When I was younger, I spent my time reading, seeing movies, or having dinner with my friends. Now, I'm shuttling my parents or myself to doctor's appointments, taking care of my young nieces, and tending to my home and garden. As baby boomers age, their lives and ours change -- but thankfully, so do the possibilities for investors to benefit.

Getting old isn't pretty
The 76 million Americans born between 1946 and 1964 are now aged between 46 and 64. Many of my friends and I are in this group, and our trips to the doctor aren't simple every-few-years checkups anymore. One friend of mine has had a knee replacement already. Another had a hysterectomy. Many of us must now work to regulate our blood pressure and cholesterol.

We're also frequently caring for parents with health issues of their own. My dad woke up one morning a few years ago to find most of his vision gone. Presto: Instant lifestyle change! My mom suddenly became the primary driver, with me pitching in when needed. My dad's vision loss meant that our family discovered a whole new swath of products, including software to vastly magnify computer screens and illuminated magnifiers for reading on the couch. My parents also own several devices to help them monitor my dad's diabetes at home, and both they and I own personal blood pressure monitors.

Investing in aging
As Boomers continue to age, demand for health-related products and services will only grow. Like my mom, many more people will begin using hearing aids in the years to come -- especially after a lifetime of loud concerts and cranked-up headphones. And if you know any hearing aid users, you know that each few years bring newer, better versions, driving upgrades for users and profits for manufacturers. Siemens (NYSE: SI) is just one company poised to benefit from this trend; more than a century old itself, the global conglomerate makes hearing aids and many other products.

Hearing isn't the only area in which boomers could use a little more help. Other notable fields that will benefit from an aging population include:

  • Medical devices, such as such as stents and replacement hips and knees. Stryker (NYSE: SYK) and Zimmer Holdings (NYSE: ZMH) rank among the companies operating in that arena, and they appear attractively valued. Years of government investigations have driven Stryker's P/E below its five-year average, but the company's finally clearing up those issues now. Zimmer's high-priced dental implants will probably get a boost as a recovering economy gives consumers more cash to spend on postponed medical needs.
  • Medications. If you're considering pharmaceutical companies for your portfolio, look for strong pipelines of potential blockbusters. My colleague Brian Orelli likes Merck's (NYSE: MRK) prospects in that department, now that the company has acquired Schering-Plough. Meanwhile, Bryan White likes Novartis' (NYSE: NVS) outlook, with its "stacked line-up of late-stage drugs in trial."
  • Health insurers such as UnitedHealth (NYSE: UNH) and WellPoint (NYSE: WLP) also stand to benefit, and not just from boomers. Health-care reforms will soon push millions of new customers under insurers' umbrella.

Lemonade from lemons
Growing old, or watching your parents do so, is no fun. Unhappy health surprises seem to lurk around every corner. But there are companies that work hard to make aging easier, and savvy investors can profit alongside them as they do. Rooting for your holdings gets even more meaningful when you know that they're helping your dad fight high blood pressure, or improving your mom's hearing.

Boomer-related developments, and the new technologies and companies appearing in any area of your life, are well worth watching. You never know -- some of them might end up being the greatest stocks of the next generation.

Longtime Fool contributor Selena Maranjian owns shares of Johnson & Johnson and Novartis. Stryker, UnitedHealth Group, and WellPoint are Motley Fool Inside Value picks. UnitedHealth Group is a Motley Fool Stock Advisor selection. Novartis is a Motley Fool Global Gains recommendation. Motley Fool Options has recommended buying calls on Johnson & Johnson, which is a Motley Fool Income Investor recommendation. The Fool owns shares of Stryker and UnitedHealth Group. Try any of our investing newsletter services free for 30 days. The Motley Fool is Fools writing for Fools.