Dear Dr. Roach: Please tell me the foods to avoid since I am a kidney-stone maker (I believe my stones are oxalate). I have had six stones to date that I have passed, and one is now lodged 鈥� and I can鈥檛 take much more. Is tea a cause of stones (since I drink quite a bit of tea, year-round)?
J.J.
Kidney stones are common in both men and women. Most women I have talked to who have both had children and passed a kidney stone say kidney stones are worse.
There are several different types of stones, and specific recommendations should be based on both a stone analysis and the results of 24-hour urine collections. However, some simple advice can effect a significant reduction in the number of stones you might have in the future. I am going to assume for the sake of this discussion that you have had proven oxalate stones.
Some dietary factors increase stone risk, so you should reduce the amount of simple sugar (sucrose and fructose) and salt you take in. Eating less animal protein is helpful. You also should reduce your oxalate intake.
You can learn more about what foods have high oxalate (there are a lot) at https://tinyurl.com/h2loheu. Brewed black tea does have a lot of oxalate (green and oolong, much less), but coffee does not. However, people who drink a lot of tea do not have higher stone risk.
Some dietary factors reduce oxalate stone risk. Increased potassium and citric acid reduce stone risk. Calcium is paradoxical: Dietary calcium reduces stone risk, but supplemental calcium increases risk.
This might be because blood levels go up quickly after a supplement, leading to high enough levels in the urine to start a stone, or it might be due to the fact that dietary calcium binds the oxalate in food (at least, that鈥檚 my hypothesis).
Perhaps the most important factor is fluid intake. Regular fluid intake throughout the day significantly reduces stone risk (perhaps that鈥檚 why tea drinking doesn鈥檛 increase stones, despite the oxalate).
Dear Dr. Roach: I have a four-year-old granddaughter who is left-handed and has been since infancy. Her mom thinks she should be right-handed and makes her take her pencil out of her left hand and place it in the right to write.
She also makes her put the scissors in her right hand to cut. When she went for a conference with her preschool teacher, they had this little girl try writing with her left hand and then her right. I am told she now does better with her right.
My question is: Why would someone make an issue of this and force a child to change? Does it really make a difference? Her great-grandpa, great-uncle and two great-cousins are left-handed. I have heard that people who are left-handed might have a higher IQ. Would you make your child go through this?
M.
Forcing naturally left-handed people to use their right hand has been done for centuries. There has long been a prejudice against left-handers (think of the term 鈥渟inister,鈥� which is Latin for 鈥渓eft鈥�). Certain diseases were thought to be more likely in left-handers (they aren鈥檛). However, you are right that people who score at the very top of many tests, such as the SAT, are more often left-handed than expected. Forcing someone to use their right hand causes a 鈥渞ewiring鈥� of the brain. Although the brain can adapt, I certainly would not recommend forcing someone to change their handedness.
听
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 ToYourGoodHealth@med. cornell.edu