Originally published on Freakonomics.com
We recently solicited questions for David Agus, the oncologist author of "The End of Illness". Now he's back with answers, including: the numbers on taking aspirin, how to get the most from a doctor visit and the top 10 actions to reduce your cancer risk. I can guarantee you that his answers will enlighten and thrill some people and enrage and confound others. Thanks to everyone for their participation, and especially to Agus for the thorough answers.
Q. I'm a 4th year medical student, and I watched your interview on "The Daily Show" when it first aired and really took issue with the way you presented many of these things. It seemed that you simplified your "solutions" to the point that it may actually be dangerous for people to listen to what you suggested. For example, you implied that everyone should be taking aspirin. This, of course, leaves out the fact that aspirin (like other NSAIDs) increases the risk for GI bleeding and other side effects. As another example, you took issue with the fact that people spend money on vitamins and supplements (giving Vitamin E increasing the risk of prostate cancer as an example), saying, "Why are we taking these things?" This, again, leaves out the many vitamins that are actually very important for people to be taking (folate in women to prevent neural tube defects, vitamin D and calcium to prevent osteoporosis, etc.) I'd love it if you would respond to why you don't present a more nuanced view that would help people see that the current medical establishment is not simply ignoring the obvious solutions you are espousing. --Abby
- After five years of daily aspirin, death due to gastrointestinal cancers decreased by 54 percent.
- After 20 years, death due to prostate cancer decreased by 10 percent.
- After 20 years, death due to lung cancer decreased by 30 percent (among those with cancers typically seen in nonsmokers).
- After 20 years, death due to colorectal cancer decreased by 40 percent.
- After 20 years, death due to esophageal cancer decreased by 60 percent.
I also state very clearly in the book that vitamins are important in some instances, and again that the decision should be made on an individual basis with a doctor. For example, pre-natal vitamins during pregnancy is certainly one of those cases. With regard to calcium and vitamin D to prevent osteoporosis, the data don't really support this claim. Remember the Women's Health Initiative study of 36,282 post-menopausal women (NEJM 345(7)669-683, 2006). The women in the study were randomized to 1000 mg elemental calcium as calcium carbonate and 400 IU vit D3 daily versus placebo pills. The results of the study showed a slight improvement in hip bone density, but no change in hip fracture. The calcium and vitamin D pills caused a significant increase in kidney stones in the women who took them.
To be clear, my recommendations are rooted in the scientific literature, and in all cases, I reiterate that any decision be based on one's personal circumstances and values. There will always be trade-offs when we decide to take -- or not take -- a certain medication, vitamin or supplement. It's up to each one of us to understand those trade-offs and consider both short-term and long-term benefits or risks in every choice we make. This isn't about one-size-fits-all medicine. Much to the contrary, I'm a huge advocate for personalize medicine (see next answer), which starts with our individual choices.
Q. It's become de rigueur to say that patients need to be more engaged and accountable for their health, but there are huge psychosocial, economic and institutional obstacles to change. Where are the best opportunities for breaking the old "I feel sick; I go to a doctor; they heal me" relationship with healthcare? --Dan B.
A. This is a great question, and one of the main reasons I wrote the book. If I had to sum up the entire book in a single phrase, it would be this: Get to know yourself. I don't mean that in a cosmic or purely psychological way. I'm a big believer in what's called personalized medicine, which refers to customizing your health care to your specific needs based on your physiology, genetics, value system and unique conditions. We are finally entering an exciting time in medicine where we have the technology to custom-tailor treatment and preventive protocols just as we'd custom-tailor a suit or designer gown to one's individual body. But it all begins with you. You have to know yourself in a manner that you've probably never done before. Right now, most of us live by sweeping, general guidelines that are one-size-fits-all. If you want to lose weight, for example, you pick a diet that's marketed to everyone and which likely recommends that you eat more fibrous vegetables and cut back on processed sugar. If you want to reduce your risk for cancer, you'll be told to avoid tobacco smoke, to exercise regularly and to take early detection seriously. But imagine being able to have a more explicit oracle into your future health, as well as a more exacting set of rules to follow today.
