Source: Apple.

With a steady stream of articles already purportedly leaking details of Apple's (NASDAQ:AAPL) iPhone 7, long gone are the days of total secrecy in Apple's product pipeline.

However, investors should rest assured that Apple probably has more in the works than the reports might suggest. In a recent example, a comment from Apple CEO Tim Cook hints that the tech giant might have a medical-themed product in the works beyond the Apple Watch it sells today.

Cook throws a curveball
Over the past few weeks, Cook embarked on his usual press tour to promote the latest member of Apple's increasingly convoluted product line -- the iPad Pro. However, during an interview with the U.K.'s The Telegraph, Cook diverted from his usual script in an interesting, and slightly confounding, way.

When asked whether Apple ever planned to submit the Apple Watch for FDA approval, Cook responded:

We don't want to put the watch through the Food and Drug Administration process. I wouldn't mind putting something adjacent to the watch through it, but not the watch. ... But you can begin to envision other things that might be adjacent to it -- maybe an app, maybe something else. 

Even as its supply chain grows beyond its control, Apple makes every effort to keep its long-term product roadmap as secret as possible. However, this is the first time I've seen in my years of covering Apple that the company has alluded to additional possible medical products. This could be reading too much into Cook's statements, and it's worth noting that Apple explores lots of ideas that never manifest into real-life products -- just look at its patent filings. However, considering healthcare is one of the most obvious long-term growth markets in the decades ahead, and one ripe for meaningful disruption, the idea that Apple could be quietly devising some kind of additional health offering isn't as crazy as it seems at first glance.

The case for moving deeper into healthcare
According to the U.N., the global population of people aged 60 or older will increase from 841 million in 2013 to over 2 billion by 2050. 

Source: Deloitte.  

Moreover, the U.S. healthcare market offers the massive scale that Apple will need to target for future new product opportunities, much like the opportunity it's exploring with Project Titan in the automotive market. The U.S. alone spent $3.8 trillion on healthcare last year, although getting a more specific sense of Apple's potential market opportunity remains elusive, since we have no idea what type of product the tech giant might have in mind. At the same time, several other additional reasons support the idea that Apple might move deeper into the healthcare market with future products.

In terms of Apple's long-term product ambitions, its software releases can provide useful signals about its future hardware ambitions, which matters immensely, as Apple has always derived the bulk of its sales and profits from hardware sales. iTunes, iOS, HealthKit, CarPlay, and HomeKit either preceded their hardware counterparts or have become public while Apple is probably developing hardware products for that software, HomeKit and CarPlay especially. Investors would do well to watch this trait closely as a marker for future hardware offerings from Apple.

Of course, extrapolating the future based on the past comes with risks, although Apple's long record of launching software before hardware increases the odds of seeing something down the road. Only time will tell whether this rumor amounts to anything more substantial, but investors should monitor this possible big-ticket Apple storyline in the months to come.

Andrew Tonner owns shares of Apple. The Motley Fool owns shares of and recommends Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.