Meanwhile, she'll be staying away from her formerly favorite beverages, coffee and red wine, as she did this summer. "It doesn't have anything to do with performance," she said. "It's entirely a health issue. My doctors say that caffeine and alcohol can interfere with calcium absorption into the bones -Deena Kastor who has suffered 2 foot injuries over the last couple of years. -runnersworld
It's true that caffeine intake is associated with a decrease in bone density. The good news is that scientists believe you may be able to prevent the loss by increasing calcium to 1,200 mg per day. eatright.org
There is also some evidence that tea drinkers actually have better bone density than non tea drinkers.
What about alcohol? According to this study from the American J of Clinical Nutrition noted by Reuters,
Men who had a glass or two of wine or beer daily had denser bones than non-drinkers, the researchers found, but those who downed two or more servings of hard liquor a day had significantly lower BMD than the men who drank up to two glasses of liquor daily
So Kastor is apparently going overboard- she should be switching to tea with milk and continue with her daily glass of wine. Enjoy!