#52: We can reduce our cancer risk

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Cancer is the second leading cause of death, and while it sparks fear for good reason, 40% of cases are preventable. In this episode, I outline six practical, evidence-based steps that can help reduce your risk.

We begin by understanding which cancers are most common based on gender—breast, colon, and lung in women; prostate, colon, and lung in men. While some rare cancers (like pancreatic or ovarian) evoke greater fear, the focus here is on the ones we’re more likely to face and can meaningfully act on.

Next, I break down risk factors into two categories. Some are unavoidable—your sex, age, or family history. For example, if a close relative had breast or colon cancer, early screening or genetic testing may be warranted. However, only about 5–10% of cancers are directly linked to inherited genetic mutations (American Cancer Society
).

The more empowering list? Avoidable risk factors—where our actions matter most. Smoking remains the leading modifiable cause of cancer, responsible for about 19% of all cases. Excess weight and obesity account for another 8% and are especially tied to hard-to-treat cancers like pancreatic and ovarian (ScienceDirect
) and PubMed
). Visceral fat appears more predictive than BMI alone. Alcohol, especially in large quantities, is also linked to liver, GI, and breast cancers.

Some risks are cancer-specific. HPV causes nearly all cervical cancers, and melanoma is largely driven by UV exposure. Air pollution, especially particulate matter, may slightly increase lung cancer risk (ASCO Global Oncology
).

Step three is to act on what you can. Quit smoking, aim for a healthy weight, wear sun protection, and ensure your kids get their routine HPV and Hepatitis B vaccines
. Exercise plays a major role too—high activity levels correlate with 10–20% lower risk of several major cancers (JAMA
). In colon cancer survivors, regular exercise reduced recurrence by 30% (PubMed
).

Step four is awareness: don’t ignore new symptoms like unexplained bleeding or lumps. Early detection can be life-saving.

Step five is screening. If you're 45 or older, colonoscopy is now recommended. Women should get regular mammograms and PAP smears, and individuals with smoking history may benefit from lung CT scans. For rarer cancers with family history, targeted screenings may apply. I also address why whole-body MRIs
 and liquid biopsies
 aren’t ready for routine use.

Step six? Don’t put your hope in supplements. Large trials show omega-3s, vitamin D, beta carotene, and vitamin C offer no real protective benefit (NEJM VITAL Study
, Meta-analysis on Vitamin C
, JNCI on aspirin
).

Takeaways:
You can reduce your cancer risk by modifying lifestyle factors like smoking, weight, and activity. Don’t delay screenings—they catch cancers early when treatment is most effective. And remember: no supplement replaces proven preventive strategies.

Visit drbobbylivelongandwell.com
 for more evidence-based tools, and listen to the full episode for actionable steps to help you live long and well.

Episode Transcript

SPEAKER_00 (00:01):
Cancer is probably the most feared diagnosis that
your doctor could tell you.
And it's common.
It's the number two cause ofdeath.
Are there evidence-based ways tolower that risk?
The answer is definitely yes.
Listen for six practical stepsthat may save you from this

(00:24):
tragedy.
Hi, I'm Dr.
Bobby Du Bois, and welcome toLive Long and Well, a podcast
where we will talk about whatyou can do to live as long as
possible and with as much energyand figure that you wish.

(00:48):
Together we will explore whatpractical and evidence-supported
steps you can take.
Come join me on this veryimportant journey, and I hope
that you feel empowered alongthe way.
I'm a physician, Iron Mantriathlete, and have published
several hundred scientificstudies.

(01:10):
I'm honored to be your guide.
Now, this is the fourth in theseries of Can You Reduce Your
Risk?
We did heart disease, cognitivedecline, and stroke.

(01:32):
And here is the fourth.
If there are other categories ordiseases you'd like to
understand about lowering risk,send it my way.
Love to get feedback andsuggestions.
About one in three people in theUnited States will develop
cancer during their lifetime.
And hearing that word bringsfear and tears to most of us.

