Overweight or obese individuals (BMI ≥25 kg/m2) have chronic, low-grade inflammation, characterized by an increased production of proinflammatory biomarkers, such as IL-6 and TNF-α. Chronic inflammation can lead to more serious health problems including osteoporosis, atherosclerosis, and even some cancers, such as kidney, prostate, or colorectal cancer [1].
“Some past research suggests that eating dairy foods (like milk, yogurt, and cheese) might reduce inflammation, particularly in those with increased risk factors for chronic disease,” says Andrea Josse, an associate professor at York University, “but benefits are weak.” Moreover, many studies only used certain dairy products.
Therefore, Josse and her colleagues asked whether eating more dairy foods could change levels of inflammation or improve heart-related health markers in overweight or obese people. Their study, published in the Journal of Nutrition, found that indeed, it could; however, the effects were modest [2].
The study used a within-group, crossover study design in which individuals completed two randomized, 6-week long dietary interventions. In one intervention, individuals consumed a high-dairy diet, which consisted of 3 servings of dairy per day (2% milk, yogurt, and full-fat cheddar cheese) for 6 weeks. In the other intervention, they consumed their routine, low-dairy diet (less than 1 serving per day) for 6 weeks. All study participants completed both interventions, and these are separated by a 4-week break to allow the participants’ bodies to reset. Due to the nature of the study design, the participants were not blinded. The researchers intentionally used several different types of dairy products to more accurately reflect a normal diet [2].
After each intervention, the researchers measured inflammatory and metabolic biomarkers, such as IL-6, IL-4, TNF-α, and C-reactive protein (CRP); glutathione, a modulator of oxidative stress; and the participants’ vasculature to assess endothelial function [2].
The researchers observed no significant differences in inflammatory biomarkers IL-6 IL-10, IFN-γ, or IL-1β [2].
“However, two inflammation-related chemicals in the blood did show improvement on the high-dairy diet,” says Josse. “TNF-α, a chemical linked to harmful inflammation, went down, and IL-4, a chemical linked to calming inflammation, went up.”
A high-dairy diet may help lower inflammation in overweight or obese individuals, but the effects from the study are small [2]. This is consistent with previous studies showing that even just one extra serving of dairy per day can modulate inflammation. The data may also indicate that the dairy products are acting through specific mechanisms [3, 4].
In addition, the researchers found significant differences in the percent change of glutathione between the interventions, with the low-dairy diet trending downwards. The data suggest that a high-dairy diet may be better at protecting the body from oxidative stress [2].
There were no significant changes to the participants’ weight, body fat, cholesterol, blood pressure, or vasculature.
Given the short intervention period, Josse notes that the results were “interesting, but not surprising.”
“The specific, modest, beneficial pattern observed in this study is very much in line with what prior research has suggested,” she says. “The results match the general scientific literature in this area highlighting that dairy, even the consumption of high-fat dairy, doesn’t worsen inflammation or lead to weight gain.”
Moreover, the researchers found that men and women had different responses to the high- and low-dairy diets; however, their study was not powered to investigate sex-based differences. It would be interesting to explore this in the future, particularly in a long-term study.
As such, the study suggests that increasing dairy consumption may help support improved long-term health and well-being.
“The improvements… point in a positive direction,” says Josse. — By Brittany T. Truong, PhD, International Milk Genomics Consortium.
References
- Pahwa R, Goyal A, Jialal I. Chronic inflammation [Internet]. Treasure Island, FL: StatPearls Publishing. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493173/.
- Prowting JL, Fraschetti EC, Pereira TJ, Tucker JA, Gagnon S, Cheng N, et al. Inflammatory cytokine responses to 6 wks of increased dairy intake in individuals with overweight and obesity-a randomized crossover trial. J Nutr. 2025 Oct 30.
- Labonté M-È, Cyr A, Abdullah MM, Lépine M-C, Vohl M-C, Jones P, et al. Dairy product consumption has no impact on biomarkers of inflammation among men and women with low-grade systemic inflammation. The Journal of Nutrition. 2014 2014/11/01/;144(11):1760-7.
- Pei R, DiMarco DM, Putt KK, Martin DA, Gu Q, Chitchumroonchokchai C, et al. Low-fat yogurt consumption reduces biomarkers of chronic inflammation and inhibits markers of endotoxin exposure in healthy premenopausal women: A randomised controlled trial. Br J Nutr. 2017;118(12):1043-51.
