I understand that vinegar may help lower blood sugar levels. Will lemon juice be just as helpful?
I love this sort of question because it lets me discuss how science works.
I have been skeptical about patients who come in and tell me that they are taking vinegar for their health. This is usually apple cider vinegar and it just seemed silly to me but I have also felt that this is like so many supplements -- probably not harmful but probably not helpful. However, it appears that this "silly" idea may have some merit. As I reported a few weeks ago, vinegar might be helpful for controlling blood sugar (A Look at Vinegar and Diabetes, 12/02/09). A small study but encouraging.
It seems a simple leap to say that it might be the acidic nature that is helping, and that lemon juice might be just as helpful, but we don't really know why the vinegar works. I have searched the literature and did not find a study that looked at this. We could make the leap that vinegar helps control blood sugar, and both vinegar and lemon juice are acidic, so lemon juice also helps control blood sugar. Unfortunately, science doesn't work this way. Just because A = B and B = C, one can't make the leap that A = C.
That said, lemon juice is really good for you. Two tablespoons contains about 15 mg of Vitamin C (25% of the RDA). I love the bright fresh taste in so many recipes and lemon juice adds so much flavor without adding calories. So it may not help control blood sugar in the same way as vinegar, but it can help by adding rich, low calorie, high vitamin flavor.
Thanks for writing,
Timothy S. Harlan, M.D.