You Can Do a Lot to Prevent Some Cancers

Americans seem very afraid of cancer. Much of this fear is legitimate. Cancer is a significant cause of death. Unlike other causes, it often seems to come out of nowhere. It's the "silent killer".

But evidence increasingly argues that cancer may be preventable, too. Unfortunately, this has inflamed as much as it has assuaged people's fears.

Cancer prevention is the topic of this week's Healthcare Triage.


John Green -- Executive Producer
Stan Muller -- Director, Producer
Aaron Carroll -- Writer
Mark Olsen -- Graphics

And the housekeeping:

[anonEDM]

Twitch chat is the fastest growing source of cancer in today's youth.

[morgan]

I just wanted to say I love your channel! I'm going to university to study statistics and biology, and your focusing about statistical trials in medicine really excites me about the future career I want to have. It also shows everyone how important well designed studies are in medicine, and how bad studies can truly flip findings on their head. Thanks for a great channel!

[annakaiser]

Cancer is one of those terms that everyone knows, and most people have a story that pops in to their mind when they hear the term. Whether it be about their own battle with cancer or a battle they experienced second hand through a friend or family member, almost everyone has an experience with cancer. I myself have never not been surrounded by it, even from a young age. In my own personal family history, I have numerous different types of cancer ranging both on my father and mother’s side. Cancer, for me, is almost an inevitable fate. That is one of the reasons why this particular video really stuck out to me. How can we, as mere mortals, prevent something so much more destructive than ourselves? The idea of being able to prevent cancer is something that people have thought about for decades. Cancer prevention is an attainable thing to a certain extent. A healthy diet and lifestyle can greatly impact your risk of getting cancer. Whether it be eating healthier or staying out of the sun during the summer, we all know the common preventative measures taken in order to reduce our risk of getting one of the many different forms of cancer. It has recently been discussed that these “preventative measures” are actually extremely underestimated in their abilities to help prevent it though. But can we really prevent cancer in all of its entirety? I mean look at my situation, I am surrounded by cancer on both sides of my family tree. Genetically speaking, the probability that I will get some form of cancer at some point in my life is extremely high. So does that mean I shouldn’t follow these preventative steps because, even if I carefully follow all of the preventive measures that I possibly can, the likelihood of me getting cancer is basically 99.9%? From a girl who has accepted that I will have cancer at some point in my life I still plan on taking any preventative steps that I can because, well, why not? Maybe I will be in the 0.1% that magically, against all odds, doesn’t get cancer because I did everything I could to prevent it. And maybe if all of society thought this way about cancer, and other health issues, the statistics could drop and maybe then we wouldn’t all have a “cancer story” that pops into our heads when we hear that word.

[BrotherAlpha]

I'm three out of the four. I'm exercising more recently, so hopefully my weight will go down.

[eugenetswong]

I never thought that a video on cancer could cheer me up.

[DynamixWarePro]

I am in the low risk group as I don't drink or smoke, don't take dangerous drugs, exercise every day and maintain a healthy weight. The one thing that does bother me though is vehicle fumes and their negative effect on health and cancer risk from those, as its often hard to avoid vehicles these days unless you live in the middle of a wilderness somewhere away from most vehicles. I watched a program on TV earlier this year and have also read studies that showed that, even if your inside a car, you can still be exposed to lots of harmful toxins and driving in an electric car was better for your health than a car that used fossil fuels. Could you make a video on vehicle pollution and health?

[Rabbitthat]

I'm in the low risk group! Woo! But I'm planning on becoming a health professional.. so I'll probably be so stressed I stop exercising and start eating. I recently started cycling to work and it rules. I save 30 minutes a day, I get exercise, and I enjoy it.

[AbbeyB]

The thing I hate most about all this cancer prevention stuff that has gone a bit crazy and produced zealots that think they can avoid cancer by doing everything right is that sometimes, cancer is totally random and that sucks. My mom was 46 when she was diagnosed with stage 2-3 (they couldn't agree on the number) breast cancer. So many people would quiz her on all this prevention stuff until they started getting into the strange stuff like using paraben based soap and eating sugar to try to find a reason it happened to her and wouldn't happen to them. She wasn't a smoker, overweight, tall, inactive, immunocompromised, or from a family prone to cancer, and young. It was random misfortune and some people just refuse to accept that it could happen to them even if they did everything "right".

[krystalcounterman]

We know that the risk of cancers like lung cancer or skin cancer are increased by smoking or excessive exposure to the sun, but there is still so much about cancer that we haven't yet figured out. I agree with what the video say about being careful with how much weight we put on lifestyle causes of cancer. The idea that most cancer is preventable should help influence one's lifestyle choices hopefully, as long as it doesn't get to the point of not treating cancer that could have been prevented with the same diligence that we treat less avoidable cancers. I believe that this is one of those 'slippery slope' situations that we should try and avoid. However, it is also important to spread awareness about ways we can live a more "low-risk" lifestyle.

