Longevity Gene Found

quixote9 writes "Calorie restriction while maintaining nutrient levels has long been known to dramatically increase life spans. Very different lab animals, from worms to mice, live up to 50% longer (or even more) on the restricted diets. However, so far, nobody has been able to figure out how this works. Scientists at the Salk Institute have found a specific gene in worms (there's a very similar one in people) that is directly involved in the longevity effect. That opens up the interesting possibility that doctors may someday be able to activate that gene directly and we can live long and prosper . . . without giving up chocolate."

Comments

Interesting similarities

[mapkinase]

BBC article has a link to another BBC article about an example of a man who followed this diet:

On a typical day, I will eat an oatmeal-based recipe for breakfast, which is about 455 calories and it gives me about half of my daily nutrients.

I don't eat lunch - after this breakfast I just don't feel hungry - so that leaves me about 1,350 calories for my evening meal, which is a lot.

This is very close to the dieting of the Muslims when they fast (obligatory fast during Ramadhan or voluntary fast during the month of Sha'ban, on Mondays and Thursdays, on 13,14 and 15th of each Islamic month or other recommended days).

We have a breakfast (Suhur) before dawn and do not eat or drink until sunset. After sunset we have a usual meal (Iftar). The only difference to the diet described in this BBC article is that we do not drink while Mr. Cavanaugh does.

abstract of original article

[mapkinase]

Abstract of original article in Nature:

Reduced food intake as a result of dietary restriction increases the lifespan of a wide variety of metazoans and delays the onset of multiple age-related pathologies. Dietary restriction elicits a genetically programmed response to nutrient availability that cannot be explained by a simple reduction in metabolism or slower growth of the organism. In the nematode worm Caenorhabditis elegans, the transcription factor PHA-4 has an essential role in the embryonic development of the foregut and is orthologous to genes encoding the mammalian family of Foxa transcription factors, Foxa1, Foxa2 and Foxa3. Foxa family members have important roles during development, but also act later in life to regulate glucagon production and glucose homeostasis, particularly in response to fasting. Here we describe a newly discovered, adult-specific function for PHA-4 in the regulation of diet-restriction-mediated longevity in C. elegans. The role of PHA-4 in lifespan determination is specific for dietary restriction, because it is not required for the increased longevity caused by other genetic pathways that regulate ageing.

The paper has a supplement PDF which unfortunately you won't be able to see unless your institution is subscribed to Nature. The figure S2 in it is an alignment of PHA-4 protein product to 3 most similar proteins in human. Some domains called forkhead are 85% identical, but really good alignment covers only about 90 of 506 residues of PHA-4 protein product. From my experience with proteins that qualify as orthologs, this alignment does not qualify. Homologene does not have a family of orthologs containing that worm product as well.

It does not mean that FOXA family does not do something for our longer lives, it just mean that article does not prove that via sequence similarity. Since I enjoy "trolling" I would add that (once again) Nature capitalizes on the subject importance and publishes articles with overstretching conclusions.

Re:OTOH

[syntaxglitch]

What is "Mainainence level"? Maintaining social security? Or maintaining rate of growth?

Maintaining raw population, meaning a growth rate greater than or equal to zero. Many first-world nations (notably, Japan and much of Europe) have more people dying than being born, resulting in negative population growth.

In general, education level and availability of technology correlate negatively with birth rate, and this holds true both between countries and between socio-economic groups within countries.

Re:Earlier death

[tomhudson]

All sugars promote tooth decay.

Also http://www.medicalnewstoday.com/medicalnews.php?ne wsid=65470, http://jcem.endojournals.org/cgi/content/full/89/6 /2963, http://www.sciencedaily.com/releases/2005/05/05050 3152956.htm

Fructose depresses leptin and insulin levels. Leptin is normally produced when you eat, and this triggers the "ok, I'm no longer hungry" signal in your brain so you stop eating. Lowering the leptin level causes you to still feel hungry, even after you've eaten. Switching from fructose to sucrose will allow your body to regulate itself better.

Its probably going to take some major lawsuits (and bankruptcies) to fix this problem ...

Re:Earlier death

[pla]

Seriously, if you want to extend life, ban fructose as a sweetener. Unlike regular sugar, fructose blocks the hormones that make you "feel full"

So people still fall for this one, eh?

Newsflash - Plain ol' table sugar (aka "sucrose") contains nearly the same amount of fructose as that big-bad-boogeyman, High Fructose Corn syrup!

Sucrose has a 50/50 mix of fructose and dextrose, while HFC contains from 43 to 55% fructose.


But by all means, keep blaming American's fat asses on HFC rather than admitting that we simply eat way too much and exercise way too little...

Re:Earlier death

[steelfood]

Sucrose is 50/50 fructose and glucose. http://en.wikipedia.org/wiki/Sucrose

HFCS in foods is largely 90/10. http://en.wikipedia.org/wiki/High_fructose_corn_sy rup

Only in sports drinks is the glucose content of HFCS higher than that of in sucrose.

The wikipedia article also mentions that the most common sweetener for processed foods and soft drinks is HFCS 55 (55/45), which isn't much greater in fructose content than the 50/50 of sucrose. However, they don't mention whether HFCS 90 or HFCS 55 is cheaper to process, which would make that the more prevalent variety. Regardless, it's safe to assume that HFCS foods have more fructose than if they were to have used sugar instead.

I'm not disagreeing that obesity is a result of eating too much and exercising too little. But what we eat also contributes to our health. And consuming large amounts of HFCS through processed foods doesn't help.