Dairy products or milk products, also known as lacticinia, are food products made from (or containing) milk.[1] The most common dairy animals are cow, water buffalo, nanny goat, and ewe. Dairy products include common grocery store food around the world such as yogurt, cheese, milk and butter.[2][3] A facility that produces dairy products is a dairy.[a][4] Dairy products are consumed worldwide to varying degrees.[5] Some people avoid some or all dairy products because of lactose intolerance, veganism, environmental concerns, other health reasons or beliefs.
Milk is produced after optional homogenization or pasteurization, in several grades after standardization of the fat level, and possible addition of the bacteria Streptococcus lactis and Leuconostoc citrovorum. Milk can be broken down into several different categories based on type of product produced, including cream, butter, cheese, infant formula, and yogurt.
Milk varies in fat content. Skim milk is milk with zero fat, while whole milk products contain fat.
Milk is an ingredient in many confectioneries. Milk can be added to chocolate to produce milk chocolate.
Rates of dairy consumption vary widely worldwide. High-consumption countries consume more than 150 kilograms (330 lb) per capita per year. These countries are: Argentina, Armenia, Australia, Costa Rica, most European countries, Israel, Kyrgyzstan, North America and Pakistan. Medium-consumption countries consume 30 kilograms (66 lb) to 150 kg per capita per year. These countries are: India, Iran, Japan, Kenya, Mexico, Mongolia, New Zealand, North and Southern Africa, most of the Middle East, and most of Latin America and the Caribbean. Low-consumption countries consume under 30 kg per capita per year. These countries are: Senegal, most of Central Africa, and most of East and Southeast Asia.[5][6]
Dairy products may upset the digestive system in individuals with lactose intolerance or a milk allergy.[7][8][9] People who experience lactose intolerance usually avoid milk and other lactose-containing dairy products, which may cause mild side effects, such as abdominal pain, bloating, diarrhea, gas, and nausea.[7][8] Such individuals may use non-dairy milk substitutes.
It has been suggested that consumption of insulin-like growth factor 1 (IGF-1) in dairy products could increase cancer risk, particularly prostate cancer.[17][18] However, a 2018 review by the Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment (COC) concluded that there is "insufficient evidence to draw any firm conclusions as to whether exposure to dietary IGF-1 is associated with an increased incidence of cancer in consumers".[18] The COC also stated it is unlikely that there would be absorption of intact IGF-1 from food by most consumers.[19]
A 2019 review concluded that higher-quality research was needed to characterise valid associations between dairy consumption and risk of and/or cancer-related mortality.[20] A 2021 umbrella review found strong evidence that consumption of dairy products decreases risk of colorectal cancer.[21]Fermented dairy is associated with significantly decreased bladder cancer and colorectal cancer risk.[22] A 2023 review found no association between consumption of dairy products and breast cancer.[23]
The British Dietetic Association have described the idea that milk promotes hormone related cancerous tumour growth as a myth, stating "no link between dairy containing diets and risk of cancer or promoting cancer growth as a result of hormones".[24] In 2024, Cancer Research UK stated "there is no reliable evidence that casein or hormones in dairy causes cancer in people".[25]
The American Medical Association (AMA) recommends that people replace full-fat dairy products with nonfat and low-fat dairy products.[26] In 2017, the AMA stated that there is no high-quality clinical evidence that cheese consumption lowers the risk of cardiovascular disease.[27] In 2021, they stated that "taken together, replacing full-fat dairy products with nonfat and low-fat dairy products and other sources of unsaturated fat shifts the composition of dietary patterns toward higher unsaturated to saturated fat ratios that are associated with better cardiovascular health".[26]
In 2017, the National Heart Foundation of New Zealand published an umbrella review which found an "overall neutral effect of dairy on cardiovascular risk for the general population".[28] Their position paper stated that "the evidence overall suggests dairy products can be included in a heart-healthy eating pattern and choosing reduced-fat dairy over full-fat dairy reduces risk for some, but not all, cardiovascular risk factors".[29]
