Keep Your Grains as Whole as Possible
Grains (and other seeds, including beans and pseudograins like quinoa) exist on a continuum between fully refined (bleached flours) and completely whole (berries and kernels). The more grains you eat towards the ‘whole’ end of the spectrum, the better off you’ll be.
Grains begin as large, relatively tough to digest kernels (often called berries, such as “wheat berries” or “rye berries”—they’re not really berries!) which resist digestion because of limited surface area. When we grind them into flour (including alternative flours, like quinoa or garbanzo bean flour), we exponentially increase the surface area which allows our body to break down the carbohydrates (and fat and protein) much faster. This increased rate of digestion is reflected through the increasing glycemic index of increasingly processed foods.
Whole grains are more complicated to digest also because the fiber they contain surrounds the digestible carbohydrates, forcing our digestive enzymes to work around it. When a grain is pulverized, the fiber is still present and will still impact rate of digestion to some extent, but the difference is kind of like trying to dig gold out of a hardened clump of dirt vs. smashing the dirt clod first and then grabbing the gold. Either way, the nutrient is there, but when we thoroughly grind a food first, it makes it much easier for our body to get “the good stuff” (i.e., calories—not as good as gold!).
When grains are whole, they also form a fiber-like substance called “resistant starch”—starch which is resistant to digestion. This starch passes through our digestive tract whole and is then consumed by our gut bacteria, forming the healthy short-chain fat butyric acid and helping to support a health colony of gut bugs.
For these reasons, the form of carbohydrate-rich food you eat is ultimately more important than exactly what carbohydrate-rich food you eat. Beans are generally healthier than grains, but whole grains are better for you than bean flour. Whole potatoes are better than sweet potato chips, and steel-cut oats are better than rolled oats. Rolled oats are still better than any flour-based product, regardless of the type of flour that went into it. You get the point—eat your grains as whole as possible, and your heart will thank you!