I know some users here choose not to eat apples because of the "bags of sugar" label, but assuming I do choose to eat them, has anyone studied the different varieties for variation in sugar and carb content? There's a huge difference in taste between a red delicious (which I can't stand, way too sweet) and a tart pie apple like Cortland (which are wonderful and very much in season right now).
It seems like modern apple varieties have been bred to be as sweet as possible since the modern palate is phobic about anything with a sour taste. If anyone has a link where this has actually been measured, please post--and thanks!
My philosophy is if it grows on a tree and is in it's natural form, it's probably ok. If I get hung up on the minutia, it drives me crazy. Could a paleo person have eaten an apple? Would they? Good enough. That being said I prefer the tarter varieties, as I have lost my tolerance for very sweet things.
Sorry not to bring a definitive answer to your question, but I just wanted to add my experience with wild apples that go along with your observations.
I found a crabapple tree the other day while walking in the woods and was delighted by the idea of really gathering food and eating it. Those small apples were so sour that my tongue was burning after eating just a couple. It goes along with the idea that fruits in nature are probably not as addictive as today's varieties. I had to stop eating them, not because I had had enough, but because it actually started to physically hurt.
This was the best I could find. It seems that people rarely publish the sugar content of apple varieties. Most commercially available varieties seem to have similar sugar content. I think this is hard to judge by taste as sour flavours can mask sweetness. Gala apples taste much sweeter than braeburn even though this study suggests they have less sugar. It is also hard to standardise sugar content of fruit as it can vary due to climate, rainfall and time of harvest.
I would guess that generally the size of the apple will have more influence on the sugar content than the variety. If you eat apples eat the ones that taste best to you.
The following is from this paper, many of the apples tested are regional European apples: Sugar-, acid- and phenol contents in apple cultivars from organic and integrated fruit cultivation.
OBJECTIVE: This study was carried out to obtain data about the sugar-, acid- and phenol content of apple cultivars from organic and integrated fruit cultivation, with reference to their role in human health and especially for diet recommendations
Proportion of sugar components of integrated and organically grown cultivars.
CONCLUSION: Knowledge of the sugar content is very important for diabetic patients, owing to the assumption of general diet recommendations that 100 g fruit contain 12 g carbohydrates. This applies to most well-known cultivars like Golden Delicious or Gala, but not to most of the regional cultivars. For diabetics, it is necessary to know the carbohydrate content of food precisely, in order to adapt the amount of insulin to the ingestion. So, it is helpful to know the sugar content of each regional cultivar. Moreover, very high levels of phenolic compound in organically grown cultivars, and with it its importance for human health leads to the recommendation to eat regional fruits from organic fruit growing instead of those grown under integrated cultivation.
I would wager that the more sour/tart tasting varieties (granny smith comes to mind) would have relatively less sugar. Here is a link that has a PDF you can download that seems to be exactly what you are looking for: http://www.springerlink.com/content/w763735512l3q668/
If you're stressed over eating a measly apple because you're worried it might somehow destroy your delicate metabolism I would venture to say you're either afflicted with a very dangerous underlying physical health condition or alternatively you're suffering from a deluded mental state and are taking this Paleo stuff way too seriously.