
Fish oil supplements linked to prostate cancer (2013) - leib
https://www.nhs.uk/news/cancer/fish-oil-supplements-linked-to-prostate-cancer/
======
rossdavidh
There is, I am starting to believe (regardless of whether or not this
particular finding holds up), an ongoing problem with our approach to
nutrition. The anti-pattern goes like this: 1) people who eat/drink X have
health benefits 2) it seems to be related to X having Y in it 3) let's sell Y
as a pill 4) dang, no health benefits, how did that happen?

Now this could be for several reasons. Maybe eating/drinking X is a marker for
a lifestyle that is healthy, or for coming from a background that includes
beneficial genes of some sort. Maybe Y is not the only thing in X which
matters, it's just the most obviously related thing, and you really need the
whole package. Maybe the amount of Y you get from eating/drinking X is good,
but in concentrated form at high levels there are drawbacks of some sort.

But, however you look at it, putting Y into a pill (that can often be patented
and sold as medicine) is not the same as eating/drinking X, and despite the
financial incentives for claiming it is, we need to recognize that.

~~~
noneeeed
It's like the whole thing with vitamin supplements. Unless you are actually
deficient in one of them, taking them isn't going to do much for you, and in
some cases might actually cause you harm. It's like fertiliser on a field,
after a certain point the plants can't use any more and it just runs off to
the rivers.

Vitamin C is a good one for that, I seem to remember reading that at best
taking large doses just means your piss contains a lot of it, and at worst, if
you mega-dose for long periods, it raises your chance of getting some cancers.

It reminds me of the adverts on the London Underground. Every time I travel
through London to see my parents there will be adverts medicalising lack of
sleep and exhaustion, flogging supplements and "remedies" for what is
basically being tired, or "chronic tiredness syndrome" as one advert described
it. I'm so glad I didn't choose that life.

~~~
ip26
Also risk of kidney stones.

~~~
noneeeed
Did not know about that one. Another reason not to waste my money :)

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dpatrick86
This was based on the SELECT trial data, which means that it could just as
easily be measuring the effects of a very large and prolonged dose of 400 IU
of alpha-tocopherol as it is omega-3. Greater than 12x RDA.

Moreover, it's been many years since this was published. If prostate cancer-
promoting effects were so plainly an obvious effect of marine omega-3
supplementation, you'd expect to have seen it abundantly replicated by now.

~~~
ip26
Maybe not, it's a very slow growing cancer, so they say.

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anaphor
Keep in mind that this does not mean you have a 70% chance of getting prostate
cancer if you take fish oil supplements.

Based on this[0], it's roughly an increase from about 0.02% chance to about
0.034% chance (given no other information to base your risk on)

[0][https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2706483/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2706483/)

~~~
com2kid
My understanding was that basically every man will, if they live long enough,
have some cancerous cells in their prostate.

The main risk seems to be going from "so slow growing you die of old age
first" to "fast enough growing it becomes a problem", unless I am horribly
mistaken.

~~~
papa_bear
I worked in a lab that was studying prostate cancer for a summer internship,
and most of our samples came from young men who died in motorcycle accidents.
They found that a majority of the samples had some presence of benign tumors,
but it only really becomes noticeable once malignant tumors develop.

I don't know how representative the samples were of the entire population -
one theory was that our young motorcycle samples had significantly higher
testosterone on average and were more likely to develop those tumors.

~~~
sandworm101
Young, and _dead_ motorcyclists. Young male motorcyclist is the definition of
testosterone-fueled lethality. (I grew out of sportbikes after two good
friends died.)

~~~
nabla9
The so called balls to brain ratio.

~~~
chillwaves
I ride bikes but am low T. For shame.

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sigmaprimus
Kind of an old article, here is a link to an article written around the same
time that was updated last summer.

[https://www.health.harvard.edu/blog/fish-oil-friend-or-
foe-2...](https://www.health.harvard.edu/blog/fish-oil-friend-or-
foe-201307126467)

~~~
kensai
At a certain point it says:

"Evidence linking fish oil and cancer has been all over the map. Some research
suggests diets high in fatty fish or fish oil supplements might reduce the
risk of certain cancers, including prostate cancer. Other research shows just
the opposite, a link between eating a lot of oily fish or taking potent fish
oil supplements and a 43% increased risk for prostate cancer overall, and a
71% increased risk for aggressive prostate cancer."

Go figure! I guess, inconclusive at best.

~~~
pmoriarty
What dose of fish oil does one need to consume in order for the diet to be
considered "high in fish oil"?

Also, I've read in the past that it's important to balance omega-3's with
omega-6. I wonder if any of this research takes that balance in to account.

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vfc1
The article does not talk about alternatives. A great alternative for Omega-3s
are ground flax seeds, one tablespoon a day mixed for example in your oatmeal
is enough - [https://nutritionfacts.org/topics/omega-3-fatty-
acids](https://nutritionfacts.org/topics/omega-3-fatty-acids)

Also for the derived DHA/EPA, there are pollutant-free alternatives based on
algae oil.

