Dear Dr. Roach: I have a long history of calcium oxalate kidney and bladder stones. My urologist recently recommended a low-oxalate diet to mitigate stone recurrence. Unfortunately, the diet is so restrictive that I don’t think I can reasonably follow it long-term. Would calcium citrate be a possible therapy? I understand it binds the oxalate anion in the digestive system so that it never gets to the kidneys.
J.S.
A low-oxalate diet is a great idea in people with recurrent calcium oxalate stones, the most common type of kidney stones. However, a low-oxalate diet is not a “no oxalate” diet, and you are probably restricting yourself more than you need to.
There are six very high oxalate foods: spinach, rhubarb, rice bran, buckwheat groats, almonds and miso soup — don’t eat those. Be mindful of the other foods on the list, and eat these less often and in small amounts.
Taking calcium by diet reduces stone risk. Experts sometimes prescribe calcium citrate, and you can certainly talk to your urologist or nephrologist about it. But I would first see whether you still have stone issues on a low-oxalate diet.
You are correct in that calcium reacts with oxalate in the gut, forming calcium oxalate, which is not well-absorbed. Further, the citrate in urine inhibits crystal formation.
I recommend the following as a great resource for people with kidney stones on a low-oxalate diet: kidneystones.uchicago.edu/how-to-eat-a-low-oxalate-diet/.
Dear Dr. Roach: Are intramammary lymph nodes problematic? (i.e., can they become cancerous?)
R.P.
Lymph nodes are normal structures and are not problematic themselves. They often become enlarged when there is infection. However, enlarged lymph nodes in a person with cancer are concerning because they might represent the spread of cancer, as many cancers first spread to the lymph nodes before going to more distant sites such as the lungs.
Enlarged intramammary (within the breast) lymph nodes in a person with breast cancer are usually removed for pathological evaluation, although their appearance on a mammogram and sonogram can give the radiologist a good idea of whether they are likely to be benign or malignant.
exposure with someone who is confirmed as HIV positive (he admitted it when I confronted him). For a different reason, I was administered a three-day dexamethasone injection of high dosages. It was on the 11th, 12th and 13th day after exposure. I continue to experience symptoms: diarrhea, rashes, weakness, two swollen lymph nodes in my neck and rapid weight loss. My fourth-generation HIV test, which I took 70 days post-exposure, returned with a nonreactive result. My question is, can the dexamethasone injection affect the lab test and give a false negative result?
A.L.
Few test results cause as much stress as an HIV test, but after 70 days, the results of a fourth-generation test (which looks for both HIV antibodies and a viral antigen called p24) are extremely accurate. Seventy days after exposure, the minimum sensitivity is 99.8%, and most studies show 100%. There is never a guarantee, but it is much more likely that your symptoms are caused by stress or something entirely unrelated. The dexamethasone injection you took has no effect on the HIV results now.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected]
