I'm sure you've heard it many times -- fruit juices, even unsweetened ones, are still just glasses of sugar, and you might as well be drinking a soda or Tang (remember that?). According to nutritiondata.com, a cup of orange juice contains 21g sugars. They don't "itemize" in the OJ entry, but if we look at the ratios oranges we can calculate that of those 21g, roughly 11 g are sucrose, 4.5 g are glucose and 5.5 g are fructose. Thus for each cup (8 oz) of OJ, you get around 11g of the dastardly fructose poison. This is roughly the same as you would get in the same amount (small can!) of orange soda.
Certainly in LC circles, giving kids juice is seen as tantamount to giving them a cup and unlimited refills at a Coke dispenser. Personally, I'm not a big fan of juice for those with weight issues, because I do believe there's much to be said about the fiber and act of chewing and other stuff that comes along with eating the whole fruit with the skin where applicable. Many of us do not seem to sense liquid calories very well. Also, this issue is muddied with "juice drinks" -- some with like 10% fruit juice and the rest is flavored sugar water.
Are juices just as culpable as sodas for trends in diseases of metabolic mahem? Perhaps it's time to stop demonizing juices and treating them all the same. Because below is just the first page of a Google Scholar search on OJ and diabetes produces some positive sounding results. (BTW, those links down the right are to the free full texts. These are often different from the direct links to the journal where they may be hidden behind a paywall. For this reason I always do a Google Scholar search on any PubMed link that doesn't offer free full text, and quite often you will find it hosted elsewhere.)
Fortification of orange juice with vitamin D: a novel approach for enhancing vitamin D nutritional health
Maybe, just maybe, there's something to all the other stuff that comes with the fructose in OJ that's worth considering ... even if we have to do so "despite" the fructose. Or maybe fructose isn't the issue after all, it's just the delivery method and ridiculous doses for the heavy beverage drinkers that's the problem. I haven't read all of the above and the last one there makes the case for fruit over fruit juice. That most certainly makes a packaging case!
What prompted this post was a study cited by a review paper blogblog mentioned in the discussion of starch vs. sugar. I'm not all that impressed with that paper because the focus seems to be comparing whole starches with refined sugars, a comparison that's not really fair. As I mentioned in a comment, I decided to search the doc on "fruit" and only had a few hits. The one referring to whole fruit was positive:
In a study of 38 moderately hypercholesterolemic free-living men by Turley et al. , low-GI carbohydrates were increased by the use of grains, vegetable, legumes and fruit. This increased carbohydrate consumption reduced LDL and the LDL/HDL ratio with minor changes in HDL and triglycerides.
The others seemed to all reference fruit juices, and one "hit" on fruit landed me at cite 106: Surrogate Markers of Insulin Resistance Are Associated with Consumption of Sugar-Sweetened Drinks and Fruit Juice in Middle and Older-Aged Adults. Here's what the review paper had to say about that study:
"To determine the association between surrogate markers of insulin resistance (fasting insulin, fasting glucose, homeostatic model assessment of insulin resistance (HOMA-IR), and the insulin sensitivity index (ISI0.120)) and SSB consumption, Yoshida et al.  used data from 2500 subjects with an average age of 54 years from the Framingham Offspring Study. 53% of the study population consumed SSB’s and did this with an average of two servings per week. After adjustment for potential confounding variables, the frequency of SSB intake was positively associated with fasting insulin. The associations between the frequency of SSB consumption and fasting plasma insulin and HOMA-IR remained statistically significant after further adjustment for dietary glycemic index, fruit intake, or vegetable intake. No significant associations were found between SSB intake and fasting glucose or ISI0.120. In this study, the HOMA-IR largely reflected fasting insulin concentrations. Both insulin resistance and β-cell dysfunction precede type 2 DM, and thus increased consumption of calorically sweetened beverages containing rapidly absorbable simple sugars may contribute to an increased risk of type 2 DM ."
I think the conclusion, despite the wishy-washy "may contribute" is still not warranted by that study and findings. Indeed I believe the title of that study is outright misleading. Yes, there are associations, but as you'll see below, the association is "bad" for SSB's but "good" for fruit juices. Here are the findings from the study itself:
Sugar-sweetened drink consumption was positively associated with fasting insulin (none vs. ≥2 servings/d, 188 vs. 206 pmol/L, P-trend <0.001) after adjusting for potential confounders. Sugar-sweetened drink consumption was not associated with fasting glucose or ISI0,120.
Fruit juice consumption was inversely associated with fasting glucose (none vs. ≥2 servings/d, 5.28 vs. 5.18 mmol/L, P-trend = 0.006), but not with fasting insulin (none vs. ≥2 servings/d, 200 vs. 188 pmol/L, P-trend = 0.37) or ISI0,120 (none vs. ≥2 servings/d, 26.0 vs. 27.0, P-trend = 0.19) in multivariate models.
So SSB's are associated with slightly increased fasting insulin but not glucose, while fruit juice associated with slightly decreased glucose but not fasting insulin. The tabulated data with different models is instructive. I do believe that the review characterizing the study group as 53% consuming more than 2 SSB's per week is also misleading. It's true, but it exaggerates the SSB consumption. I've crunched down Table 2 below (took out the diet soda data), and note that the second models are those corrected for confounders. Here is the data:
So less than 10% of the study subjects consumed a full SSB or more daily, and only 3.8% consumed 2 or more per day. BTW -- weren't we talking how there must be some uber beverage drinkers out there skewing the numbers?! So for SSB's, there was a difference in fasting insulin from 188.1 pmol/L for non-drinkers to 206.1 pmol/L for 2+/day drinkers. That hardly seems significant to me, and further, although it's not significant, there is a slight decrease in fasting glucose. It would seem that whatever the nominal "hyperinsulinemia", there's no hepatic IR going on. The 18 point insulin is less than a 10% increase over non-consumers
Now look at the juicers. There are certainly more of them! Only 12% drink no juice at all, 48% drink less than one serving daily, 31% have one-to-two servings daily, and 9% have two or more servings per day. Among these there was no stat.sig. association with insulin, but the trend was for an inverse relationship! In the corrected model, fasting insulin went from 199 pmol/L for non-drinkers to 184.6 pmol/L for the 2+ daily consumers. Meanwhile there was an inverse association with FBG, 5.28 mmol/L to 5.18 mmol/L. Granted, this is also not clinically significant (from 95 to 93.2 mg/dL) but there certainly isn't any hepatic insulin resistance going on here.
The subjects were from the Framingham Offspring study, around 54 yo, average BMI for all around 27. Note to Gary Taubes and Robert Lustig! Between non-consumers of SSB's there was a statistically significant difference in BMI in favor of consumers, though that's likely an artifact of that group containing more men. Maybe that's why they're also more active? Not significantly by the numbers, but statistically (P<0.001), again in favor of the consumers who were more active! Imagine that ....