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TED2010

William Li: Can we eat to starve cancer?

February 10, 2010

William Li presents a new way to think about treating cancer and other diseases: anti-angiogenesis, preventing the growth of blood vessels that feed a tumor. The crucial first (and best) step: Eating cancer-fighting foods that cut off the supply lines and beat cancer at its own game.

William Li - Cancer researcher
William Li heads the Angiogenesis Foundation, a nonprofit that is re-conceptualizing global disease fighting. Full bio

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Double-click the English subtitles below to play the video.
Good afternoon.
00:17
There's a medical revolution happening all around us,
00:19
and it's one that's going to help us conquer
00:22
some of society's most dreaded conditions,
00:24
including cancer.
00:26
The revolution is called angiogenesis,
00:28
and it's based on the process
00:31
that our bodies use to grow blood vessels.
00:33
So why should we care about blood vessels?
00:36
Well, the human body is literally packed with them:
00:38
60,000 miles worth in a typical adult.
00:41
End to end, that would form a line
00:44
that would circle the earth twice.
00:46
The smallest blood vessels are called capillaries;
00:49
we've got 19 billion of them in our bodies.
00:52
And these are the vessels of life, and,
00:55
as I'll show you,
00:58
they can also be the vessels of death.
01:00
Now the remarkable thing about blood vessels
01:03
is that they have this ability
01:05
to adapt to whatever environment they're growing in.
01:07
For example, in the liver they form channels
01:09
to detoxify the blood;
01:11
in the lung they line air sacs for gas exchange;
01:13
in muscle they corkscrew so that muscles can contract
01:16
without cutting off circulation;
01:18
and in nerves they course along like power lines,
01:21
keeping those nerves alive.
01:23
We get most of these blood vessels
01:25
when we're actually still in the womb,
01:27
And what that means is that as adults,
01:29
blood vessels don't normally grow.
01:32
Except in a few special circumstances:
01:34
In women, blood vessels grow every month
01:38
to build the lining of the uterus;
01:40
during pregnancy, they form the placenta,
01:42
which connects mom and baby.
01:44
And after injury, blood vessels
01:47
actually have to grow under the scab
01:49
in order to heal a wound.
01:51
And this is actually what it looks like,
01:53
hundreds of blood vessels
01:55
all growing toward the center of the wound.
01:57
So the body has the ability to regulate
01:59
the amount of blood vessels that are present at any given time.
02:02
It does this through an elaborate
02:05
and elegant system of checks and balances,
02:07
stimulators and inhibitors of angiogenesis,
02:09
such that, when we need a brief burst of blood vessels,
02:12
the body can do this by releasing stimulators,
02:15
proteins called angiogenic factors
02:18
that act as natural fertilizer
02:20
and stimulate new blood vessels to sprout.
02:22
And when those excess vessels are no longer needed,
02:24
the body prunes them back to baseline
02:26
using naturally occurring inhibitors of angiogenesis.
02:29
Now there are other situations where we start beneath the baseline
02:33
and we need to grow more blood vessels just to get back to normal levels --
02:35
for example, after an injury --
02:38
and a body can do that too,
02:40
but only to that normal level,
02:42
that set point.
02:44
But what we now know is that for a number of diseases,
02:46
there are defects in the system
02:49
where the body can't prune back extra blood vessels
02:51
or can't grow enough new ones
02:54
in the right place at the right time.
02:56
And in these situations, angiogenesis
02:58
is out of balance.
03:00
And when angiogenesis is out of balance,
03:02
a myriad of diseases result.
03:04
For example, insufficient angiogenesis --
03:06
not enough blood vessels --
03:08
leads to wounds that don't heal, heart attacks,
03:10
legs without circulation, death from stroke,
03:13
nerve damage.
03:15
And on the other end, excessive angiogenesis --
03:17
too many blood vessels -- drives disease,
03:19
and we see this in cancer, blindness,
03:22
arthritis, obesity,
03:24
Alzheimer's disease.
03:26
In total, there are more than 70 major diseases
03:28
affecting more than a billion people worldwide,
03:31
that all look on the surface to be different from one another,
03:34
but all actually share
03:36
abnormal angiogenesis
03:38
as their common denominator.
03:40
And this realization is allowing us
03:42
to reconceptualize
03:44
the way that we actually approach these diseases
03:46
by controlling angiogenesis.
03:48
