Dear Dr. Katz:
I'm the healthiest eater I know. My diet is mainly fresh fruits and vegetables, whole grains, chicken and fish, lots of water, and minimal caffeine. But the older I get (I'm 47), the more sensitive my digestive system seems to be. I frequently have bloating, cramping, and mild stomach pain. People say it's all the fiber I eat. Is that true, and if so, what can I do about it?
— Robin Rokisky
Weirton, West Virginia
I doubt fiber is the problem, unless you have suddenly begun eating a lot more. That could be a shock to your digestive system because the bacteria in your large intestine may produce noticeably more gas as it breaks down the fiber. If you slowly add fiber to your diet and then keep your intake consistently high, your digestive system adjusts and you'll notice the opposite effect—you'll have less bloating and cramping.
One reason fiber is an unlikely cause is that the recommended intake for adults is about 25 to 35 grams a day, but the average American gets only half that. Studies show health benefits from eating as much as 50 grams daily; our Stone Age ancestors consumed as much as 100 grams a day. So our digestive tract can handle much more fiber than most of us get.
The first thing you should do is run your symptoms by your doctor to make sure you don't have an ailment that needs prompt treatment—gallstones, for instance. Once you have the all clear, there are several other strategies you can try to reduce your discomfort.
Another factor that could account for a finicky GI tract is lactose intolerance, which can develop at midlife. Also, antibiotic use can upset the balance of digestive bacteria that live in our intestines. More and more studies suggest that probiotic supplements—which can replenish the bacteria—can alleviate symptoms such as yours.
The best way to pin down the source of your problems is to keep a diet and symptom diary and look for patterns—say, milk and cereal for breakfast followed by bloating by midday. If you see a connection, try eliminating those foods for a while to see if it helps. Dairy is a likely candidate, as are raw vegetables like cabbage and broccoli (eat those steamed rather than raw).
I'm glad you mentioned water, because you need to be well hydrated to process fiber. Shoot for at least eight glasses a day. Dehydration is more common than most people realize and a cause of constipation and GI upset.