David Agus helped Steve Jobs live longer. Now he want to help us all. Bryce Duffy

It's 6:30 on a Monday morning and already David Agus is doing an admirable job of sticking to the rules. Dressed in the no-nonsense uniform that one of his patients, the late Steve Jobs, encouraged him to adopt and wear daily—gray slacks and a black sweater over a white dress shirt—the pioneering biomedical researcher and oncologist meets me outside his hotel on West 56th Street in Manhattan with a large Starbucks coffee1 in his hand and a big smile2 on his face. Already he's gone for a brief morning run3, and his activity levels are being monitored by the black Nike Fuelband4 on his left wrist. The previous evening he dined on king salmon5 at Café Boulud, finishing it off with a fine Cabernet6, and, as he always does, he took a statin7 and a baby aspirin8 before falling asleep. Though he hasn't eaten breakfast,9 he looks freshly scrubbed10 and is wearing comfortable shoes11. In his new book, A Short Guide to a Long Life, he prescribes 65 rules we should follow to achieve better health; in the past 18 hours he's accomplished a solid 10.

Agus is clearly an overachiever. This morning we are heading to CBS News, where one or two times a week he banters about health topics with CBS This Morning’s Charlie Rose and the other anchors. This has been going on since May and was an outgrowth of the 2012 publication of his best seller The End of Illness, a paradigm-shifting book about how to live healthfully and well. In addition to these TV appearances, he contributes op-eds to The New York Times, appears in Nike's new Movement Matters public-awareness campaign, and is a regular participant at events like the World Economic Forum in Davos, PopTech in Maine, and the Aspen Ideas Festival.

But Agus, 49, is no average pop-doc. He's also an accomplished and well-regarded research scientist. A professor of medicine and engineering at USC, he has helped develop new drugs and landmark diagnostic tools, cofounded two health care technology companies, and made breakthroughs in both how to treat cancer and how we think about it. On top of all this, he's a clinician, devoting two and a half days a week to seeing patients—more than a few of them famous. Sumner Redstone, for example, has publicly thanked Agus for his "miracle recovery" from prostate cancer. "He thinks outside the box," says Redstone, 90. "Everything he told me to do contributed to my battle against cancer. Today I feel better than I did when I was 20." Neil Young, who mentions Agus in his recent memoir, calls him simply "my mechanic." As for Jobs, the iCEO was such a close friend that he helped Agus' first book find its audience by renaming it. (Agus' original title for The End of Illness was What Is Health?—but Jobs vetoed it, saying reading it was like "chewing cardboard.")

The combination of serious scientist and accessible communicator has earned Agus plenty of high-profile admirers. "He's disruptive" is how his friend will.i.am describes Agus. "A prophet," says Marc Benioff, chair and CEO of Salesforce.com and another buddy. "What he does is really important," vice president Al Gore says, praising Agus' willingness to defy "a certain peer pressure" that discourages "taking the discoveries of science into popular culture."

For his part, Agus isn't really trying to defy anyone. To him it's all part of a single plan. That's because Agus isn't just trying to build a career, make a pile of money, or get famous; he's trying to beat cancer. And he knows that even as he searches for breakthrough treatments and refines state-of-the-art clinical care, these accomplishments alone will not achieve this goal. Agus believes we can conquer this devastating disease only if individuals take ownership of their health. They can't do that if they don't know how. So he has taken it upon himself to educate them, one rule at a time.

Not everyone is a fan of Agus' approach. He has at times been accused of making things a little too straightforward, a little too simple. Should more of us really be taking statins? And we shouldn't take vitamins? To those critics, A Short Guide is guaranteed to rankle. Because despite its various disclaimers—“The rules in this book are not meant to be blanket recommendations"—the little volume contains Agus' starkest, most clear-cut prescriptions yet. Such reassuring confidence is expected from health proselytizers, who tend to limit themselves to advice based on scientific consensus. Cutting-edge scientists, on the other hand, are almost allergic to sweeping certainties. By definition, they work in areas that are messy, ambiguous, and subject to frequent and sometimes wholesale revision. They traffic not in answers but in questions. By combining the roles of serious biomedical researcher and dedicated wellness guru, Agus sometimes seems to have boldly decided that still-unsettled science is settled enough to be translated for the masses. He's confident in his interpretation of the data, whose message he feels is too urgent to wait for the plodding agreement of the conservative medical establishment. The result is that in a field rife with caveats, Agus speaks with a ringing clarity. Which is great, as long as he's right.

