marco:

“In regards to the iPhone, where I can compare my use of Instapaper, the [Kindle’s] screen really makes a big difference for extended reading. But the biggest advantage is the Kindle’s lack of any good use other than reading. When I pick up a Kindle, I read.”

— 5typos.net: My Kindle 2 review (before the reality distortion field) This is one reason why I love reading on the Kindle, and one reason why reading (with or without Instapaper) works so much better on _anything else_, including the iPhone and hopefully tomorrow’s thing, than on a general-purpose computer: the setting and flow of computer use don’t force (or, usually, permit) the focus needed for meaningful reading.

5 bucks says Marco actually knows what’s going on and is going to surprise everyone by being on stage today talking about instapaper on the tablet.

crazy stuff coming out of MIT.  putting screenshots into python code??

I just realized I never linked to this.  CAPRI is the Critical Assessment of PRediction of Interactions.  It is a blind protein docking competition participated in by an international community.  Really, the name is because they had to find an acronym that fit the location of the first assessment conference, Capri.  This year’s assessment conference was in Barcelona, which was great to visit.

Where am I going?  The first talk listed on this page has a write up I did of our group’s recent research on protein docking.  (I’m the D. Hall in the author’s list on the talk.)  So, if you want to know what I do for fun, you can read it.

It seems we’re quite good at what we’re doing.  I’ll rip the first couple rows out of the table from another blog post:

#   Human groups:   Automatic Servers:   Scoring Exp.:
1   Sandor Vajda        CLUSPRO        Alexandre Bonvin
2   Martin Zacharias    HADDOCK          Paul Bates

We don’t participate in the “Scoring Experiment”, but if you read the first link, you would know I’m in Sandor Vajda’s group and work on the ClusPro server, which were each evaluated as the best performing over the last couple years of CAPRI in protein docking.  Suspend disbelief, but I actually work with some pretty smart people that manage to make me look good.  Pretty exciting stuff.

saltandfat’s reasoned respsonse.  I recant my accusations of denialism.  I blame the book I’m reading.

saltandfat:

cowsandmilk:

So, what do we see?  Forty two years of studies involving hundreds of thousands of patients, all with long follow up times on intervention.  And the longer the follow up time, the more pronounced the effect, indicating that continuing to eat more salt or eat less salt over longer periods of time had even more impact.

So, I don’t know where saltandfat gets their information on the lack of scientific links, but it seems to be bunk to me.  Large studies written up in major medical journals disagree with him, leaving him appearing to be the salt version of climate change denialists.

I knew this link was going to get me in trouble, I never thought I’d have the pleasure of being equated with a climate change denier. And the blog’s only been up a day! Is climate change denial the new Godwin’s Law?

My overall point is that people generally think that salt causes hypertension, full stop, but the evidence doesn’t bear that out. From Harold McGee’s “On Food and Science” p. 642-643:

Medical scientists have long suspected that constant excessive salt intake results in an excessive volume of plasma being contained in our blood vessels, and therefore causes high blood pressure, which damages the blood vessels and increases the risk of heart disease and stroke. However, low-salt diets have been found to lower high blood pressure only modestly,and only in some people. And low-salt diets have surprising side effects of their own, including undesirable increases in blood cholesterol levels. At this time, it appears that most beneficial non-medical influences on blood pressure are general dietary balance — more vegetables, fruits, and seeds rich in potassium, calcium and other minerals — together with physical exercise that conditions the whole cardiovascular system.

Gary Taubes has more on the political science of salt and the clash of public health and good science.

However, it would appear I was somewhat wrong, or at the very least poorly expressed my point. I do agree that we eat too much salt, thanks largely to processed food and that reducing that intake is a good thing. Cooking more is a great way to do that, but you shouldn’t fear the salt in your own kitchen. My big concern is a grand pronouncement that tells everyone to stop eating salt leading to vast misconceptions and bad science.

As far as I understand it, the science goes something like this: sodium is a necessary component of human health. Salt causes a temporary retention of water until it can be processed by the kidneys. People who already have hypertension or are at risk for strokes or other cardiovascular problems, due to a variety of lifestyle choices, should watch their salt intake. Modern, particularly western, diets have vastly more salt than the human body requires, largely thanks to processed foods, which also contain all kinds of other nasties, like refined carbohydrates and hydrogenated fats. Eat fewer processed foods, cook more, but don’t be afraid to use salt in the kitchen.

I have no desire to get into a fight over this and I’m certainly not going to back and forth reblog NO YOU’RE WRONG. I think that if more people ate more real food and less refined, prepackaged, high-sodium foods, we’d be better for it.

saltandfat:

Having already defeated smoking and trans fats, Michael Bloomberg has now turned his attention to salt. I’m certainly a fan of eliminating the first two but here I think Bloomberg’s gone too far in his coddling of New Yorkers. Salt is as misunderstood as it is an important component of the human diet and, in my mind, unfairly lumped together with truly noxious additives — like hydrogenated fats, artificial sweeteners and the dreaded high fructose corn syrup.