[angiera]

Love the video! Could you do a video on menopause for my mum haha. I think a lot of women get confused on the advice given to them by other women and on the Internet.

[anja]

I appreciate the work you're doing in making these videos!

[observingrogue]

I learned from the anime, Cells At Work, that laughter helps reduce cancer, because laughter energizes Natural Killer cells.

[lindseygamm]

Many people have a misconception about cancer, and that if you get cancer you just have "bad luck" and cannot prevent it. People often talk about cancer being one of their biggest fear but do they do anything to attempt to prevent cancer? Fitting in the four categories of the low-risk of cancer isn't anything too extreme. As discussed in the video the four requirements are: never smoking or have quit for over 5 years, moderately consumption of alcohol which was 1 drink or less per day for women and 2 drinks or less for men, having a BMI between 18.5 and 27.5, and completing 150 minutes of moderate activity or 75 minutes of strenuous activity. These requirements aren't as difficult as most people like to assume, and are quite reasonable. I think the problem is that people like to make up too many excuses for trying to meet these requirements. Some many argue that they don't have enough time to complete 150 minutes a week of moderate exercise but that breaks down to less than 30 minutes a day of exercise. That may seem like a lot, but think of how many minutes you spend watching tv, or scrolling through Facebook a day. Also, you don't have to be "skinny" to fit into the low-risk group either. The BMI for overweight as mentioned has a cut off of 25, whereas the requirement says no more than 27.5 BMI which means you just cannot be obese which is 30 BMI. Not smoking should be a reasonable requirement, as well as the moderate drinking. This does not say that you have to refrain from drinking, but rather drink a less amount. I think if more people knew about these requirements that they would try to meet them before they think it is impossible to quit drinking, or workout throughout the week.
The next point that stood out in this video is that although meeting those four requirements that were discussed, it does not completely eliminate your risk for cancer. It was stated that overall 25% of cancer in women and 33% of cancer in men could be prevented. That means that about 75% of cancer in women and 67% of cancer in men cannot be prevented. There is still a higher percentage of cancer that cannot be prevented but you cannot look at it from the negative viewpoint. These percentages do not mean don't try to prevent cancer. It is still beneficial to attempt to meet these four requirements not only to prevent cancer but to also prevent other health issues by living a healthier life.

[Kiimoro]

Techno should have watched this RIP techno 😢

[BaphomentIsAwsome]

Best way to avoid cancer is to fast a few times a year for at least 7 days.

[aalexaa]

most cancers are, in fact, due to stochastic mutations = bad luck. the study in question gets this right. they estimate about 1/3 of cancers are due to extrinsic factors, which is congruent with other estimates. 70-90% from the nature article significantly exceeds most estimates.

"If you interpret Vogelstein’s estimate the way it’s been represented in
the press and by Vogelstein, as representing the percentage of cancers
that are due primarily to “chance” and thus not related to environment
and not potentially preventable (a not unreasonable interpretation, by
the way), it turns out not to be such a bad first approximation at all.
It’s actually not far off from what has been a fairly accepted estimate
for quite a few years now, namely that between one third and one half of cancers are potentially preventable,
implying that they are due to environmental causes that can be altered,
such as smoking or diet. Given the level of uncertainty inherent in
such estimates, even if you interpret Vogelstein and Tomasetti’s
conclusion that two thirds of cancers are due to “bad luck, ” their
estimate of the percentage of cancers that are probably not preventable
is definitely in the ballpark of commonly-accepted estimates, albeit at
the lower end. Does that mean they’re on to something in concluding that
stem cell replication over one’s lifetime primarily determines the
“stochastic” component of cancer risk for each organ? That remains to be
seen, but their preliminary finding makes sense, both from the
perspective of producing a result that’s in the ballpark of what we
already know based on epidemiology and being biologically plausible
based on basic cancer biology."

"What this study suggests is that at least 2/3 of all all cancers are
due to random mutations – bad luck. The figure may be higher once breast
and prostate cancers are included. Of the remaining third it is not
clear how much is due to inherited genes vs lifestyle factors.
The logic of the study is sound, in my opinion. The authors assume
that lifestyle and genetic factors affect the risk of tissue-specific
cancers, but not cancer in general. This study would miss, however,
lifestyle or genetic factors that affected the risk of all cancers
(regardless of tissue type) equally. One might argue, therefore, that it
overestimates the role of random mutations, but that is only if you

"experts estimate that more than 4 in 10 cancer cases could be prevented by lifestyle change"


"“A large percentage of cancers, approximately 40%, are caused by
lifestyle factors, infectious diseases and environmental or
occupation-related hazards, meaning they arepotentially preventable”,
said Professor David Hill, Union for International Cancer Control (UICC)
President 2008-2010."