You might say that Agus is genetically predisposed to his career trajectory. His father, Zalman Agus, is a professor emeritus of medicine and physiology at the University of Pennsylvania. His grandfather, Jacob Agus, was a rabbi and theologian who wrote books with titles like The Evolution of Jewish Thought. When he died, in 1986, The New York Times noted that he'd "promoted dialogue between Christians and Jews." Now grandson David has combined these passions, promoting a dialog about health and medicine with the fervor of a devout scholar.

It wasn't always this way. To hear him tell it, he was an introverted if precocious science nerd almost from birth—puttering in the lab as a child, competing in national science contests, publishing three papers in peer-reviewed journals before he went to college. He attended the best schools: undergrad at Princeton, med school at Penn, and a residency at Johns Hopkins. He remembers being told, when it came time to pick a specialty, that oncology was "career suicide." At the time, he recalls, the field "was an insipid branch of medicine bereft of hope and innovation." But fresh out of Hopkins in 1994, he accepted an oncology fellowship at Memorial Sloan-Kettering Cancer Center in New York City.

While working in the lab of David Golde, then Sloan-Kettering's physician in chief, Agus was part of a team that discovered that while vitamin C might help prevent cancer, it can become an archenemy when you have cancer. It turned out that tumors feed on it. He also worked to develop a new lymphoma drug under Golde and is among those who did the initial work that led to the pharmaceutical called Perjeta (pertuzumab), which binds to a protein on the surface of about a quarter of breast cancers, effectively turning one of their "on switches" to off.

But as formative as this research was for Agus, the relationships he forged were really what shaped his methods. Andy Grove, former CEO of Intel, had gone public about his fight with prostate cancer in 1996. The men became close after meeting at a "who's who in cancer research" retreat in 1998. So when Grove offered some constructive criticism, Agus was hard-pressed not to listen. "I love what you're doing in the lab, but you're not any good at telling people about it," Grove said to the young researcher. Agus was defensive at first. "What does that have to do with anything? It's good science," he countered. Nonetheless, he began scheduling talks at hospitals around the New York area, 150 over the following year. "I forced myself to be a better presenter," he says.

It was Grove who encouraged Agus to move to California, where Agus took a position at Cedars-Sinai Medical Center in Los Angeles in 2000. Already, word was spreading about this young doctor who was developing new therapies. But Agus had yet to flesh out his systemic approach to cancer, which would be spurred by two key moments. The first occurred in 2004, when Clifton Leaf, a cancer survivor, wrote a cover story in Fortune called "Why We're Losing the War on Cancer." Leaf made a compelling case that the medical community was approaching cancer the wrong way—spending more energy trying to understand it and not enough trying to control it. The article gnawed at Agus. Why was he so powerless to treat advanced cancer?

The second moment occurred five years later, at the Aspen Ideas Festival. There Agus met the famed physicist Murray Gell-Mann, who had won the Nobel Prize in 1969 for his work on the theory of elemental particles. Talking to Gell-Mann crystallized the ideas that Leaf's article had set in motion. "My 'Aha!' moment came when he talked about the complex systems he confronted in physics and how he would go about trying to build models," Agus wrote in The End of Illness. Physicists were able to build theoretical models of things they still didn't completely understand and make discoveries using those models. Why hadn't doctors approached medicine like this? he wondered.

That same year, Agus stood before thousands of colleagues at a meeting of the American Association for Cancer Research in Denver and did not mince words: "We've made a mistake." For 50 years, he said, too many resources had been aimed at analyzing how cancer works. "We don't necessarily need to understand cancer to control it," he remembers saying. There were hisses in the audience. It wouldn't be the last time.

