australian Dietary Guidelines. 2013 Available here.
The recommendations for children’s dairy intake in the U.S. and Canada are: (6)USDA. United States Department of Agriculture. All about the dairy group. Available here. (7)Health Canada. How Many Food Guide Servings of Milk and Alternatives Do I Need? Available here.

  • For 2-3 years old – 2 servings in the U.S. and 2 in Canada;
  • For 4-8 years old – 2.5 servings in the U.S. and 2 in Canada;
  • For 9 years old and older – 3 servings in the U.S. and 3-4 in Canada.

These recommendations, however, are intended for the majority of the population that is not highly sensitive to lactose or allergic to it. Please note that being sensitive to lactose doesn’t mean that one cannot have dairy. (read more..)

Current recommendations are based on the optimum daily calcium requirements necessary for good bone health. They also take into consideration other beneficial nutrients present in dairy products, such as protein, vitamin B12, vitamin A, riboflavin, phosphorus, potassium, magnesium and zinc.

Despite the available information on the recommended dairy intake, there is no scientific evidence for a specific safe daily limit of dairy consumption. Therefore, a clear upper limit is not set.

Dairy group foods are considered to be all fluid milk products and other dairy products, except those with little or no calcium, such as cream cheese, cream and butter. The dairy group also includes calcium fortified dairy substitutes, like soy milk. (8)USDA. United States Department of Agriculture. All about the dairy group. Available here. (9)Health Canada. How Many Food Guide Servings of Milk and Alternatives Do I Need? Available here. (10)Australian Government. National health and medical research council. Australian Dietary Guidelines. 2013 Available here.:

What is a serving? (11)Australian Government. National health and medical research council. Australian Dietary Guidelines. 2013 Available here.
1 serving of dairy products = 1 cup of milk = 1 cup of yogurt = 1 cup of soy milk = 1.5 oz. (42g) of natural cheese = 2 oz. of processed cheese

How much milk is too much?

Milk products are not only important for strong and healthy bones but they also play a role in reducing the risk of various medical conditions, such as colon cancer, improving heart health, managing blood sugar levels in type 2 diabetes due to the low Glycemic Load, and protecting against tooth decay. (read more..)

However, although there are many known benefits of drinking milk, it is important to question if drinking too much milk can have negative health consequences and what are the daily limits for each particular group of people.

When is drinking too much milk bad for you?

Official dietary recommendations do not stipulate safe limits” of dairy consumption for the general population. Science shows, however, that for some specific groups, certain amounts of milk and dairy products should be restricted due to serious health consequences.

The following are the main results for these groups:

  1. If you are male – 2 servings
    Observational studies conducted on the association between milk and dairy products consumption and the risk of developing prostate cancer are inconsistent.Two major meta-analysis studies were conducted over the last 10 years.

    The older study, from 2008, has not found an association between dairy product consumption and prostate cancer. (12)Huncharek M, Muscat J, Kupelnick B. Dairy Products, Dietary Calcium and Vitamin D Intake as Risk Factors for Prostate Cancer: A Meta-Analysis of 26,769 Cases From 45 Observational Studies. Nutrition and Cancer. Volume 60, Issue 4, 2008. Available here.

    However, the most recent study, from 2014, showed that men who had 2.5 or more servings of milk products per day have a greater chance of developing prostate cancer than those who consume 0.5 or fewer servings per day. In this study, milk fat was excluded as a possible cause by showing that the risk was also elevated with an increased consumption of low-fat milk. (13)Aune D, Rosenblatt D, Chan D, Vieira AR, Vieira R, Greenwood DC, et al. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. Am J Clin Nutr. ajcn.067157. Available here. (14)Health Concerns about Dairy Products Available here.

    The studies that found an association between high consumption of milk products and prostate cancer, were not able to find the exact causes. However, some studies show possible links with the high amounts of calcium and proteins from dairy sources, the insulin-like growth factor 1 (IGF-1), either from animal protein or as a result of the growth hormone injections in cows (read more..), and the estrogen hormones from pregnant cows (15)Melnik BC, John SM, Carrera-Bastos P, Cordain L. The impact of cow’s milk-mediated mTORC1-signaling in the initiation and progression of prostate cancer. Nutrition & Metabolism20129:74. Available here. (16)Aune D, Rosenblatt D, Chan D, Vieira AR, Vieira R, Greenwood DC, et al. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. Am J Clin Nutr. ajcn.067157. Available here..Since dairy products also possess a vast range of health benefits, the overall net effect of milk consumption for men needs to be weighted considering both: the reduced risk of some diseases and the increased risk of prostate cancer.

