Yeast Intake Linked To Longevity

[nobimbo]

Monday, 30 May, 2005

Yeast intake linked to longevity
Restricting the amount of yeast in the diet can increase life expectancy by 50%, research into fruit flies has shown.
It is not yet clear whether the same might be true in humans.

But the authors say their findings hint it might be what you eat rather than total calorie intake that influences longevity, contrary to current belief.

The University College London team told PLoS Biology how it could be down to metabolic pathways triggered by foods.

Quality not quantity

Lead researcher Professor Linda Partridge said: "Yeast and sugar trigger different metabolic pathways with different effects on life span.


Diet is an important issue we have largely ignored until recently
A spokesman from the International Longevity Centre UK

"The dramatic impact of reducing yeast suggests that protein or fat plays a greater role in fly longevity than sugar."

She said the results made a "strong case" that calories per se are not the important factor in prolonging life - at least in fruit flies.

A spokesman from the International Longevity Centre UK said: "At this point in time, it is difficult to state whether or not diet, rather than simply calorific intake, has a major bearing on life expectancy in humans."

Mediterranean foods

But he added: "Diet is an important issue we have largely ignored until recently.

"It is well established that obesity can be both highly unpleasant and harmful to life expectancy.

"It is interesting to note however that studies (such as Healthy Ageing: A Longitudinal Study in Europe) appear to confirm that a Mediterranean diet, rich in plant foods and fish, low in meat and dairy products, and with a high ratio of monounsaturated fatty acids to polyunsaturated fatty acids, strongly correlated with a lower mortality risk for cardiovascular disease and cancers.

"It seems likely, therefore, that calorific intake per se is not the only factor in assessing diet.

He said that a Mediterranean diet combined with exercise, moderate alcohol consumption and abstaining from smoking gave a person more years of good heath than any of these lifestyle factors alone.

He stressed that too little food could also be harmful.

For example, because metabolism slows with age, this often means the appetite for calories falls behind the nutritional needs for fluids, vitamins, minerals and protein, leaving the older person vulnerable to unnecessary malnutrition and disease, he said.




http://news.bbc.co.uk/1/hi/health/4583063.stm

[DietSka]

a Mediterranean diet, rich in plant foods and fish, low in meat and dairy products
Either the Italians aren't Mediterranean or they don't eat their famous (and yummy) cheeses. Mozzarella, Parmeggiano, mmm, drool. :yum:
The Greek also mustn't be Mediterranean, since their traditional diet staples are goat cheese and olives.

I wonder, is there a Mediterranean country that is actually eating this Mediterranean diet all the "experts" are raving about? :sarcasm:

[ojoj]

Although its about time the experts started looking at how calories work in the body and stopped sticking all "calories" under one heading - I'm not a fruit fly!

Jo

[Dodger]

The reasearch was on yeast in fruit flies, but the article suddenly shifted to pushing the 'Mediterranean' diet in humans, which has nothing to do with yeast or fruit fllies.

[Ayln]

So all those veal and sausage dishes I saw in Italian restaurants were just posers? And the thousands of different cheeses around that region... all a figment of my imagination!

In regards to yeast, they did not specify what type of yeast nor if the yeast was alive or dead. So should we all stop drinking wine, beer, and fermented drinks such as kvass? What about yeasted bread (which I personally don't condone for other reasons) and nutritional yeast, which the vegetarian and vegan communities are so fond of? I think they should be a little more specific when they publish articles such as this one.

[ceberezin]

Tha article contradicts itself. First it says that protein and fat seem to be key to longevity, at least in fruit flies, then the researchers recommend a diet low in meat and dairy products. They don't seem to be able to make up their minds, which is typical of researchers who are so bamboozled by the lipid hypothesis that they fail to understand the consequences of their own studies.

I see one major advance here. The researchers are saying that the important thing is not calories but the metabolic pathways stimulated by particular foods. Anything that focuses people on metabolic pathways as the key issue is an advance. We are witnessing a paradigm shift in medical science: from the disease management model to the metabolic pathway management model. This study has confirmed the new paradigm, but the researchers are not yet able to make the switch. So they don't understand the results of their study. The low carbohydrate way of eating is in the vanguard of the new paradigm. Progress is slow and halting, but it's happening, as this article shows.

[Nancy LC]

Here's a better article on the same subject.

http://www.newscientist.com/article.ns?id=dn7442

[tom sawyer]

So now we know how to shorten the lifespan of flies. That is good, I'm no great fan of the little buggers.

As far as calorie restriction and longevity in humans, I think one can end up eating fewer calories if one abstains from the majority of carbs.

And if you knew you could live an extra 20 years if you lived on a near-starvation diet, would you even want to? Would it really be worth it?

[Wyvrn]

It is interesting to note however that studies (such as Healthy Ageing: A Longitudinal Study in Europe) appear to confirm that a Mediterranean diet, rich in plant foods and fish, low in meat and dairy products,... It always makes me cringe to see plant foods (and especially grains) mentioned as something a diet is "rich" in, because a diet "rich" in plant materials is nutritionally inferior to a diet "poor" in plant foods.

