What does the research show about dairy?

Dairy

Pooled cohorts found milk was not linked to hip fracture overall, while yogurt and cheese were linked to fewer. Trials found no weight change from dairy unless calories were cut. Total dairy was not linked to heart disease or death, and yogurt was linked to less type 2 diabetes. Cohorts link dairy to acne and slightly more prostate cancer.

Add to Bio HackChecked 2026-11-13

Status: A food, not a regulated health product. The Dietary Guidelines for Americans, 2025-2030 say that when consuming dairy, include full-fat dairy with no added sugars, and set a goal of 3 servings a day in a 2,000 calorie pattern [1]. Milk is one of the nine major food allergens under US law [2].
Also called: milk, cow's milk, whole milk, skim milk, low-fat milk, full-fat dairy, cheese, yogurt, yoghurt, dairy products, dairy foods
Studied for: strong bones, preventing fractures, osteoporosis, calcium, protein, weight loss, blood sugar, diabetes prevention, heart health, blood pressure, colon cancer prevention, acne concerns, prostate cancer concerns

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help3

StrongLinked to 18% lower type 2 diabetes per daily serving of yogurt in pooled cohorts. Total dairy showed no link in one review and 3% lower risk in another.
ModerateLinked to 6% lower high blood pressure for each extra 200 g a day of milk or low-fat dairy, in pooled cohorts.
ModerateLinked to 17% lower colorectal cancer per extra 400 g a day of total dairy and 9% lower per 200 g of milk, in pooled cohorts. Cheese showed no link.

Reported risks7

LimitedA national survey estimated convincing milk allergy in 1.9% of US adults. Self-reported milk allergy ranged from 1.2% to 17% across studies.Common
StrongLinked to 25% higher odds of acne with any dairy against none, in pooled observational studies of people aged 7 to 30, with the strongest link for skim milk.How often is not known
ModerateLinked to slightly more prostate cancer in men, 7% per extra 400 g a day of total dairy and 9% per 50 g of cheese, in pooled cohorts.How often is not known
ModerateA systematic review of trials found most adults with lactose intolerance or malabsorption tolerated 12 to 15 g of lactose, about one cup of milk.How often is not known
LimitedLinked in two Swedish cohorts to 15% higher death per daily glass of milk in women and 3% in men, and to more hip fractures in women.How often is not known
LimitedSmall crossover studies found milk and yogurt cut ciprofloxacin absorption by 30% to 36%, and milk cut tetracycline absorption by 65%.How often is not known
LimitedOne crossover study found 12 ounces of 2% milk taken with levothyroxine lowered thyroxine absorption against levothyroxine alone.How often is not known

What it was studied for, and what was found

Shown to help3

Strong

Type 2 diabetes

Linked to 18% lower type 2 diabetes per daily serving of yogurt in pooled cohorts. Total dairy showed no link in one review and 3% lower risk in another.

Compared with one fewer serving a day [10]; 50 g a day less yogurt or 200 g a day less total dairy, in dose-response models [9]

The numbers and sources

Effect: Across 14 cohorts, each daily serving of total dairy was not linked to type 2 diabetes (RR 0.98, 95% CI 0.96 to 1.01), and each daily serving of yogurt was linked to lower risk (RR 0.82, 95% CI 0.70 to 0.96). In three US cohorts, neither low-fat nor high-fat dairy was appreciably linked [10]. A later review linked 3% lower risk to each extra 200 g a day of total dairy and 7% lower risk to each extra 50 g a day of yogurt [9].
Population: 459,790 participants and 35,863 cases in 14 cohorts, including 194,458 US adults followed up to 30 years [10]. Cohort studies [9].
Sources: [10], [9]
Caveats: Observational. People who eat yogurt may differ in other habits. The reviews pooled different cohorts and dose units.

Moderate

High blood pressure

Linked to 6% lower high blood pressure for each extra 200 g a day of milk or low-fat dairy, in pooled cohorts.

Compared with 200 g a day less milk or low-fat dairy, in a dose-response model [9]

The numbers and sources

Effect: Each extra 200 g a day was linked to lower hypertension for low-fat dairy (RR 0.94, 95% CI 0.90 to 0.98) and milk (RR 0.94, 95% CI 0.92 to 0.97). Total dairy showed a nonlinear association [9].
Population: Cohort studies within a review of 42 articles [9].
Sources: [9]
Caveats: Observational. One review.