Now I'm going to focus on cancer
03:51
because angiogenesis is a hallmark of cancer,
03:53
every type of cancer.
03:56
So here we go.
03:58
This is a tumor: dark, gray, ominous mass
04:00
growing inside a brain.
04:02
And under the microscope, you can see
04:04
hundreds of these brown staining blood vessels,
04:06
capillaries that are feeding cancer cells,
04:08
bringing oxygen and nutrients.
04:10
But cancers don't start out like this.
04:13
And, in fact, cancers don't start out
04:15
with a blood supply.
04:17
They start out as small, microscopic nests of cells
04:19
that can only grow to
04:22
one half a cubic millimeter in size;
04:24
that's the tip of a ballpoint pen.
04:27
Then they can't get any larger because they don't have a blood supply,
04:29
so they don't have enough oxygen or nutrients.
04:31
In fact, we're probably forming these
04:34
microscopic cancers all the time in our body.
04:36
Autopsy studies from people who died in car accidents
04:40
have shown that about 40 percent of women
04:43
between the ages of 40 and 50
04:46
actually have microscopic
04:48
cancers in their breasts,
04:50
about 50 percent of men in their 50s and 60s
04:52
have microscopic prostate cancers,
04:54
and virtually 100 percent of us,
04:57
by the time we reach our 70s,
04:59
will have microscopic cancers growing in our thyroid.
05:01
Yet, without a blood supply,
05:04
most of these cancers
05:06
will never become dangerous.
05:08
Dr. Judah Folkman, who was my mentor
05:10
and who was the pioneer of the angiogenesis field,
05:12
once called this "cancer without disease."
05:15
So the body's ability to balance angiogenesis,
05:19
when it's working properly,
05:22
prevents blood vessels from feeding cancers.
05:24
And this turns out to be
05:26
one of our most important defense mechanisms
05:28
against cancer.
05:31
In fact, if you actually block angiogenesis
05:33
and prevent blood vessels from ever reaching cancer cells,
05:35
tumors simply can't grow up.
05:37
But once angiogenesis occurs,
05:39
cancers can grow exponentially.
05:41
And this is actually how
05:44
a cancer goes from being
05:46
harmless to deadly.
05:48
Cancer cells mutate
05:50
and they gain the ability to release
05:52
lots of those angiogenic factors, natural fertilizer,
05:54
that tip the balance in favor of blood vessels
05:56
invading the cancer.
05:58
And once those vessels invade the cancer,
06:00
it can expand, it can invade local tissues.
06:02
And the same vessels that are feeding tumors
06:05
allow cancer cells to exit into the circulation
06:07
as metastases.
06:10
And, unfortunately, this late stage of cancer
06:12
is the one at which it's most likely
06:15
to be diagnosed,
06:17
when angiogenesis is already turned on
06:19
and cancer cells are growing like wild.
06:21
So, if angiogenesis
06:25
is a tipping point
06:27
between a harmless cancer and a harmful one,
06:29
then one major part of the angiogenesis revolution
06:32
is a new approach to treating cancer
06:35
by cutting off the blood supply.
06:37
We call this antiangiogenic therapy,
06:40
and it's completely different from chemotherapy
06:43
because it selectively aims
06:45
at the blood vessels that are feeding the cancers.
06:47
And we can do this because
06:50
tumor blood vessels are unlike normal, healthy vessels
06:52
we see in other places of the body:
06:54
They're abnormal;
06:56
they're very poorly constructed;
06:58
and, because of that, they're highly vulnerable
07:00
to treatments that target them.
07:02
In effect, when we give cancer patients
07:05
antiangiogenic therapy --
07:07
here, an experimental drug for a glioma,
07:09
which is a type of brain tumor --
07:12
you can see that there are dramatic changes that occur
07:14
when the tumor is being starved.
07:17
Here's a woman with a breast cancer
07:19
being treated with the antiangiogenic drug called Avastin,
07:21
which is FDA approved.
07:24
And you can see that the halo of blood flow
07:26
disappears after treatment.
07:29
Well, I've just shown you
07:32
two very different types of cancer
07:34
that both responded to antiangiogenic therapy.
07:36
So, a few years ago, I asked myself,
07:39
"Can we take this one step further
07:41
and treat other cancers,
07:43
even in other species?"
07:45
So here is a nine year-old boxer named Milo
07:49
who had a very aggressive tumor
07:51
called a malignant neurofibroma growing on his shoulder.
07:53
It invaded into his lungs.
07:56
His veterinarian only gave him three months to live.
07:58
So we created a cocktail of antiangiogenic drugs
08:00
that could be mixed into his dog food
08:03
as well as an antiangiogenic cream
08:05
that could be applied on the surface of the tumor.
08:07
And within a few weeks of treatment,
