I find the idea that excessive sugar intake messes with all sorts of our systems entirely plausible - we definitely aren't designed to consume the quantities of sugar that we on average do consume; and especially not non-stop for years and decades.
Teasing out all the causal chains will be hard work, though. Metabolism is really complicated. Sugar increases levels of insulin; fructose kicks liver into overdrive; how does that excessive metabolic activity work out in remote parts of the body such as the brain?
Teasing out all the causal chains will be hard work, though. Metabolism is really complicated. Sugar increases levels of insulin; fructose kicks liver into overdrive; how does that excessive metabolic activity work out in remote parts of the body such as the brain?