(In 2011, Novak Djokovic owned the world of tennis. On the eve of the Wimbledon championship, we look back at his diet claims.)
By Dr. Larry Chiaramonte
First of all, congratulations to Novak Djokovic for his victory over Rafael Nadal at Wimbledon. He has had a great year. But what is responsible for his fantastic 2011?
An article in the Wall St. Journal (echoed in People Magazine) says this: “Last year, Djokovic’s nutritionist discovered that Djokovic is allergic to the protein [gluten], which is found in common flours. Djokovic banished it from his diet and lost a few pounds. He says he now feels much better on court.”
I have worked with a company called NPD that surveyed over 50,000 people in the US several times and found that about twenty percent think they are allergic to a food. While the most recent study shows a higher incidence of food allergy prevalence than previous studies, it is nowhere near the levels of people who think they have them.
The WSJ journalist does a conscientious job of distinguishing gluten allergy from celiac disease, but does not explain the difference between gluten allergy and the kind of allergy that causes asthma, hay fever, eczema, or even most food allergies, called atopic allergy. While both are immunological, the mechanisms are different.
There is no mention of what Djokovic’s symptoms actually were, and while I have no doubt that he did feel better, it seems to me that a teaching moment was lost.
Gluten allergy is not the same as wheat allergy, although wheat does contain gluten. The article says nothing about symptoms we associate with regular, atopic, IgE food allergies such as hives, stomach upset, breathing problems, itching and so forth. There’s no question that with the ubiquity of wheat in the typical diet, the immune system could be in a state of almost perpetual challenge if wheat allergy were the problem.
As we say in our book, “In some people [gluten allergy] causes inflammatory changes in the gut stemming from immunological processes, although they are not related to IgE. However, the range of claims that are made about its widespread presence seems to us to be excessive. If you suspect you have a problem with gluten, eliminate it in all forms from your diet for two to four weeks and see if you feel better.”
The WSJ article focuses on energy levels and mental attitude, which we see time after time in the event of false perceptions about food allergy. As for weight loss or gain, for an athlete who trains year round, calorie intake would be the key factor and when you read the list of what the new Wimbledon champ eliminated from his diet–“pasta, pizza, beer, French bread, Corn Flakes, pretzels, empanadas, Mallomars and Twizzlers”–you won’t be surprised that he shaved off a bit of extra tissue and feels better.
David Levitsky, professor of nutrition and psychology at Cornell University, told the reporter, “It’s mostly mental energy you’re talking about, not energy supplied to muscle tissues… The other part of the story is, if you believe in a cause of your disorder, it becomes the cause…We see this in many different studies. If you believe it, you change your behavior in the direction of being cured.” So is it real gluten allergy or not? Based on the evidence here, the jury is out.
I take nothing from any champion athlete. Whatever they can do legally to enhance their performance is okay with me. When John McEnroe was playing, there was something called the “Hass Diet” which involved eating lots of avocados. Asked if he was on the Hass Diet, McEnroe said, “No, I’m on the Haagen-Dazs diet.” Who knows? If he had been eating more avocados and less ice cream he might have won more than the measly seven majors that he did win.
If not eating all those foods helped Djokovic lose some weight and increase his stamina, fine, and if it enhances his career so much the better. Millions of us probably consume too much of the things he has stopped eating, although most of them might fall under the heading “junk food” rather than “gluten-rich”. But in the absence of evidence of true allergies, I think this report just confuses the issues and true public health crisis that food allergy entails.