08:10
we were able to slow down that cancer's growth
08:12
such that we were ultimately able to extend milo's survival
08:15
to six times what the veterinarian had initially predicted,
08:18
all with a very good quality of life.
08:21
And we subsequently treated more than 600 dogs.
08:24
We have about a 60 percent response rate
08:27
and improved survival for these pets
08:29
that were about to be euthanized.
08:31
So let me show you a couple of
08:34
even more interesting examples.
08:36
This is 20-year-old dolphin living in Florida,
08:38
and she had these lesions in her mouth
08:40
that, over the course of three years,
08:42
developed into invasive squamous cell cancers.
08:44
So we created an antiangiogenic paste.
08:47
We had it painted on top of the cancer
08:50
three times a week.
08:52
And over the course of seven months,
08:54
the cancers completely disappeared,
08:56
and the biopsies came back as normal.
08:58
Here's a cancer growing on the lip
09:02
of a Wuarter horse named Guinness.
09:04
It's a very, very deadly type of cancer called an angiosarcoma.
09:06
It had already spread to his lymph nodes,
09:09
so we used an antiangiogenic skin cream for the lip
09:11
and an oral cocktail, so we could treat from the inside
09:14
as well as the outside.
09:17
And over the course of six months,
09:19
he experienced a complete remission.
09:21
And here he is six years later,
09:24
Guinness, with his very happy owner.
09:27
(Applause)
09:30
Now, obviously, antiangiogenic therapy
09:33
could be used for a wide range of cancers.
09:35
And, in fact, the first pioneering treatments
09:38
for people, as well as dogs,
09:40
are already becoming available.
09:42
There's 12 different drugs, 11 different cancer types.
09:44
But the real question is:
09:47
How well do these work in practice?
09:49
So here's actually the patient survival data
09:51
from eight different types of cancer.
09:54
The bars represent survival time
09:56
taken from the era
09:58
in which there was only chemotherapy,
10:00
or surgery, or radiation available.
10:02
But starting in 2004,
10:05
when antiangiogenic therapies first became available,
10:07
well you can see that there has been
10:09
a 70 to 100 percent
10:11
improvement in survival
10:13
for people with kidney cancer, multiple myeloma,
10:15
colorectal cancer, and gastrointestinal stromal tumors.
10:18
That's impressive.
10:22
But for other tumors and cancer types,
10:24
the improvements have only been modest.
10:27
So I started asking myself,
10:30
"Why haven't we been able to do better?"
10:32
And the answer, to me, is obvious;
10:35
we're treating cancer too late in the game,
10:37
when it's already established
10:39
and, oftentimes, it's already spread or metastasized.
10:41
And as a doctor, I know
10:44
that once a disease progresses to an advanced stage,
10:46
achieving a cure
10:49
can be difficult, if not impossible.
10:51
So I went back to the biology
10:54
of angiogenesis
10:56
and started thinking:
10:58
Could the answer to cancer
11:00
be preventing angiogenesis,
11:02
beating cancer at its own game
11:05
so the cancers could never become dangerous?
11:07
This could help healthy people
11:11
as well as people who've already beaten cancer
11:13
once or twice
11:15
and want to find a way to keep it from coming back.
11:17
So to look for a way to prevent angiogenesis in cancer,
11:20
I went back to look at cancer's causes.
11:23
And what really intrigued me
11:25
was when I saw that diet
11:27
accounts for 30 to 35 percent
11:29
of environmentally caused cancers.
11:31
Now, the obvious thing is to think about
11:34
what we could remove from our diet, what to strip out, take away.
11:36
But I actually took a completely opposite approach
11:40
and began asking: What could we be adding to our diet
11:43
that's naturally antiangiogenic,
11:46
that could boost the body's defense system
11:49
and beat back those blood vessels that are feeding cancers?
11:51
In other words, can we eat to starve cancer? (Laughter)
11:54
Well, the answer's yes,
11:58
and I'm going to show you how.
12:00
Our search for this
12:02
has taken us to the market, the farm and to the spice cabinet,
12:04
because what we've discovered
12:07
is that mother nature has laced a large number
12:09
of foods and beverages and herbs
12:11
with naturally occurring inhibitors
12:13
of angiogenesis.
12:15
So here's a test system we developed.
12:17
At the center is a ring from which hundreds of blood vessels
12:19
are growing out in a starburst fashion.
12:21
And we can use this system
12:23
to test dietary factors
12:25
at concentrations that are obtainable by eating.
12:27
So let me show you what happens when we put in
12:30
an extract from red grapes.
12:32
