Can we eat to starve cancer? - William Li

good afternoon there's a medical revolution happening all around us and it's one that's going to help us conquer some of society's most dreaded conditions including cancer and the revolution is called angiogenesis and it's based on the process that our bodies use to grow blood vessels so why should we care about blood vessels well the human body is literally packed with them 60,000 miles worth in a typical adult and the end that would form a line that would circle the Earth twice the smallest blood vessels are called capillaries we've got 19 billion of them in our bodies and these are the vessels of life and as I'll show you they can also be the vessels of death now the remarkable thing about blood vessels is that they have this ability to adapt to whatever environment they're growing in for example in the liver they form channels to detoxify the blood in the lung they line air sacs for gas exchange in muscle they corkscrew so that muscles can contract without cutting off circulation and in nerves they course along like power lines keeping those nerves alive and we get most of these blood vessels when we're actually still in the womb and what that means is that as adults blood vessels don't normally grow except in a few special circumstances in women blood vessels grow every month to build the lining of the uterus during pregnancy they form the placenta which connects mom and baby and after injury blood vessels actually have to grow under the scab in order to heal a wound and this is actually what it looks like hundreds of blood vessels all growing towards the center of the wound so the body has the ability to regulate the amount of blood vessels that are present at any given time and it does this through an elaborate and elegant system of checks and balances stimulators and inhibitors of angiogenesis such that when we need a brief burst of blood vessels the body can do this by releasing stimulators proteins called angiogenic factors that act as natural fertilizer and stimulate new blood vessels to sprout and when those excess vessels are no longer needed the body prunes them back to baseline using naturally-occurring inhibitors of angiogenesis now there are other situations where we start beneath the baseline and we need to grow more blood vessels just to get back to normal levels for example after an injury and a body can do that too but only to that normal level that's setpoint but what we now know is that for a number of diseases there are defects in the system where the body can't prune back extra blood vessels or can't grow enough new ones in a right place at the right time and in these situations angiogenesis is out of balance and when angiogenesis is out of balance a myriad of diseases result for example insufficient angiogenesis not enough blood vessels leads to wounds that don't heal heart attacks legs without circulation death from stroke nerve damage and on the other hand excessive angiogenesis too many blood vessels drives disease and we see this in cancer blindness arthritis obesity Alzheimer's disease in total there are more than 70 major diseases affecting more than a billion people worldwide that all look on the surface to be different from one another but all actually share abnormal angiogenesis as their common denominator in this realization is allowing us to reconceptualize the way that we actually approach these diseases by controlling and your genesis now I'm going to focus on cancer because angiogenesis is a hallmark of cancer every type of cancer so here we go this is a tumor dark grey ominous mass growing inside a brain and under the microscope you can see hundreds of these brown staining blood vessels capillaries that are feeding cancer cells bringing oxygen and nutrients but cancers don't start out like this and if that cancers don't start out with a blood supply they start out as small microscopic nests of cells that can only grow to one half a cubic millimeter in size that's the tip of a ballpoint pen then they can't get any larger because they don't have a blood supply so they don't have enough oxygen or nutrients and in fact we're probably forming these microscopic cancers all the time in our body autopsy studies from people who died in car accidents have shown that about 40% of women between the ages of 40 and 50 actually have microscopic cancers in their breasts about 50% of men in their 50s and 60s have microscopic prostate cancers and all virtually a hundred percent of us by the time we reach our 70s will have microscopic cancers growing in our thyroid yet without a blood supply most of these cancers will never become dangerous dr. Judah Folkman who was my mentor and who was the pioneer of the angiogenesis field once called this cancer without disease so the body's ability to balance angiogenesis when it's working properly prevents blood vessels from feeding cancers and this turns out to be one of our most important defense mechanisms against cancer in fact if you actually block angiogenesis and prevent blood vessels from ever reaching cancer cells tumors simply can't grow up but once angiogenesis occurs cancers can grow exponentially and this is actually how a cancer goes from being harmless to deadly cancer cells mutate and they gain the ability to release lots of those angiogenic factors natural fertilizer that tipped the balance in favor of blood vessels invading the cancer and once those vessels invade the cancer it can expand it can invade local tissues in the same vessels that are feeding tumors allow cancer cells to exit into the circulation as metastases and unfortunately this late stage of cancer is the one at which it's most likely to be diagnosed when angiogenesis has already turned on and cancer cells are growing like wild so Evandro Genesis is a tipping point between a harmless cancer and a harmful one then one major part of the angiogenesis revolution is a new approach to treating cancer by cutting off the blood supply we call this anti-angiogenic therapy and it's completely different from chemotherapy because it's selectively aims at the blood vessels that are feeding the cancers and we