Why DNA damage from smoking and UV rays cause cancer in some but not others

ggmays about 2 hours ago 70 commentsRead Article on cam.ac.uk

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aantix•about 1 hour ago

Anecdotally, whenever I go swimming with my kids in the summer, and I don't put sunscreen on right away, but let myself get some intense direct sun, I feel good and sleep really well that night.

As long as I don't let myself get in a red, sunburn situation.

krrrh•about 1 hour ago

The number one reason I wear an Apple Watch all summer is the UV index complication. If the number is at 4 and trending down I let the kids run free.

pazimzadeh•about 1 hour ago

Interestingly the best time to go out is at solar noon, when the UVB/UVA ratio is higher. Just go for a shorter amount of time to compensate for the higher overall intensity.

tartoran•about 1 hour ago

That's only if you don't have a lot of time out. If you're planning to be out for a while I'd avoid being too exposed during the 12-3 window.

Rnonymous•about 1 hour ago

Care to explain? Isn't UVB more harmful than UVA?

bob1029•about 1 hour ago

I can spend a solid hour in the sun before I start to burn, assuming I have a hat on my head.

I've also noticed some correlation between my diet and how fast I burn. Whenever my metabolism is running at/near ketogenesis, it seems like it takes a lot longer for the sun to affect me.

Ralfp•about 1 hour ago

Yes, some stuff make your skin more sensitive to light than others. For example, you should avoid vitamin A creams and some herbs during summer because they increase risk of permanent skin discoloration.

pazimzadeh•about 1 hour ago

Which herbs

spacephysics•about 1 hour ago

I experienced similar reaction when i was doing keto. It became far more difficult to burn that summer

ShinyLeftPad•39 minutes ago

Why did you stop?

IshKebab•about 1 hour ago

Just so you know, burning & cancer isn't the only reason to avoid strong sunlight - it also causes skin aging (i.e. wrinkles). If you don't want to be super wrinkly when you're old, wear suncream!

causalmodels•41 minutes ago

When we were dating, the first thing my now wife did was get me on a regimin of sunscreen and tretinoin. I now have significantly fewer wrinkles than my younger siblings (2-3 years).

ThrowawayTestr•about 1 hour ago

Vitamin D deficiency

GlickWick•about 1 hour ago

Definitely not. Vitamin D takes a while to synthesize and build up. A quick fix like this isn't possible.

pixel_popping•43 minutes ago

It's just that getting sun is healthy (in moderation) and our body reward us, we have this new anti-sun obsession which is likely to cause many health (and mental health) issues

brightball•about 1 hour ago

I typically do the same thing. I only wear sunscreen if I am planning on being in direct sun for an extended period of time where I can't easily get back in the shade.

The more you're able to build up a base tan the less you need it to avoid a burn at least.

stevekemp•26 minutes ago

I'm a pale-skinned redhead, covered in freckles. For me there is no such thing as a "base tan".

I get can get sunburnt from as little as 30 minutes in the sun at times, and I almost always wear sunscreen in the summer for that reason.

(Biggest issue is wearing sandals and forgetting to cover my feet, or when jumping in the lake after sauna and not covering up again quickly enough.)

vondur•about 1 hour ago

I'm pretty light skinned and the burn pretty easily. I just put on sunscreen by default when going hiking/mountain biking. I'm really excited for the new sunscreens coming out here in the US that have those new to us ingredients that the Euro's have had forever.

brightball•42 minutes ago

Agreed completely. I also leverage sun shirts quite a bit.

NikolaNovak•about 1 hour ago

Isn't tanning basically body's reaction to cellular damage? It reduces further damage but that's due to damage done?

(It's largely irrelevant to myself, I pretty much burn immediately and don't / can't really tan, but my wife and her family tan well).

HedonicEscal8r•14 minutes ago

Yes, tanning is downstream of the activity of the p53 tumor suppressor protein in response to UVB-induced damage: https://www.lesswrong.com/posts/EFiCGc3YwadZBzvZ3/contra-byr...

brightball•about 1 hour ago

30 years ago I was a lifeguard and got to experiment with this some. I can't tell you the biology specifically, but I have always tanned quickly. The less tan I am, the more easily I burn.

Always been that way for me at least.

worldsavior•43 minutes ago

The damage gets healed at sleep. Tanning reduces the need to heal.

JoshGlazebrook•about 1 hour ago

So we're just out here perpetuating myths on here now as well?

brightball•about 1 hour ago

Correction - The less you need it to avoid a burn.

TaupeRanger•about 1 hour ago

Very common press release/headline meme: the question in the title of the article is literally never answered (or the opposite of the headline's claim is true). This research plainly DOES NOT explain why certain mice got cancer and others didn't, let alone why smoking/UV rays cause cancer in some humans but not others. There was no control group for exposed mice that would've allowed them to look at which biological differences made one group get tumors and the others not (the study doesn't appear to actually be interested in that question).

