What are the keys to health, quality of life?

DEAR DR. ROACH: I’m a male who is 71 years old, 5 feet 6 inches tall and weighs 138 pounds.

I play, on average, three softball games (left field) a week, as well as bike 25 miles and swim 1 mile per week.

My diet is mostly fruits and veggies, lean meat, fish, nuts and nonfat milk with a cup of coffee. Also, I have one or two glasses of red wine in the evening.

I feel good all the time, despite a few aches and pains at times, which seem to go away at the start of our ballgames.

I probably still can outrun 90 per cent of the people alive (especially our overweight Americans). This is not the norm. Why can’t it be?

ANSWER: Every day, I get letters from readers who tell me that if only I told everybody to eat a good diet, all their medical problems would go away. I get similar letters about exercise.

A few people tell me that it is stress management that is the key to good health.

In a sense, they all are right. Each of these is important. Not smoking is more important than all of those.

Unfortunately, I see people who have excellent health habits (they eat a good diet, exercise regularly, have strong relationships, manage stress, don’t smoke and drink modestly or not at all) who still get disease.

There is no doubt that these behaviours improve your chances of having the excellent health you have in your 70s (and I hope it lasts many more years). However, genes also have a role to play, and so does chance.

In medical school, reading about the diseases that can affect us, students often wonder how anyone survives into adulthood — there are so many different problems that can arise.

Everybody hopes to have the kind of results you have. One recent study showed that those who don’t smoke, exercise regularly, drink no more than moderately (if at all), maintain a healthy body weight and get adequate sleep have a dramatically lower risk of chronic disease.

Unfortunately, only 6 per cent of Americans do all of these behaviours.

DEAR DR. ROACH: How detrimental is it to consume one grapefruit, once a week, while on simvastatin? Is it dangerous?

ANSWER: Grapefruit juice reduces the level of an important enzyme (cytochrome P4503A4) that is crucial in the metabolism of many drugs, including simvastatin.

Taking 8 ounces of grapefruit juice (about half a grapefruit, though they vary) increases the blood level of the simvastatin. It’s like taking a higher dose of the medication.

This probably is not a good idea if you are already taking a very high amount of simvastatin (say, 80 mg, which is seldom prescribed now). Otherwise, the risk of damage to the liver or to muscle is small.

There is a theoretical increased benefit from a higher dose of statin for preventing heart disease or slowing progression of existing disease.

Is it dangerous? Probably not. There have been very few reports of serious adverse effects from the combination of statins and grapefruit juice, and I would say consuming a reasonable amount, such as half a grapefruit or 8 ounces of juice daily, probably is safe.

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.