The Dairy-free Diet

Milk allergy is an immune response that occurs each and every time the patient consumes milk protein. Therefore, patients with milk allergy must follow a dairy-free diet. It is a reproducible, IgE-mediated response, whereby mast cells release histamine and other potent mediators resulting in symptoms minutes (or up to 2 hours) after eating dairy or drinking milk. An allergic reaction to milk can lead to anaphylaxis. Therefore, a patient with a milk allergy must strictly avoid milk and dairy, including dental products that contain milk or milk protein. Although uncommon, there have been reported cases of accidental exposure and severe allergic reactions to the milk protein, casein, in dental products.^31,32

Many patients are avoiding dairy because they have lactose intolerance, which is a problem digesting foods that contain lactose, the naturally occurring sugar found in dairy products. These patients may experience bloating, stomach pain or diarrhea after consuming dairy.³³ A patient with lactose intolerance lacks the enzyme, lactase, which is responsible for breaking down the milk sugar into glucose and galactose for absorption. This does not mean that the lactose intolerant patient must follow a dairy-free diet, since a few simple swaps are often all that’s needed to relieve GI symptoms. These patients can incorporate dairy into their diet in the form of lactose-free milk, lactose-reduced dairy products, aged hard cheeses and/or fermented dairy products.³⁴

Interest in the dairy-free diet has grown in the past few years causing it to gain significant popularity in the trending diet category. Even though the science-based research does not support a dairy-free diet for weight control, many of our patients are avoiding milk and dairy products, such as cheese and yogurt, in order to lose weight. There is evidence-based research surrounding the controversial role of milk and dairy products in weight-loss programs. While cross-sectional epidemiological studies have shown that including dairy-rich foods in the diet is associated with less adipose tissue in both adults and children; prospective studies and randomized controlled intervention trials have yielded inconsistent results.³⁵ Even so, most of the current evidence-based research suggests that dairy foods do not cause weight gain and that dairy consumption actually reduces body fat and increases lean body mass. Evidence shows that yogurt consumption contributes to reduced weight gain. In addition, consuming fermented dairy, such as yogurt and aged cheese, is linked to a lower risk for cardiovascular disease, and protection against type 2 diabetes.³⁶ Recent studies show that including dairy as part of a healthy eating pattern results in weight loss, weight control and even improvements in body composition. A large meta-analysis of 27 randomized controlled trials (RCT) discovered that when adults ages 18-50 years old consumed low-calorie diets that included 2-4 servings of dairy per day, they had greater weight loss and fat loss, while preserving their lean mass, compared to controls.³⁷ A clinical trial of 100 healthy, overweight or obese premenopausal women revealed that increasing low-fat milk consumption as part of a low-calorie diet, significantly reduced obesity and that low-fat dairy intake helped to promote weight loss.³⁸ A recent 6-month intervention trial discovered that increasing low-fat dairy in the diet led to weight loss and more favorable bone mineral density in overweight and obese postmenopausal women.³⁹ Additionally, increasing dairy intake was associated with weight loss and a decrease in waist circumference in overweight and obese individuals in a weight loss community initiative.⁴⁰

While there is limited research surrounding the role of dairy and oral health, researchers have found that milk, cheese and unsweetened yogurt play a key role in supporting the health of the hard tissues in the oral cavity. A prospective study of the Danish population found that milk and dairy intake was associated with lower future dental caries risk.⁴¹ Wu et al found that drinking yogurt provided a protective factor against the development of dental caries among Chinese children.⁴² Ohlund et al reported that cheese intake may have a caries-protective effect in 4-year-old children using fluoridated toothpaste and residing in an area where overall caries prevalence rate is low.⁴³ Llena et al discovered a negative association between caries and cheese consumption among 6-10 year old Spanish children; and a positive association with caries when consuming sweets, refined carbohydrates and SSB.⁴⁴ A recent study using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2016, assessed the associations between milk and dairy products and the risk of dental caries in children and adolescents. This study ascertained that while a high yogurt intake was associated with a decreased risk of dental caries, cheese did not appear to offer a caries protective effect.⁴⁵ Daily yogurt consumption may decrease caries risk by preventing cariogenic biofilm according to a RCT published in the European Journal of Clinical Nutrition. In this study, when volunteers ate yogurt twice a day for 8 weeks, they had lower salivary counts for Streptococcus mutans and lactobacilli.⁴⁶ Additionally, a large systematic review and meta-analysis of 32 studies revealed that dairy products containing probiotics increased salivary pH and were effective in reducing Streptococcus mutans and Lactobacillus spp. levels.⁴⁷ The clinical relevance of these studies is the potential role of milk, cheese and yogurt consumption to support caries prevention.

To date, few studies have comprehensively explored the associations between milk and dairy consumption and the soft tissues in the oral cavity. The available research does confirm that patients who regularly consume milk and dairy have a decreased prevalence of periodontal disease. Dairy foods are good sources of nutrients needed for optimal bone development and bone health, including calcium, protein, magnesium, potassium, zinc, and phosphorous.⁴⁸ Thus, dairy calcium may have a favorable effect on periodontal health by enhancing alveolar bone density.⁴⁹ In a parallel-designed non-blinded study, 50, 25-year-old students, had better gingival health after drinking a probiotic milk drink for 8 weeks. There was a decrease in elastase activity and MMP3 in their gingival crevicular fluid.⁵⁰ A cross-sectional study looking at the intake of dairy products and periodontitis in 135 older Danish adults reported that milk and fermented foods may protect against periodontitis.⁵¹ Shimazaki et al. learned that Japanese adults consuming yogurt and fermented milk beverages had significantly lower values in mean probing depths compared to those not eating these foods.⁵² Results from a new relatively large study including 9798 Korean adults, suggest that frequent intake of milk and dairy, defined as ≥ 7 servings per week, may have a protective effect on periodontal disease. Even after adjusting for confounding variables, including age, sex, education, income, smoking status, alcohol consumption, BMI, diabetes status, calcium intake, tooth brushing and flossing, a higher dairy intake was associated with a 26% lower risk of periodontal disease.⁴⁹

The bottom line: Milk and dairy does not promote weight gain and may even foster weight control. Dairy fits into a healthy dietary pattern and is beneficial for a healthy oral cavity. Fermented dairy products may play a protective role against both caries development and periodontal disease. Do not use any dental product containing milk or casein to treat any patient with an Ig-E mediated milk allergy.