If a gluten-free diet can help propel an athlete to the top of his or her sport, then does that mean it's for you? What about dairy-free or vegan eating?
With an increasing number of high profile athletes adopting less than mainstream eating habits, athletes and active individuals of all levels may be a little curious about pushing the dietary envelope for the sake of performance.
Let's take a closer look at the impact these changes can make on your performance and your lifestyle - for better or for worse.
A rapidly growing trend, gluten-free eating has also become popular for elite athletes, counting the likes of world No. 1 tennis player Novak Djokovic among its followers. Djokovic made headlines this year not only for having one of the most successful years in the history of the sport, but also for attributing at least part of his success to his new dietary regime.
So does that mean a gluten-free diet is a recipe for athletic success? Frankly, that depends. New research has demonstrated gluten can be an issue not only for those with fullblown celiac disease, an autoimmune disorder that causes damage to the small intestine, but also for another subset of the population who have a less severe, but still clinically significant sensitivity to gluten. These individuals can experience bloating, fatigue, headaches and other digestive ailments when they consume gluten, a protein found in wheat, barley and rye.
The problem, however, is that while celiac disease can be diagnosed through blood tests and small bowel biopsy, there is no agreedupon diagnostic tool for gluten sensitivity, aside from trial and error. (If you do suspect you have an intolerance to gluten, you should speak to your physician before you adopt a glutenfree diet.) That leaves the condition up to significant interpretation; some individuals, for example, are sensitive to wheat, but not all gluten, which means they could still enjoy other gluten-containing foods, such as spelt.
So, for all the trouble it can be to follow a gluten-or wheat-free diet, what is the benefit for an athlete? Those who are genuinely sensitive to gluten may find improvements in the health of their skin and digestive health, and many report less tangible changes to energy and mental clarity that could be placebo effects.
In terms of athletic performance, there is no evidence to suggest a gluten-free diet will make you faster or more efficient in your training or competition; in fact, at least one study showed that taking wheat gluten after a race actually improved recovery in a group of runners.
For those who are genuinely intolerant, the benefits of following a gluten-free diet would likely be derived through improvements to overall health, rather than athletic performance, per se. The costs of gluten-free eating, both financially, and in terms of the lifestyle change, however, can be significant, and need to be weighed carefully against any real or perceived benefits.
Dairy-free diets are on the rise, often partnered with a gluten-free diet. But will putting the kibosh on the cow give you a performance edge? Once again, that depends. While dairy is, without a doubt, a source of nutritional controversy, when it comes to sport, there is convincing evidence it can provide an edge. Whey protein, a component of the total protein in milk products, is particularly important for muscle recovery, especially when taken in the first 30 minutes after a workout. The crucial nutrient appears to be leucine, an amino acid found plentifully in milk that triggers an anabolic (muscle-building) state. More efficient than casein (another milk protein), or vegetable protein sources like soy or peanut butter, consuming milk protein in recovery seems to be particularly helpful for athletes training on back-to-back days, or twice in the same day.
Since dairy products can also play an important role in helping athletes to meet their higher-than-average protein needs, and also provide calcium and potassium for bone and muscle health, the bottom line is that dairy can give you a potential edge in both training and competition.
Along with the rise of gluten-free and dairy-free eating, a growing number of athletes, including hockey enforcer Georges Laraque, are choosing to go vegan, which means they avoid all animal products and by-products in their diet. While vegan eating can make meeting protein needs particularly difficult, it is certainly not impossible, but careful planning is necessary.
For female vegan athletes, however, iron deficiency can be an issue: iron is better absorbed in the heme form from animals than the non-heme form from plants, and females of child-bearing age have particularly high iron needs.
Since iron also plays a crucial role in endurance (it makes up part of the oxygen-transporting hemoglobin molecule in the bloodstream), vegan athletes, and women in particular, should be mindful of their iron status (as well as their vitamin B12 status, which is also important for red blood cell formation), and supplementation may be necessary.
Jennifer Sygo is a dietitian in private practice at Cleveland Clinic Canada (clevelandclinic.ca), which offers executive physicals, prevention and wellness counselling and personal health care management.