I come across those lines many times, and while I have a very nuanced position on
whole grain, I can also say that those arguments based on antinutrients such as phytate and lectin are, mostly, mechanistically arguments that don't hold much water when you look up the empirical data:
- The current coverage about phytic acid tends to be presented in a black-and-white view, without regards to its global impact to the body. I believe that phytic acid, in small and occasional quantities, actually forces the body to enhance its nutrient absorption through hormetic nutrient deprivation process. This is similar to the "paradoxical" effect of oxydation and free radicals on cardiovascular health. In brief, whatever we call them, antinutrients and antioxidants are both good and bad!
- When grains are properly soaked/sprouted, there is a natural degradation of lectins and phytates going on. As a result, the phytate content, after careful preparation and cooking, is dramatically lower than in its original raw form (mainstream Paleo community probably don't like this). This is similar to the discussion on the allegedly harmful effects of gluten or lactose - in that we tend to ignore the natural degradation processes of allegedly-harmful chemicals when food are not industrialized.
However, I am also aware of many factors that can increase grain's carbohydrate content. Eating grains without brans and germs (e.g., most grains) is a good way to dramatically increase blood sugar, as it deprives the need of naturally-slow digestive processes, and the sugar can now travel in the bloodstream at a much quicker rate. Whole grains that have been through a series of artificial selection could also be subject to higher concentration of carbohydrate than the wild varieties.
Also, cooking is yet another way one can increase grain's carbohydrate level. As such, I believe that fast boiling for half an hour or more, or grains with soft/chewy texture, should be a sign of concern - as one might start to disrupt the oral microflora, and find their grain sticking to their teeth and gums more frequently.
Incidentally, much of what's been said here about grains also apply to beans and legumes, the latter of which is invariably consumed by the centenarians in the Blue Zones. I don't know, phytic acid at work perhaps?
But going back to the link between insulin resistance and visual acuity. I guess what I'm encouraging, is to have some people - who are currently into carb cycling - to test their incidence of clear flashes while they are both in and out ketosis. This should eliminate the individual variabilities and might even eliminate intermittent fasting as a potential confounder of visual improvement.