One of the worst misconceptions about salt is that it’s linked to high blood pressure and other heart diseases, despite no scientific evidence definitively linking the two. I’ll have more to say about salt in the future but put me down as an opponent of top down regulations against its use.

Saying studies aren’t definitive or that large enough studies haven’t been done is always a good way to fight something.  You can always do a larger study.

I don’t know where saltandfat got this bit about “no scientific evidence definitively linking” salt and high blood pressure.  The only scientist in the article says something very different, that reducing the amount of salt might result in Americans underconsuming and having ill effects.  This is a generic science quote though, as almost every substance has an optimal range for consumption.  Generally, Americans are well fed and are actually above this range.  The people who don’t get enough are those who are hungry, not those who merely reduce their consumption of salt.

So, I decided to visit pubmed.org and see if there was any evidence and any large studies relating salt intake to hypertension and/or cardiovascular disease.  I figured there should be, since this is a topic directly related to kidney failure, the most well funded disease in the US.  It has long been known that it is the system to study if you want to come up with something that makes consistent money, resistant to the health insurance status of the sick.  (In case you didn’t look at the link, when your kidneys fail, you almost automatically get on Medicare.)

What did my search find?  Let’s start with hypertension.  Lots of articles linking the two.  The best, just looking at the first few results, is from the American Journal of Hypertension.  Let’s just look at the abstract:

Background High dietary salt consumption is considered a risk factor for hypertension.

Methods In order to determine the relationship between dietary sodium and blood pressure in the Chinese population, several nationwide epidemiological surveys have been conducted to investigate salt intake and the incidence of high blood pressure.

Results These surveys found that the residents living in the cold northern and northwestern areas of mainland China consume significantly more sodium than people from the south, that the average blood pressure and prevalence of hypertension are higher in the high-salt-consuming population, and that salt consumption correlates with blood pressure. It was also found that the nationwide prevalence of hypertension increased threefold over the past 30 years, but there was no parallel increase in salt consumption. In the same period, due to improved living standards, the occurrence of overweight or obesity in adults has increased significantly, which might contribute to the elevated prevalence of hypertension.

Conclusion Thus, approaches to preventing hypertension should entail both dietary salt restriction and weight control.

So, this sounds like a pretty good review to me.  Nationwide studies in China showing that people who eat more salty food have higher blood pressure.  But blood pressure has also gone up independent of salt intake over time.  So there are other things that cause high blood pressure, including obesity.  So, if you have someone with high blood pressure, you can either encourage him to lose weight or to reduce his salt intake, or both, and his blood pressure will go down.  Based on the number of articles in pubmed, none of which seemed to have wishy-washy abstracts, this link seems pretty definitive.

Let’s move on to other cardiovascular diseases, which saltandfat claims also are not linked to salt intake.  Let’s look at the abstract to a British Medical Journal article:

Objective To assess the relation between the level of habitual salt intake and stroke or total cardiovascular disease outcome.

Design Systematic review and meta-analysis of prospective studies published 1966-2008.

Data sources Medline (1966-2008), Embase (from 1988), AMED (from 1985), CINAHL (from 1982), Psychinfo (from 1985), and the Cochrane Library.

Review methods For each study, relative risks and 95% confidence intervals were extracted and pooled with a random effect model, weighting for the inverse of the variance. Heterogeneity, publication bias, subgroup, and meta-regression analyses were performed. Criteria for inclusion were prospective adult population study, assessment of salt intake as baseline exposure, assessment of either stroke or total cardiovascular disease as outcome, follow-up of at least three years, indication of number of participants exposed and number of events across different salt intake categories.

Results There were 19 independent cohort samples from 13 studies, with 177 025 participants (follow-up 3.5-19 years) and over 11 000 vascular events. Higher salt intake was associated with greater risk of stroke (pooled relative risk 1.23, 95% confidence interval 1.06 to 1.43; P=0.007) and cardiovascular disease (1.14, 0.99 to 1.32; P=0.07), with no significant evidence of publication bias. For cardiovascular disease, sensitivity analysis showed that the exclusion of a single study led to a pooled estimate of 1.17 (1.02 to 1.34; P=0.02). The associations observed were greater the larger the difference in sodium intake and the longer the follow-up.

Conclusions High salt intake is associated with significantly increased risk of stroke and total cardiovascular disease. Because of imprecision in measurement of salt intake, these effect sizes are likely to be underestimated. These results support the role of a substantial population reduction in salt intake for the prevention of cardiovascular disease.

So, what do we see?  Forty two years of studies involving hundreds of thousands of patients, all with long follow up times on intervention.  And the longer the follow up time, the more pronounced the effect, indicating that continuing to eat more salt or eat less salt over longer periods of time had even more impact.

So, I don’t know where saltandfat gets their information on the lack of scientific links, but it seems to be bunk to me.  Large studies written up in major medical journals disagree with him, leaving him appearing to be the salt version of climate change denialists (see http://tumblelog.cowsandmilk.net/post/344498729/salt-and-science).

Excellent article about a well thought out piece of battlefield technology.