The language here is also pretty hyperbolic. We've known for decades that certain gene mutations cause increased cancer risk in the context of a certain genetic background (BRCA1/2, etc.). Using language like "for the first time" is just juvenile, or purposeful lying at worst.

tombert•about 1 hour ago

I've only ever smoked like a quarter of one cigarette when I was eighteen and I thought it was fucking gross so I never picked up the habit (fortunately).

That said, I'm a pretty pale dude and my sister has gotten skin cancer twice now [1], so I've started getting a bit worried that that's going to happen to me. I've started wearing a baseball cap every time I go outside to protect my scalp (since my body has decided I don't need nearly as much hair anymore), I almost never go outside without jeans and often now a hoodie even when it's relatively warm outside. If I think I'm going to be outside for more than ~30 minutes, I wear sunscreen on the exposed parts.

I have to admit that I kind of hate it. I don't like the slimy feeling of sunscreen on my skin, I don't really like how hats feel on my head, and of course wearing a lot of clothes when it's warm outside isn't terribly comfortable.

[1] Fortunately caught very early since she gets frequent checks, so she's fine.

zamadatix•40 minutes ago

Timing is also a big part. Going out for an hour at 1 pm can be a burn while going from 7 to sunset for the week might not even register.

If you must go out at certain times then the clothing selections from others are probably the best bet.

brightball•about 1 hour ago

Sun shirts are a great option for me at least.

thisoneisreal•about 1 hour ago

Check out mineral based sunscreens, I have sensitive skin and I find them infinitely more tolerable.

pilgrim0•about 1 hour ago

Also share the icky for greasy sunscreen. But there are some with a matte dry texture that not only serves the purpose but also make your skin looks nicer, since it levels out those small color variations. It’s a big market, so they really do research on those things.

itsmartapuntocm•about 1 hour ago

A fairly bad sunburn was the reality check I needed to start scheduling annual screenings. 30 minutes or so a year for peace of mind.

Mezzie•about 1 hour ago

Strong recommend a UV umbrella. I also hate the feeling of sunscreen and will also fry the minute I so much as look at the sun.

Also, linen clothing. Far more comfortable in heat while keeping you covered. Hoodies and jeans sounds miserable.

tombert•about 1 hour ago

I've more or less gotten used to the jeans.

Probably due to a combination of undiagnosed autism and some very mild bullying in middle school (due to me growing rapidly and people making fun of me for wearing "short shorts"), I have been almost exclusively wearing jeans for everywhere but the gym since eighth grade.

The hoodies are a more recent thing and are more miserable. I'll check out linen clothing.

Mezzie•about 1 hour ago

Yeah, there are linen pants too, so you don't have to wear shorts if you don't feel comfortable showing your legs. Linen in general is a great option if you want to not die of heat and you don't feel like showing your whole body to the world.

Since you're autistic, you might want to buy them in person: the tactile sensation of linens can be pretty different, so you might want to touch them before buying if sensory issues are a clothing concern.

One thing to look out for is that a lot of clothing that will come up when you search for linen are linen blends, which are better than a hoodie by far, but aren't going to have the same breeziness as 100% linen. Also, 100% linen wrinkles, so you've got to hang it right out of the dryer if you care about that.

Krssst•about 1 hour ago

I would bet on the sunscreen being a better protection since it also protects against reflected light, but UV umbrellas are so much more convenient. Takes 2s to take out rather than 5min to apply sunscreen properly.

(except when it's windy. Rain usually follows the wind, sunlight does not)

Mezzie•44 minutes ago

Good point re: wind. We don't really get substantial wind + sunlight where I live often. Definitely something to keep in mind.

I'm not sure re: the sunscreen being better. Maybe as a platonic ideal, but it's really easy to miss places when applying sunscreen, whereas a UV umbrella does cover everything with no fuss.

ShinyLeftPad•38 minutes ago

How is UV umbrella different from any normal umbrella?

leawi•about 1 hour ago

A bit offtopic, but have you tried different sunscreen types? There are quite a lot of formulations from matte creams to solid sticks. Mentioned because I remember avoiding sunscreens precisely because of that slimy feeling I got from the drugstore ones, that is, until I found an "invisible" one that doesn't feel like anything at all on my skin.

tombert•about 1 hour ago

I have not. Do you have any recommendations for specific brands? I'll order a bottle and try it out.

leawi•about 1 hour ago

There are honestly quite a lot of them, I usually take whatever's on sale. My favorite so far is Haruhatu Airyfit, but I was also happy with La Roche-Posay (Athelios dry-touch) and Neutrogena (dry-touch or matte). I also like to take Abib stick with me when I travel, it's just really easy to reapply and fits in the pocket.

Edit: I'd also say avoid anything that says "moisturizing" unless you have a really dry skin, they all claim their product is not greasy, and they are all lying, from my experience.

