The grains - wheat, barley and rye - are increasingly on the DO NOT EAT list because they contain gluten. That's unwelcome news to a TOJ because grains taste good (like pancakes and beer), contain some important minerals, and have been a carbohydrate relied upon by athletes for years as an energy source. But things change.
For 1% of the population, gluten is a problem because it's the cause of celiac disease, a serious auto-immune disorder. However, in the past couple of years, many of the other 99% have come to believe they might have problems with gluten as well.
The Paleo guru Robb Wolf in The Paleo Solution, for example, recommends total elimination of grains from every one's diet, and offers some good scientific reasons. It seems that many people who do not have actual celiac disease do have sub-symptomatic inflammatory response. Grains may cause their bodies to react with an immune response as if something truly harmful has been introduced. Also, grains may disrupt digestion and degrade the lining of the gut.
It would be ironic indeed if after eating grains for 10,000 years, evidence emerges that they are actually poisonous. So much for the Staff of Life. At present, there is not irrefutable evidence that this is true. That said, some valid questions have been raised that warrant more investigation.
Meantime, more and more athletes are not waiting for science to catch up with real-life evidence. Active.com had an article about a tiny handful of world class athletes that have stopped eating grains and have watched their performances improve. For instance, the road biking Garmin-Cervélo Team won the team competition at The Tour de France while eating a diet with no grains. Word of their and others successes is spreading fast.
The reason these athletes are seeing positive results may be due to having more of the valuable nutrients in other foods make it through their digestive tracts and into their cells. The nutrients help them recover faster.
Going without grains still leaves plenty of tasty options, as shown below:
Sometimes to test the impact of foods on your health and fitness requires some really hard choices, like following the vegan regimen of someone like Brendan Brazier. This is much easier -- just stop eating grains and see if it makes a difference.