Many of the purported health benefits of beer are based on the antioxidant prenylﬂavonoids present in the hops. In the ale style, the beer is generally hopped more than lagers, and therefore has about twice as much prenylﬂavonoid as lagers (see Table 2). These compounds do have some estrogenic traits (i.e., they can act like the hormone estrogen) which can be unhealthy in large quantities, however, the quantities in ales are generally accepted as safe (see the previous link). As for subjective health (i.e., how good people feel), beer intake in general has been shown to have a negative correlation to perceived health (i.e., the more beer people drink, the worse they feel). That study did not test against different types of beer, however, so we can't conclude anything specifically about real ales.
Another study concluded that low-alcohol real ales are particularly rich in antioxidant flavonoids and those flavonoids get are readily absorbed by the body. The study didn't, however, test against types of beer other than low-alcohol real ale.
I can't seem to find any studies that show any positive or negative health effects of carbonation
or consumption of live yeast (see edit below). I do speculate that the unfiltered nature of real ales would, at a minimum, provide some additional dietary fiber.
Edit: Since live ales are unfiltered, one consumes a greater amount of yeast when drinking them versus drinking another type of beer. Yeast is rich in healthy nutrients like thiamin and folic acid, however, it can also contribute to an increase in production of uric acid, which can contribute to gout. Alcohol also causes an increase in uric acid, though, and at a relatively higher level than is caused by yeast, so the uric acid contribution of yeast is likely negligible.
This book would probably have some good references, however, I do not have a copy.