----- "Geoffrey Purcell" <[log in to unmask]> wrote: 
> 
> Oh, I agree the 90g a day figure was merely tentative, but few figures get touted online, just the general scientific concensus that fructose in fruits is fine because it's in small amounts, with corn-syrup being viewed as too high in fructose, and with almost all the studies focusing solely on corn-syrup as regards damage done by fructose. But , realistically speaking, for claims that fructose in fruit is harmful to be correct, there would have to be studies showing some massive liver damage the more fruit one ate in one's diet. 

You persist in implying, without evidence that the fructose in fruit, qua fructose, is somehow less pernicious than the fructose in HFCS. But there is simply no reason to believe this. You've provided no support other than vague hand-waving about bacteria and enzymes. Studies of the beneficial effects of fruits and vegetables do not typically track total fructose load, so it's difficult to make any clear inferences. Standard HFCS is 55% fructose. The sugar in apples is about 70% fructose (http://www.thepaleodiet.com/nutritional_tools/fruits_table.html). Granted, most people probably don't eat enough apples to achieve a very high net amount of fructose, but they may easily drink enough apple and orange juice to do so. And they may snack on grapes in large amounts. To say "fructose in fruits is fine because it's in small amounts" presupposes that people, in fact, consume small amounts of fruit or fruit juices. This may generally be true, but a more accurate statement would be, large intake of fructose *from any source* promotes NAFLD, metabolic syndrome, and increase uric acid. Fructose also suppresses leptin and increases ghrelin levels, which tends to promote appetite-energy imbalance. What we need is a clearer picture of how much is too much. Moreover, we need to consider the metabolic differences between people who already have metabolic syndrome and those who don't. The former may be able to tolerate little or no fructose at all. 

Ray Audette (welcome back, Ray!) makes the point in Neanderthin that fruits were only seasonally available to paleo people, and were much less sweet than their cultivated descendants. I think the recent science on fructose and NAFLD, leptin, etc., give solid support to his "handle with care" approach. But if you claim that whole fruits are paleo, and therefore perfectly harmless, you can be sure that at least some people will see this as a license to consume pints of organic fruit juice, and to snack on grapes by the pound. My point is that, apart from getting a few extra vitamins and some fiber, these people won't be appreciably better off than if they were drinking multiple HFCS-sweetened sodas a day. 

Todd Moody 
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