~~~
muterad_murilax
I prefer flax seed oil to ground flax seeds, due to cyanide being present in
the shells.

~~~
tachion
And do you think shells aren't pressed when the flax seeds are for oil
extraction?

~~~
muterad_murilax
Hydrogen cyanide is not fat soluble, so the levels are presumably much lower
in the oil.

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raverbashing
> It is worth bearing in mind that this study did not assess participants’
> diet and use of supplements. Researchers measured blood levels of fatty
> acids and analysed the association with prostate cancer risk. However, it is
> likely that the very high levels of fatty acids found in some participants’
> blood came from supplements.

Important point

2nd point to consider: is this for all types of cancer? More, less aggressive?
Benign enlargement of prostate? In the article (comparison of the lowest Om3
quartile with the highest Om3 quartile):

> 44% increased risk of low grade prostate cancer (HR (hazard ratio) = 1.44,
> 95% CI (confidence interval) = 1.08 to 1.93) > 71% increased risk of high
> grade prostate cancer (HR = 1.71, 95% CI = 1.00 to 2.94) > 43% increased
> risk of total prostate cancer (HR = 1.43, 95% CI = 1.09 to 1.88)

3rd point: could this be associated with something else (for example: heavy
metals in fish)

As most guidance by the NHS, this is very well explained and de-
sensationalized

> However, it cannot show that fish oil supplements cause prostate cancer and
> it is possible that other confounders affected men’s risk (although the
> researchers tried to take these into account)

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vannevar
The study in question does _not_ link fish oil supplements to cancer. It
correlates (with no clear evidence of causality) high blood levels of fatty
acids with actual cases of prostate cancer. It is _speculated_ that for at
least _some_ of the subjects, the high levels of fatty acids _may_ have come
from supplements.

FTA: "It is worth bearing in mind that this study did not assess participants’
diet and use of supplements. Researchers measured blood levels of fatty acids
and analysed the association with prostate cancer risk. However, it is likely
that the very high levels of fatty acids found in some participants’ blood
came from supplements."

------
newnewpdro
I prefer eating quality canned sardines regularly instead of taking these
supplements which can be viewed as a heavily processed industrial food derived
from sources of unknown provenance.

They have plenty of omega-3s and are very low on the food chain.

~~~
thefounder
A good meal is definitely better than a dozen of pills.

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golemotron
I don't like the reflexive notion that high levels of X in one's diet
necessarily translate into high levels of X in one's blood chemistry.

There should be a name for that nutritional fallacy.

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nickpsecurity
What about the packaging or matetial of the pill itself that contains the
supplements? And any additives in the process? The processed stuff usually has
higher risks. I wonder if any studies have been done on what contains the
drugs which they also consume.

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aitchnyu
NHS's Behind the Headlines is a welcome relief from pseudoscience. They
apparently have a beef with The Mail Online.

[https://www.nhs.uk/news/](https://www.nhs.uk/news/)

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willart4food
How about some "studies" to figure out the components of a well-balanced diet?

* macros

* what's out (well, this is easy actually)

* what's in

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vibrato
Let me give an alternative view of this epidemiological study.

"Those more interested in their health (motivated to take supplements or eat a
high omega-3 diet) more likely to be diagnosed by their doctor with common
health issues"

~~~
nraynaud
Participants were selected by having a cancer. Have you read the article? it's
about growth rate.

~~~
pmoriarty
According to the article, _" In this type of study, cases of people who have a
particular outcome - in this case, prostate cancer - are matched against a
random group of people who do not develop the condition."_

That sounds to me that in fact they were looking at cancer-free people as
well.

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internet_user
tocopherols have been shown to have negative effects, including increased
mortality, in other studies too. Nothing new here.

~~~
tth3uoku
Most research has focused on α-tocopherol, which is thought to displace
γ-Tocopherol. In a 2000 study of the relationship between α-tocopherol,
γ-tocopherol, selenium, and prostate cancer, men in the highest fifth of the
distribution for γ-tocopherol were five time less likely to develop prostate
cancer than men in the lowest fifth. [1]

"Recent epidemiological and preclinical studies have indicated that γ- and
δ-tocopherols may be more effective because they are more efficient traps for
reactive oxygen and nitrogen species." [2]

1\.
[https://academic.oup.com/jnci/article/92/24/2018/2633585](https://academic.oup.com/jnci/article/92/24/2018/2633585)
2\.
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5337152/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5337152/)

