In this week's House Call, a reader asked, "If one is lactose intolerant, but has no other intolerance to dairy, (e.g. casein and whey) is it ok to consume dairy products while having Hashimoto's?"

By now, most of my readers probably know how I feel about dairy—it's nature's perfect food—but only if you're a calf. We have no biological requirement for this food, and yet, we've been told over and over again that dairy is a great source of calcium, milk makes healthy bones and we should drink it daily. I'm here to tell you that this is not true.

Based on research and my experience practicing medicine, I typically advise most of my patients to avoid dairy products completely.

Here are some facts to consider:

• Countries with the lowest rates of dairy and calcium consumption (like those in Africa and Asia) have the lowest rates of osteoporosis.

• Research shows that higher intakes of both calcium and dairy products may increase a man's risk of prostate cancer by 30 to 50 percent. Dairy consumption increases the body's level of insulin-like growth factor-1 (or IGF-1)—a known cancer promoter.

• Calcium isn't as bone-protective as we thought. Studies of calcium supplementation have shown no benefit in reducing fracture risk. In fact, vitamin D appears to be much more important than calcium in preventing fractures.

These are just a few of the findings related to the harm that dairy can cause.

About 75 percent of the world's population is genetically unable to properly digest milk and other dairy products—a problem known as lactose intolerance—which is what our reader is asking about.

I often find that symptoms of lactose intolerance are actually caused by difficulty digesting casein, the main protein found in milk, which is often used in other food products as a binding agent. Casein proteins can actually induce inflammation leading to things like eczema, ear infections, congestion and sinus problems. So, I highly recommend avoiding casein, no matter who you are.

Whey protein contains very little lactose, so there is a chance that someone with lactose intolerance might be able to have whey. However, I know some people who can tolerate whey protein and others who cannot, so you might want to test it out for yourself.

Overall, I recommend avoiding dairy, especially if you're lactose intolerant. Dairy consumption can lead to increased cancer risk, increased fracture risk, constipation, irritable bowel, bloating, gas, diarrhea, allergies, eczema and acne. None of that sounds good to me!

One dairy product that many people can tolerate is ghee. Ghee is simply clarified butter which has had all the water and milk solids removed from it. That means it can be consumed by those who are allergic to dairy. Again, some people do well with ghee and others do not. It really depends on the individual.

How to Test for Dairy Sensitivity

I recommend getting off of all dairy—except for grass-fed butter and ghee for three weeks. That means eliminating milk, cheese, yogurt, products with casein and ice cream to see if you feel better. You should notice improvements with your sinuses, post-nasal drip, headaches, irritable bowel syndrome, energy and weight. Then start reintroducing dairy again and see how you feel. If you feel worse, you should try to give it up for life.

If you do consume dairy, always choose grass-fed. If you're going to consume butter or other dairy products, remember that grass-fed is best. The milk these cows produce has an omega-6 to omega-3 ratio of 1:1 which is optimal. Conventionally raised cows eat grains and other crops that make their fatty acid profiles more inflammatory. The milk they produce—and as a result the butter and cheese made from it—contains more omega-6 fats.

Personally, when I eat little to no dairy, I feel much, much better. Give it a shot, what's to lose? Besides all the miserable symptoms and a little weight, that is…