As a dietitian for people who have cystic fibrosis, I frequently hear these questions about food trends:

• Should I be eating gluten-free?
• Is sugar bad?
• What is clean eating?
• Should I pay the extra money for organic foods?
• Do I need to buy antibiotic-free meat?

All of these food trends mean something different for people with CF. I will try to answer some of those questions here.

Gluten-free Diets

Gluten -- which is a protein found in wheat, rye and barley -- is a big deal right now whether you have a gluten allergy (celiac disease) or not. Within the last 10 years, the number of gluten-free items at the grocery store and restaurants has multiplied. Previously, someone with celiac disease would have had to order foods from specialty companies because there was very little available at local supermarkets.

But, what about CF and a gluten-free diet? First, if you have both CF and celiac disease, you must follow a strict gluten-free diet to avoid damage to your small intestine. Second, the symptoms of celiac disease are similar to those who have CF but do not have a gluten allergy: abdominal pain, bloating, diarrhea, constipation and fatigue.

Before you eliminate a large group of foods from your diet, you should have a blood test to tell if you are allergic to a protein in gluten. If you do not have celiac disease, a gluten-free diet will not provide any health benefits.

There are some people who do not test positive for celiac disease but have similar symptoms and feel better when they restrict gluten. Because people with this gluten sensitivity also seem to have problems in their small intestine, researchers are focusing their current research on understanding this condition.

Sugar

Sugar does not cause diabetes, and avoiding sugar does not prevent diabetes. Sugar is a carbohydrate. Carbohydrates are the body's preferred energy source, so some sugar can be included in the diet of people with CF.

If you have diabetes and are eating foods that have a high sugar or carbohydrate content, it will be best if you have them as part of a meal. The other foods will “dilute” the carbohydrate load. For example, eating a sugary food by itself as a snack will cause a quick, large rise in blood sugar but having the same food in a meal with protein and fat will cause a slower, smaller rise.

Clean Eating

There is no official definition of what a clean diet is, but usually it refers to using minimally processed, whole foods (think eating a fresh apple versus an apple pie), and focusing on plant-based protein rather than animal protein.

But ... is a “non-clean” diet dirty or unhealthy? No. Honey from the comb can cause high blood sugar for people with diabetes just as easily as table sugar. A high-fat diet -- even though you are using organic, cold-pressed, extra virgin olive oil -- could be unhealthy for someone who does not need the extra calories. There are perfectly fine foods that could be part of a healthy diet that will not have a “clean” nutrition label, such as whole wheat bread, milk, tuna in a can and frozen vegetables. But some foods that claim to be “natural” and “clean” offer no special health benefit.

Organic Foods

Is organic food worth the extra money? Organic means the food was grown and processed without any synthetic fertilizers, synthetic pesticides or genetic modification. For meats, it means no antibiotics or growth hormones.

Studies have not shown any additional nutritional benefit offered by organic products. Organic products have been found to be as likely to cause illness as nonorganic products, but with organic products, you would probably have a lower exposure to potentially harmful ingredients (fertilizers and pesticides).

Antibiotic-free

Antibiotic residue in animal meat is banned by the U.S. Food and Drug Administration (FDA), so you are not eating antibiotics when you eat conventionally raised meat.

The goal of antibiotic-free meats is to limit antibiotic resistance among the bacteria in animals, as overuse of antibiotics has led to the development of antibiotic-resistant bacteria in humans. Having said that, there are no “superbugs” in humans that came from animals treated with antibiotics.

Still, the FDA has asked meat producers to use antibiotics only to treat something - not as a routine preventive measure -- and to have a veterinarian manage their use.

I hope you have found this interesting and useful. If you have any questions, please submit them to ggarlow@partners.org, and I will try to answer them in another blog post.