Living Longer: Calories that Count (Longevity

Living Longer: Calories that Count

By Dr. Roy Walford

The maximum life span of humans is about 110 years; of mice, about 39 months. Thus far, mice over 39 months of age have not been produced by anything except selective restriction of calories in the diet. Calorie restriction (CR) has extended the 39-month maximum life span of mice to an impressive 56 months, which would correspond proportionally to a 158 year-old human. And the long-lived mice stay youthful in appearance, in mental and physical abilities, and show enhanced resistance to disease. These well-established facts are why the CR diet is now one of the principal areas of research in gerontology, and is receiving major emphasis from the National Institute on Aging.

So let's run briefly through the history of this remarkable CR phenomenon, and discuss what precisely it is, how and why it works to retard aging (to the extent that this is known), and whether it will work as dramatically in humans as it does in rodents. Historically, the field's development can be divided into five phases:

(1) The demonstration that mean and maximum life spans are greatly extended in rodents by a CR diet. This was first shown at Cornell University as long ago as 1935, and has been confirmed dozens of times elsewhere, right up to the present time. Also, the frequencies of a wide variety of diseases -- including virtually all types of cancer, cardiovascular disease, diabetes, kidney disease, autoimmune disease, ocular degeneration, plus others -- have been documented as being greatly reduced in CR animals. The reduction ranges from twofold to as much as tenfold. (For example, 50 percent of female control mice of a particular genetic strain develop breast cancer, but only 5 percent of the same strain if on a CR diet.)

(2) CR's effect on life span has been dramatic in every species so far tested, from invertebrates (spiders, worms, etc) up through fish and rodents. One may cautiously presume that it may be a "general" effect, and not simply a rodent phenomenon.

(3) How CR animals look, how they respond in tests of mental and physical abilities, their levels of blood sugar, insulin, blood lipids, blood pressure, and essentially all their physiologic parameters correspond to those of chronologically much, much younger animals. This area of research, namely the effect of CR on physiologic systems, was first opened in my laboratory in the early 1970s, with the immune system as representative yard stick. Over the past twenty years, we've continued this research for biochemical, endocrine, molecular genetic, and behavioral markers in a number of university laboratories.

(4) The search for the mechanism whereby a selective restriction of calories exerts such global effects upon so many systems; and finally

(5) The question whether those same effects would obtain in primates including humans. Can human aging be slowed and life span extended by a CR diet, and by how much?

What precisely is the CR diet? Giving animals fewer calories than they would consume by choice makes them live longer, with enhanced faculties, and with fewer diseases, but these fewer calories cannot come from the mouse counterpart of the typical junky American diet. While reduced in calories, the quality of the diet must be increased so that essential nutrients like vitamins, minerals, and amino acids are not reduced. The reason the semi-starved populations in parts of Africa or the Orient don't live longer is that they are not only calorie restricted, they are malnourished. The "adequate nutrition" side of CR is essential. Given that, then the fewer the calories, the longer the life, down to about 50 percent restriction in rodents, and the other beneficial effects noted above follow along proportionately. In other words, CR is not an all or none phenomenon. Even 10 percent restriction has a measurable beneficial effect. Of course, there is a lower limit. Below 50 percent takes you into actual calorie starvation, and the death rate increases. Fifty percent restriction is not recommended for humans. That's too close to being too few in the way of calories!

What is the mechanism behind CR's marvelous effects? If we knew the mechanism, perhaps we could achieve the same results by an easier method than restricting food intake. One thing is certain. The effect is only related to calories. As long as essential nutrients are present, the relative amounts of protein, carbohydrate, and fat make no difference. Life is extended and health is enhanced. Beyond that simple fact, we have an embarrassment of possibilities. The mechanism of CR can be interpreted according to most of the current theories of aging:

• CR increases the ability of the body to repair damaged DNA,
• Definitely decreases oxidative (free radical) damage in the body,
• Increases the levels of certain protective/repair proteins that respond to stress,
• Improves glucose-insulin metabolism,
• Delays age-related immunological decline as shown by virtually all immune functional tests.

CR is the strongest cancer-preventive technique known, although it's important to point out that disease prevention is a side effect of CR, and not the primary reason for the age-retardation or life span increase.
Dr. Richard Weindruch and I postulated some years ago that the mechanism is related to an increase in "metabolic efficiency." This can be thought of as leading to less "friction" in the body's generation of energy. Others have referred to this concept as "improved glucose fuel use." From the standpoint of evolutionary theory -- another approach to understanding the mechanism -- it has been proposed that CR kicks into play an "adaptive response." This response allows animals, faced by episodic periods of food shortage in the wild, to shift more of their metabolic energy into maintenance and repair, and so outlive or survive the period of deprivation.

In the one closely monitored human study (inside Biosphere 2 for two years), CR sharply lowered blood cholesterol (by up to 35 percent), blood sugar and blood insulin (by 15 to 20 percent), blood pressure (20 percent or more), and induced other changes paralleling those seen in CR rodents and (more recently) monkeys.