(01:56):
We all have loved ones orourselves that have received the
diagnosis of cancer.
You may have also heard thatthere's a rising number of colon
cancer cases, even andespecially in people under the
age of 50.
Before diving in, I wanted toshare that I've tried to create

(02:19):
a safe space for you with thispodcast, where I'm not selling
anything.
There's no ads, there's nosubscriptions, there's no
companies I own.
There's no hidden agenda, justevidence-based insights.
I hope you can trust.
Look, I at times I may be wrong,but I'm certainly not being
driven by any profit motive.

(02:41):
I just wanted you to know that.
On to our cancer story.
It's a good news, bad newsstory, as like many of the
topics we discuss here on thispodcast.
40% of cancer cases arepreventable.
And it's been estimated we'velowered the number of cancer
deaths over the last 50 years by5 million.

(03:04):
Now, 80% of that is betterprevention and better screening.
20% of that is our treatmentshave gotten better.
That's the good news.
Now the bad news is 60% are notpreventable.
But that doesn't mean we shouldgive up thought and hope.

(03:25):
If we can find those cancersearly, we will be much better
off.
So I've put together a six-stepframework, six steps you can
take to reduce your cancer risk,all built around evidence.
And I hope you'll listencarefully and I hope you will
take them to heart and try them.

(03:46):
Okay, step one, determine whichcancers are more common or most
commonly might affect you.
And then, of course, we're goingto focus on ways to prevent
those.
So the most common cancersdiffer between men and women.
For women, it's breast cancer,colon cancer, and lung cancer.

(04:08):
Now, uterine cancer, ovariancancer, very worrisome, but
somewhat less common.
Men, it's prostate cancer, coloncancer, and once again, lung
cancer.
Now, we all think lung cancerdue to smoking, and that's true
for most cases.
But 10 to 20% of lung cancercases are in non-smokers.

(04:32):
So we do need to think aboutthose as well.
Now you may be thinking, well,what about skin cancer?
That's very common.
Well, if we get rid of thenon-malignant ones and focus on
uh like melanoma, then it's notthat common overall, but we will
talk about ways to prevent thatas well.

(04:53):
Obviously, there are cancersthat we fear that aren't in that
top list, like pancreatic canceror ovarian cancer, because it's
really hard to treat them, andso we fear them.
Of course, there's leukemias andmyelomas and brain cancer and
kidney cancer.
But right now we're going to tryto focus on the most common ones

(05:15):
and the ones where we think, Ithink you can have the best
impact.
Now, even if uh cancers do cropup, basically we want to get to
that cancer as early aspossible, and that is one of the
steps.
All right, step two, define yourrisk factors for cancer.

(05:38):
Now, some of those are going tobe unavoidable.
So if you're a woman, you're atincreased risk for breast
cancer.
If you're a man, you're going tohave an increased risk of
prostate cancer.
And as you get older, cancersare more commonly going to
happen.
So those are what I call the anunavoidable set of factors.

(05:59):
There's also your familyhistory.
Do you have a family history ofbreast cancer that happened in a
mom or a sister or an aunt?
If so, you might want to undergosome genetic counseling and
testing, like the BRCA gene thatyou might want to know about.

(06:19):
If colon cancer runs in yourfamily at young ages, you might
need earlier screening.
But let's also keep in mind thatonly 5 to 10% of all cancers are
known to be strongly linked to agene defect, a mutation that
came from a parent.

(06:40):
Cancers in general do havemutations, but I'm talking about
the ones that come from yourparents that are truly
inherited.
That's a pretty small number.
So obviously, you want to beaware of it and do what you can,
but it's not, for most people,it will not impact their risk of
cancer.