Think about what it would be like, for instance, to know precisely how to tweak your diet to effortlessly lose 20 pounds for good, or to have a detailed list of things to avoid and things to embrace that make you feel fantastic and be in tip-top shape, or to know what the perfect amount of medicine X is for you to combat affliction Y successfully with no side effects. That's the promise that personalized medicine has to offer. But, once again, you won't be able to enjoy the benefits of personalized medicine until you get up close and personal with yourself. Nothing about health is one-size-fits-all, so until you know how to perform your own "fitting," you won't be able to live the long and happy life that's awaiting you.
I created a downloadable checklist (which is offered in the book as well) to give each of us a first step in the right direction. This questionnaire was designed to help you prepare for a checkup with your doctor, giving you clues to discuss during your visit. It also aims to help you to know yourself better so you can form a new relationship with your healthcare providers today -- one that will allow you to take advantage of what current medicine and technology have to offer. This questionnaire is downloadable online here, where you'll find a version that you can respond to directly on the page to print for your records and/or take to your doctor. That way you will get the 'most' out of the doctor's visit and be in charge.
Q. 1) As a medical student, I think some of the ideas you champion do and will have a place in Medicine. But I also think that these innovations, like all medical innovations perhaps, will be very costly. How long do you think it will take before insurance companies will cover genomic sequencing or other molecular technologies? What about Medicare? 2) What do you think about IBM's Watson wearing a white coat? If you ran your own hospital, what would "Dr. Watson" do there? 3) If one of your relatives declared that he/she wanted to see his/her genetic profile without consulting any medical professional, how would respond? --Abhi Pandey
A. 1) You make a very important point about technology -- the cost factor. Insurance companies and Medicare will pay for technology when they have been shown to definitively improve outcome. I don't think that is as far away as some people think. Certainly genomic sequencing in certain cancer patients is covered because it clearly changes the therapeutic options and patient outcome. Remember, too, that while new technologies tend to be costly, the more they are used and the quicker they evolve, the less expensive (and more accessible) they become. To use a non-medical analogy, just think of how expensive and rare cell phones were just ten or fifteen years ago. Now virtually everyone has one. I have no doubt that we'll see a lot of revolutionary technologies in medicine emerging that will be very accessible and economical. And it won't be just due to the speed of technology -- it'll be a product of consumer demand much like those cell phones.
2) He would collect data and look for patterns in the data that predict clinical outcome. I don't think this will be far away in the real world. While I don't think "Dr. Watson" will ever be able to practice "the art of medicine," I do think it will help the medical community make many decisions that are needed in the care of patients.
3) I don't believe genetic testing should be performed today without the involvement of medical professionals.
Q. What's your thinking of relative roles of nurture vs. nature in the progression, or lack thereof, of major diseases we see later in life, i.e. heart disease, cancer, dementia, etc. How much is environment and life choices and habits, vs. how much is genetic and may be influenced only through genomic assessments and interventions? --MrAtoZ
A. In my book, I show a bunch of pie charts that display how much genetics or, conversely, environmental factors play in various disorders and diseases. It's quite thought-provoking to actually see these percentages and think about how much we can affect the outcomes in our health lives. Some of the listed illnesses -- like the ones you mention: heart disease, cancer and dementia -- would seem to be controlled largely by genetics, but remember, the environment can play both direct and indirect roles in our health risks. Environment, which entails a mesh of overlapping factors from diet and exercise to exposure to toxins and stress, can ultimately affect the genes that you've inherited for good or bad. The genetic side of the equation represents inherited risk factors -- they are not necessarily causal genes to the ailments. So, for example, if you look at obesity, 33 percent of this disease is attributed to environmental influences; and 67 percent is attributed to inherited markers on particular genes that can increase risk but don't necessarily cause obesity per se. If your DNA profile puts you at a higher risk of developing obesity, that doesn't mean it's your fate. You can take control of the environmental side of the equation and reduce your overall lifetime risk by a lot.