He was already at work on The End of Illness, which he'd begun in 2008. "I wrote the book out of weakness, not out of strength," he says. "I knew I couldn't treat advanced disease. So we had to do everything we could to get people to understand that there were ways to prevent it, ways of thinking about it differently, and to spur the field to change." In the book, he would propose a shift in our approach to managing disease and prolonging quality of life. Most crucially, he offered a new way to think about cancer. It's not something the body has, he asserted, so much as something the body does. Cancer is not a noun, in other words, but a verb—as in, we need to stop our bodies from "cancering."

Agus says one of his main goals in becoming an author has been to empower individuals, to give them the best data available and tell them how to use it. "There's a portion of the population who still want to be told what to do. You can't ignore them," he says. But still, he adds, his central aim—counterintuitively—has been to inspire his readers to speak up, ask questions, and challenge accepted norms. Even if that means they challenge him. Rule 27 is "Partner with your doc," which is fitting, as Agus seems bent on partnering with us all.

No one doubts Agus' devotion to data. But some say he can take it too far—to the detriment of patients' pocketbooks and their emotional well-being. Nowhere has that criticism played out more publicly than on ABC News, which did two reports on Agus in 2012—the first in January, just as The End of Illness went on sale, the other in October, right after it came out in paperback. Bill Weir, the correspondent who did both reports, billed the first one as "the assignment that saved my life." But in the second he admitted, "Now I'm not so sure."

Weir, a seemingly fit 44-year-old husband and father, volunteered to let Agus use him as a test subject to show how cutting-edge technology can extend life. The newsman underwent a battery of tests, including a full-body CT scan, and then sat down to get the results on camera. He was stunned to hear Agus say that he had lesions with calcification in major coronary arteries. He could be at risk for a heart attack. Agus told Weir that he might become "the 45-year-old who went jogging and died." Weir needed to develop a regular schedule,12 Agus said, improve his diet, stop taking vitamins, and move around more throughout the day. "At that moment I vowed to change," Weir reported.

But even as Agus' book became a best seller, some in the medical community were questioning one of its central premises: That more information is the key to making good decisions, even when the tests used to glean that information may do damage (full-body CT scans, for example, involve radiation exposure). "I started hearing from people the morning after that first report aired," Weir told me. What they said was that Agus was, as Weir put it in his second report, "a good example of bad medicine." In his second piece, Weir reported that five doctors had asserted that Agus had overstated Weir's risk of dying.

RULES TO LIVE (LONGER) BY

1. RULE 18 Start a sen­sible caffeine habit. "Consuming caffeine in moderation from natural sources like the coffee bean and tea leaf has long been shown to confer positive benefits on our health."

2. RULE 29 Smile. "The act itself will trigger the release of pain-killing, brain-happy endorphins and serotonin."

3. RULE 17 Jack your heart rate up 50 per­cent above your resting baseline for at least 15 minutes every day.

4. RULE 2 Measure yourself. "You might want to consider adding a tracking app or device of some kind to your life."

5. RULE 37 Eat more than three servings of cold-water fish a week.

6. RULE 10 Have a glass of wine with dinner.

7. RULE 21 Inquire about statins if you're over-the-hill.

8. RULE 22 Take a baby aspirin. Low-dose aspirin can not only prevent strokes and heart attacks, it reduces the risk of dying from cancer.

9. RULE 41 Never skip breakfast.

10. RULE 11 Practice good hygiene—in bed and out.

11. RULE 59 Avoid stilettos and other sneaky sources of inflammation. Wear comfortable shoes.

12. RULE 49 Pick up a pooch. Dogs keep you on a regular schedule.

13. RULE 62 Don't take vitamins and supple­ments. In randomized trials, most show no benefit, and some actually increase mor­tality.

14. RULE 5 Eat real food.

15. RULE 60 Avoid juicing. "Does the body really like consuming 10 carrots all at once?" he asks. "I think not." RULE 54 Avoid detoxes.

16. RULE 31 Be positive.

17. RULE 57 Avoid sunburns.

18. RULE 56 Avoid airport backscatter x-ray scanners. Until science can prove the safety of such machines, he explains in his new book, "I'll be requesting the manual pat-down massage when I go through the TSA's gateway at airports. You should too."