    Milk and dairy products reduce the risk of developing some of the deadliest diseases of the 21st century, such as coronary heart disease, stroke and colorectal cancer. The overall death toll from these diseases is much greater than from prostate cancer. (see the most deadly diseases here..)

    Considering that the scientific studies on the association between dairy products consumption and prostate cancer are not of high quality, and that milk reduces the risk of an important range and statistically significant diseases it may be concluded that some amount of milk and milk products is beneficial for men’s health.

    This amount is most likely to be around 2 servings per day, 0.5 serving less than the amount shown to increase prostate cancer risk and still within the recommended range to benefit from the protective properties of milk.

  1. If you are allergic to milk protein – avoid any dairy
    People with milk allergy should not drink milk or eat dairy products at all due to potentially serious allergic reactions. (read more..)
  1. If you are lactose intolerant – find your own limit
    Since there are different levels of intolerance for each individual, the level of milk consumption and other milk products needs to be established on an individual basis. (read more..) 

    This can be done with the help of a nutritionist or dietician by using the elimination diet method. The elimination diet method works by first eliminating all possible foods that may cause symptoms and then, after all the symptoms have disappeared, re-introducing small amounts of suspect foods and observing if the symptoms come back. (17)The Food Intolerance Institute of Australia. Elimination Diet (Journal Method). Available here.

  1. If you have gastroenteritis – avoid non-cultured dairy
    Non-cultured milk and milk products, such as cheese or ice-cream, should be avoided altogether if you have gastroenteritis. Gastroenteritis is a disease that causes inflammation of the intestine. Non-cultured milk products may worsen inflammation.
    Cultured milk products such as yogurt, cottage cheese and butter milk can be introduced in the diet 24-26 hours after the symptoms of diarrhea, vomiting and nausea have subsided. (18)The University of Wisconsin-Madison. Gastroenteritis – Upset Stomach. Available here.

Conclusion

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Considering the current official dietary recommendations and the insufficient scientific studies on the negative effects of excessive consumption of dairy products, you should avoid milk if you:

  • Have a milk allergy,
  • Are highly sensitive to lactose and
  • Suffer from gastroenteritis

You should also limit the intake to 3 servings if you are a woman and 2 servings if you are a man (due to prostate cancer risk).

In addition, since most of the population have some level of lactose intolerance, within the above limits, every individual should establish their own optimal amount which doesn’t induce the unpleasant side-effect of lactose intolerance while enjoying the full range of health benefits of milk and dairy products.

The best dairy foods are from organic products from grass-fed cows, with no added sugar and preferably fermented, such as yogurt or kefir.

References   [ + ]

1. USDA. United States Department of Agriculture. All about the dairy group. Available here.
2. Health Canada. How Many Food Guide Servings of Milk and Alternatives Do I Need? Available here.
3. Nutrition Australia. Serves of dairy. Available here.
4. American Heart Association. Suggested Servings from Each Food Group. Available here.
5. Australian Government. National health and medical research council. Australian Dietary Guidelines. 2013 Available here.
6. USDA. United States Department of Agriculture. All about the dairy group. Available here.
7. Health Canada. How Many Food Guide Servings of Milk and Alternatives Do I Need? Available here.
8. USDA. United States Department of Agriculture. All about the dairy group. Available here.
9. Health Canada. How Many Food Guide Servings of Milk and Alternatives Do I Need? Available here.
10. Australian Government. National health and medical research council. Australian Dietary Guidelines. 2013 Available here.
11. Australian Government. National health and medical research council. Australian Dietary Guidelines. 2013 Available here.
12. Huncharek M, Muscat J, Kupelnick B. Dairy Products, Dietary Calcium and Vitamin D Intake as Risk Factors for Prostate Cancer: A Meta-Analysis of 26,769 Cases From 45 Observational Studies. Nutrition and Cancer. Volume 60, Issue 4, 2008. Available here.
13. Aune D, Rosenblatt D, Chan D, Vieira AR, Vieira R, Greenwood DC, et al. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. Am J Clin Nutr. ajcn.067157. Available here.
14. Health Concerns about Dairy Products Available here.
15. Melnik BC, John SM, Carrera-Bastos P, Cordain L. The impact of cow’s milk-mediated mTORC1-signaling in the initiation and progression of prostate cancer. Nutrition & Metabolism20129:74. Available here.
16. Aune D, Rosenblatt D, Chan D, Vieira AR, Vieira R, Greenwood DC, et al. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. Am J Clin Nutr. ajcn.067157. Available here.
17. The Food Intolerance Institute of Australia. Elimination Diet (Journal Method). Available here.
18. The University of Wisconsin-Madison. Gastroenteritis – Upset Stomach. Available here.