It's easy to get answers about health and nutrition! Just send your question by email to firstname.lastname@example.org and Dr. Harlan will respond to selected questions of general interest. Answers will be posted in the Ask Dr. Gourmet newsletter (sign up now!) and archived in the Ask Dr. Gourmet section of the website.
I've recently been diagnosed as being lactose intolerant over the past year and have been VERY careful about eating dairy products. On vacation I slipped up and ate ice cream one night and have felt awful for about a week. I work with a personal trainer and she suggested that I drink apple cider vinegar diluted w/water. Any truth to this? She also recommends on a daily basis to take probiotics.
This is the first that I have heard about vinegar helping the symptoms of lactose intolerance. After reviewing the medical literature I can't find good evidence to support this, but it's likely not to be harmful. We do have some evidence for using apple cider vinegar in helping control blood sugars in diabetics.
There have also been a number of recent small studies that indicate probiotics can be helpful with lactose intolerance. There has not been a large scale study to support this and it is also important to keep in mind that the term "probiotic" can mean any number of hundreds of various bacteria that can live happily in your intestines and potentially provide benefit to you. Because the studies are often small and incorporate only limited numbers of bacteria (and often only one), it's hard to know exactly what to recommend.
We do know that most people who are lactose intolerant can tolerate some lactose. One recent study put that level at as much as 12 to 15 grams of lactose. Here's a list of amounts of lactose in certain foods.
Thanks for writing,
Timothy S. Harlan, MD, FACP