DEAR DR. ROACH: I’m a 68-year-old man, weighing 130 pounds and standing 5 feet, 7 inches tall. I’m in good health and exercise regularly. I had my prostate removed in 2023 after about six years of monitoring my condition, and I’ve just completed radiation therapy.
I’ve been taking vitamins for as long as I can remember. My routine includes Centrum Silver multivitamins, fish oil, calcium, and vitamin D for bone health. Recently, I learned that selenium and vitamin E might not be advisable for those with prostate cancer, and both are in Centrum Silver. There are mixed opinions about fish oil; some say it’s beneficial while others advise against it in prostate cancer cases.
Should I keep taking these vitamins, or should I stop? Is there any chance that they could have worsened my cancer? If I decide to discontinue them, should I gradually wean off or quit suddenly? What do you suggest regarding these vitamins and supplements in relation to my health? I’d really hate to think they might be doing more harm than good. I maintain a healthy diet with plenty of fruits, vegetables, chicken, fish, and lean red meats, and I drink green tea and lots of water to stay hydrated. — Anon.
ANSWER: Certain supplements have been linked to a heightened risk of prostate cancer. The evidence for vitamin E is fairly compelling; a significant study aimed at assessing its benefits was halted due to safety concerns, revealing a 17% increased risk of prostate cancer associated with vitamin E.
Some research indicates fish oil may increase prostate cancer risk, while other studies do not support this. In my view, men who have prostate cancer—or are at a significant risk for it—should avoid vitamin E. Unless there is a clear recommendation for fish oil based on your triglyceride levels or a specific medical reason, I wouldn’t suggest taking it either.
Since your multivitamin contains both vitamin E and selenium, which may elevate prostate cancer risk, I recommend discontinuing it for anyone with prostate cancer. There’s no need to gradually taper off.
Regarding diet, a more plant-based approach rich in fruits, vegetables, whole grains, and healthy fats, along with a limited intake of animal fats, processed meats, and refined carbs, has been shown to lead to better outcomes for prostate cancer survivors. While lean meats are a better choice than fatty options, emphasizing plant-based foods is still important. There’s some speculation about the benefits of green tea, but those claims remain unproven.
DEAR DR. ROACH: I’m a healthy 78-year-old male. Due to some symptoms (foamy urine and a previous eGFR of 55), my nephrologist has advised me to have a metabolic blood test. He instructed me not to fast before the test. I’ve always thought that fasting would provide more accurate results.
My research indicated that fasting gives a more accurate reading, but not fasting supposedly wouldn’t affect creatinine levels. What should I do? Should I fast or not? — B.E.
ANSWER: It’s important to follow your nephrologist’s guidance. Non-fasting blood tests offer a snapshot of your body’s chemistry under typical conditions. You’re right that creatinine levels are generally stable despite dietary intake; however, heavy meat consumption may slightly elevate those levels.
It’s worth noting that fasting generally impacts blood sugar and lipid tests. Lipid tests are typically standardized for fasting states, while blood sugar evaluations need to be contextualized based on whether fasting occurred. Measuring blood sugar after consuming a known quantity of sugar is the most effective method for diagnosing diabetes.
