Dairy products are one of the most confusing foods.
Wonderful marketing – “Got Milk” and “Milk it does the body good” – contribute to the confusion.
Yet when milk and other dairy products are put to the research test they perform poorly, especially in bone health.
Milk and Bone Health
The Nurses’ Health Study, which has studied over 120,000 women since 1976, showed that those who drank three or more servings of milk a day had a slightly higher rate of bone fractures compared to women who drank little or no milk (1).
I know. I was surprised too.
As always there is a biological reason why milk might not do your body good after all.
In order to lose calcium from your bones, which is what happens in osteoporosis, your body must be in a negative calcium balance.
In other words, you eat calcium-rich foods, but your body excretes more calcium than it absorbs.
Calcium Absorbed < Calcium Excreted = Negative Calcium Balance
The biggest problem concerning osteoporosis is not low calcium intake or even poor calcium absorption; the most important factor in predicting if you will develop osteoporosis is a high rate of calcium excretion through the urine(1).
Research has shown that increased urinary excretion of calcium occurs when you eat animal protein – meat and dairy products (2).
Eating animal proteins results in high acid levels in your blood, this causes calcium to leach out of your bones to help neutralize the acid.
And guess what, research shows that plant foods protect you from osteoporosis.
Plant foods contain protein, but plant protein is not acid-forming, and therefore leaves your bones alone.
In addition fruits and vegetables buffer the acids formed from animal proteins and reduce calcium loss (3).
Maybe we could start a new marketing campaign for green vegetables?
Perhaps new slogans – “Got Veggies” or “Salad it does the body good” – could catch on.
(1) Fuhrman, J. (2011). Eat to live: the amazing nutrient-rich program for fast and sustained weight loss (Rev. ed.). New York: Little, Brown and Co.
(2) Sellmeyer, D.E., Stone K.L., Sebastian A., Cummings S.R. (2001 Jan). A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women: study of Osteoporotic Fractures Research Group. American Journal Clinical Nutrition. 73 (1): 118-122
(3) Wynn E., Krieg M.A., Lanham-New S.A., et al. (2010 Feb). Postgraduate symposium: positive influence of nutritional alkalinity on bone health. Proc Nutr Soc. 69 (1): 166-173