While I don't disagree with the argument from a evolutionary standpoint, it seems the article is assuming we were healthier prior to the agricultural revolution due to our lack of consumption of wheat, which I do not believe is true. I don't have any authority in this field but what of the possibility that wheat is a double edged sword which provides many nutritional benefits to live longer lives but also is a poison that will kill us in the end.
An example of this would be the chemicals we put in our drinking water. There are studies that show that the chemicals we put in our drinking water cause cancer. My Water Treatment professor fully admitted this as well. But, the reason we still use these chemicals is because they effectively kill other waterborne diseases along with us. So, more or less, it comes down to the choice whether you want to die at age 40 from a waterborne disease or 80 from the chemicals that kill that waterborne disease.
I wonder if wheat works in a similar fashion. It helped allowed us to double or even triple our life expectancy but will help kill us in the end. I am also making the assumption that grain, especially wheat, helped extend our life expectancies, which may not be fully true, but its tough to ignore the health benefits of wheat.
http://www.organicfacts.net/nutritio...nd-barley.html
http://nutrition.suite101.com/articl..._of_wheat_germ