19. RULE 16 Get off your butt more. S-t-r-e-t-c-h.

20. RULE 9 Cultivate om in the office.

Holly Wales

Weir says he quickly realized he'd unwittingly waded into an ongoing argument about what comprises overtesting in health care. He also conceded to me that as a guy who'd long avoided doctors and who paid no attention to what he ate or what his ancestors had died from, he "probably needed a wake-up call." But the way Agus had delivered his diagnosis—his unwavering certainty—bothered Weir.

What Weir wishes Agus had told him, he says, was "You are going through a machine that is the best we have in terms of seeing into the crevices and crannies of your body, but to be completely honest with you, the smartest people in the world can't agree on how to interpret the data it creates." While Weir acknowledges that Agus changed his behavior for the better—he eats more salmon now and carries a FitBit in his pocket—he thinks Agus' evaluation lacked context.

When Agus and I talk about Weir, he laments that Weir's reports made him sound like an unquestioning proponent of CT scans (in fact, he thinks they need improvement; he does not recommend them in either of his books). But Agus stands by his findings. Yes, the chance of Weir having a heart attack is low. But they did find plaques. "This is somebody who has existing heart disease, and he wasn't on any preventive measures," Agus says. Why risk letting it get worse? I ask what he would say to Weir if they talked about the reports today. "It changed your life with no real downside except for cost," he says. "This was a gift!"

This is hardly the only controversy around Agus. He has effectively waged war on the vitamin and supplement industry, telling his readers to forgo the pills and powders13 and consume fresh food instead.14 He shuns practices like juicing and detoxing,15 which many equate with healthy living. Then there's his belief that most people over 40 should talk to their doctor about taking a statin. Statins do more than cut down on cholesterol; they reduce inflammation in the body, which is key, Agus believes, to maintaining good health.

Many disagree with Agus on statins. Among them is David Newman, director of clinical research, emergency medicine, at Mt. Sinai Hospital and editor in chief of TheNNT.com, a site that analyzes peer-reviewed research to help make recommendations on therapies and treatments. "What's missing from the conversation is something about whether or not there is a downside," Newman says, noting that some people suffer side effects from statins. "If he's even implying that healthy people should be taking a statin, I disagree with that."

The problem, Newman says, is that Agus' approach offers so little room for doubt. "Asking the question 'Why not do more to prevent illness?' is so lopsided. It doesn't offer the possibility of having an intelligent conversation about what is good and what is bad. It just assumes there is only good."

Agus takes issue with this portrayal. "The data is very clear on a society level that statins make people live longer," he tells me. "If you have side effects as an individual, you have to weigh that. If everyone in your family lives to be 100 with no heart disease and no cancer, then maybe you don't need to be on a statin. But if some of them died in their fifties of a heart attack, then you probably do." What he wants, he says, is for people to investigate the potential benefits and side effects for themselves.

"I'm not saying, 'Everybody take a statin!'" Agus says. He is saying that everybody should consider it for its impact on inflammation in the body. "A discussion with your physician has to happen. The data is that good. And to really make that discussion happen, you have to make things black and white." (The American Heart Association and American College of Cardiology recently issued new guidelines suggesting that more people should take statins, though the recommendations were immediately challenged by some prominent doctors.)

Certainty and simplicity—they are Agus' most effective tools, and they also earn him the most blowback. On our day together in New York, he shows me an email he's received from a renowned physicist at an Ivy League university. The professor heard Agus on NPR talking about how chemo­therapy helps people with cancer live longer and better. Apparently the professor found Agus' comments too enthu­siastic. "It sounded like you were doing an infomercial for the local rubes," the man wrote.

If Agus is tempted to call the guy an elitist, he doesn't admit it to me. His response, which he reads to me, is gracious and stresses the importance of educating the public and helping them cut through all the confusing messages about health. "Educate or mislead?" Mr. Ivy League fires back, but Agus refuses to be baited. "I agree that chemotherapy is not the future," he writes back amiably, "but I see it benefit patients daily. We need much better, but it does work."

