The Effect of Milk Products on Inflammation

Systemic inflammation is a recognized factor in the development of several conditions. Increased levels of certain inflammatory biomarkers, including C-reactive protein, IL-6 and TNF-alpha, have been associated with an increased risk of cardiovascular disease, type 2 diabetes and metabolic syndrome^1-3.

The evidence

In a 2019 systematic review of 16 randomized controlled trials in healthy individuals and those who were overweight or obese and who had metabolic syndrome or type 2 diabetes, it was found that the consumption of milk or dairy products did not show a pro-inflammatory effect. In fact, the majority of studies showed an anti-inflammatory effect in both healthy individuals as well as those with metabolic abnormalities.¹

Similarly, another systematic review of 52 clinical trials published in 2017 by Bordoni et al. concluded that dairy products, including both low- and high-fat, as well as fermented dairy products, have anti-inflammatory effects.²

A 2013 systematic review of eight randomized controlled nutritional intervention trials found that milk product consumption exerted neutral effects on inflammation in four studies and beneficial effects in the other four studies. The conclusion from this systematic review is that milk products do not have adverse effects on biomarkers of inflammation among overweight or obese adults.³

In a randomized cross-over trial, 37 adults with metabolic syndrome, who typically have a low dairy intake, were randomized to either 3 servings of low-fat dairy or a carbohydrate-based control. After two 6-week treatments, the authors observed that 3 daily servings of dairy products improved both systemic inflammation and liver function.⁴

In a multicentre randomized cross-over study, the impact of dairy products on biomarkers of inflammation among 112 adults with low-grade inflammation was tested. During each 4-week treatment period, the participants received either 3 servings of dairy (including low-fat milk, low-fat yogurt and regular-fat cheese) or energy-matched foods as a control. From the study findings, the authors concluded that “short-term consumption of a combination of low- and high-fat dairy as part of a healthy diet has no adverse effects on inflammation".⁵  

Potential mechanisms

The mechanisms by which milk products could potentially influence systemic inflammation are not well understood.

Vitamin D, present in fortified milk, has anti-inflammatory properties and may modulate the effect of certain pro-inflammatory cytokines.⁷

Calcium in milk may also suppress inflammatory stress and enhance the anti-inflammatory action of vitamin D.^6,7

Milk also contains bioactive peptides such as angiotensin-converting enzyme inhibitory peptides. These inhibit the stimulation of the renin-angiotensin system, thereby suppressing inflammatory responses.⁶

Dairy fatty acids, such as conjugated linoleic acid, may also have anti-inflammatory actions via the modulation of cytokine gene expression and production.⁷

Conclusions

Milk and milk products, including high-fat dairy products, have not been shown to have an adverse effect on inflammatory biomarkers. In fact, there is some evidence to suggest that milk product consumption may actually be beneficial against systemic inflammation.

More research is needed to confirm this potential anti-inflammatory effect of milk products and  which types of milk products may be most beneficial.

Mechanistic studies would also be useful to elucidate the mechanisms by which milk products may improve biomarkers of inflammation.