Fructose (and its not just high fructose corn syrup...sucrose is 50% fructose, HFCS is 55% fructose) does indeed seem to be deleterious above and beyond just adding calories
I’ve heard this claim often, and I appreciate your pointing out that sucrose is hardly better than HCFS.
What evidence is there for human health being improved by avoiding fructose (on the margin, not absolutely)? Isn’t it pretty weak? There are plenty of high-dose rat studies, but I don’t typically adjust my lifestyle every time a rat study shows something.
I think you may want to look at the fact that glucose can enter the blood stream and be used as glucose by muscle/brain/other tissues. Fructose does not leave the liver as glucose does but is trapped there. It is used by the liver to make glycogen and when glycogen is not needed it is used to make triglyeride fats in LDL cholesterol packets. Much, much more of the fructose goes into storage molecules then into immediate energy use by tissues compared to glucose.
Fructose also creates problems in the gut.
Sucrose is less soluble and so less can be used for sweeting drinks etc. More fructose can be used with HFCS.
That sounds reasonable. I’ve heard that glycogen is stored in proximity to muscle for fuel, and if you do a lot of work (e.g. a long walk) any available glycogen is used to replenish those stores. That is, the only time it’s reasonable to gorge on carbs (which in practice always means some fructose) is when you’ve somewhat depleted your muscle glycogen.
There are human studies as well on fructose showing that it causes problems, one of which is obesity (but other problems like liver scarring are more serious). I am not going to include citations but if you go to ScienceDaily news and search on fructose you will find the latest research.
I’ve heard this claim often, and I appreciate your pointing out that sucrose is hardly better than HCFS.
What evidence is there for human health being improved by avoiding fructose (on the margin, not absolutely)? Isn’t it pretty weak? There are plenty of high-dose rat studies, but I don’t typically adjust my lifestyle every time a rat study shows something.
I think you may want to look at the fact that glucose can enter the blood stream and be used as glucose by muscle/brain/other tissues. Fructose does not leave the liver as glucose does but is trapped there. It is used by the liver to make glycogen and when glycogen is not needed it is used to make triglyeride fats in LDL cholesterol packets. Much, much more of the fructose goes into storage molecules then into immediate energy use by tissues compared to glucose.
Fructose also creates problems in the gut.
Sucrose is less soluble and so less can be used for sweeting drinks etc. More fructose can be used with HFCS.
That sounds reasonable. I’ve heard that glycogen is stored in proximity to muscle for fuel, and if you do a lot of work (e.g. a long walk) any available glycogen is used to replenish those stores. That is, the only time it’s reasonable to gorge on carbs (which in practice always means some fructose) is when you’ve somewhat depleted your muscle glycogen.
There are human studies as well on fructose showing that it causes problems, one of which is obesity (but other problems like liver scarring are more serious). I am not going to include citations but if you go to ScienceDaily news and search on fructose you will find the latest research.