National Institute on Aging

AgePage

Life Extension:

Science Fact or

Science Fiction?

Bill just died of a heart attack at age 67.

His brother, Jim, twelve years older, still

enjoys playing golf once a week. Why is

Jim living so much longer? Does he take

after their mother’s family who all lived

into their eighties? Or, does he just have

a healthier lifestyle?

What makes people grow old?

How can we live longer? Why do

members of some families seem

to live longer than others? Can

people live to 150 years old? Would

you want to? These questions have

fascinated people for centuries.

Now scientists who study aging,

called gerontologists, are trying

to answer them.

Genes now being studied may

one day answer some of these questions. Genes might be considered

little packets of information found

in each cell in our bodies. These

packets contain instructions that

tell our bodies how to grow and

work. For example, they control

whether we get our grandmother’s

blue eyes or our father’s crooked

little finger. For some people

genes may affect how long

they live.

Areas of Research

Several “longevity genes” have

been found in some living

organisms. Scientists studying

certain worms and fruit flies

have found several genes

that seem to control how

long these creatures

live. By making a

change in just

one of these

genes, they

have almost

doubled the

average

lifespan of

both fruit

flies and one type of

1 2 
National Institute on Aging

AgePage

Life Extension:

Science Fact or

Science Fiction?

Bill just died of a heart attack at age 67.

His brother, Jim, twelve years older, still

enjoys playing golf once a week. Why is

Jim living so much longer? Does he take

after their mother’s family who all lived

into their eighties? Or, does he just have

a healthier lifestyle?

What makes people grow old?

How can we live longer? Why do

members of some families seem

to live longer than others? Can

people live to 150 years old? Would

you want to? These questions have

fascinated people for centuries.

Now scientists who study aging,

called gerontologists, are trying

to answer them.

Genes now being studied may

one day answer some of these questions. Genes might be considered

little packets of information found

in each cell in our bodies. These

packets contain instructions that

tell our bodies how to grow and

work. For example, they control

whether we get our grandmother’s

blue eyes or our father’s crooked

little finger. For some people

genes may affect how long

they live.

Areas of Research

Several “longevity genes” have

been found in some living

organisms. Scientists studying

certain worms and fruit flies

have found several genes

that seem to control how

long these creatures

live. By making a

change in just

one of these

genes, they

have almost

doubled the

average

lifespan of

both fruit

flies and one type of

1 2 
National Institute on Aging

AgePage

Life Extension:

Science Fact or

Science Fiction?

Bill just died of a heart attack at age 67.

His brother, Jim, twelve years older, still

enjoys playing golf once a week. Why is

Jim living so much longer? Does he take

after their mother’s family who all lived

into their eighties? Or, does he just have

a healthier lifestyle?

What makes people grow old?

How can we live longer? Why do

members of some families seem

to live longer than others? Can

people live to 150 years old? Would

you want to? These questions have

fascinated people for centuries.

Now scientists who study aging,

called gerontologists, are trying

to answer them.

Genes now being studied may

one day answer some of these questions. Genes might be considered

little packets of information found

in each cell in our bodies. These

packets contain instructions that

tell our bodies how to grow and

work. For example, they control

whether we get our grandmother’s

blue eyes or our father’s crooked

little finger. For some people

genes may affect how long

they live.

Areas of Research

Several “longevity genes” have

been found in some living

organisms. Scientists studying

certain worms and fruit flies

have found several genes

that seem to control how

long these creatures

live. By making a

change in just

one of these

genes, they

have almost

doubled the

average

lifespan of

both fruit

flies and one type of

1 2 
National Institute on Aging

AgePage

Life Extension:

Science Fact or

Science Fiction?

Bill just died of a heart attack at age 67.

His brother, Jim, twelve years older, still

enjoys playing golf once a week. Why is

Jim living so much longer? Does he take

after their mother’s family who all lived

into their eighties? Or, does he just have

a healthier lifestyle?

What makes people grow old?

How can we live longer? Why do

members of some families seem

to live longer than others? Can

people live to 150 years old? Would

you want to? These questions have

fascinated people for centuries.

Now scientists who study aging,

called gerontologists, are trying

to answer them.

Genes now being studied may

one day answer some of these questions. Genes might be considered

little packets of information found

in each cell in our bodies. These

packets contain instructions that

tell our bodies how to grow and

work. For example, they control

whether we get our grandmother’s

blue eyes or our father’s crooked

little finger. For some people

genes may affect how long

they live.

Areas of Research

Several “longevity genes” have

been found in some living

organisms. Scientists studying

certain worms and fruit flies

have found several genes

that seem to control how

long these creatures

live. By making a

change in just

one of these

genes, they

have almost

doubled the

average

lifespan of

both fruit

flies and one type of

1 2 
or even to show that taking

DHEA is safe.

DHEA travels through the

bloodstream in a special form

called DHEA sulfate. It turns

into DHEA when it enters a cell.

Levels of DHEA sulfate are high

in younger people but tend to go

down with age. The body changes

DHEA into two other strong hormones: estrogen and testosterone.

Taking DHEA supplements can

cause some people’s bodies to

make large amounts of these two

hormones. This could be dangerous. High levels of naturally made

testosterone in men and estrogen in women may play a role in

prostate cancer in men and breast

cancer in women. Experts do not

know if supplements of DHEA

will increase your chance of

developing these cancers.