This is an important distinction because far too many people adopt fatalistic views when it comes to their DNA and how it translates to their health. Of course, it helps to know more about your DNA and make better decisions with your health, which is where genomic assessments come into play. Being able to know where your risks are not only gives you knowledge to make better decisions, but it also incentivizes you in powerful ways. It all comes down to incentives. I can tell you that you have a 30 percent chance of becoming obese based on the general population, which is probably meaningless to you. But if I could tell you that your risk of becoming obese in your lifetime is 60 to 80 percent based on your genetics, this would likely mean something, wouldn't it? That might be enough to inspire you to pay more attention to the lifestyle habits that factor into your weight. That might be enough to motivate you in ways you never thought possible to control your waistline. That's the power genetic testing can have on individuals.
Another way to look at it: If you knew that your personal risk for having a heart attack in your life was 90 percent, you'd probably do everything you could to treat your heart well. Hearing another umbrella statistic such as "heart disease is the leading killer in our country" has little impact, if any. But learning that your genetic profile puts you in a higher-than-average risk group for suffering from a heart attack speaks much louder than general statistics. This kind of information ultimately allows you to consider the personal trade-offs that you might have to accept. For example, if you know that you possess a higher risk of developing heart disease, then drinking a glass of wine a day could be a good thing to make part of your health protocol, assuming you enjoy drinking. We've known for some time now that moderate alcohol intake, especially from red wine, can reduce one's risk for heart disease but potentially increase one's risk for breast cancer. This is the trade-off, and together with your doctor you can weigh those pros and cons to create a personalized health plan.
Q. Three questions: What do you think of the talk on anti-angiogenesis here and in particular, of the foods he recommends to combat cancer? Do you think vitamins that are food based make any difference, or they are all just problematic? What about b-complex for vegetarians, Vitamin D3 and omega fatty acid supplementation? Japanese people have low rates of cancer. If you were to guess, do you think it's possibly the high level of consumption of seafood, cruciferous vegetables or fermented foods? --vimspot
A. Interesting ideas, but I don't think there is sufficient data to make recommendations on these foods to combat cancer. I am not aware of any studies that clearly show a benefit, and which meet the rigors of the scientific method. Perhaps that will happen in the future, but for now we need to base our recommendations on real science.
The book goes into deep detail on this subject, but I think getting nutrients from real food is ideal and makes better sense. Avoid the pills unless there is a particular medical problem to treat.
To the contrary, Japanese people have significant rates of cancer, but the types of cancer they typically have are different from those who live in North America. This is a fascinating area of study today. It just may be that the reasons aren't necessarily associated with diet but that different types of intestinal ecosystems harbor different microbes that affect risk factors for certain diseases, including cancer.
Q. Do you recommend taking probiotics? I read your book and I thought you might be going there, but I don't think you ever directly said that it seems like a good idea, so then I wondered whether taking probiotics (at least as they are currently available as not specific to an individual's system) could instead interfere with one's system and thus be akin to taking vitamins. --Jennifer G
A. I think the science of probiotics is an evolving one (we are just learning how to characterize the bacteria in probiotics). Future research will bear out the value, or perhaps risks, of taking probiotics. As with my general recommendation to eat real food for vitamins and nutrients, it's ideal to get your probiotics from real food than a pill.
Q. A friend of mine recently became a Type 1 diabetic in her 50s, ostensibly through a combination of intense daily exercise and a low-carb diet. When I tell people about her, people think I must be mistaken, but it is true. (The doctors thought that she somehow triggered an auto-immune response that damaged her pancreas.) Have you heard of such a thing happening? More generally, do you think extreme exercise is more of a risk (especially for Baby Boomers) than is commonly recognized? --PaulD
A. I don't think there is evidence to show that the combination of intense daily exercise and a low-carb diet causes Type 1 diabetes. There's plenty of evidence to show that exercise decreases one's risk for diabetes. It's impossible to comment on this particular case without all the details, and without being her doctor. There's likely a medley of factors at play in your friend's health; overall, however, it's naïve to blame a diagnosis of Type 1 diabetes purely on exercise, rigorous or not. A lack of physical activity will get you into more health troubles than engaging in regular, daily exercise.