Moderate

Colorectal cancer

Linked to 17% lower colorectal cancer per extra 400 g a day of total dairy and 9% lower per 200 g of milk, in pooled cohorts. Cheese showed no link.

Compared with 400 g a day less total dairy, 200 g a day less milk or 50 g a day less cheese, in a dose-response model [12]

The numbers and sources

Effect: The relative risk of colorectal cancer was 0.83 (95% CI 0.78 to 0.88) per 400 g a day of total dairy, 0.91 (95% CI 0.85 to 0.94) per 200 g a day of milk and 0.96 (95% CI 0.83 to 1.12) per 50 g a day of cheese. The links appeared in men and women and were limited to colon cancer [12].
Population: 19 cohort studies [12].
Sources: [12]
Caveats: Observational. The search ran to 2010 [12].

Mixed results2

Strong

Hip fracture

Mixed results: milk was not linked to hip fracture overall in pooled cohorts, while yogurt and cheese were linked to 22% to 32% lower hip fracture.

Compared with one fewer glass of milk a day [3]; the lowest consumption category [4][5]

The numbers and sources

Effect: In women, each daily glass of milk was not linked to hip fracture (RR 0.99, 95% CI 0.96 to 1.02). In men the estimate was 0.91 (95% CI 0.81 to 1.01) [3]. In a 2020 review, the highest against the lowest intake was linked to lower hip fracture for yogurt (RR 0.78, 95% CI 0.68 to 0.90) but not milk (RR 0.86, 95% CI 0.73 to 1.02) or cheese (RR 0.85, 95% CI 0.66 to 1.08). Milk was linked to lower hip fracture in US cohorts (RR 0.75, 95% CI 0.65 to 0.87) and not in Scandinavian ones (RR 1.00, 95% CI 0.85 to 1.17) [4]. In a 2018 review of cohorts, yogurt (RR 0.75, 95% CI 0.66 to 0.86) and cheese (RR 0.68, 95% CI 0.61 to 0.77) were linked to lower hip fracture, and milk (RR 0.91, 95% CI 0.74 to 1.12) and total dairy (RR 1.02, 95% CI 0.93 to 1.12) were not [5].
Population: 195,102 women with 3,574 hip fractures and 75,149 men with 195 hip fractures in cohorts [3]. Prospective cohorts [4]. 10 cohort and 8 case-control studies [5].
Sources: [3], [4], [5]
Caveats: Observational. Yogurt eaters may follow other habits that also affect bone [4]. The US link may reflect vitamin D added to milk there, according to the review authors [4]. Calcium supplement trials are on the calcium page.

Strong

Body weight

Mixed results: trials found no weight change from adding dairy without cutting calories, and 1.2 to 1.3 kg more weight loss when dairy was part of calorie-restricted diets.

Compared with control diets lower in dairy [6][8]; usual weight loss diets with less dairy [7]; 200 g a day less dairy, in a dose-response model of cohorts [9]

The numbers and sources

Effect: Across 29 trials, dairy did not change body weight overall (-0.14 kg, 95% CI -0.66 to 0.38, I² 86.3%) and modestly reduced body fat (-0.45 kg, 95% CI -0.79 to -0.11). Weight fell in energy-restricted or short trials, and rose in trials without energy restriction or lasting a year or more [6]. Without energy restriction, more dairy did not significantly change weight, fat or waist size, while high-dairy weight loss diets gave 1.29 kg more weight loss (95% CI -1.98 to -0.60) [7]. In energy-restricted trials in adults aged 18 to 50, mostly women, 2 to 4 servings a day gave 1.16 kg more weight loss (95% CI -1.66 to -0.66) and less loss of lean mass [8]. In cohorts, overweight or obesity was 25% lower per extra 200 g a day of total dairy [9].
Population: 2,101 adults in 29 trials [6]. 14 trials [7]. 27 trials, median 16 weeks, 90% women [8]. Cohort studies [9].
Sources: [6], [7], [8], [9]
Caveats: Heterogeneity was high [6]. The calorie-restricted results come largely from women [8]. Cohort links are observational.

Not shown to help1

Moderate

Heart disease, stroke and death from any cause

Not linked to heart disease, cardiovascular disease or death from any cause for total dairy or milk, in 29 pooled cohorts.

