Diet drink sales are falling fast as more news becomes available about health risks associated with artificial sweeteners. A recent study by the American College of Cardiology indicated that consumption of diet soda can increase the risk of cardiovascular disease in older women. However, those same artificial sweeteners often show up in coffees and teas.

In 2013 overall soft-drink sales fell 3% by volume to the lowest levels since 1995, according to a report from Beverage Digest. That marks the ninth-straight year of decline and is more than double 2012's decline. 

Meanwhile, sales for Starbucks (SBUX 0.29%) have continued to grow since its initial public offering in the early 1990's. The company just announced its 17th consecutive quarter of above 5% comparable-sales growth. 

Now it's true that it isn't a direct apples-to-apples comparison when soft drink companies are put up against a retail establishment. However, the companies do have a great deal of similarities with one another. Their target audiences are not segmented by gender, age, or other demographics. They all specialize in caffeinated beverages. And while they are all very popular globally, none of them are truly staple requirements.

Health concerns over beverages only go so far. It's interesting to note that while health concerns have received the blame for the decline in sales of soft drinks, the concern is apparently not over caffeine, as 12 ounces of coffee from Starbucks can contain as much as five times as much caffeine as a soda.Survey data from the NPD group, which tracks trends in what Americans eat and drink, finds that 18- to 24-year-olds are turning to coffee, rather than caffeinated sodas, as their buzz of choice. Whatever the reason for the trend, it doesn't change the impact it has had on the earnings of the soft drink companies.

In its first-quarter results for fiscal 2014 PepsiCo (PEP 0.33%) reported revenue of $12.62 billion, 0.3% more than its revenue in the year-ago period. In its report, PepsiCo attributed its higher-than-expected revenue to higher sales from its Frito-Lay North America segment (in other words, not the beverage segment). In comparison with the same quarter of last year, PepsiCo's Frito-Lay North America segment grew revenue by 3% from $3.12 billion to $3.22 billion.

PepsiCo has turned to its long-lasting relationship with Taco Bell and Yum! Brands to improve its beverage sales. The second most popular drink at Taco Bell is the Pepsi product "Baja Blast," which until now was only available in-store. However, starting in May, PepsiCo will bottle and sell the drink at retail. 

Meanwhile, during the past five years, Coca-Cola's (KO -0.14%) net income jumped 26% from $6.8 billion to $8.6 billion. Between 2009 and 2013, Coca-Cola's revenue rose an impressive 51% from $31 billion to $46.9 billion.

Coca-Cola outperformed PepsiCo in 2013 by increasing global volume 2%, while PepsiCo posted 1% beverage volume growth. However, in the first quarter of 2014 the company's global soft-drink volume fell for the first time since 1999. The slide was attributed to a double-digit soda decline in Great Britain, where the company switched to smaller bottles but maintained pricing. North American sales only declined by 1%.

Dr Pepper Snapple Group (DPS) reported first-quarter 2014 adjusted earnings of $0.74 per share, beating analysts' estimates of $0.59 by 25.4%.

During the first quarter, Dr Pepper's net sales rose 1% year-over-year to $1.4 billion. Sales volume rose 1% year-over-year. Adjusted gross profit increased 4.5% to $832 million.

A 40% earnings increase year-over-year was attributed to strong margins and solid revenue from beverage concentrates and Latin America beverages, despite a recent soda tax instituted in Mexico. Dr Pepper Snapple primarily operates in North America, where the U.S. made up 88% of the top line last year. 

Would you like coffee with that?
In a quarter plagued with difficult weather which kept retail customers at bay, Starbucks still reported strong sales and revenue growth. Quarterly net income leaped 9.4% to $427 million, or $0.56 per share. The company also put up global comparable-sales growth of 6% and revenue of $3.9 billion.

Growth was particularly strong in the China and Asia Pacific regions, where "high traffic" in China drove the growth rate up to 7% for the quarter. (Also, notably, where the company was not plagued by multiple winter storms.) Starbucks also reported great results in the Europe, the Middle East, and Africa, or EMEA, region where sales rose by 6%.

Earnings per share grew to $0.56, up 17%, excluding a $0.03 non-routine gain in the prior year's second quarter related to the sale of the company's equity in its Mexico joint venture.

Starbucks is one of the most respected companies in the world, and its second-quarter earnings show why. The company is on a record-setting financial pace, but the stock has dropped 7% in 2014. It currently trades at around $71, with the potential to go much higher. Starbucks' stock is one of the most exciting investment opportunities around. If you haven't jumped on this stock already, now is the time to get in while the stock is low and take advantage of its continued successful run.