At first glance, the phrase “intellectual flexibility” brings to mind someone who has no principles, but I’d like to propose that intellectual flexibility is a good thing. If you’re passionate about food, health, and nutrition science, as I am, being intellectually inflexible can be a big liability.

The dawn of nutrition science

Nutrition is a young science. Even simple concepts, such as vitamins and minerals, only gained wider understanding in the 20th century. More complex dietary puzzles still aren’t solved. We have some good ideas about how nutrition and health are connected, to be sure, but the fine details elude even the experts.

For example, we know that a plant-based diet pattern consistently is linked with lower risk of the chronic diseases that plague modern man. This includes heart disease, diabetes, stroke, hypertension, osteoarthritis, and some types of cancer. Plant-based refers to any dietary pattern that is based around eating plenty of fresh and minimally processed vegetables and fruit, legumes (beans and peas), nuts, seeds, and whole grains (brown bread doesn’t count), regardless of whether it contains modest amounts of animal foods.

The Mediterranean diet is an example of this type of eating pattern. The Okinawa diet is another example. Both of these dietary patterns are linked with excellent health, especially when compared with the processed food and meat-heavy fare typical of the American diet.

Accepting the evidence and new ideas

Although many nutrition experts agree that eating more plants is a good way to improve health, agreement begins to break down when we delve into specific dietary components. This is where the benefits of intellectual flexibility are most evident. I experienced this in my own life very recently.

I had written a newsletter about a comprehensive analysis of research on multivitamins and mortality. Previous observational research suggested multivitamins increased risk of death, and vitamin skeptics raised the alarm. This new study however, which included only controlled clinical trials—the gold standard of evidence—suggests the alarm is unwarranted. The study conclusion: taking multivitamins has no affect on risk of death due to any cause.

I wrote up the “take away” message, noting that it’s fine to take a multivitamin, it’s unlikely to harm health, but it’s not likely to help much either. End of story. Or so I thought. I received comments back from the medical editor, indicating that I had failed to mention that many people took vitamins “for energy.” I chuckled to myself and responded that vitamins don’t give people energy (unless they have a vitamin deficiency). If someone claims vitamins give them energy, it’s probably placebo effect.

My colleague pointed out a double-blind, placebo-controlled clinical trial, in which participants who received the multivitamin reported significantly greater reductions in anxiety and perceived stress compared with people who received the placebo. The vitamin recipients also rated themselves as less tired and better able to concentrate following treatment.

Maintaining my intellectual flexibility

What?! This flew in the face of everything I had ever believed about multivitamins as a harmless, yet ineffective way to alter how people actually feel. I quickly searched the medical literature, and confirmed that yes, vitamins can improve energy and feelings of well being.

One study found that participants receiving a mix of B vitamins, minerals, and vitamin C had significant improvements in mental and physical stamina, concentration, and alertness compared with the placebo group. Other placebo-controlled, blinded trials concurred with these findings.

My strongly held conviction that vitamins cannot objectively improve physical or mental well being was challenged, and I was forced to reexamine my beliefs. I concluded that I had been wrong. And I changed my opinion. That is intellectual flexibility: being open to new evidence, and the willingness to admit that previously held beliefs may be incorrect.

Are you (or your nutrition guru) intellectually inflexible?

This is just one example of intellectual flexibility, but there are many others I’ve experienced in my own life and work.  Unfortunately, many self-proclaimed nutrition experts are unwilling to walk the path of intellectual flexibility.

There are vitamin D experts, who refuse to acknowledge the possibility that high, though still normal, blood levels of vitamin D may increase the risk of some types of cancer. Paleo diet pushers who, despite strong evidence to the contrary, insist that legumes harm, rather than improve health. And Atkins’ diet proponents who deny that higher intakes of meat are linked with increased risk of heart disease and cancer.

Why take your advice from a nutrition guru who is dogmatic and inflexible, and who clings to opinions about nutrition and health that have been challenged with good evidence? Doing so is a recipe for making poor nutrition choices. When it comes to nutrition science, exercising your intellectual flexibility is an important part of the learning process.

What and where is gluten?

Gluten and related proteins are found in wheat, rye, barley, and possibly oats. The jury is still out on whether oat proteins, or proteins from other grains that contaminate oats are the main problem for those on a gluten free diet.

Thousands of foods contain these grains, which means that completely avoiding gluten is no small task. Pretty much, any processed food not specifically labeled gluten-free should be considered suspect.

