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Medicine Science

Reducing One Amino Acid Could Increase Lifespan 286

Posted by timothy
from the for-compulsive-food-sorters dept.
John Bryson writes "Eating less of one amino acid might lengthen your life. There have been lots of previous studies showing that many species live long on highly restricted calories, but a lot of this benefit may be possible by only restricting one amino acid. Amino acids that have shown this have been tryptophan and methionine. A recent study, published online December 2 in Nature, a highly respected journal, may help explain some of the health benefits of restricted-calorie diets."
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Reducing One Amino Acid Could Increase Lifespan

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  • Yes, but... (Score:2, Interesting)

    by mano.m (1587187) on Sunday December 06, 2009 @02:52AM (#30341774)
    how do you screen for one amino acid that may keep popping up in a hundred different foodstuff in various amounts? Unless you took a daily dose of something to chelate out that one a.a. from the body. Hmm....
  • by Tangentc (1637287) on Sunday December 06, 2009 @03:27AM (#30341882)
    RTFA indeed, if you read as far as the third paragraph you'd know that it was also proven on mice, dogs, and baboons. That makes this pretty likely to apply to humans as well. Though I'm confused as to why the summary says that tryptophan also has this property, as the article doesn't even use the word. I couldn't find the original Nature article, but the linked one certainly said nothing about it.
  • by Anonymous Coward on Sunday December 06, 2009 @03:27AM (#30341886)

    What's methionine found in?

    From wikipedia: Methionine is one of only two amino acids encoded by a single codon (AUG) in the standard genetic code (tryptophan, encoded by UGG, is the other). The codon AUG is also the "Start" message for a ribosome that signals the initiation of protein translation from mRNA. As a consequence, methionine is incorporated into the N-terminal position of all proteins in eukaryotes and archaea during translation, although it is usually removed by post-translational modification.

    Wild speculation on my part is that methionine and tryptophan could be amino acids that have particularly strong effects on protein synthesis generally (e.g if you don't have enough methionine you can't even start making each protein).

  • Amino Acids (Score:4, Interesting)

    by LightPhoenix7 (1070028) on Sunday December 06, 2009 @04:08AM (#30341980)

    So... what they discovered is that limiting diets reduce reproduction at the expense of lifespan?

    Color me skeptical, but this is not exactly new. It's well known that limited diets reduce reproductive metabolism in favor of survival. After all, what good is reproduction if you don't live to do it.

    Now, I'm not saying this is all bunk. I don't know. What I am saying is that all this really proves is that methionine is necessary for egg-laying and lifespan in Drosophila. That's a far stretch from saying that reducing methionine increases lifespan in well-fed humans. In fact, what TFA says is that there is a discrepancy in studies. In fact, TFA doesn't even mention tryptophan, so I don't know where the submitter got that.

    Unfortunately, I can't access the Nature article right now. However, I'll definitely be taking a look at it tomorrow, because I am extremely skeptical of these claims.

  • by shawb (16347) on Sunday December 06, 2009 @05:47AM (#30342290)
    True, to get sleepy from the tryptophan in turkey, one would have to figure out how to eat that turkey without eating the other amino acids present... it only promotes sleepiness when consumed on its own.

    However, there is still a twisted nugget of almost truth if you follow one of the current theories on postprandial sedation. The whole chain goes something like this:
    Eating large amounts of starchy food -> increased blood sugar levels.
    elevated blood sugar -> insulin release
    elevated insulin levels -> increased absorption of long chain amino acids into muscle tissue
    increased absorption of long chain amino acids -> decreased blood serum levels of long chain amino acids
    decreased serum long chain amino acid levels -> increased serum ratio of short chain/long chain amino acids
    tryptophan is a short chain amino acid, and higher serum ratios of tryptophan lead to increased production of seratonin and melatonin, leading to sleepiness.

    So yes, there is some tryptophan in turkey. And tryptophan supplements can induce sleepiness, but they need to be taken on an empty stomach to do so. That is because digesting pure tryptophan will also increase the serum ration of tryptophan to other amino acids. However in a traidional thankgsiving feast, it's the massive overload of carbs in the stuffing, corn, bread, mashed potatoes, green bean casserole, sweet potatoes, cranberry marshmallow fluff, pie, whipped cream and even gravy (it's thickened with starch) that lead to the sleep inducing increased serum ratio of tryptophan. Some of the sleepiness can also be blamed on redirecting a good portion of blood flow to the digestive system to tackle the huge meal just consumed. A glass of wine or two can provide enough alcohol for the final KO providing the need to sleep.
  • Re:Yes, but... (Score:1, Interesting)

    by Anonymous Coward on Sunday December 06, 2009 @08:16AM (#30342716)

    Those problems may be solvable, however. We may be able to extend the average healthy human lifespan to 100+ years and reverse problems like mental decline, cancer, etc. Probably not in our lifetime though.