Compared with lower intakes, in dose-response models [11]

The numbers and sources

Effect: No associations were found for total dairy, high-fat or low-fat dairy, or milk with death from any cause, coronary heart disease or cardiovascular disease. Fermented dairy was linked to slightly lower death (RR 0.98, 95% CI 0.97 to 0.99, per 20 g a day) and cardiovascular disease (RR 0.98), and cheese to 2% lower cardiovascular disease per 10 g a day, but these links weakened when one large Swedish study was removed [11].
Population: 938,465 participants with 93,158 deaths, 28,419 coronary cases and 25,416 cardiovascular cases in 29 cohorts [11].
Sources: [11]
Caveats: Observational. Heterogeneity was very high for the fermented dairy estimates (I² 94.4% and 87.5%) [11].

Amounts studied

The hip fracture review modeled risk per daily glass of milk, about 300 mg of calcium [3]. Other reviews modeled risk per 200 g of milk, 400 g of total dairy, 50 g of yogurt or cheese, or 20 g of fermented dairy a day [9][11][12]. Weight trials gave 2 to 4 standard servings of dairy a day, or 20 to 84 g a day of whey protein, over a median 16 weeks [8]. The lactose review found 12 to 15 g of lactose, about one cup of milk, was tolerated by most adults with lactose intolerance [18]. The drug absorption studies used 300 ml of milk or yogurt [21] and 12 ounces (355 ml) of 2% milk [23].

Risks

Reported risks7

LimitedCommon

Cow's milk allergy

A national survey estimated convincing milk allergy in 1.9% of US adults. Self-reported milk allergy ranged from 1.2% to 17% across studies.

The numbers and sources

How common: Common: between 1 in 100 and 1 in 10 people.
Effect: Among 40,443 US adults, convincing milk allergy was estimated at 1.9% (95% CI 1.8 to 2.1) [19]. A meta-analysis found self-reported milk allergy from 1.2% to 17%, far higher than objective measures [20]. Milk is one of the nine major food allergens under US law [2].
Population: 40,443 US adults surveyed [19]. 51 studies of infants, children and adults [20].
Sources: [19], [20], [2]
Caveats: Survey estimates rest on reported symptoms [19]. Heterogeneity between studies was marked [20].

StrongHow often is not known

Acne

Linked to 25% higher odds of acne with any dairy against none, in pooled observational studies of people aged 7 to 30, with the strongest link for skim milk.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Against no intake, odds of acne were 1.25 (95% CI 1.15 to 1.36) for any dairy, 1.28 for any milk, 1.32 for low-fat or skim milk, 1.22 for cheese (95% CI 1.00 to 1.50) and 1.36 for yogurt. One glass of milk a day gave odds of 1.41 against less than weekly [13]. A second review found higher odds for dairy (OR 2.61, 95% CI 1.20 to 5.67), total milk (OR 1.48) and skim milk (OR 1.82), and no link for yogurt or cheese [14]. A third found odds of 1.16 (95% CI 1.09 to 1.24) for milk drinkers against non-drinkers [15].
Population: 78,529 children, adolescents and young adults aged 7 to 30 in 14 studies [13]. Observational studies [14]. 71,819 participants in 13 studies [15].
Sources: [13], [14], [15]
Caveats: Observational, mostly case-control and cross-sectional. Adjusted results were weaker than unadjusted ones, and publication bias was detected [13]. The reviews disagree on yogurt and cheese.

ModerateStudied in menHow often is not known

Prostate cancer

Linked to slightly more prostate cancer in men, 7% per extra 400 g a day of total dairy and 9% per 50 g of cheese, in pooled cohorts.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Per extra 400 g a day of total dairy, the relative risk of prostate cancer was 1.07 (95% CI 1.02 to 1.12). It was 1.03 (95% CI 1.00 to 1.07) per 200 g of milk, 1.06 per 200 g of low-fat milk and 1.09 (95% CI 1.02 to 1.18) per 50 g of cheese. Dietary and dairy calcium were linked, and nondairy or supplemental calcium were not [16].
Population: Men in 32 prospective studies [16].
Sources: [16]
Caveats: Observational. The review covers total prostate cancer, and few studies reported results by subtype [16].