Q. I met David in Davos and I was really impressed. I had dinner with him one night and I followed his recommendation; statins and baby aspirin. I also read "The End of Illness" in one weekend! Loved it! But two days ago I read that statins will get a warning label because of danger of diabetes. I am a professor of Economics at Columbia, and I am confused with so much contradictory advise. Unless you say otherwise I will continue with statins and baby aspirin (as you suggested at the Davos dinner)… but it is hard for the non-experts to keep up with the news. My strategy for now is "do what Agus says". For some reason and even though I met him twice in a week, there is something in his eyes that makes me trust him. Problem is that he also recommends to work with my doctor and I do not trust the degree of preparation of this doctor when he gives me advise that contradicts "The End of Illness". Hence, I am in a state of profound confusion: about to turn 50, completely healthy, taking statins and baby aspirin and ready to do a DNA and proteomics test. Any advise, doctor? P.S. Looking good at the Oscars. My wife (the professional triathlete that sat at our table in Davos and I were happy to see you at the Oscars) --Xavier Sala-i-Martin
A. Certainly, the recent warnings about statins by the FDA have been confusing. The data are very clear that statins will delay the onset of cardiovascular disease, reduce the risk of many cancers and make people live longer. But, like most things, there is no 'free ride.' Statins do have real side effects, all of which are reversible. They include liver function abnormalities, memory problems, muscle aches and diabetes. These problems are very rare, and the drug can be stopped if these happen and they will reverse. It worries me that physicians and patients may overreact to the recent FDA announcement. The data described in the FDA notice is not new and again very rare. Patients and physicians need to be aware of side effects and watch for them.
I wish we didn't have to make broad recommendations to patients like "take statins," but the current technologies don't yet choose who will and who won't benefit. Hopefully this will happen in the future.
The decision to take a statin is one that should be discussed with your physician. I want the discussions of the risks and benefits to happen, because there is no 'right' answer. There's only one right answer for you that will come from a candid discussion with your doctor that respects your value system. It helps to remember that there are trade-offs in everything we do. We get into our cars and drive every day knowing that we put ourselves at greater risk of dying in a car accident. The toys we buy for our kids come with warning labels that we barely notice anymore. Again, everything has trade-offs. It's up to each of us to know what those trade-offs are, how they apply to us, and what we should do about them given our unique circumstances. For some, the pros outweigh the cons. For others, the cons are too big to bear. As I point out in my book numerous times, nothing about medicine (or life in general) is one-size-fits-all.
Q. I am a first year medical student and have seen several of your interviews on TV, have read several other descriptions of your work and generally agree with your point of view of treating the human body as a complex emergent system. You make mention of several studies indicating, for example, an increased or decreased risk of cancer when consuming certain products, and likewise for other diseases. Isn't that the same basic argument that studies have been making for a while? Shouldn't you instead be concerned with the overall mortality rate when taking a medication compared to not taking it? Ultimately, shouldn't not dying (i.e. living longer) be more important than just not getting cancer, considering you might die of some other cause sooner instead because the same item that reduced your risk of cancer increased your risk of fatality otherwise? --Evan
A. Living longer is a goal of any medical intervention, but such studies can take decades to complete in many cases (especially prevention studies). Short of survival, we use surrogate end points, such as the incidence of important medical events (e.g., cancers, heart attacks, etc.), to understand the effect of therapeutic interventions.
Q. What are the top 10 actions I can take to reduce my cancer risk? --Ben D
- Avoid vitamins and supplements
- Discuss aspirin and statins with your doctor
- Participate in the prescribed cancer screening programs
- Exercise regularly and move during the day
- Have lean body mass
- Avoid tobacco products
- Avoid direct sun exposure without sunscreen
- Avoid sources of inflammation
- Get a yearly flu shot
Q. It's natural that we should try to prolong our lives but how do we become reconciled to our mortality? Isn't the search for "the end of illness" just a denial of the inevitable? --Henry Jarmuszewski
A. Not in the least. "The End of Illness" is a philosophy of empowerment and prevention. I believe we can prevent or delay most disease until the 9th or 10th decade. The goal is to prevent anything that can affect your quality of life prior to those years! By the time many of us get to the 9th or 10th decade, who knows where the new medical and science will take us? I am an optimist!
For more on aging gracefully, click here.