    Then we'll probably have to deal with overpopulation. There's a limited amount of natural resources here on Earth. Probably we'll have colonies in space by them. It'll probably be a lousy quality of life for everyone involved though, assuming we haven't killed everyone off in wars by then.

  • Re:Yes, but... (Score:3, Interesting)

    by biryokumaru (822262) * <biryokumaru@gmail.com> on Sunday December 06, 2009 @08:35AM (#30342810)

    I'm not advocating euthenasia or anything so extreme

    Many civilizations throughout history have not considered euthanasia extreme by any means. Just because our particular religious influence is somewhat more restrictive than those of other civilizations doesn't mean that their practices were barbaric. It's entirely possible that once all this Christ nonsense dies down, people might have a much more reasonable view of what constitutes "extreme."

    I am advocating euthanasia. Or, more precisely, assisted suicide. Adults of sound mind should have the option while their mind is still sound.

  • Re:Yes, but... (Score:3, Interesting)

    by Quickening (15069) on Sunday December 06, 2009 @12:06PM (#30343966) Homepage

    So they say but not necessarily for all people. They discovered almost 30 years ago that low tryptophan diets duplicated the effects of caloric restriction (in lab rats). It's not so difficult to lower tryptophan in a vegetarian diet, for instance, if your primary protein source is yogurt.. This works because tryptophan and phenylalanine compete to cross the blood-brain barrier and you can easily identify which foods have the highest ratio of phe to try. I made it part of my life extension program decades ago, and heh, it works for me. The group of Bulgarian centenarians who have eaten large amounts of yogurt their whole lives supports it too.

  • Re:Yes, but... (Score:5, Interesting)

    by PopeRatzo (965947) * on Sunday December 06, 2009 @12:17PM (#30344024) Homepage Journal

    It's not politicians that would attempt to prevent the general availability of a longevity drug. It's much more probable that the drug company that held the patent would restrict it's use by keeping the price artificially high.

    Look at the case of ulcer drugs. At one time, anti-ulcer medications were the top money-makers for drug companies. Even long after research showed that ulcers were caused by bacteria, and could be easily cured by cheap generic antibiotics, drug companies tried to suppress that research in order to maintain their profits. Even after it was widely known and accepted by health providers, drug companies spent tens of millions trying to convince doctors that this simple fix was somehow not in their patients' best interest. It's one example of how a profit motive does not favor the public good.

    Currently, drug companies only fund research that is guaranteed to develop drugs that can be patented, ignoring completely commonly available substances that could be beneficial.

  • by Idiomatick (976696) on Sunday December 06, 2009 @12:59PM (#30344346)
    Bronze age != hunter gathers.

    And the abundance thing is true in some places... In places where we still see hunter gather societies they haven't grown because their food is such a pain in the ass to get it sucks up all their time. And the reason hunter gather groups were LIMITED to sizes of about 50 people was because of scarcity. If food were less scarce larger populations could have been supported. Perhaps there was a good food:human ratio but like starving people in africa prove. Food existing doesn't mean you can get at it.

    Err... and you get progressively more 'naturalistic fallacy' and end up on the bible :S

    I got work or I'd debate, if another /.er wants to, go right ahead.
  • Re:Yes, but... (Score:3, Interesting)

    by ultranova (717540) on Monday December 07, 2009 @09:36AM (#30352754)

    Do try and remember economic leaders are human beings.

    Actually, doesn't research show that economic leaders - corporate CEOs, specifically, but judging by their behavior many large investors should be included too - have a very high incidence rate of psychopathy? A psychopath is missing what's usually termed "humanity"; consequently, I must question your assertion.

    But it is doubtful they'd conspire against us, especially when it would mean shortening their own lifespans and their children's.

    A psychopath is someone completely lacking empathy, and thus care for his children or anyone else. And even perfectly ordinary humans have a truly wonderful capacity for doing horrible things. So no, I don't think that it's at all certain that they wouldn't conspire against others.

    Once the cat isout of the bag they have no reasonable means of keeping it too expensive.

    In the long run, yes; but in the short, human enchancement technology will almost certainly increase existing class divisions, especially considering the current unfortunate trend of ultra-liberal economic policy.

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