(07:01):
Okay, now we get to theall-important avoidable risk
factors.
These are risk factors that wecan do something about.
The number one risk factor forpreventable cancer is smoking.
It still is smoking, even thoughfewer people in the United
States smoke.
It's been estimated that about a19% of all cancer cases are due

(07:26):
to smoking.
Here's another one.
We understand being overweightas it affects our heart, it
affects our brain, but it istruly a risk factor for cancer.
And it isn't just for people whoare obese, you know, a BMI above
30.
People who are overweight, whichis typically referred to as BMI

(07:49):
of 25 to 30, they are also atrisk for cancer and an increased
risk at that.
We haven't really talked toomuch about sort of general fat
and visceral fat, the fat that'saround your organs and in your
muscles and such.
That fat is at an increased riskfor cancer, more so than just

(08:13):
cosmetic fat.
And I may do a podcast episodeif you want on visceral fat.
How do you measure it?
What does it mean?
What can we do about it?
Well, also, alcohol is amodifiable risk factor for
cancer.
Now, for cancers like livercancer or GI cancer, generally

(08:37):
the amount of alcohol thatpeople have been drinking is a
fair bit.
But I did talk in my episode onalcohol that there can be a
slight increase in cancer, evenfor fairly small amounts of
alcohol intake.
So listen to that episode ifit's of interest.
So those are general causes thatare modifiable.

(09:02):
But there's also somecancer-specific things that are
also preventable.
So most cervical cancers inwomen are due to HPV virus
infection, human papillomavirus, almost 100%.
So if you can stop the infectionfrom happening, your risk of

(09:24):
cervical cancer may fall closeto zero.
Melanoma, the skin cancer, themalignant thing that we all
fear, that's pretty much drivenby UV radiation.
Obviously, there are some casesunrelated, but generally it's
felt to be due to sun exposure.
And lung cancer.
Lung cancer, of course, smokingis a critical one, but there's

(09:48):
also some data about airpollution.
Air pollution in a meta-analysisof 61 studies, now these were
observational studies, theyfound that tiny particulate
matter in air pollution mayincrease your risk of lung
cancer.
And you know, if you're sittingin a city that has pop

(10:09):
pollution, I'll come in just afew minutes on maybe what you
want to consider.
It's not clear if air pollutionuh increases your risk of other
cancers, but it does seem toaffect that uh lung cancer.
Colon cancer, there's data thatsuggests that your diet is
influential.

(10:29):
People talk about fiber.
I talked in my bacon episodenumber 41 about processed meats.
In that episode, I netted out toif there's any increase, it's a
tiny, tiny increase.
So if you enjoy your bacon likeI do, I still eat my bacon.
Okay, so now we have figured outwhich cancers we might focus on.

(10:53):
We figured out what our riskfactors are, some avoidable,
some not.
Now we're going to get to partthree, step three.
Avoid what you can.
Get rid of the risk factors,reduce the risk factors if you
can.
Smoking, obviously.
If you are able to cut back onsmoking, please do so.

(11:15):
Visit your doctor, find out allthe different ways they might
support you in that.
If you don't smoke, wonderful.
All right, obesity, even beingoverweight.
Look, it's hard, it's hard todeal with weight issues.
I've talked about it multipletimes, but if there's another
reason to think carefully aboutlosing the weight, maybe uh

(11:37):
trying an Ozempic or a Monjar orone of those, avoidance of
cancer might be a key one.
And being overweight or obese isrelated to some of the cancers
that are really hard to avoidand treat, like pancreas and
ovary.
So, yes, being obese oroverweight affects lots of

(11:57):
cancers, but particularly thosetwo, which are quite worrisome.
All right, try to reduce yourexposure to the sun.
Now, that doesn't mean don't getyour early morning sun to help
your circadian rhythms and yoursleep at night, but wear a
long-sleeve shirt, put sunscreenon regularly throughout the day,

(12:20):
and that can help reduce yourrisk of skin cancer.
I mentioned certain viruses likethe HPV virus and cervical
cancer.
Get the vaccines to preventthose infections.
So HPV and hepatitis B vaccinesare part of the routine kids'
immunization schedule.