JoeAltmaier•about 2 hours ago

In mice

htek•about 1 hour ago

Mice are used for inhalation and skin studies because they're cheap, we know their genome, they have a short lifespan for whole lifecycle observation and they're ideal for mapping to human respiratory and skin responses.

add-sub-mul-div•about 1 hour ago

These comments are filled with people who believe that everyone else here is dumber than they are. Leaving shallow dismissive comments explaining something that doesn't need to be explained is like crack to them.

manarth•about 1 hour ago

It's a bit more than that.

The migration from mouse models to human understanding is long and complex, and although it's a meme, "in mice" is a good shortcut for saying "This is a good start, but it's not ready to extrapolate into conclusions against the impact to human beings".

https://www.in-mice.com/

baxtr•about 1 hour ago

Mice smoke?

theoreticalmal•about 1 hour ago

Only the cool ones

manarth•about 1 hour ago

  > "Mice smoke?"

The experiment summary:

  > "The team bred four strains of mice.
  >  They then exposed the mice to a single dose of the liver carcinogen diethylnitrosamine (DEN).
  >  DEN is found in tobacco smoke."

They simulated the "consequences" of smoking in mice.

pasc1878•about 1 hour ago

When near the lab's Bunsen burner.

kraquepype•about 1 hour ago

Only if they grew up near a BBQ joint

coolThingsFirst•about 1 hour ago

Even if smoking didnt cause cancer it would still be terrible.

6 months since i quit using nic gums.

doctoboggan•about 1 hour ago

Isn't this sort of like asking "Why does getting shot kill some but not other?" It depends on which part of the body was shot, and which part of the DNA was damaged.

mr_mitm•about 1 hour ago

The way I read the article was that cancer is caused by deficiencies in the body's repair mechanism. It appears as if some have a more robust mechanism than others, depending on genetics.

dyauspitr•about 1 hour ago

My mom had 14 siblings and only one of them got breast cancer (she was a nun and never breastfed which drastically increases a woman’s odds of breast cancer). But prior to that, her mother’s family, which was also large never had a case of cancer. My mom’s siblings also had around 30 kids between them some now in their 60s. There hasn’t been a single case of cancer amongst the kids either. So it’s something like 150 people with only one instance of cancer over the last 3 generations. There is definitely a strong genetic component to this.

tartoran•about 1 hour ago

Yes, genetics play a big part but my understanding that cancer is influenced by both genetic and environmental factors. It's possible to have similar habits in the family with respect to sun exposure, alcohol consumtion, diets etc..

Noaidi•about 1 hour ago

No. Genetics and nutrition make a big difference here. It is like one person is wearing a bullet proof vest and both were shot in the same place.

Noaidi•about 1 hour ago

This is why Zinc is needed to prevent cancer[1].

The gene they are focusing on in the study [2] is Methylated-DNA--protein-cysteine methyltransferase (MGMT) and it needs zinc as a cofactor [3].

Not enough zinc, lower MGMT, and less DNA protection and repair.

Nutritional deficiencies and genetic differences increase the risk of cancer.

[1] https://link.springer.com/article/10.1007/s12011-023-03818-6 [2] https://www.nature.com/articles/s41586-026-10821-z [3] https://www.uniprot.org/uniprotkb/P16455/entry

SketchySeaBeast•about 1 hour ago

That would imply that red meat eaters would be less likely to get cancer which doesn't seem to be the case. I'm not saying that zinc isn't a factor, but I think that saying a blanket "Zinc is needed to prevent cancer" is irresponsible. We should be so lucky that we can narrow it down to a single dietary element or be able to blame it simply upon nutrition.

kelipso•about 1 hour ago

That’s not how statistical implication works… Learn about sufficient condition vs required condition before you start criticizing people. Taking zinc and smoking cigarettes still increases your chances of cancer, for example.

SketchySeaBeast•37 minutes ago

I understand that entirely. I'm saying that the way that GP is presenting their information it sounds like a "one neat trick", which of course it isn't because nothing ever is, which you and I are in agreement upon.

crims0n•about 1 hour ago

As a millennial growing up it was beaten into our head that smoking was a death sentence. I recently looked up what the actual cancer rate among smokers was... about 125k people in the US die of lung cancer annual. 25 million people smoke annually. That is a 0.5% chance for occasional smokers. Even if you smoke a pack a day your entire life, the cancer rate is less than 15%.

I am in no way saying it is okay to smoke, there are obviously other health risks associated with it... but researching that made me feel much better about that one pack a year I buy for vacation.

wpm•about 1 hour ago

And that 125k includes people who don't smoke and never have. Sometimes the DNA in a single cell just gets fucked up in just the right way to cause cancer. Smoking just increases the odds.

dblohm7•24 minutes ago

Cancer is not the only complication...

gdulli•13 minutes ago

Exactly. Hypertension, emphysema, people who don't smoke not wanting to be anywhere near you,

pdntspa•41 minutes ago

The actual infection rates for some STIs are also similarly low, per-encounter. But they are high enough that if you are promiscuous and have a large number of at-risk encounters then you will eventually get a bad roll of the dice.