LimitedHow often is not known

Death and fractures in two Swedish cohorts

Linked in two Swedish cohorts to 15% higher death per daily glass of milk in women and 3% in men, and to more hip fractures in women.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: In women, 3 or more glasses of milk a day against less than one was linked to higher death from any cause (HR 1.93, 95% CI 1.80 to 2.06). Each daily glass was linked to higher death in women (HR 1.15, 95% CI 1.13 to 1.17) and men (HR 1.03, 95% CI 1.01 to 1.04). In women, each glass was linked to hip fracture (HR 1.09, 95% CI 1.05 to 1.13) and not to any fracture (HR 1.02). In men, fracture was not linked [17].
Population: 61,433 Swedish women followed a mean 20.1 years and 45,339 Swedish men followed 11.2 years [17].
Sources: [17]
Caveats: One pair of cohorts. The authors call for cautious interpretation because of residual confounding and reverse causation [17]. Pooled cohorts found no link between milk and death [11].

ModerateHow often is not known

Lactose intolerance

A systematic review of trials found most adults with lactose intolerance or malabsorption tolerated 12 to 15 g of lactose, about one cup of milk.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Moderate-quality evidence indicated that 12 to 15 g of lactose is well tolerated by most adults with lactose intolerance or malabsorption. Evidence was insufficient that lactose-reduced milk (0 to 2 g lactose) reduced symptoms against milk with more than 12 g, and insufficient for probiotics or gradual adaptation [18].
Population: 36 randomized trials in people with lactose intolerance or malabsorption [18].
Sources: [18]
Caveats: Most trials studied lactose malabsorption, not symptoms of intolerance [18]. The review gives no prevalence figure.

LimitedHow often is not known

Lower absorption of some antibiotics

Small crossover studies found milk and yogurt cut ciprofloxacin absorption by 30% to 36%, and milk cut tetracycline absorption by 65%.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Taken with 300 ml of milk or yogurt instead of water, 500 mg of ciprofloxacin had a 36% and 47% lower peak blood level and 30% to 36% lower total absorption [21]. Milk reduced absorption of tetracycline by 65% and minocycline by 27% against water [22].
Population: 7 healthy volunteers in a randomized crossover trial [21]. Two groups of 8 volunteers [22].
Sources: [21], [22]
Caveats: Small single-dose studies measuring blood levels, not treatment outcomes.

LimitedHow often is not known

Lower absorption of levothyroxine

One crossover study found 12 ounces of 2% milk taken with levothyroxine lowered thyroxine absorption against levothyroxine alone.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: The area under the curve of total thyroxine after 1,000 µg of levothyroxine was 67.3 with milk and 73.5 without (p = 0.02) [23].
Population: 10 healthy adults with normal thyroid function, mean age 33.7, with a four-week washout [23].
Sources: [23]
Caveats: One small study using a single high dose in people without thyroid disease. Levothyroxine is on its own page.

Claims tested and not found

That drinking more milk prevents hip fracture. Each daily glass of milk was not linked to hip fracture in women [3], and milk was not linked to hip fracture in two other pooled reviews of cohorts [4][5].
That adding dairy causes weight loss on its own. Trials without calorie restriction found no significant change in weight or body fat [6][7].
That dairy raises heart disease or death. Total dairy and milk were not linked to coronary heart disease, cardiovascular disease or death from any cause in 29 pooled cohorts [11].