....and with a high ratio of monounsaturated fatty acids to polyunsaturated fatty acids, strongly correlated with a lower mortality risk for cardiovascular disease and cancers. This gives me hope... the link between excess dietary PUFAs is at least being acknowledged, even if the author can't bring himself to admit that saturated fats are not the bogey they've been branded as.

For example, because metabolism slows with age, this often means the appetite for calories falls behind the nutritional needs for fluids, vitamins, minerals and protein, leaving the older person vulnerable to unnecessary malnutrition and disease, he said. And again, the author betrays his prejudice against fats by omitting them from his list of vital nutrients.

Wyv

[Ayln]

And if you knew you could live an extra 20 years if you lived on a near-starvation diet, would you even want to? Would it really be worth it?

Agreed! I'd rather live till 70 eating steaks and barbecue than 90 eating bran flakes and skim milk. At least I'd still be kicking when that time rolls around!

[Turtle2003]

Why are these studies set up so strangely and reported even more strangely? Why didn't all three groups on reduced calorie diets get the same amount of calories? Why 521 for the yeast/sugar diet but 860 for the two groups that got either more or less yeast vs sugar? And why give the exact percentage for the increase in life span of the lowest calorie diet flies but only say "But the flies on the higher calorie diet with reduced yeast intake did very well too." What does 'very well' mean? Knowing how desperately most researchers are to have their results support the lipid hypothesis makes me wonder if statistical shenanigans are going on here.

The message seems to be that if you want to live longer you should go on a reduced calorie, high sugar diet. Does anyone here really believe that?

[Nancy LC]

The 521 diet was the calorie restriction diet that yielded a longer lifespan. So they were comparing the 860 to that.

What is puzzling to me is that they said the fat/protein limited ones did nearly as well as the 521 calorie ones. I assume that yeast is protein? They're making the assumption that it was limiting protein that caused the life span increase, maybe fruit flies don't do well on yeast!

Also, the experimental groups were in-between the calorie restricted and control group, so how much of the effect was due to some calorie restriction?

So the researchers divided up their Drosophila melanogaster fruit flies into four groups and put them on different diets. The control group got the standard fruit fly lab meal of yeast, which contains protein and fat, and sugar - a meal boasting about 1200 kilocalories per litre.

The second group was fed on a calorie-restricted diet, with equal amounts of yeast and sugar - about 521 kilocalories per litre. The third group was given more yeast than sugar, while the fourth group got more sugar than yeast. The latter two diets had about 860 kilocalories per litre each.
Choice meal

The flies on the calorie restricted diet lived the longest - 82% longer compared to the controls. But the flies on the higher calorie diet with reduced yeast intake did very well too.

Lowering the amount of protein and fat in the flies’ diet helped increase lifespan by nearly 65%. “It accounts for nearly all of the effect,” says Partridge. “It cannot just be calories.” Eating less sugar increased longevity on

[ceberezin]

Let's remember that we're talking about fruit flies, creatures well adapted to subsist on the sugar in fruit, as we are not. Is it any wonder that they do better on reduced protein and fat, things that they are not adapted to but that we are.

The real meesage here may be that creatures do best on the diet to which they have adapted through evolution.

[Dodger]

The only things that the fruit flies were fed were yeast and sugar. The yeast was the source of protein and fat. The experiment really didn't determine anything about yeast because all the flies got yeast. Some got more yeast and less sugar and some less yeast and more sugar and others less yeast and less sugar.

[Turtle2003]

Let's remember that we're talking about fruit flies, creatures well adapted to subsist on the sugar in fruit, as we are not. Is it any wonder that they do better on reduced protein and fat, things that they are not adapted to but that we are.

Ah, very good point. Reminds me of those experiments where they fed lots of fat/cholesterol to rabbits, which caused their arteries to clog, which helped with early support for the cholesterol/lipid theory. They were using results gained from feeding a creature a diet which was not natural for it.

[ItsTheWooo]

Either the Italians aren't Mediterranean or they don't eat their famous (and yummy) cheeses. Mozzarella, Parmeggiano, mmm, drool. :yum:
The Greek also mustn't be Mediterranean, since their traditional diet staples are goat cheese and olives.

I wonder, is there a Mediterranean country that is actually eating this Mediterranean diet all the "experts" are raving about? :sarcasm:

People in the mediterranean eat richly when they can, and the foods they covet are fish, red meat like lamb, lots of fresh dairy (soft and hard aged cheeses). They eat lots of fat - animal meat, dairy, nuts, seeds, olives. They do eat plenty of carbs from refined grain and honey and dried fruits too but at least in my experience observing my north african side of the family, the "center of the meal" and what really "makes it" isn't the grain. The grain is there to "stretch the meal", the real prize is the fat and protein.

[322432]

Not worth my time