Still, how can he be so sure of things—so black and white, to use his words—in a field so thoroughly gray? "That's the greatest question ever!"16 he says, launching into an answer that basically boils down to this: Because somebody has to. "At some point, everything in medicine has to hit a critical mass of data so it becomes fact," he says. "When there are enough studies that are big enough and statistically sound, we need leadership to make that statement—to say, 'Listen, we need to have a normative change here.' You need to make declaratory statements." Someone, in other words, must step up, look at the data, and be brave enough to make a call. Agus is more than willing to be that person—even if it means occasionally taking a hit for it.

"For me to be criticized a little is nothing," he says. "Because I get to see people who are dying of disease. So if I get criticized for trying to prevent disease?" He pauses. "Bring it on!"

After Agus' appearance on CBS This Morning, we get into a black sedan and head downtown. He's due to film a talk on cancer for TEDMED, the medical offshoot of the famed big-ideas conference, but before we can get there, Agus' phone begins to buzz with the news that Howard Stern has just mentioned him by name on SiriusXM. Agus has a quizzical look on his face, but he quickly figures out that Robin Quivers, Stern's sultry-voiced sidekick, has gone public this morning about her triumph over uterine cancer. Agus consulted on her case.

On the show, a remarkably emotional Stern says, "I do want to thank Dr. Agus, one of Robin's doctors, for stepping in ... He's a genius. Genius." Later, Stern goes so far as to spell the doctor's name, "A-G-U-S," and lauds him for helping Quivers choose a course of treatment. Soon hundreds of emails will start pouring in to Agus' inbox. Thank you, they'll all say in one way or another. Thank you for taking care of our Robin.

The cavalcade of A-listers in Agus' life has boosted his public persona and made him famous in his own right. This is something his friends have encouraged him to think about. One of them, Dov Seidman, a business ethicist and author, tells me about a conversation he and Agus had just before The End of Illness came out. The gist, Seidman says, was that he warned Agus about the lure of fame. "David's sweet spot is that the white coat is really on," Seidman says. "He's in the lab, staying close to scientific breakthroughs. He's got the legitimacy and gravitas that comes with being the person who is engaged in medical science on the cutting edge. Many people who've gone broad and popular have disconnected from that." Seidman told Agus that popularity could be seductive and urged him not to let it interfere with his work in the lab.

Bold-Face Patients

David Agus has treated a roster of high-profile patients. Here's a sampling.

Steve Jobs

Cofounder, chair, and CEO of Apple

Illness: pancreatic cancer (died 2011)

"An amazing adviser. Such a heart."

Robin Quivers

Radio personality, The Howard Stern Show

Illness: uterine cancer

Neil Young

Singer-songwriter, musician

Illness: undisclosed

"Agus is a genius. He cures people of cancer."

Sumner Redstone

Executive chair, CBS and Viacom

Illness: prostate cancer

Ted Kennedy

US senator

Illness: brain cancer (died 2009)

"Agus has given us a remarkable peek into our health."

Lance Armstrong

Former pro cyclist

Illness: testicular cancer

Dennis Hopper

Actor

Illness: prostate cancer (died 2010)

Johnny Ramone

Guitarist, the Ramones

Illness: prostate cancer (died 2004)

"Agus is keeping me alive, month by month by month. He's on the leading edge."

Tom Sherak

Former president, Acad­emy of Motion Pic­ture Arts and Sciences

Illness: prostate cancer

Getty Images

It's a helpful reminder that alongside his controversies and TV appearances and best sellers, Agus is also a renowned scientist. Take, for example, his work with Danny Hillis, an inventor, scientist, and entrepreneur.

A pioneer of parallel computing and a former vice president of Walt Disney Imagineering, Hillis is Agus' partner in a company called Applied Proteomics. They met after Agus reached out for Hillis' help. At first Hillis ignored the doctor's calls, but then one day (in fact, all in one day), Al Gore, John Doerr, and Bill Berkman contacted Hillis and told him to pick up the phone.

