
Dietary Carbohydrates Impair Healthspan and Promote Mortality - hunterjrj
http://www.cell.com/cell-metabolism/fulltext/S1550-4131%2817%2930562-4#.WeA77GhVXhk.reddit
======
fasteo
Note that this is probably _not_ what you are thinking (low-carb, very-low
carb or even keto diets are good for your healthspan).

The lowest quintile in this study were consuming 46,4% of kcal from carbs
(that's about 230 gram of carbs for a 2000 kcal total intake). Not even close
to low carb by today's standard in the health blogosphere.

The authors make this explicit in the discussion section:

>>> However, the absence of association between low carbohydrate intake (eg,
<50% of energy) and health outcomes does not provide support for very low
carbohydrate diets. Importantly, a certain amount of carbohydrate is necessary
to meet short-term energy demands during physical activity and so moderate
intakes (eg, 50–55% of energy) are likely to be more appropriate than either
very high or very low carbohydrate intakes.

~~~
randallsquared
> Importantly, a certain amount of carbohydrate is necessary to meet short-
> term energy demands during physical activity [...]

Why would they make such a claim? Anyone who has done keto and worked out has
probably had the experience of doing quite a lot of physical activity while
having had no carbohydrate intake at all for half a day before, or more.

~~~
mkrecny
Half a day of carb restriction wouldn't meaningfully deplete glycogen stores.

~~~
didgeoridoo
I’ve been <20g of carbs per day since February 2016. My athletic performance
was impaired for the first 6-8 weeks, but has since increased dramatically.

At low circulating insulin levels, most cells in your body can efficiently
metabolize fatty acids. For the minority of cells that cannot, your liver
converts protein into sugar by a process known as gluconeogenesis.

It’s very possible to be a performance athlete and eat very low carb.

------
cageface
This study is highly flawed:

[https://www.hsph.harvard.edu/nutritionsource/2017/09/08/pure...](https://www.hsph.harvard.edu/nutritionsource/2017/09/08/pure-
study-makes-headlines-but-the-conclusions-are-misleading/)

Be careful making any changes to your diet based on these "findings". The
healthiest populations on the planet eat plenty of carbs, but not refined
sugars.

~~~
CuriouslyC
I always wonder, when nutrition studies are usually so poorly designed and
controlled, why people don't just look at the blue zone diets for nutrition
guidance.

~~~
cloverich
Had not heard of "Blue zone"s before [1]. (EDIT: Added [2])

[1]:
[http://www.npr.org/sections/thesalt/2015/04/11/398325030/eat...](http://www.npr.org/sections/thesalt/2015/04/11/398325030/eating-
to-break-100-longevity-diet-tips-from-the-blue-zones)

[2]: [http://bluezones.com/recipes/](http://bluezones.com/recipes/)

------
shlant
I'm not surprised to see this at the top of HN considering how many people
seem to be fans of the Keto Diet. I am very excited for people who find
something that works for them, but I would be very wary of a study like this
if you are looking for confirmation for multiple reasons:

1\. The study "did not analyze which specific source of carbohydrates (e.g.,
sugar/refined carbs versus whole-grain products) may contribute to the
detrimental effects of carbs observed, especially since income and wealth do
impact the quality of dietary choices significantly."

This is HUGE. Any study or person that attempts to label an entire
macronutrient as "bad" or "evil" is not helping anyone understand the whole
picture. The most nutritious foods in the world are carbs. Many of the least
nutritious foods are also carbs. Not distinguishing the two gets us nowhere.

2\. With this study and most high fat/keto diet studies as well, the timeline
is not long enough to tell us about true "lifespan" impact. This one is over
7.4 years. I know it's more difficult to do 10, 20, 30 year studies, but until
something can be correlated over those timespans, I would not bet everything
on that diet for longevity. There are a handful of generational studies, and
almost all have shown that "high carb" or more specifically "plant based" ARE
good for longevity. Not saying high fat aren't good for longevity as well, but
we have yet to really see examples yet.

3\. As many who have tried Keto specifically will tell you (as some have
mentioned in the comments), it is very difficult to maintain a ketogenic
state. You have to be very disciplined, and this is made harder when you are a
social person. This is a big problem when talking about diet and longevity. If
it's not fairly easy to maintain, then it's not a feasible diet for longevity
where the average person is concerned.

4\. As someone else mentioned, the percentage of carbs that the studies
participants were eating were not even close to the level required for a Keto
Diet

------
cup-of-tea
I've read a lot of, often conflicting, dietry guidance. I have realised one
very important thing: humans will very easily accept that something they enjoy
is bad for them (see fat, sex etc.) So listening to what people _say_ is bad
for them is stupid.

Instead I have taken a simpler approach: I observe the lifestyles of people
who are healthy and live a long time. I have observed that eating simply
"good, old-fashioned" home cooked food is important. My grandmother lived into
her 90s. Ate fat and carbs. Julia Child lived into her 90s. Ate fat and carbs.
Edna Lewis lived into her 90s. Ate fat and carbs. I could go on. Just do what
they did and you'll have as good a chance as any.