Growth Hormone

Similar claims of more energy

and muscle strength and less

body fat are also made for human

growth hormone (hGH) supplements. This hormone is made

naturally by the pituitary gland.

Children need hGH to grow

✦ Vitamin C—at least 75 milligrams (mg) per day for women

and 90 mg for men, although

smokers need more. No one

should have more than 2,000

mg per day.

✦ Vitamin E—at least 15 mg per

day from food and not more

than 1,000 mg per day.

DHEA

DHEA is short for dehydroepiandrosterone. This is a hormone that has

modified some age-related changes

in animals. When given to mice,

it boosted some components of

the immune

system and

helped prevent

some kinds of

cancer. Several

studies in older

people have

shown that

DHEA helps

build muscle,

but other studies have not agreed.

Some people hope DHEA will

improve energy and immunity,

increase muscles, and decrease

body fat, but there is not enough

research to support these claims

9 10 
or even to show that taking

DHEA is safe.

DHEA travels through the

bloodstream in a special form

called DHEA sulfate. It turns

into DHEA when it enters a cell.

Levels of DHEA sulfate are high

in younger people but tend to go

down with age. The body changes

DHEA into two other strong hormones: estrogen and testosterone.

Taking DHEA supplements can

cause some people’s bodies to

make large amounts of these two

hormones. This could be dangerous. High levels of naturally made

testosterone in men and estrogen in women may play a role in

prostate cancer in men and breast

cancer in women. Experts do not

know if supplements of DHEA

will increase your chance of

developing these cancers.

Growth Hormone

Similar claims of more energy

and muscle strength and less

body fat are also made for human

growth hormone (hGH) supplements. This hormone is made

naturally by the pituitary gland.

Children need hGH to grow

✦ Vitamin C—at least 75 milligrams (mg) per day for women

and 90 mg for men, although

smokers need more. No one

should have more than 2,000

mg per day.

✦ Vitamin E—at least 15 mg per

day from food and not more

than 1,000 mg per day.

DHEA

DHEA is short for dehydroepiandrosterone. This is a hormone that has

modified some age-related changes

in animals. When given to mice,

it boosted some components of

the immune

system and

helped prevent

some kinds of

cancer. Several

studies in older

people have

shown that

DHEA helps

build muscle,

but other studies have not agreed.

Some people hope DHEA will

improve energy and immunity,

increase muscles, and decrease

body fat, but there is not enough

research to support these claims

9 10 
or even to show that taking

DHEA is safe.

DHEA travels through the

bloodstream in a special form

called DHEA sulfate. It turns

into DHEA when it enters a cell.

Levels of DHEA sulfate are high

in younger people but tend to go

down with age. The body changes

DHEA into two other strong hormones: estrogen and testosterone.

Taking DHEA supplements can

cause some people’s bodies to

make large amounts of these two

hormones. This could be dangerous. High levels of naturally made

testosterone in men and estrogen in women may play a role in

prostate cancer in men and breast

cancer in women. Experts do not

know if supplements of DHEA

will increase your chance of

developing these cancers.

Growth Hormone

Similar claims of more energy

and muscle strength and less

body fat are also made for human

growth hormone (hGH) supplements. This hormone is made

naturally by the pituitary gland.

Children need hGH to grow

✦ Vitamin C—at least 75 milligrams (mg) per day for women

and 90 mg for men, although

smokers need more. No one

should have more than 2,000

mg per day.

✦ Vitamin E—at least 15 mg per

day from food and not more

than 1,000 mg per day.

DHEA

DHEA is short for dehydroepiandrosterone. This is a hormone that has

modified some age-related changes

in animals. When given to mice,

it boosted some components of

the immune

system and

helped prevent

some kinds of

cancer. Several

studies in older

people have

shown that

DHEA helps

build muscle,

but other studies have not agreed.

Some people hope DHEA will

improve energy and immunity,

increase muscles, and decrease

body fat, but there is not enough

research to support these claims

9 10 
or even to show that taking

DHEA is safe.

DHEA travels through the

bloodstream in a special form

called DHEA sulfate. It turns

into DHEA when it enters a cell.

Levels of DHEA sulfate are high

in younger people but tend to go

down with age. The body changes

DHEA into two other strong hormones: estrogen and testosterone.

Taking DHEA supplements can

cause some people’s bodies to

make large amounts of these two

hormones. This could be dangerous. High levels of naturally made

testosterone in men and estrogen in women may play a role in

prostate cancer in men and breast

cancer in women. Experts do not

know if supplements of DHEA

will increase your chance of

developing these cancers.

Growth Hormone

Similar claims of more energy

and muscle strength and less

body fat are also made for human

growth hormone (hGH) supplements. This hormone is made

naturally by the pituitary gland.

Children need hGH to grow

✦ Vitamin C—at least 75 milligrams (mg) per day for women

and 90 mg for men, although

smokers need more. No one

should have more than 2,000

mg per day.

✦ Vitamin E—at least 15 mg per

day from food and not more

than 1,000 mg per day.

DHEA

DHEA is short for dehydroepiandrosterone. This is a hormone that has

modified some age-related changes

in animals. When given to mice,

it boosted some components of

the immune

system and

helped prevent

some kinds of

cancer. Several

studies in older

people have

shown that

DHEA helps

build muscle,

but other studies have not agreed.

Some people hope DHEA will

improve energy and immunity,

increase muscles, and decrease

body fat, but there is not enough

research to support these claims

9 10