He did, and Agus got right to the point: If he only had a better way to measure proteins in the blood, he could better evaluate each patient's cancer and prescribe more effective treatments. When you are "cancering," you see, your body's proteins change. Hillis was intrigued but skeptical, at least at first. "The problem is you have hundreds of thousands of proteins in your blood—many more than you have genes, actually," Hillis says. "And to detect the kinds of subtle changes cancer causes, you need to measure how much of them you have, not just whether they are there. But David convinced me that this was a really important problem."

A beat, and then he adds, "He's very convincing."

In 2007 the two men founded Applied Proteomics to explore the problem in earnest. They decided that a good first product for their company to develop was a diagnostic test for colon cancer. Agus finds the current test, a colonoscopy, flawed in that—while it enables the removal of precancerous polyps—many people avoid it because they can't bear the idea of being scoped. A less invasive diagnostic test would definitely save lives. Using advanced computing power, Hillis and Agus succeeded in finding a way to analyze small protein changes that occur in the body when polyps are present. They expect their test to be on the market as early as next year. It wouldn't have happened, Hillis says, without Agus' persuasiveness.

Agus combines three characteristics rarely seen in the same person, Hillis says. "One is tremendous personal charisma and enthusiasm. He also is a great abstract thinker. And then he is a great observer. Very keen. He really sees the way you're moving, the gaze in your eye, the color of your skin. Usually people who are working on a theoretical plane—like me—are kind of oblivious to things like that. But he's able to make that bridge between the clinical and the theoretical and then get other people excited about it."

If there's one thing that ties all of Agus' divergent activities together, it's this: He's a connector. Whether developing a new diagnostic tool or urging readers to use sunscreen,17 he believes the critical thing is connecting with people and getting them not just to understand what needs to be done but to act on it. This fundamental goal underlies all that Agus does.

Three days after we return from New York City,18 I pay a visit to Agus' Beverly Hills clinic. As he ushers me into his modest office, there is more evidence that he follows his own rules: a treadmill desk.19 But it's in the examination room that I finally see, up close, what drives him.

Today one of his patients is Tom Sherak, a longtime studio executive and former president of the Academy of Motion Picture Arts and Sciences. Sherak, 68, has been fighting prostate cancer since 2001. For five years another doctor kept the disease in check, but in 2006, when the cancer grew more aggressive, Sherak's friends told him to contact Agus. Sherak is no whiner, but he admits that the disease has taken its toll: Chemo robs him of his energy, his sex drive, sometimes even his will.

Agus is treating Sherak with Taxotere, a drug that interferes with cell division. It's powerful stuff—after each treatment (Sherak's on his fifth) he can do little but lie in a recliner for at least a week. As the chemo enters his body via an IV drip, Sherak—in a white hospital gown, with a blanket tucked snugly around his lower half—appears upbeat, at least at first.

"Are we doing a good job or what?" he asks as Agus takes a seat next to him. The doctor smiles and squeezes Sherak's ankle. The news is good: The aggressive cells are in retreat. But instead of looking overjoyed, the patient's face clouds over.

"We're stopping after six treatments," Sherak says, locking eyes for a moment with his wife, who is sitting on a chair near his feet.

"OK," Agus responds. "Things are looking good."

"I need to stop at six," Sherak repeats.

"That's fine. You've got to listen to your body," Agus says, his voice calm,20 but it's impossible to ignore the anxious question that hangs in the air. Would a seventh cycle prolong this man's life? Or an eighth?

"I need a break," Sherak says. There are tears in his eyes. "I need to see what my body will come back to."

At this Agus throws up his hands in faux exasperation. "It's like that movie where they say, 'You had me at hello,'" he says gently. But then he adds, "I'm there. I agree. We don't have an algorithm for how many cycles to give, but we're in a good spot. No matter where we stop now, I'm comfortable."

When it comes to treating disease, Agus knows better than most how elusive certainty is. There is no algorithm. Things are not black and white. "Listen, if there were one right way to do it, we would all be doing it," he says. The hard part comes in using your gut, he says, to interpret the best data you have. The hard part comes in daring to step into the void and make those tough calls—to serve up the rules that so many of us crave or often need. Agus believes with all his heart that the benefits of doing so far outweigh the risks.