Roach: Tumor of brain lining doesn’t increase
To Your Good Health
DEAR DR. ROACH: I am a faithful reader of your column, but I don’t read many questions about brain tumors. I am 53 years old, diagnosed almost four years ago with multiple meningiomas.
I had an atypical meningioma removed, followed up with gamma knife. My question is whether I will be at a greater risk for Alzheimer’s disease or Parkinson’s disease because of these brain tumors. -- J.Z.
ANSWER: A meningioma is a type of tumor of the lining of the brain. It is considered a brain tumor, but is most commonly benign. You had an atypical meningioma, which, though still benign, is closer to a rare (1 to 3 percent) malignant (cancerous) meningioma. Meningiomas, even those that are malignant, rarely spread, but they are harder to completely eradicate.
Treatment for benign meningiomas is with surgery, usually preferred if the tumor is in a location where surgery is possible, or with radiation if surgery is difficult or impossible. Gamma knife is a precision type of radiation treatment. Atypical meningiomas often are treated with both surgery and follow-up radiation to reduce the risk of recurrence.
Because the tumors are on the outside of the brain, not brain tissue itself, the tumors and surgery should not increase your risk of Alzheimer’s or Parkinson’s disease. However, a review of studies showed that many people with meningiomas do have some decrease in some areas of brain function before treatment.
Brain tissue is relatively resistant to radiation. Although high doses of radiation to the whole brain can cause memory issues (but still not Alzheimer’s disease), the smaller amount of radiation from gamma knife and the limited area of the brain affected make development of dementia (like Alzheimer’s) or Parkinson’s unlikely. In the same large study on meningioma patients, treatment actually improved brain function.
DEAR DR. ROACH: Your recent column regarding probiotics was very interesting. While I would think that following the Mediterranean diet is excellent advice, for folks like myself, with IBS, it isn’t a totally doable thing. Therefore, the questions asked by the writer are important: “Does the number of bacteria matter more than the types listed on the container? Does one take them daily, for a brief time period, or for extended time periods?” -- P.J.S.
ANSWER: My column on healthy bacteria in the gut noted that a healthy diet, such as the Mediterranean diet, induces a change in the microbiome associated with better health outcomes. But P.J.S. is right that this diet isn’t right for everyone.
I do not recommend probiotics for everybody. In fact, for people with no gut symptoms, probiotics are unnecessary. However, they have been shown to be useful in some gastrointestinal conditions, such as inflammatory bowel disease and irritable bowel syndrome.
There are no good studies to directly answer your question about type versus concentration of bacteria. However, my suspicion is that the type of bacteria is more likely to matter: Examples of probiotics that have some evidence showing improvement in IBS include Bifidobacterium infantis and Lactobacillus salivarius. Other species of the same bacterial genus also have shown benefit.
The trials using these probiotics generally lasted four to eight weeks. As the goal is to change the types of bacteria living in the gut, a general recommendation is taking them only four to eight weeks. At least one study showed that symptoms continued to improve a year after finishing the probiotics.