In 2019 the National Heart Foundation of Australia published a position statement on full fat dairy products, "Based on current evidence, there is not enough evidence to recommend full fat over reduced fat products or reduced fat over full fat products for the general population. For people with elevated cholesterol and those with existing coronary heart disease, reduced fat products are recommended."[30] The position statement also noted that the "evidence for milk, yoghurt and cheese does not extend to butter, cream, ice-cream and dairy-based desserts; these products should be avoided in a heart healthy eating pattern".[30]
Recent reviews of randomized controlled trials have found that dairy intake from cheese, milk and yogurt does not have detrimental effects on markers of cardiometabolic health.[31][32]
Consumption of dairy products such as low-fat and whole milk have been associated with an increased acne risk, however, as of 2022[update] there is no conclusive evidence.[33][34][35] Fermented and low-fat dairy products are associated with a decreased risk of diabetes.[36][37] Consumption of dairy products are also associated with a decreased risk of gout.[38]
A 2023 review found that higher intake of dairy products is significantly associated with a lower risk of inflammatory bowel disease.[39]
Some groups avoid dairy products for non-health-related reasons. Some religions restrict or do not allow the consumption of dairy products. For example, some scholars of Jainism advocate not consuming any dairy products because dairy is perceived to involve violence against cows.[40] Orthodox Judaism requires that meat and dairy products not be served at the same meal, served or cooked in the same utensils, or stored together, as prescribed in Deuteronomy 14:21.[41]
Veganism is the avoidance of all animal products, including dairy products, most often due to the ethics regarding how dairy products are produced. The ethical reasons for avoiding meat and dairy products include how dairy is produced, how the animals are handled, and the environmental effect of dairy production.[42][43] According to a report of the United Nations' Food and Agriculture Organization in 2010 the dairy sector accounted for 4 percent of global human-made greenhouse gas emissions.[44][45]
Growing awareness of dairy products' environmental impact, specifically greenhouse gas emissions, has led to many people reducing or avoiding dairy. In the EU, dairy is responsible for 27% of all diet related emissions, on average, while plant-based milks cause 2.5–4.5 times fewer emissions.[46][47]
^ ab"Lactose Intolerance". National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health. 2021. Retrieved 5 April 2021.
^ ab"Lactose intolerance". Genetics Home Reference. 8 February 2016. Archived from the original on 25 January 2016. Retrieved 12 February 2016.
^Aghasi M, Golzarand M, Shab-Bidar S, Aminianfar A, Omidian M, Taheri F (2018). "Dairy intake and acne development: A meta-analysis of observational studies". Clinical Nutrition. 38 (3): 1067–1075. doi:10.1016/j.clnu.2018.04.015. PMID29778512. S2CID29167833.
^Dall'Oglio F, Nasca MR, Fiorentini F, Micali G (2021). "Diet and acne: review of the evidence from 2009 to 2020". International Journal of Dermatology. 60 (6): 672–685. doi:10.1111/ijd.15390. PMID33462816. S2CID231643205.
^Zhang K, Bai P, Deng Z (2022). "Dose-Dependent Effect of Intake of Fermented Dairy Foods on the Risk of Diabetes: Results From a Meta-analysis". Can J Diabetes. 46 (3): 307–312. doi:10.1016/j.jcjd.2021.09.003. PMID35568432. S2CID239148132.
^Wiley, K.L. (2004). Historical Dictionary of Jainism. Historical Dictionaries of Religions, Philosophies, and Movements Series. Scarecrow Press. p. 78. ISBN978-0-8108-6558-7. Retrieved 15 April 2019. In recent times, out of concern for the treatment of cows in commercial dairy farming, some Jains in the diaspora and in India now observe a vegan diet and discourage the use of dairy products in temple rituals.
Fuquay, John W. ed. Encyclopedia of Dairy Sciences (2nd Edition, 4 vol 2011), comprehensive coverage.
Rankin, H. F. (1922) Imbucase: the Story of the B. C. I. C. of the Ministry of Food. Edinburgh: Edinburgh Press (B.C.I.C.=Butter and Cheese Imports Committee).