Human Application

Will CR retard aging (and do all the other wonderful things it does in lower animals) in primates, including humans? My answer is, "It almost certainly will." I say "almost" because it has not been applied in either monkey or human studies long enough to allow the demonstration of a change in maximum life span. Monkey studies will answer this first, and they are ongoing in three different laboratories (University of Wisconsin, University of Maryland, and the National Institute on Aging). It may be 10 to 12 years before we have unequivocal results. (Monkeys live a long time, although not as long as humans.)

So much for the "almost." The "certainly" in my answer is because (a) as so far tested, CR works across the whole animal kingdom, so it would indeed be surprising if it did not work in humans, and (b) studies on monkeys in the above three laboratories, and by me on the humans secluded for two years inside Biosphere 2, show quite clearly that the extensive physiologic and biochemical changes seen in CR rodents are also found in CR primates, including humans.

See one day in the life of a calorie restricted diet...

# For more information about the calorie restricted diet and Roy Walford, visit his Web site.

You get to live to be 150, but you have to eat three heads of cabbage each day...

I tried...but I could only get two down at a sitting.

Somehow downing a third gives me constipation.

Privately....I think the Cabbage Patch Kids are owned by Metemucil"

>"For example, 50 percent of female control mice of a particular genetic strain develop breast cancer, but only 5 percent of the same strain if on a CR diet." [paragraph 3]
>>Can I get a grant to determine why there are only 8 buns in a bag but 10 hot dogs in a package?

Of all the stupid
crap that gets funded these days,
why criticize this,

which actually
reports a repeatable
method for almost

eliminating
many cancers? It's a dream
come true. (But it's not

magic pills. It can't
be packaged and sold. It takes,
simply, self-control.)

This study might be
"evolution in action."
One group of people

will ignore it. They
will be -- statistically -- more
inclined to feel tired,

get sick, die young, not
compete with the folks who take
the study to heart.

Over time, the genes
that contribute to smartness
preferentially

will get passed on more
and simple numbers will make
our whole world smarter.

That is, I suppose,
if evolution does work
as it's supposed to...

>The amusing part is that he was a member of the "ecosphere" project. It turns out that the designers of that sealed environment neglected a teensy fact...

An academic
who performs experiments
on himself rather

rather than pale-skinned
grad students or unaware
population groups?

This guy certainly
is out of touch with modern
academia...

Admit it, you live in Wisconsin but you're a transplant, right?

You caught me. Left the land of fruits and nuts some six years ago, and still can't understand the obsession with cabbage here.

Brats, however, I understand fully...

Somehow downing a third gives me constipation.

That's the point. The first two give you the runs.

At least, they do if you are eating them correctly...

All you have to do is go to third world countries. A small percentage of people are healthy at 90. The bad news is most of the people taking low calories have what we doctors call "piss poor protoplasm". They are weak, have lousy immune systems, and die of minor infections.

Since these long lived rats don't come in contact with normal mice who have the mice versions of diarrhea, skin infections, or colds, of course they live longer.

So if you want to starve yourself to live longer, don't go outside or let anyone visit you who might have a cold...

I took a look at that recipe - too much preparation time, and too many ingredients. If that is representative of what the evening meal recipes are like, then that diet is a sure failure at my house. Not to mention sweet potatoes in manicotti! Good heavens.

>I took a look at that recipe - too much preparation time, and too many ingredients.

According to Sears,
all that you need to do is
cut 40%

off a "typical"
healthy 2,500
calorie diet.

Eat any balanced
load of 1,700
calories per day.

If you think in terms
of lean meat and fresh veggies,
that's a lotta food.

For people who think
(as I once did) in terms of
burgers, donuts and

Mountain Dew, it is
nothing. I'm trying to get
better. But it's hard...

Many thanks for the ping.

It would seem that this effect has been reasonably established. Why, then, have not the details been researched more vigorously?

There is Political Correctness even in science, albeit driven by a motive different from traditional partisan politcs, that simply will not allow entree to a radical finding---no matter how impecable the research design.

For example, consider the Nature vs Nurture fiasco on gender and sexual reassignment: Nature won--nurture cost a few kids their sanity (and genitals)---despite the Nurture-Bound scientists' bent toward a leftist, liberal agenda.

It took years, and much hardship for patients who were sexually reassigned as infants and who all failed in their doctor-imposed-but false-gender, to conclusively demonstrate the point:

Don't mess with Mother Nature.

My wife's great-grandmother lived to be 101. She was an old-fashioned Italian who was always cooking and telling everybody to "Eat, Eat, Eat." She was "portly" all her life and was never thin. My paternal grandmother is still alive today at age 91, the same age as Ronald Reagan. She lives in Alabama and ate southern cooking all her life. She gets up at 4AM every day and fixes biscuits and gravy every morning. She chews tobacco (snuff) and makes the best fried chicken I've ever had.

SO I don't know what to make of this study. I guess if I can live to be into my 90s eating what I'm eating, I'll be happy enough.

So I don't know what to make of this here study.

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