July 14, 2014 at 1:00 am

Which diet is the right diet?

Dear Dr. Roach: I am taking Zetia and niacin for extremely high cholesterol and triglycerides. Exactly what type of diet should I be on to lower my cholesterol and triglycerides? Many of the processed (cheese, ice cream, cookies, etc.) fat-free, cholesterol-free foods are high in sugar. Should I be on the South Beach Diet or a strictly vegetarian diet? How many calories, carbohydrates and fat grams should I consume daily to lose weight? I’m a 5­feet-4-inch-tall, 160 pound female. When I was on the Atkins diet for more than 20 years, I was always slim and had no health problems.

J.D.

Dear J.D.: You are asking how to lower cholesterol, but I think what you really want to know is what diet reduces risk of heart disease. The right question is: What diet should you be on that will help you be healthier in the long term? All of the diets you mention have their strengths and weaknesses. Almost everyone agrees that avoiding sugar and processed grains is a key factor in reducing heart disease risk, but, despite decades of research and controversy, there isn’t agreement on the best diet for overall health.

I think it’s possible to take some wisdom from all the diets you mention, and to avoid some of their potential pitfalls. Both the Atkins and South Beach plans avoid simple sugars and excess carbohydrates, and I would emphasize that red meat and saturated fats should be kept at reasonable levels. A vegetarian diet emphasizes vegetables and fruits, but some people will gain weight on this diet, especially if they aren’t careful to choose good sources of protein and healthy fat, or choose refined carbohydrate sources like the cookies you mention.

I’ve often recommended the Mediterranean diet, since there is high-quality evidence it reduces heart disease risk. This diet calls for lots of vegetables and fruits, lean proteins such as fish, healthy fat such as from olive oil and nuts, and whole grains.

The medications you’re taking, ezetimibe (Zetia) and niacin, lower cholesterol, but it isn’t cer­tain either of them really cuts risk of heart disease. The statin class of drugs is best shown to reduce heart disease risk in people of above-average risk.

Dr. Roach Writes: Many people have written about treatment for obstructive sleep apnea. I recommended CPAP machines and singing. I haven’t discussed oral appliances, which either move the jaw or the ton­gue to change the back of the throat anatomy, letting the airway to stay open during sleep. Only a few studies have been done, but these suggest the oral appliances are near­ly as effective as CPAP for people with mild or moderate OSA. Peo­ple with severe OSA probably sh­o­uld use CPAP, since it’s more effective.

They are certainly an option for people who can’t tolerate CPAP.

Email questions to ToYourGoodHealth@med.cornell.edu.