The active ingredient's resveratrol,
12:35
it's also found in red wine.
12:37
This inhibits abnormal angiogenesis
12:39
by 60 percent.
12:42
Here's what happens when we added an extract from strawberries;
12:44
it potently inhibits angiogenesis.
12:47
And extract from soybeans.
12:50
And here is a growing list of our
12:54
antiangiogenic foods and beverages
12:56
that we're interested in studying.
12:58
For each food type,
13:00
we believe that there are different potencies
13:02
within different strains and varietals.
13:04
And we want to measure this because,
13:07
well, while you're eating a strawberry
13:09
or drinking tea,
13:11
why not select the one that's most potent
13:13
for preventing cancer.
13:15
So here are four different teas that we've tested.
13:17
They're all common ones:
13:20
Chinese jasmine, Japanese sencha,
13:22
Earl Grey and a special blend that we prepared.
13:24
And you can see clearly
13:26
that the teas vary in their potency
13:28
from less potent to more potent.
13:30
But what's very cool
13:33
is when we actually combined the two
13:35
less potent teas together,
13:37
the combination, the blend,
13:39
is more potent than either one alone.
13:41
This means there's food synergy.
13:44
Here's some more data from our testing.
13:49
Now, in the lab, we can simulate tumor angiogenesis
13:51
represented here in a black bar.
13:54
And using this system, we can test the potency of cancer drugs.
13:56
So the shorter the bar,
13:59
less angiogenesis, that's good.
14:01
And here are some common drugs
14:04
that have been associated with reducing the risk
14:06
of cancer in people.
14:08
Statins, nonsteroidal anti-inflammatory drugs
14:10
and a few others,
14:12
they inhibit angiogenesis too.
14:14
And here are the dietary factors
14:17
going head to head against these drugs.
14:19
You can see, they clearly hold their own
14:22
and, in some cases, they're more potent
14:24
than the actual drugs.
14:26
Soy, parsley, garlic,
14:28
grapes, berries;
14:30
I could go home and cook a tasty meal
14:32
using these ingredients.
14:34
So imagine if we could create
14:36
the world's first rating system
14:38
in which we could score foods
14:40
according to their antiangiogenic,
14:42
cancer-preventative properties.
14:44
And that's what we're doing right now.
14:46
Now, I've shown you a bunch of lab data,
14:49
and so the real question is:
14:51
What is the evidence in people
14:53
that eating certain foods can reduce
14:55
angiogenesis in cancer?
14:57
Well, the best example I know
15:00
is a study of 79,000 men
15:02
followed over 20 years,
15:04
in which it was found that men who consumed
15:06
cooked tomatoes two to three times a week
15:08
had up to a 50 percent reduction
15:10
in their risk of developing prostate cancer.
15:13
Now, we know that tomatoes are a good source of lycopene,
15:16
and lycopene is antiangiogenic.
15:19
But what's even more interesting from this study
15:22
is that in those men who did develop prostate cancer,
15:24
those who ate more servings of tomato sauce
15:27
actually had fewer blood vessels
15:30
feeding their cancer.
15:32
So this human study is a prime example
15:34
of how antiangiogenic substances
15:36
present in food and consumed at practical levels
15:38
can impact on cancer.
15:41
And we're now studying
15:43
the role of a healthy diet
15:45
with Dean Ornish at UCSF and Tufts University
15:47
on the role of this healthy diet on markers of angiogenesis
15:50
that we can find in the bloodstream.
15:53
Now, obviously, what I've shared with you has some far-ranging implications,
15:56
even beyond cancer research.
15:59
Because if we're right, it could impact on consumer education,
16:01
food services, public health
16:04
and even the insurance industry.
16:06
And, in fact, some insurance companies
16:08
are already beginning to think along these lines.
16:10
Check out this ad from Blue Cross Blue Shield of Minnesota.
16:12
And for many people around the world,
16:16
dietary cancer prevention
16:18
may be the only practical solution
16:20
because not everybody can afford expensive end-stage cancer treatments,
16:22
but everybody could benefit from
16:25
a healthy diet based on local, sustainable,
16:27
antiangiogenic crops.
16:30
Now, finally,
16:33
I've talked to you about food,
16:35
and I've talked to you about cancer,
16:37
so there's just one more disease that I have to tell you about
16:39
and that's obesity.
16:42
Because it turns out that
16:44
adipose tissue, fat,
16:46
is highly angiogenesis dependent.
16:48
And, like a tumor, fat grows when blood vessels grow.
16:50
So the question is: Can we shrink fat
16:53
by cutting off its blood supply?
16:56
So the top curve shows the body weight
16:58
