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Old 06-14-2004, 02:57 PM   #1
Brian Hand
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This document

http://www.nal.usda.gov/fnic/foodcom...her/herr48.pdf

has a database of sugar breakdowns, including fructose content. This will help identify fruits low in fructose. Fructose has a low GI, but has to wait on the liver to be broken down into monosaccarides. If I understand correctly, this backlog can foul up insulin levels. Also, it competes with fat metabolism in the liver, and thus can lead to high triglycerides.

Sneak peek, the lowest ones are
apricots (8%), nectarines (13%), peaches (15%), bananas (17%), pineapple (18%), grapefruit (25%), cantaloupe (21%), plums (24%), and oranges (28%);

the high ones are pears (61%), apples (57%), raisins (52%), blueberries (49%), papaya (46%), strawberries (44%), cherries (42%), grapes (42%), kiwi (42%), dried figs (39%), and watermelon (37%).

Still not sure how much fructose is too much, but at least this information helps choose lower fructose fruits.
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Old 06-16-2004, 12:06 PM   #2
Sebastian
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Damnit, I really like raisins and eat alot of blueberries and strawberries and apples. *mutter*
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Old 06-16-2004, 03:14 PM   #3
Patrick Walsh
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yeah, apples and peanut butter are one of my favorite snacks.
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Old 06-17-2004, 04:49 AM   #4
Sebastian
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Of course, you have to remember there are other things at play here rather than just the fructose content of these fruits and berries. I know blueberries in particular have many other nutrients, anti-oxidants, etc. which are quite beneficial. I believe a wide variety of fruits, vegetables, and meats is the way to go, nutrition wise.
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Old 06-17-2004, 09:20 AM   #5
Brian Hand
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Keep in mind that many of the fruits listed are fairly low calorie. For example 3/4 cup of blueberries is only 50 calories and so only about 6 grams of fructose. Also keep in mind that the GI of some of the low fructose fruits is high.

Again I don't know how much fructose is too much, I wish I did. I figure if I can eat less, I will. I have just been using this to help make decisions at the grocery store. For example, I like apricots, nectarines, peaches, plums, apples and pears about equally, I don't care which one I pack for lunch; so I'll just buy the apples and pears less often now.
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Old 06-17-2004, 02:18 PM   #6
Paul M
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I kinda doubt that by eating whole foods like fruits that you'll ever really have problems. The big problem comes in when you're eating high fructose corn syrup. 1 can of Coke has something like 40-42 grams of sugar - almost all of it in the form of high fructose corn syrup. To put it in perspective, that's the amount of fructose you'd get from eating over 5 cups of blueberries. And many people drink 5-10 soft drinks per day. That level of fructose intake could never be reached on real food, I don't think. Even eating 6-8 servings of fruit in a day, you'd only reach 1 can of Coke's worth of fructose if you ate the higher fructose containing fruits like blueberries. And if you're following something like the Zone and getting more variety in your carb sources, you probably won't even eat 6-8 servings of fruit in a day.

I think the vitamin/mineral/antioxidant/fiber/etc contents of fruit probably outweigh the fact that you'd be getting fructose from them.

-Paul
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Old 06-21-2004, 04:41 PM   #7
Brian Hand
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I redid the calculations based on total fructose, which includes half the sucrose. Changes the picture a little...

Pineapple 31%
Apricots 35%
Bananas 38%
Apricots, Dried 40%
Cherries, sweet 43%
Figs, Dried 44%
Plum 44%
Grapes, American46%
Grapefruit 47%
Peaches 47%
Kiwi 47%
Nectarines 49%
Blueberries 51%
Oranges 52%
Cantaloupe 52%
Raisins 52%
Strawberries 53%
Mango 53%
Watermelon 57%
Papaya 61%
Pears 70%
Apples 70%

Based on this article:
http://www.mercola.com/2001/dec/12/syndrome_x.htm
which references a study at UMN where 17% of total energy came from fructose, and led to triglyceride problems, I think you can get into trouble with fruit on the Zone, isocaloric, athlete's Zone, etc.
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Old 06-21-2004, 09:10 PM   #8
Mark Roughton
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Brian, some of the items at the top of your list have a really high glycemic index (pineapples and bananas especially). I guess the fructose content and the GI aren't related, because watermelon has just about the highest GI and it falls a lot closer to the bottom of your list. I'm wondering, which do you think is more important, the GI or the fructose content? (I thought the higher GI fruits were the ones to avoid because of the insulin spike.)

If this list is saying it's OK to eat more pineapple, I can live with that...
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Old 06-21-2004, 09:17 PM   #9
Paul M
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Brian,

I just read over the article from the U. Minnesota people. You can download it here:

http://www.ajcn.org/cgi/content/full/72/5/1128?maxtoshow=&HITS=10&hits=10&RESULT FORMAT=&searchid=1087876812084_19168&stored_search =&FIRSTINDEX=0&sortspec=releva nce&volume=72&firstpage=1128&journalcode=ajcn


I have a few problems with the study, which makes me question the validity of the results. First off, if you look at Table 3, its missing the information at Day 0. While they give the initial blood lipid values for the entire group (split by age) in Table 1, they should've given the information for the initial values of the test groups. Its clear that the higher fructose group has higher blood tryglycerides than the higher glucose value from Table 3. What's not clear is if that difference existed before the diet. In fact, at the end of the study (day 42), both groups actually have lower their tryglyceride levels than on day 7.

The other problem that I have is that they didn't spend any time on any sort of control diet. During the study, the diets that the subjects ate could vary from their regular diets. The resulting changes in blood lipid levels from either new diet would interfere with the results.

That kind of missing information makes it hard to know what the validity of the results are. With only 12 men in the study (the paper found no difference in the women in the study) the possibility of large errors from the small numbers is high. Personally, if I were the referee on this paper, I'd have only accepted it on the condition that they add more complete data.

Finally, I still think that getting 17% of your calories from fructose is hard, unless fruit is your only carb. And most of the other studies that show that fructose raises tryglycerides have been in rat studies where the rats get over 50% of their calories from fructose.

-Paul
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Old 06-22-2004, 04:43 AM   #10
Brian Hand
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Paul, thank you very much for finding that study. All the points you make are well taken! Reviewing the study certainly sheds light on the results, and in this case raises more questions than answers.

Mark, in light of Paul's remarks, I don't think there's much cause for concern if you're not getting all your carbs from fruit. The relationship between high GI and low fructose is no coincidence - the fructose has to be converted by the liver and thus shows up slowly as glucose in the blood.

Right now I'm eating most of my carbs from fruit. I'll probably make a few minor changes. I'll eat bananas or pineapple after workouts; I'll avoid apples and pears, which I used to eat a lot of, just because they are way up on the list; and I'll replace some of the fruit with other starches, hopefully low GI, probably oats or rice, squash, yams, and potatoes.

Paul, thanks again for doing my homework for me!
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