For most consumers, the choice between Coke and Pepsi is one made in a grocery store’s aisles. Investors face a similar choice between the two companies.

Oh, PepsiCo (NYSE:PEP) and Coca-Cola (NYSE:KO) might not be a perfect apples-to-apples comparison, but they’re close enough to make for an either/or situation when it comes time to make room for a new position in a stock portfolio.

Which one’s the top dog now? First things first.

Third-Quarter Results

PepsiCo — the purveyor of Pepsi-branded drinks and Frito-Lay snack foods — posted last quarter’s results on Wednesday morning. By and large, it was more of the same … which isn’t necessarily a good thing when “the same” is a slowly dwindling bottom line.

In the third quarter, PepsiCo earned $1.20 (operating) per share, which was shy of the year-ago figure of $1.25, but better than the anticipated bottom line of $1.16. More troubling is the 5% tumble in revenue, which is considerable for a food and beverage company. It’s the third straight quarter PepsiCo has watched its bottom line sink compared to year-ago results.

The problem? More than anything, currency fluctuation. Volume, or the total weight of all the food and rink it sold, was actually up 1.0% last quarter even though sales and profits faded.

Pepsi’s results follow on the heels of Coca-Cola’s numbers, which were brought to light Tuesday. Coca-Cola earned 51 cents per share, right in line with analysts’ expectations, and 3 cents stronger than the year-ago income of 48 cents. Revenue was up 1%, reaching $12.34 billion, though short of analysts’ forecasts of $12.4 billion. Total volume was up by 4%.

If one flaw could be noted for Coke’s numbers last quarter, it would be the drags created by a strong U.S. dollar (which dilutes overseas revenue when converted back into greenbacks), though headwinds in Asia and Europe also contributed.

Currency issues are a seemingly small detail at first glance. But when you take a step back and look at the bigger picture, the international aspect could end up making one of these names the smarter consumer-goods choice for investors.

One of These Things Is Not Like the Other

There’s no denying it: Coke is an all-American brand, and a staple for millions of U.S. consumers. Yet, about two-thirds of its business comes from foreign markets.

The dependence on international sales is so significant, in fact, that the company estimates the oddly strong dollar crimped total sales by 5% in Q3, and translated into 7% less income than would have been realized had the U.S. dollar not gone ballistic.

It gets worse for Coke, though.

While China’s growing consumer market was all the rage — and a key focal point for Coke’s expansion plans — in 2010 and 2011, the country is losing its consumerism fizz for non-Chinese companies. Coke’s sales volume in growth in China was only 3%, versus analyst expectations of 4.5% growth.

Part of the challenge might stem from the fact that nation-state is making a concerted effort to rekindle interest in home-grown brands. Coca-Cola already might be feeling that pressure above and beyond its currency woes, in the form of disappointing sales growth there in the third quarter.

That’s not to say PepsiCo is a purely American company, because it’s not. About half of its sales stem from foreign sources, and China — as was the case with Coke — is one of its key markets. In fact, Pepsi has replaced the No. 1-selling cola in China, and sales volume grew by about 5% there last quarter.

Shocked? Most people are, but it’s true. The leap to the top spot was largely achieved when PepsiCo simply sold its Chinese bottling operation to Tingyi and Asahi (major bottlers in that geographic market), then got out of the way to let Tingyi and Asahi do their thing. One also has to wonder if the country’s renewed push to “buy local” also includes local bottlers, even if they’re selling American brand names. It certainly seems like that could be the case.

Simultaneously, emerging markets like Latin America are just as meaningful growth spots. Indeed, PepsiCo saw 11% growth in volume in the third quarter.

Bottom Line

In spite of the recent tapering of income, and despite the fact that Coke is the much more recognizable name, PepsiCo actually might be the better long-term holding now.

It seems to have finally found a winning formula in overseas markets, where Coca-Cola has generally led the way, and at least as of today, it’s also a winner in the dividend pageant, yielding 3.1% to KO’s 2.7%.

Perhaps its Coke’s sheer dominance that makes it so vulnerable to Pepsi now. In the same vein as Avis’ (NASDAQ:CAR) slogan, “We’re #2, so we try harder,” it looks like Pepsi has made a point of doing things differently with its bottlers all over the world … and it works. While being entrenched with consumers, retailers and bottlers has kept Coke well-shielded on most fronts, it also might have meant Coke lacked flexibility.

PepsiCo looks to be using that to its advantage now.

As of this writing, James Brumley did not hold a position in any of the aforementioned securities.