Re: speculation. Given that raw vegan with supplementation fails for
many people, I doubt that better or "higher brix" produce will
do the trick.

Most plant fooods contain secondary compounds designed to
discourage herbivores. This is even true for fruit, but to a lesser
degree. Speculation: higher nutrient levels are associated
with higher levels of nutritional inhibitors. The inhibitors
reduce bioavailability of nutrients.

Tom Billings