Diary products is controversial topic for me. Although I am not against it, I do not believe it has any health benefits either and there is a reason in TICM we do often avoid it. But there are health issues that do arise from diary.
Milk and other diary products do not provide calcium as we are led to believe. Best sources of calcium are from dark green leafy vegetables such as kale.
Dairy products are considered very damp, heavy, cold foods that slow and weaken digestion (Stomach and Spleen) when eaten excessively. Dairy products have very concentrated properties, so a little bit goes a long way in their effect on the body. This is why TICM recommends they be eaten in small quantities. For people with damp or phlegm conditions such as allergies, asthma, and sinusitis, dairy foods are best avoided entirely.
Dampness is a by product of eating foods that clog the free flow of energy inside your body. Popular foods such as cheese, yogurt, white flour and sugar are all culprits in the formation of dampness. Dampness causes stagnation which creates blockages in the body, causing it to break down and resulting in pain and disease
Signs of damp accumulation will show up in our respiratory system. Ever notice after eating ice cream, drinking a cold smoothie, or after eating greasy foods, you may cough up a bit of phlegm, or your sinuses get congested even though you may not have any known allergies. This is no coincidence. Another key issue is vaginal discharge in women when they have damp in their system.
Always always everything in moderation as per Sunnah as balance is key, after all, but do remember that dairy = dampness and dampness = disease.