During a panel discussion Tuesday at Fortune’s Brainstorm Health conference in Dana Point, Calif., Lacy argued against the concept of data overwhelm.

“The average person has literally no information about their health,” he said, which is where preventive medicine comes into play. 

“The challenge that we face as a health system is that we are taught that we are normal—until we all of a sudden are diagnosed with advanced disease, whether that’s cancer or a chronic health condition,” he said. “Our health declines pretty precipitously at that point, and then we’re spending an awful lot of money trying to keep us alive with poor health.” 

But ailments like cancer don’t appear overnight, Lacy stressed. They fester over time, too often unbeknownst to their hosts. But it doesn’t have to be that way.

“The starting point here should be providing folks with a comprehensive look inside, and it’s only through that that we can actually understand what it is that we can do as individuals to improve our healthspan and lifespan,” he said. “I don’t think we’re close to a problem of too much data, if I’m being totally honest. I think that the challenge is there’s not enough data.”

Alexa Mikhail, Fortune senior health and wellness reporter, moderated the panel featuring Lacy; Daisy Robinton, PhD, cofounder and CEO of Oviva Therapeutics; and Alina Su, cofounder and CEO of Generation Lab.

“What we are trying to do—the people who are on this stage—is really to bring the accessibility and also the knowledge, the power to the audience,” Su said, “so everyone is having the right to be healthy again. This should be the right that everyone is having, rather than giving that to the doctor.”

However, our ability to interpret biomedical data is only as good as the available corresponding body of research, which Robinton noted has historically failed to include women and people of color.

“We have this aspiration around how these data will inform personal choice and give us agency in doing so, but we’re really severely limited by that quality of data and the diversity of that data,” Robinton said. “The averages that we might use to guide clinical decisions—certainly in our health care system today, but even at the personal level—are really limited by our ability to understand on that bell curve what actually is normal for you and the background that you bring.”

Robinton added, “Over the next five to 10 years, we’re going to see a lot of change to repopulate the data landscape, to help inform how we actually understand human health and then how we make decisions based on that new understanding.”

For more on healthy aging:

• I tried the $2,500 full-body MRI that Kim Kardashian and Cindy Crawford are obsessed with. It may have benefits—but also some major downsides
• Most Americans would rather feel 25% healthier than live 25% longer. Here’s how to lengthen your health span
• Healthspan may be more integral to your well-being than lifespan. Here is how to lengthen it 
• The 5 best supplements for healthy aging, according to a longevity expert