Why the fear of gluten?

Celiac disease is a condition in which the immune system reacts to gluten and related proteins. For people with celiac disease (CD), there is no question that a 100% gluten free diet is absolutely necessary to maintain good health.

With CD, failure to avoid gluten can lead to very serious health problems, including thyroid disease, joint damage, neurological effects, alopecia (hair loss), skin rashes, intestinal cancer, and of course, damage to the intestinal tract. This can cause malabsorption of nutrients, leading to conditions such as osteoporosis and anemia.

In short, if you have celiac disease, avoiding gluten should be your number one diet priority.

Given that the number of people affected by celiac disease is on the rise, and the scary list of symptoms that can accompany it, it’s not surprising that fear of gluten is on the rise too. But there’s a catch.

Most of the people who have celiac disease (CD) don’t know it. And contrary to popular opinion, not everyone with CD has gastrointestinal symptoms. Only 35% of those with CD report experiencing diarrhea, for example.

Who is gluten free?

Numbers are hard to come by, but celiac disease experts believe that of the roughly 2 million Americans with CD, about 80% or 1.6 million don’t know they have it. Conversely, approximately 1.6 million people in the US without CD are believed to be following a gluten free diet.

Sadly, this means that many who need a gluten free diet aren’t on one, and many who are on a gluten free diet don’t need it. This is why I often refer to CD as the “simultaneously most under- and over-diagnosed” condition in the US.

For those who truly have CD, the time from onset of symptoms to diagnosis can be agonizingly long, up to 10 years for many adults. Yet, many people diagnose themselves with CD without any evidence that they have the condition.

Many of life’s common woes – fatigue, stress, anxiety, lack of energy, insomnia, weight gain – are attributed to gluten, despite a lack of evidence to support these claims.

Gluten intolerance without celiac disease

If you suspect you are sensitive to gluten, yet a blood test for celiac disease indicates you do not have the condition, you may have something called non-celiac gluten sensitivity. Undoubtedly, some people without celiac disease still don’t digest gluten very well. But as with celiac disease, it appears likely that many more people believe they have non-celiac gluten sensitivity than actually do.

As Dr. Stefano Guandalini, Director of the Celiac Disease Center at the University of Chicago recently told the NY Times, a gluten free diet, “is not a healthier diet for those who don’t need it,” and that many people are essentially “following a fad.” Dr. Guandalini hastened to add, “And that’s my biased opinion.”

Should you go gluten free?

You should consider going gluten free if you have reason to believe you have celiac disease. Why might you have CD?

If someone in your family has it, this increases the likelihood that you may develop the condition too. If you or anyone in your family has an autoimmune disease, especially type 1 diabetes, rheumatoid arthritis, autoimmune thyroid or liver disease, Addison’s disease, or Sjögren’s syndrome, this too can increase the odds of CD.

And to confirm your suspicions, ask your doctor for a blood test. There’s one caveat: Do not go gluten free before you get the blood test. Doing so can render the test completely inaccurate.

The gray area

What about non-celiac gluten intolerance? It is possible you’ll feel better without gluten in your diet, but for many people, feeling better results from cutting out junk food, not gluten. Going gluten free means far fewer baked goods, pretzels, chips, cookies, pies, and other nutrition bombs.

Simply paying better attention to what you put in your mouth, and eliminating most processed food will make anyone feel better, gain energy, and lose weight. You can accomplish this without nixing gluten… Not a bad idea, given that gluten free does not mean healthy. Many people end up eating a less-nutritious diet when cutting out gluten.

To avoid this pitfall, talk to a dietitian or doctor who specializes in gluten free diets to help you sort it out. With his or her help, you can do something called an elimination diet. Gluten can be one of those things you eliminate, and you can track your symptoms accordingly.

With professional help, you can apply the elimination approach to many potential dietary trouble spots, in a systematic fashion. You may just discover some other dietary culprit that is making you feel poorly. And given how difficult it is to completely avoid gluten, you’ll probably be glad to narrow down your issues to something else.

For everyone else?

Don’t give in to the fad.

As Dr. Alan Leichtner, MD, senior associate in medicine at Boston Children’s Hospital Division of Gastroenterology and Nutrition says, “There are no studies showing that the gluten-free diet has an impact on anything other than celiac disease. The medical data simply aren’t there.”