Calcium Fermented foods

Sources

US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. realfood.gov. 2026. https://cdn.realfood.gov/DGA.pdf
US Food and Drug Administration. Food Allergies. FDA. Content current as of 2026-03-11. https://www.fda.gov/food/nutrition-food-labeling-and-critical-foods/food-allergies
Bischoff-Ferrari HA, Dawson-Hughes B, Baron JA, et al. Milk intake and risk of hip fracture in men and women: a meta-analysis of prospective cohort studies. Journal of Bone and Mineral Research. 2011. https://doi.org/10.1002/jbmr.279
Hidayat K, Du X, Shi BM, Qin LQ. Systematic review and meta-analysis of the association between dairy consumption and the risk of hip fracture: critical interpretation of the currently available evidence. Osteoporosis International. 2020. https://doi.org/10.1007/s00198-020-05383-3
Bian S, Hu J, Zhang K, et al. Dairy product consumption and risk of hip fracture: a systematic review and meta-analysis. BMC Public Health. 2018. https://doi.org/10.1186/s12889-018-5041-5
Chen M, Pan A, Malik VS, Hu FB. Effects of dairy intake on body weight and fat: a meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition. 2012. https://doi.org/10.3945/ajcn.112.037119
Abargouei AS, Janghorbani M, Salehi-Marzijarani M, Esmaillzadeh A. Effect of dairy consumption on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. International Journal of Obesity. 2012. https://doi.org/10.1038/ijo.2011.269
Stonehouse W, Wycherley T, Luscombe-Marsh N, et al. Dairy Intake Enhances Body Weight and Composition Changes during Energy Restriction in 18-50-Year-Old Adults: A Meta-Analysis of Randomized Controlled Trials. Nutrients. 2016. https://doi.org/10.3390/nu8070394
Feng Y, Zhao Y, Liu J, et al. Consumption of Dairy Products and the Risk of Overweight or Obesity, Hypertension, and Type 2 Diabetes Mellitus: A Dose-Response Meta-Analysis and Systematic Review of Cohort Studies. Advances in Nutrition. 2022. https://doi.org/10.1093/advances/nmac096
Chen M, Sun Q, Giovannucci E, et al. Dairy consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis. BMC Medicine. 2014. https://doi.org/10.1186/s12916-014-0215-1
Guo J, Astrup A, Lovegrove JA, et al. Milk and dairy consumption and risk of cardiovascular diseases and all-cause mortality: dose-response meta-analysis of prospective cohort studies. European Journal of Epidemiology. 2017. https://doi.org/10.1007/s10654-017-0243-1
Aune D, Lau R, Chan DSM, et al. Dairy products and colorectal cancer risk: a systematic review and meta-analysis of cohort studies. Annals of Oncology. 2012. https://doi.org/10.1093/annonc/mdr269
Juhl CR, Bergholdt HKM, Miller IM, et al. Dairy Intake and Acne Vulgaris: A Systematic Review and Meta-Analysis of 78,529 Children, Adolescents, and Young Adults. Nutrients. 2018. https://doi.org/10.3390/nu10081049
Aghasi M, Golzarand M, Shab-Bidar S, et al. Dairy intake and acne development: A meta-analysis of observational studies. Clinical Nutrition. 2019. https://doi.org/10.1016/j.clnu.2018.04.015
Dai R, Hua W, Chen W, et al. The effect of milk consumption on acne: a meta-analysis of observational studies. Journal of the European Academy of Dermatology and Venereology. 2018. https://doi.org/10.1111/jdv.15204
Aune D, Navarro Rosenblatt DA, Chan DS, et al. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. The American Journal of Clinical Nutrition. 2015. https://doi.org/10.3945/ajcn.113.067157
Michaëlsson K, Wolk A, Langenskiöld S, et al. Milk intake and risk of mortality and fractures in women and men: cohort studies. BMJ. 2014. https://doi.org/10.1136/bmj.g6015
Shaukat A, Levitt MD, Taylor BC, et al. Systematic review: effective management strategies for lactose intolerance. Annals of Internal Medicine. 2010. https://doi.org/10.7326/0003-4819-152-12-201006150-00241
Gupta RS, Warren CM, Smith BM, et al. Prevalence and Severity of Food Allergies Among US Adults. JAMA Network Open. 2019. https://doi.org/10.1001/jamanetworkopen.2018.5630
Rona RJ, Keil T, Summers C, et al. The prevalence of food allergy: a meta-analysis. The Journal of Allergy and Clinical Immunology. 2007. https://doi.org/10.1016/j.jaci.2007.05.026
Neuvonen PJ, Kivistö KT, Lehto P. Interference of dairy products with the absorption of ciprofloxacin. Clinical Pharmacology and Therapeutics. 1991. https://doi.org/10.1038/clpt.1991.174
Leyden JJ. Absorption of minocycline hydrochloride and tetracycline hydrochloride. Effect of food, milk, and iron. Journal of the American Academy of Dermatology. 1985. https://doi.org/10.1016/s0190-9622(85)80041-4
Chon DA, Reisman T, Weinreb JE, et al. Concurrent Milk Ingestion Decreases Absorption of Levothyroxine. Thyroid. 2018. https://doi.org/10.1089/thy.2017.0428

Everything in the library

Shown to help3

Reported risks7

What it was studied for, and what was found

Shown to help3

Mixed results2

Not shown to help1

Amounts studied

Risks

Reported risks7

Claims tested and not found

Related

Sources