August 30, 2011
By Trista Cornelius, Contributing Writer
Dr. Amy Lanou is not only a professor of health and wellness at the University of North Carolina, she also serves as senior nutrition scientist for the Physicians Committee for Responsible Medicine and recently published Building Bone Vitality: a revolutionary diet plan to prevent bone loss and reverse osteoporosis. Dr. Lanou took time to answer a few questions before her upcoming presentations at the Professional Health Conference (Sept. 16) and Portland VegFest (Sept. 17).
Q. Healthy bones, drinking milk, and calcium are all synonymous phrases in our culture. Has it been challenging to convince people that dairy products are not our only source of calcium nor the solution to preventing osteoporosis? What have been reactions from other health professionals as well as laypersons?
A. People generally are aware that some other foods contain calcium, but often they have been misled to think that they would have to eat enormous portions of those foods to get appreciable calcium, which, of course, is not true. In Mexico the primary source of calcium in people's diets is corn tortillas, for example. The two most important missing pieces of information relative to calcium sources are that many vegetable and legume sources of calcium are absorbed at a higher rate than the calcium in cow's milk or non-dairy milks. Most of the cabbage family vegetables have calcium absorption rates of 50 to 65%, while the calcium absorption from cow's milk is about 32%. This means that a cup of cooked kale, for example, has about 1/2 the calcium in amount, but delivers the same amount of absorbable calcium as a cup of cow's milk or fortified orange juice.
The hardest thing I find for people to understand is that dietary calcium is not as important as many other dietary factors with respect to bone health. We know now that adding more calcium to the diet from dairy products or supplements or fortified foods does not reliably reduce fracture risk. I think my most important message is that we need to focus on dietary patterns rather than a single nutrient (calcium) if we want to have a positive impact on bone health in children and adults and osteoporosis-related fracture risk in older adults.
Reactions have been surprisingly positive. Most of us get it that the dietary strategy we have been using (3 to 4 servings of dairy a day and calcium supplements) is not preventing osteoporosis. People are hungry for a better solution--especially one that is not pharmacologically-based.
Q. What initially inspired your research of bone health?
A. Two things: the high rates of osteoporotic fracture in the US (including some people in my family) and the "calcium paradox" information in the literature. The World Health Organization uses "calcium paradox" to refer to the fact that those countries that consume the most dairy products and the most total calcium also suffer the highest hip fracture rates (50% higher rates than in countries that consume little or no dairy).
Q. Why do you recommend that dairy products should not be a part of a vegetarian diet?
A. Wow. This is a hard one to answer succinctly. The short version: cow's milk and other dairy product consumption is not necessary for health and increases risk of a variety of chronic diseases and conditions from prostate cancer to overweight to kidney stones to autoimmune conditions and gastrointestinal disorders. And, consumption of dairy products at the high levels recommended by the US Dietary Guidelines (3 to 4 servings a day) do not reduce fracture risk. In fact, some dairy products such as cheese (as well as all meats) increase calcium lost from the body in urine due to their increasing the acid load in the blood stream. This acid must be neutralized to keep the blood at an appropriate pH. We generally do this by pulling calcium compounds out of bone to buffer that acid. So, why chance it?
Q. When it comes to your own diet, what are your favorite foods? Has your research changed the way you eat and/or your relationship to food?
A. My favorite foods are a selection of foods we typically think of as vegetables: artichokes, potatoes, onions/garlic, any type of cooked green, avocados, cucumbers, mushrooms, etc.
Yes, it is because of my understanding of the nutrition and chronic disease literature that I choose to eat a diet built entirely from plant foods.
Q. In addition to your research about bone health, you teach women's health classes. Is there one thing you'd recommend all women include or avoid in their diets?
A. I would recommend that all women avoid cheese to the extent that they possibly can, and I think everyone should make friends with the cabbage family vegetables--they are vitamin and mineral rich, alkaline-forming, cancer preventing and extremely versatile from a culinary perspective. Not too many foods can boast that set of qualities!