(12:42):
So make sure that your kids,grandkids are getting those.
And here's one of my favoriteones: exercise.
As we know, exercise helpsprevent stroke, it helps prevent
heart attack, it helps preventcognitive decline.
Guess what?
It has an apparent uh connectionto cancer as well.
In a large study where theycombined a bunch of smaller

(13:05):
studies, they had over a millionpeople and they looked at how
much they exercised and the riskof 26 different cancers.
And when they compared thepeople who did a lot of exercise
versus very low exercise, thehigh exercise people had a 10 to
20 percent lower risk of coloncancer, lung cancer, breast

(13:28):
cancer, and other cancers.
Now, like a lot of observationalstudies, they didn't adjust for
everything.
So maybe the exercise peoplewere skinnier.
And as we've talked about, beingoverweight is related to cancer.
So it's possible it's not justthe exercise solving the problem
or helping the problem.

(13:48):
It may be mediated throughweight loss.
If you can exercise, if you canget your weight under control.
But here's a really neat studythat was done in colon cancer
patients.
So these people already hadcolon cancer, but they got
treated and they were in fullremission.
They followed these people foreight years and they divided

(14:10):
them in a randomized way into anexercise group or a not no
additional exercise group.
And what they found was a 30%reduction in recurrence of the
colon cancer in patients whounderwent the exercise regimen.
That's amazing.
Now, obviously, we don't allhave colon cancer, but I believe

(14:31):
it says something about cancerin general, and I'm obviously
very bullish on that in terms ofexercise.
Okay, number six here, you mightconsider dietary changes.
In my episode number 47 aboutorganic foods, I described some
studies that compared people whoate five servings of fruits and

(14:54):
vegetables a day versus twoservings.
And guess what?
The people who had the morefruits and vegetables, they had
a one-third reduction in cancer.
Of course, this is confounded.
We don't know did they fullyadjust for, you know, people who
eat a lot of fruit andvegetables might be eating fewer
Twinkies and croissants, andtherefore those people might

(15:18):
have been skinnier.
So we can't disentangle that,but more fruits and vegetables
seems like a thing we should tryto do, and the data supports it.
There's also data on your dietrelated to fiber and colon
cancer.
There's a large meta-analysisdone in the journal Lancet that
looked at a whole bunch ofobservational studies, but also

(15:41):
58 randomized trials.
And what they found was thecancer rate, the colon cancer
rate, was 3% lower for every 15grams of fiber that people had.
So ideally, you'll get somethinglike a cup of lentils a day, or
a couple of cups of beans oroatmeal.

(16:04):
That kind of amount would bevery, very potentially helpful
to reduce your risk of coloncancer.
Again, confounded by issues ofweight, because we know weight
is a problem too.
I have to at least mention againabout the issue of bacon.
Do listen to my episode on that,or alcohol, which is my episode

(16:27):
24.
What else can you do?
Well, if you're in an airpollution-laden area, you're
living in a city where that'slikely to be the case, you can
get a HEPA filter in your home.
And it does get rid of some ofthe particulates in the home.
There are no clinical trialsshowing reduction in cancer, but

(16:48):
it's something if you wish youmight consider.
We don't have HEPA filters here,but then we live on a ranch and
uh we're not exposed to too muchpollution.
And lastly, that one of thethings you can do is get your
HPV vaccine and your hepatitis Bvaccine.
All right, step four.

(17:11):
Don't ignore new symptoms.
If you notice a lymph node or alump somewhere, if you have
blood coming from a place thatit shouldn't be, like you're
coughing blood, you're peeingblood, you have blood in your
stools, there's blood that mightbe uh coming from your vagina.

(17:31):
Even if it's tiny amounts, don'tignore it.
Go see your doctor, get checkedout, because it could be an
early warning sign of cancer.
And just because the bleedingstops, oh, I bled for a day or
two, but then it went away, thatdoesn't mean it's not something

(17:52):
serious because cancers bleedintermittently.
All right, step five, screen.
Get your cancer screening forthe items that make sense.
So for women, obviously amammogram and a pap smear.
For a man, potentially a PSA,but that's a whole nother topic.