~~~
maxxxxx
The problem is that simple home cooked food can't be commercialized. So all
advice that gets published will be for something where you can buy a product.

Same for exercise. We already know how to exercise but there are always people
who want to make money by repackaging it.

~~~
moretai
I don't know why, but I always felt that there was a market for a no-bullshit
movement, but I fear that the appeal of more money perverts the movement, and
then it just becomes like every other commodity. I think most things probably
start as well-intentioned, and whether it's money or power, something happens
along the way and subverts the whole thing.

------
whalesalad
I’ve been living a ketogenic lifestyle for a few years now. I go in and out
once and a while but seeing the “fat is bad” theory thrown out the window with
research like this makes it easier to remain committed.

The trouble comes with the way society has been conditioned to have carbs with
every meal. Like 90% of the food my peer group eats are surrounded in carbs.
Even for a company-wide lunch in the office: the go-to is usually a couple
dozen pizzas.

Once you’ve lived low carb for a long time you look at people in line at a
coffee house grabbing a bagel and a milkshake and just feel bad for the crash
they will have later.

I’m happy to see Keto becoming more and more socially known. Accessiblity
around low carb options is getting better and better. My favorite will always
be a protein style burger from In-N-Out though.

~~~
hduwvzvshsuz
You hit the nail on the head for exactly why I couldn't stick with a ketogenic
diet. It became too much of a burden on the people I was with to feed just me
because everything they wanted was stuff like tacos, pizza, rice dishes, fried
dishes, etc. I have an unresearched (by me) theory that the reason we have so
many carb heavy diets is due to the fact that carbs are such cheap calories.
They were good for surviving when we were poor but now we should move past
them

~~~
smn1234
agreed. I wish ketogenic meal kits and keto-friendly restaurant ratings /
reviews / guides / accreditation were more prominent.

~~~
toomuchtodo
Check out the /r/keto sidebar on Reddit. I keep various PDFs in Dropbox of
keto options at various fast food establishments. You can always get taco
bowls with no tortillas, McDonald's without the buns, a burger without the
buns at a burger joint, etc.

For emergencies, I keep a few shaker bottles in my car with protein power
already added. I just add water if we go somewhere with no keto options.

------
cko
> Next, a number of studies have evaluated the effects of specific
> macronutrients on lifespan, initially in S. cerevisiae (Lin et al., 2002),
> subsequently in C. elegans (Schulz et al., 2007 and follow-ups), and mice.
> Out of the latter, two studies in the previous issue of Cell Metabolism have
> studied this in mice starting at 12 months of age. In regards to the PURE
> study, most notably, the almost complete removal of carbohydrates (<1%) from
> the diet to generate a ketogenic diet extended lifespan compared to a high-
> carb diet. However, reconstituting only 10% of energy of the ketogenic diet
> by sugar abolished this effect (Roberts et al., 2017), suggesting that
> specifically sugar (rather than carbohydrates in general) has the most
> relevant effect on lifespan. Along this line, it is also interesting to note
> that when nutritive sugar content is kept constant, a different (and less
> extreme) high-carb diet exerts the best effects on murine lifespan. By
> contrast, a high-fat diet still containing the same amount of sugar, but no
> other carbs reduced lifespan slightly. Lastly, when combining high-fat and
> high-carb components from the two previous diets, the worst effect on
> lifespan was observed (Keipert et al., 2011). Moreover, lifespan extension
> in mice was also obtained when dietary protein was replaced by carbs,
> possibly independent of the total uptake in calories (Solon-Biet et al.,
> 2014). Taken together, these studies suggest that dietary sugar may be one
> important, but not the only, nutritional factor in limiting healthspan in
> rodents, hence additional studies are definitely required to establish firm
> evidence in model organisms.

This section of the article does not correspond to the title. In fact it
seemed all over the place, then goes on to conclude ‘maybe it’s refined
sugars.’

------
bigtunacan
Related; I saw on Hacker News awhile back a really great website that
aggregates a lot of this health research and then gives summaries of, "What's
the current known truth" based on all of the varying research. They then re-
market that data as a service somehow. Anyone on here recall this by chance as
I'm no longer able to locate it?

~~~
lurcio
Perhaps examine.com

[https://news.ycombinator.com/item?id=8138784](https://news.ycombinator.com/item?id=8138784)

[https://news.ycombinator.com/item?id=9956839](https://news.ycombinator.com/item?id=9956839)

~~~
bigtunacan
Yes, thank you! I've favorited it so I won't lose it again.

