Dear Dr. Roach: Several months ago, you had an article in the paper about an 82-year-old man who had a constipation problem. You mentioned a couple of medications to take. I am an 82-year-old man, and just shortly after that article I became constipated for a couple of days. My wife told me to take ex-lax; I took it for two or three days, and it worked. Three days later, I had it again, so I took another ex-lax or two, and it worked again.
I was sitting in my recliner a couple of days later when I remembered when I was in my late teens and had the same problem. My mother told me to eat some prunes — wow, does that work. Wouldn’t eating prunes be more healthy than taking drugs? My wife and I have been eating three or four prunes every evening since then, and I have had no problem. We read that eating prunes every day also makes our bones stronger. Is this really true, and how many should a person eat daily?
Some over-the-counter constipation drugs used to contain phenolphthalein, which is not safe for long-term use. Occasional use of senna or docusate (the active ingredients in most OTC brands) is fine.
Prunes are a very effective treatment for constipation for many people. They are a fruit, but being dried, are higher in sugar than many others. Three to four prunes a day seems reasonable to me, and is effective for many people to treat constipation.
A recent review of studies on the effects of prune eating on bone mineral density suggested that there is some benefit. However, the studies were neither consistent nor of high-enough quality that I would recommend prunes solely for their purported benefit on bones. Moreover, most of the studies used about 100 grams of prunes per day: 10-12 average-size prunes. This is a large sugar load (less than a typical soft drink, however), and it also might cause some abdominal distention, especially if a person started out eating 10-12 prunes a day; it's smarter to increase fibre intake gradually.
Dear Dr. Roach: I have heard that endurance athletes may be at increased risk for Type 2 diabetes. What is the evidence behind this, and what do you recommend to prevent it?
A small study and some anecdotal evidence have shown that even endurance athletes are not immune to developing Type 2 diabetes. People often think of Type 2 diabetes as a condition related to obesity and inactivity, but many people with Type 2 diabetes are of normal weight, and indeed exercise is not a guaranteed protection against developing diabetes. It is possible that some of the apparent link may be due to people who know themselves to be at risk for diabetes due to family history taking up exercise.
In fact, large studies have clearly shown that regular exercise significantly, dramatically reduces the rate of diabetes, even if it doesn't eliminate it. However, many of the nutrition products sold to endurance athletes are very high in sugar. One rule of thumb is that it's not possible to outexercise a poor diet. You can take in far more grams of sugar and far more calories than you can burn off, so prevention of diabetes ideally includes both exercise and reducing simple sugars and processed carbohydrates (starches, which are rapidly converted to sugar). That definitely includes fruit juices and many sports drinks, some of which are no better than carbonated sodas. Even elite-level athletes should be careful of their sugar intake, as simple sugars are hidden in many foods.
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.