[ginnyjollykidd]

Didn't say much about breast cancer. In fact, it seems the only thing ever given was to perform self - breast exams and get mammograms. One presentation that was considered to make me low risk was fibrocystic breast disorder (Lumpy - bumpy breasts).
But I got breast cancer in 2016 as a 52-year - old. And my self - examinations didn't seem to tell me anything till one day I woke up on my belly, adjusted my boobs for comfort, and found a hazel nut - sized lump clearly on the outside perimeter of my breast, 12-o'clock high, if you will.

I learned so much about cancer during my treatment, and I found when I was in the grocery buying produce, I had cravings. I would search in Google regarding each food and cancer, and in every case, I found that there were chemicals in these fruits and veggies were being studied as candidates for creating new chemo medicines.

I didn't stop chemo and try to use only foods to cure it. If you can detect cancer, it's too late for that. But the cravings were fascinating to me. I'm a"kitchen sink" person: I'll throw everything at a problem, even the kitchen sink if I think it would help. So I followed my cravings.

Something I DIDN'T crave, strangely, was citrus fruits. Many cancer patients protest that oranges don't taste right. And I think people want to eat them because of vitamin C. That's all well and good, but vitamin C is in all fresh fruits AND vegetables.

I wanted cantaloupe, broccoli, cauliflower, rutabaga, bell peppers, grapes (especially black), blueberries, soybeans (edamame), tree nuts and peanuts, cabbage, beets, chicken AND pork (I wanted chicken soup so bad). Celery (I don't eat it most times) black beans and great northern beans, apples and Romaine lettuce, peas, potatoes, Braunschweiger, Cream of Wheat made with milk, eggs, and others. I did not prevent myself from eating meat, and my brother in law would get me a Rally's (Checkers) Baconzilla with 2 beef patties and bacon when he'd shop for me (and then made sure I ate it).

Eat fruits and veggies period. These chemicals that are being studied for chemotherapy treatment are available to everyone. The truth is, there is always one cell or another going rogue in your body, and that's what the immune system takes care of. When you eat the whole food, you get the benefit of whatever chemicals we don't know about, yet, and that can give us a benefit beyond what science knows yet.

[Rabbitthat]

We all get cancerous cells at some point, but the immune system usually recognizes it and kills it before it gets out of hand. What we call cancer is actually just too much cancer... we all get cancer all the time.
(a book called Genome and a book called Why we get Sick.. those are my sources)
I did a course on exercise and.. wow.. do we need to exercise
Also, being sedentary for long periods is bad, even if you exercise afterwards. Get up and move around every half hour!

[Vncts]

Hi Dr. Carroll,

I love watching your Healthcare Triage segments, I think they do a wonderful job at informing the public on relevant health related news of today. I am curious if you'd do a video on Physician Suicide and your thoughts on why it happens and how society might address this issue.

Thank you!

[Kara-tvns]

Some people think that cancer is the greatest cause of death when really, it is cardiovascular disease.  As mentioned in the video, some cancers are preventable while others are not.  I think it is important that people know how preventable some cancers can be, such as skin cancer.  In the summer, everyone likes to be tan and have bronze looking skin.  But do they really consider how harmful it can be to your body?  A lot of people will risk getting skin cancer from UV radiation when they want to look tan by either sitting outside in the sunlight or even going to a tanning salon.  Something as simple as wearing sunscreen can make a huge difference on someone.  I know I have a risk of getting cancer because my dad had been diagnosed with it.  Not only do I know that I have a chance of getting cancer, but I also know that it can be prevented.  Eating healthy and exercising is an effective way to prevent some cancers and since most people are worried that they will be diagnosed with cancer, everyone should be informed that sometimes those simple steps can prevent such a life threatening situation.  Unfortunately, some cancers cannot be prevented as easily because they are inherited.  Just because some cancers can be inherited, doesn’t mean that people shouldn’t try the steps to prevent it anyway.  Cancer is such a scary thing to witness whether it be first hand, or second hand through a family member or friend.  Anyone can get cancer, but anyone can also help reduce the risk of getting cancer.  With the help of chemotherapy and radiation treatment, some people are cured of cancer.  The cure for cancer has been being tested and experimented for so long and sometimes doesn’t always work.  Instead of waiting to see if they will be diagnosed with cancer, people should take the advice and use the steps to help reduce your risk of getting cancer.