------
kbougy
Does it bother anyone that this study is intentionally misleading by masking
the fact that the carbohydrates tested were refined sugars?

~~~
shlant
as I mentioned in my comment, any study that lumps together all of one
macronutrient into one group and then attempts to reach conclusions based on
that grouping has very little understanding of nutrition.

------
trevyn
I’ve found eating out socially on keto a big challenge (carbs still look
delicious) until I found a hack: unreasonably large portions of salad, covered
in salt. Salt is fucking delicious. Add olive oil too if you feel like it.

~~~
smn1234
I drown everything in olive oil. Good, European protected designation of
origin (PDO), protected geographical indication (PGI), and traditional
specialities guaranteed (TSG) type olive oils. They're delicious. And you get
full rather quickly. That feeling lasts. And I'm fairly certain the plant fat
is not what's making us jiggly

~~~
neves
Why so many labels in your oil? Isn't extra virgin sufficient?

~~~
allwein
Actually, no. A large majority of "olive oil" sold is either fake or
adulterated. Those extra labels he mentions are to identify genuine and clean
olive oil.

~~~
splintercell
Are there any brands available on Amazon which meet this criteria?

------
bmcusick
And yet many of the longest-lived populations on earth have diets rich in
carbohydrates, like the Okinawans.

I hate associational studies like this which don't distinguish between types
of carbohydrates (sugar vs starch) or other factors, like whether they were
eating whole meals of natural foods or snacking on potato chips 24/7.

But at least they've finally noticed they were completely wrong about
saturated fat for 80 years.

------
H1Supreme
tl;dr Refined sugar contributes to getting fat, and an early grave. No shit,
Sherlock. They conveniently left out any reference to fiber, or the exact
sources of said carbohydrates. Sources matter tremendously due to fiber
content and levels of refinement.

Stick to fibrous veggies, beans, nuts, some fruit (berries are best), and
you'll be just fine eating carbs.

I'm not contesting the fact that ketogenic diets work for people. But this
study is kinda bullshit since it's basically alluding to the worst kind of
high GI refined carbs

------
shepardrtc
>>> (1)The conversion of D-glucose into metabolic intermediates, namely
glycolysis, can be inhibited by compounds like (the highly efficient but
rather toxic) 2-deoxy-D-glucose or (the less efficient but completely
harmless) D-glucosamine (GlcN). The latter is widely used to treat arthrosis
with the questionable claim of inducing cartilage regeneration. Both compounds
have been shown to extend C. elegans lifespan (Schulz et al., 2007, Weimer et
al., 2014), while only GlcN extends lifespan in rodents (Weimer et al., 2014).
Notably, GlcN uptake has been also associated with reduced mortality in a
large human cohort (Bell et al., 2012).

So does this mean the glucosamine chondroitin pills I take for my joints will
help reduce glucose conversion and extend my lifespan?

------
heliodor
As usual, correlation is incorrectly assumed to mean causality.

The summary text says there's causality. A few paragraphs into the study, the
text interchangeably uses causality and correlation:

>> found that carbohydrate intake was associated with increased total
mortality.

>> By contrast, any type of dietary fat reduced the likelihood of dying.

------
sjroot
Can anyone provide a TLDR on what exactly the conclusion of this article is?
My experience with a low-carb diet is quite similar to that of @whalesalad,
and it remains much more effective than any other diet or a strict exercise
regimen.

~~~
shlant
the TLDR is that this study tells us nothing about what diet is good for
longevity.

See my comment:
[https://news.ycombinator.com/item?id=15465516](https://news.ycombinator.com/item?id=15465516)

------
marze
Take home message?

Eliminate sugar, increase saturated fat. This study provides little guidance
on question “is total keto good or not”.

------
drpgq
"Moreover, there was no link to cardiovascular events or related mortality,
except for saturated fats, which were unexpectedly associated with a lower
risk of stroke."

That's interesting.

------
metalliqaz
Man I'm screwed. Don't drink, don't smoke, but totally addicted to carbs.
Granola bars...mmmmmm

~~~
digitalsushi
are you addicted to carbs, or are the critters living in your gut that get
hangry when you starve them? more of a talking point because i dont have my
head around it. my wife had me do a "die off" diet for several weeks of doing
keto; i got super bloated, got a rash everywhere, and then all of a sudden
felt skinny and good. ...then i binged and it was all normal again

~~~
metalliqaz
I am my critters and my critters are me.

