What are the reasons to avoid dairy products in the diet, according to research?

From the Guidelines

Dairy products should be avoided due to their potential to cause digestive issues, acne, increased mucus production, and allergic reactions, as well as their contribution to cardiovascular disease risk and environmental concerns. Research suggests several reasons to avoid dairy, including:

• Digestive issues for those with lactose intolerance, affecting approximately 65% of the global population who lack sufficient lactase enzyme to properly digest lactose 1
• Acne development due to hormones and growth factors that can stimulate oil glands and inflammation
• Increased mucus production, potentially worsening respiratory conditions like asthma
• Allergic reactions in sensitive individuals, causing symptoms ranging from hives to anaphylaxis, due to casein and whey proteins in dairy products
• Contribution to cardiovascular disease risk when consumed in excess, particularly full-fat options, which contain saturated fats 1
• Potential connections between dairy consumption and certain hormone-sensitive cancers, though evidence remains mixed 1
• Environmental concerns due to greenhouse gas emissions, land use, and water consumption associated with dairy production Additionally, some studies have found that whole milk intake may be associated with an increased risk of prostate cancer mortality, with a relative risk of 1.43 (95% CI: 1.13,1.81, P = 0.003) 1. However, it's worth noting that dairy products can also have beneficial effects on gut health, particularly when consumed as probiotics, which can help restore and maintain a healthy balance of microorganisms in the gut 1. Non-dairy probiotics can also provide similar benefits, making them a viable alternative for individuals who cannot or choose not to consume dairy products 1. For those wishing to avoid dairy, numerous plant-based alternatives exist, including those made from soy, almond, oat, coconut, and rice, which can provide similar culinary functionality with different nutritional profiles.

From the Research

Reasons to Avoid Dairy

• Weight management issues: some people believe that dairy may be detrimental to health, especially in those with weight management issues 2
• Lactose intolerance: individuals with lactose intolerance may need to limit or avoid dairy products, although yogurt and hard cheese are often well tolerated 2
• Osteoarthritis and rheumatoid arthritis: some people believe that dairy may exacerbate these conditions, although there is no evidence to support this claim 2
• Cardiovascular disease: some studies suggest that high consumption of dairy products may increase the risk of cardiovascular disease, particularly if high in saturated fats 3, 4, 5
• Type 1 diabetes: some evidence suggests a possible link between cow's milk consumption and an increased risk of type 1 diabetes, although the evidence is not convincing 3
• Prostate cancer: high consumption of milk and dairy products may increase the risk of prostate cancer 3
• Autistic spectrum disorders: there is no evidence to support the use of a cow's milk-free diet as a primary treatment for individuals with autistic spectrum disorders 3
• Iron status: early introduction of cow's milk is a strong negative determinant of iron status 3
• Allergies: cow's milk protein allergy has a prevalence ranging from 2 to 7% 3

Notes on Dairy Consumption

• Moderate dairy consumption (up to 200 g/day) has no detrimental effects on cardiovascular health 6
• The effect of dairy consumption on cardiovascular health depends more on the food type (cheese, yogurt, milk) than on the fat content 6
• Low-fat or fat-free dairy products are recommended for cardiovascular health 4, 5