of a genetically obese mouse
17:01
that eats nonstop
17:03
until it turns fat, like this furry tennis ball.
17:05
And the bottom curve is the weight of a normal mouse.
17:09
If you take the obese mouse and give it
17:12
an angiogenesis inhibitor, it loses weight.
17:14
Stop the treatment, gains the weight back.
17:16
Restart the treatment, loses the weight again.
17:18
Stop the treatment, it gains the weight back.
17:20
And, in fact, you can cycle the weight up and down
17:22
simply by inhibiting angiogenesis.
17:24
So this approach that we're taking for cancer prevention
17:27
may also have an application
17:29
for obesity.
17:31
The really, truly interesting thing about this
17:33
is that we can't take these obese mice
17:35
and make them lose more weight
17:37
than what the normal mouse's weight is supposed to be.
17:39
In other words, we can't create supermodel mice.
17:42
(Laughter)
17:44
And this speaks to the role of angiogenesis
17:46
in regulating healthy set points.
17:48
Albert Szent-Gyorgi once said that,
17:51
"Discovery consists of seeing what everyone has seen,
17:53
and thinking what no one has thought."
17:56
I hope I've convinced you
17:58
that, for diseases like cancer, obesity and other conditions,
18:00
that there may be a great power
18:03
in attacking their common denominator: angiogenesis.
18:05
And that's what I think the world needs now. Thank you.
18:08
(Applause)
18:11
June Cohen: I have a quick question for you. So these drugs aren't exactly ...
18:22
they're not exactly in mainstream cancer treatments right now.
18:25
For anyone out here who has cancer,
18:28
what would you recommend?
18:30
Do you recommend pursuing these treatments now, for most cancer patients?
18:32
William Li: So there are antiangiogenic treatments
18:35
that are FDA approved,
18:37
and if you're a cancer patient
18:39
or working for one or advocating for one,
18:41
you should ask about them.
18:43
And there are many clinical trials.
18:45
The Angiogenesis Foundation is following almost 300 companies,
18:48
and there are about 100 more
18:51
drugs in that pipeline.
18:53
So consider the approved ones,
18:55
look for clinical trials,
18:57
but then between what the doctor can do for you,
18:59
we need to start asking what can we do for ourselves.
19:01
And this is one of the themes that I'm talking about
19:03
is we can empower ourselves to do the things
19:05
that doctors can't do for us,
19:07
which is to use knowledge and take action.
19:09
And if Mother Nature has given us some clues,
19:11
we think that there might be a new future
19:14
in the value of how we eat.
19:16
And what we eat is really our chemotherapy three times a day.
19:18
JC: Right. And along those lines,
19:21
for people who might have risk factors for cancer,
19:23
would you recommend pursuing any treatments sort of prophylactically
19:26
or simply pursuing the right diet
19:29
with lots of tomato sauce?
19:31
WL: Well, you know, there's abundant epidemiological evidence.
19:33
And I think in the information age,
19:36
it doesn't take long to go to a credible source
19:38
like PubMed, the National Library of Medicine,
19:40
to look for epidemiological studies
19:42
for cancer risk reduction
19:44
based on diet and based on common medications.
19:46
And that's certainly something that anybody can look into.
19:49
JC: Okay. Well, thank you so much.
19:51
(Applause)
19:53

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William Li - Cancer researcher
William Li heads the Angiogenesis Foundation, a nonprofit that is re-conceptualizing global disease fighting.

Why you should listen

Many of society’s most devastating diseases -- cancer, cardiovascular disease, diabetes and Alzheimer’s, to name a few -- share a common denominator: faulty angiogenesis, the body’s growth of new capillary blood vessels. Given excessive or insufficient blood vessel growth, serious health issues arise. While researching under Harvard surgeon Judah Folkman, who pioneered the study of angiogenesis, Li learned how angiogenesis-based medicine helps patients overcome numerous diseases by restoring the balance of blood-vessel growth.
 
Li co-founded the Angiogenesis Foundation in 1994. The foundation’s Project ENABLE -- a global system that integrates patients, medical experts and healthcare professionals -- democratizes the spread and implementation of knowledge about angiogenesis-based medicines, diet and lifestyle. Some 40,000 physicians have been educated on new treatments, ranging from cancer care to wound care, by the foundation’s faculty of medical experts, and they are bringing new, lifesaving and disease-preventing techniques to people around the world.

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