(18:13):
Talk about that with yourdoctor.
Colonoscopy used to be age 50 or55, we began.
Now the recommendations at now45.
So get your colonoscopyscreenings if you're in that age
range.
If you're a smoker or anex-smoker, then a periodic CT
scan of your lungs has beenshown to be beneficial.

(18:36):
Screening for other cancers aretough.
I mean, ovarian and pancreatic,of course, you want to avoid
those.
But there's no good screeningrecommendations for general
avoidance.
However, if you have a familyhistory of those illnesses,
there are special screeningprotocols that might be
appropriate for you.

(18:57):
Talk to your doctor.
All right, what about thathighly advertised total body MRI
that will look at you from headto toe and find all those little
things that might be cancer?
Listen to my episode on number12 on to test or not to test.
I talk about this directly.
For a typical person withoutsymptoms, it's likely to cause

(19:20):
more problems than it's going tosolve.
And finally, in the screeningworld, you hear about these
liquid biopsies.
Take a blood test.
We will determine if you haveone of 30 or 40 cancers.
You will then catch it early.
The promise is there.
The idea is wonderful.

(19:43):
And these blood tests can bepositive when you have cancer.
What hasn't been shown iswhether it makes a difference in
your outcome, in your survival.
But there haven't been thestudies to say people who did

(20:04):
the test compared to people whonever did the test.
Did the people who had the testlive longer, have fewer advanced
stage cancers?
That's the study we need to see.
And in the advance of that, Idon't suggest people spend$1,000
on the blood test because itisn't just a once-in-a-lifetime

(20:25):
thing.
Do you have to do it every year?
Do you have to do it every sixmonths?
How quickly does the cancer gofrom not present to present?
So I think it's not yet readyfor prime time, although I sure
hope at some point it is.
The final step to reduce yourrisk of cancer.
Be aware of what doesn't reduceyour risk.

(20:48):
You know, on the radio, onpodcasts, in the news media,
supplements, supplements,supplements, they will reduce
your risk of cancer.
Bottom line is the studies don'tsupport that.
Omega-3s have been tested a lotin observational studies and in
other types of studies, itdoesn't seem to help.

(21:09):
Antioxidants like beta-carotene.
There's been multiple largerandomized controlled trials, no
benefit.
Vitamin D, 25,000-person RCT,the vital study, tested vitamin
D, omega-3s, didn't help.
I will have the links to thesein the show notes, so by all

(21:29):
means take a look.
Vitamin C was touted as a greatpreventative for cancer.
Meta-analysis of seven RCTs, nobenefit.
Some people thought aspirinmight prevent cancer.
Large study in the elderly, nobig difference.
Sorry about that.
I wish it would help.

(21:50):
Okay, time to wrap up here.
Cancer is a frighteningdiagnosis, and we want to avoid
it if at all possible.
As I said at the outset, thegood news is 40% of the cases
are in fact preventable.
So find your risk factors and dowhat you can.
It might be smoking, it mayrelate to protecting yourself

(22:12):
from the sun, it may be weightcontrol as best as you can.
Do get appropriate screeningabsolutely to try to find any of
those cancers that you canscreen for in an early phase
possible.
60% I said are not preventable.
Gail, my dear wife, got uterinecancer, metastatic, and she had

(22:36):
zero risk factors.
So it can happen to you.
If it does, I have my episode onnavigating a serious illness
that might help you kind of workyour way through that journey.
As always, I hope you live longand well and do what you can to
reduce your cancer risk.

(22:58):
Thanks so much for listening toLive Long and Well with Dr.
Bobby.
If you like this episode, pleaseprovide a review on Apple or
Spotify or wherever you listen.
If you want to continue thisjourney or want to receive my
newsletter on practical andscientific ways to improve your

(23:18):
health and longevity, pleasevisit me at Dr.
Bobby Livelongandwell.com.
That's doctor as the dr bobbylivelongandwell.com.