Most people drink cow milk. I think this is alright if it comes from a happy, healthy cow (or goat for that matter) somewhere in your neighbourhood/from a small scale local farmer. However, most people drink milk that has been mass produced. Many studies claim that this milk is rich in factors that are not beneficial to humans. Especially the growth factors (such as insulin-like growth factor, IGF) cause problems, from acne to possibly even cancer. If you suffer from acne, it is probably a really good idea to stop drinking mass produced milk.
Harvard studies show that there is no positive correlation between calcium intake and prevention of osteoporosis. In fact, because it remains unclear whether dairy products contribute to development of ovarian and prostate cancer, Harvard scientists recommend no more than one glass of mass produced cow milk per day.
As for soy milk, I used to buy it and love it when I thought it was the healthy alternative. However, it seems that processed soy in soy milk is not a healthy variant of soy. The extra vitamins added to soy products are there because processed soy by itself costs our body those vitamins. So, if you have been relying on soy milk for your daily dosis of vitamin D for example, you should know that drinking soy milk actually costs your body vitamin D; it is added to the product to balance this need. To all you soy lovers out there: read this article and decide for yourself: 3 Health Foods to Avoid.
A good alternative to mass produced cow milk and soy milk is almond milk, preferably unsweetened. It has a specific flavour that might take some getting used it, especially if you are used to drinking cow milk. However, my blog is full of satisfying recipes that do not require any milk at all and I assure you – if you really want a healthier body, skip the dairy and the soy milk. It might cost some effort, but you can do it!