can do this because tomber blood vessels are unlike normal healthy vessels we see in other places of the body they're abnormal they are very poorly constructed and because of that they're highly vulnerable to treatments that target them in fact when we give cancer patients anti-angiogenic therapy here an experimental drug for a glioma which is a type of a brain tumor you can see that there are dramatic changes that occur when the tumor is being starved here's a woman with a breast cancer being treated with the anti-angiogenic drug called Avastin which is fda-approved and you can see that the halo of blood flow disappears after treatment now I've just shown you two very different types of cancer that both responded to anti-angiogenic therapy so a few years ago I asked myself can we take this one step further and treat other cancers even in other species so here is a nine-year-old boxer named Milo who had a very aggressive tumor called a malignant neurofibroma growing in his shoulder and invaded to his lungs his veterinarian only gave him three months to live so we created a cocktail of anti-angiogenic drugs that could be mixed into his dog food as well as an anti-angiogenic cream that could be applied on the surface of the tumor and within a few weeks of treatment we were able to slow down that cancers growth such that we were ultimately able to extend Milo's survival to six times what the veterinarian had initially predicted all with the very good quality of life and we've subsequently treated more than 600 dogs we have about a 60% response rate and improved survival for these pets that were about to be euthanized so let me show you a couple of even more interesting examples this is a 20 year old dolphin living in Florida and she had these lesions in her mouth that over the course of three years developed into invasive squamous cell cancers so we created an anti-angiogenic paste we had it painted on top of the cancer three times a week and over the course of seven months the cancer has completely disappeared and the biopsies came back as normal here's a cancer growing on the lip of a quarter horse named it's a very very deadly type of cancer called an angiosarcoma had already spread to his lymph nodes so we used an anti-angiogenic skin cream for the lip and the oral cocktail so we could treat from the inside as well as the outside and over the course of six months he experienced a complete remission and here he is six years later guinness with his very happy owner now obviously antigenic therapy could be used for a wide range of cancers in fact the first pioneered treatments for people as well as dogs already becoming available there's 12 different drugs 11 different cancer types but the real question is how well do these work in practice so here is actually the patient survival data from 8 different types of cancer and the bars represent survival time taken from the era in which there was only chemotherapy or surgery or radiation available but starting in 2004 when anti-angiogenic therapies first became available you can see that there has been a 70 to 100 percent improvement in survival for people with kidney cancer multiple myeloma colorectal cancer and gastrointestinal stromal tumors that's impressive but for other tumors and cancer types the improvements have only been modest so I started asking myself why haven't we been able to do better and the answer to me is obvious we're treating cancer too late in the game when it's already established and oftentimes it's already spread or metastasize and as a doctor I know that once a disease progresses to an advanced stage achieving a cure can be difficult if not impossible so I went back to the biology of angiogenesis and started thinking could the answer to cancer be preventing Andrew Genesis beating cancer its own game so the cancers could never become dangerous this could help healthy people as well as people who have already beaten cancer once or twice and want to find a way to keep it from coming back so to look for a way to prevent angiogenesis in cancer I went back to look at cancerous causes and what really intrigued me was when I saw that diet accounts for 30 to 35 percent of environmentally caused cancers now the obvious thing is to think about what we could remove from our diet what to strip out take away but I actually took a completely opposite approach it began asking what could we be adding to our diet that's naturally anti-angiogenic that could boost the body's defense system and beat back those blood vessels that are feeding cancers in other words can we eat to starve cancer well the answer is yes and I'm going to show you how and our search for this has taken us to the market the farm and to the spice cabinet because what we've discovered is that Mother Nature has laced a large number of foods and beverages and herbs with naturally-occurring inhibitors of angiogenesis so here's a test system we developed at the center as a ring from which hundreds of blood vessels are growing out in a starburst fashion and we can use this system to test dietary factors at concentrations that are attainable by eating so let me show you what happens when we put in an extract from red grapes the active ingredient resveratrol it's also found in red wine this inhibits abnormal angiogenesis by 60 percent here's what happens when we add an extract from strawberries it potently inhibits angiogenesis an extract from soybeans and here is a growing list of our anti-angiogenic foods and beverages that we're interested in studying and for each food type we believe that there's different potencies within different strains and varietals and we want to measure this because well while you're eating a strawberry or drinking tea why not select the one that's most potent for preventing cancer so here are four different teas that we've tested they're all common ones Chinese Jasmine Japanese Sencha Earl Grey and a special blend that we prepared and you can see clearly that the tea's vary in their potency from less potent to more potent but what's very cool is when we actually combine the two less potent teas together the combination the blend is more potent