It’s safe to say that no one will live forever. And yet many of us are always on the lookout for anything that will stave off death just a little bit longer, while Silicon Valley talks about the potential for new technologies to “cure” aging. That’s according to Dr. Sandro Galea, the Robert A. Knox Professor and Dean of Boston University’s School of Public Health.

What’s more, he says, we have a medical system where the ultimate goal is often to extend life as long as possible, even if those extra days come with the trade off of quantity over quality. Galea believes some of the U.S. health spending going toward extending the lives of older Americans would be better put to use investing in social, economic, and environmental infrastructure advances that could improve overall quality of life.

Speaking at Fortune’s second annual Brainstorm Health conference in San Diego on Wednesday, Galea said no amount of technological advancement will change the fact that there is a natural limit in terms of life expectancy and recent research suggests that humans will never live much longer than 115 years. In other words, no one is going to live forever.

“We actually want to live a long and healthy life until we die,” Galea said.

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During a talk titled “Dying Healthy,” Galea noted that at least 95% of the more than $3 trillion the U.S. spends on health care each year is directed toward treating diseases, with the rest going toward disease prevention. “How many of you would rather have a drug that effectively treats your Alzheimer’s, vs. not getting Alzheimer’s at all?” Galea asked the audience at Brainstorm Health.

While many new treatments exist that can help prolong your life, Galea said, such extensions are often only for a limited amount of time. As an example, he cited cancer treatment, where less than 20% of new cancer drugs are actually proven to increase patients’ survival time—and, even then, the average increase in survival time may only be a few months. “Treatment by itself is never going to be enough,” Galea said.

So, how can the U.S. better put its trillions of dollars in annual health spending to use? Galea argued that more of that money should be invested in public health improvements in areas such as early childhood education, which saves taxpayer money down the road with reductions in crime and teen pregnancy. Likewise, investments in public transit systems can reduce air pollution, improving quality of life, and saving cities money in associated health costs.

“We have to invest in building a healthier world. We have to invest in the structures around us that generate health,” Galea said. “Investing in biotechnology alone is not enough, and it’s never going to be enough.”

Galea also offered an example of how investments in public safety have improved overall health in the past, citing the country’s efforts over several decades to cut down on deaths from car accidents. Promoting seatbelt use and investing in infrastructure to build better, safer roads helped the U.S. significantly cut the motor vehicle death rate in the 20th Century, even as more and more motorists hit the road.

Spending an ever-growing amount of money on medicine will not necessarily make us live longer, Galea argued, but investing more in areas that can improve our quality of life can ultimately help us lead richer, healthier lives. “That’s how we build a healthier world,” Galea said.