than either one alone this means there's food synergy here's some more data from our testing now in the lab we can simulate tumor angiogenesis represented here in a black bar and using the system we can test a potency of cancer drugs so the shorter the bar less angiogenesis that's good and here are some common drugs that have been associated with reducing the risk of cancer in people statins non-steroidal anti-inflammatory drugs and a few others they inhibit angiogenesis - and here are the dietary factors going head-to-head against these drugs you can see they clearly hold their own and in some cases they're more potent than the actual drugs soy parsley garlic grapes berries I could go home and cook a tasty meal using these ingredients so imagine if we could create the world's first rating system in which we could score foods according to their anti-angiogenic cancer preventative properties and that's what we're doing right now now I've shown you a bunch of lab data and so the real question is what is the evidence in people that eating certain foods can reduce angiogenesis in cancer well the best example I know is the study of 79 thousand men followed over 20 years in which it was found that men who consumed cooked tomatoes two to three times a week at up to a 50% reduction in their risk of developing prostate cancer now we know that tomatoes are a good source of lycopene and lycopene is anti-angiogenic but what's even more interesting from this study is that in those men who did develop prostate cancer those who ate more servings of tomato sauce actually had fewer blood vessels feeding their cancer so this human study is a prime example of how anti-angiogenic substances present food and consumed impractical levels can impact on cancer and we're now studying the role of a healthy diet with Dean Ornish at UCSF and Tufts University on the role of this healthy diet on markers of angiogenesis that we can find in the bloodstream now obviously what I've shared with you has some far ranging implications even beyond cancer research because if we're right it could impact on consumer education food services public health and even the insurance industry and in fact some insurance companies are already beginning to think along these lines check out this ad from Blue Cross Blue Shield of Minnesota and for many people around the world dietary cancer prevention may be the only practical solution because not everybody can afford expensive end-stage cancer treatments but everybody could benefit from a healthy diet based on local sustainable anti-angiogenic crops now finally I've talked to you about food and I've talked to you about cancer so there's just one more disease that I have to tell you about and that's obesity because turns out that adipose tissue fat is highly angiogenesis dependent and like a tumor fat grows when blood vessels grow so the question is can we shrink fat by cutting off its blood supply so the top curve shows the body weight of a genetically obese Mouse that eats non-stop until it turns fat like this furry tennis ball and the bottom curve is the weight of a normal Mouse if you take the obese Mouse and give it an angiogenesis inhibitor it loses weight stop the treatment gains the weight back restart the treatment loses the weight again stop the treatment gains away back in fact you can cycle the weight up and down simply by inhibiting Andra Genesis so this approach that we're taking for cancer prevention may also have an application for obesity the really truly interesting thing about this is that we can't take these obese mice and make them lose more weight than what the normal Mouse is weight is supposed to be in other words we can't create supermodel mice and this speaks to the role of angiogenesis in regulating healthy setpoints albertson Georgie once said that discovery consists of seeing what everybody is seen and thinking what nobody is thought I hope I've convinced you that for diseases like cancer obesity and other conditions that there may be a great power in attacking their common denominator angiogenesis and that's what I think the world needs now thank so these drugs aren't exactly they're not exactly in mainstream cancer treatments right now for anyone out here who has cancer what would you recommend do you recommend pursuing these treatments now for most cancer patients so there are anti energetic treatments that are you should ask there are many clinical trials the in geneticist foundation respond almost 300 companies consider the approved ones look for clinical trials but then between what the doctor can do for you we need to start asking what can we do for ourselves and this is one of the themes that I'm talking about is we can empower ourselves to do the things that doctors can't do for us which is a use knowledge of take action and if Mother Nature has given us some clues we think that there might be some new future in the value of how we eat and what we eat is really our chemotherapy three times a day right and along those lines for people who might have risk factors for cancer would you recommend pursuing any treatment sort of prophylactically or simply pursuing the right diet with lots of tomato sauce well you know there's a abundant epidemiological evidence and I think an Information Age it doesn't take long to go to a credible source like PubMed the National Library of Medicine to look for epidemiological studies for cancer risk reduction based on diet and based on common medications and that's certainly something that anybody can look into okay well thank you so much you

Channel: TED-Ed

Views: 2,159,505

Rating: 4.8981218 out of 5

Keywords: William Li, TED, TED Talk, TED-Ed, TEDEducation, TED Ed, cancer, tumor, growth, cancer spread, eating, nutrition, health

Id: OjkzfeJz66o

Length: 20min 1sec (1201 seconds)

Published: Tue Apr 08 2014

Reddit Comments

[u/paidinteeth]

No sure how many of you have seen William Li's TED talk about angiogenesis (the proliferaton of blood vessels), but I found it very interesting. He gives a list of foods he believes inhibits blood vessel formation, and as you probably guessed they are almost all vegan. Enjoy.