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SALMAN KHAN: I'm here with Dr. David Agus, who is a professor of engineering and medicine at USC. DAVID AGUS: Um-huh. SALMAN KHAN: And we're looking at pictures here of things that seem very different to me. What is the commonality right here? DAVID AGUS: The commonality is inflammation. So inflammation can be manifest by a runny nose in a cold or getting the flu. It could be manifest by an infection in your toes. It could be hitting your head playing football or hitting your arm when you fall playing a sport. All of those can cause inflammation. SALMAN KHAN: Because inflammation has a certain meaning in everyday language. At least when I imagine it, it means something that's swollen and red. But here, we're talking about inflammation in more of the medical or the scientific sense. Things are swollen and red because of inflammation. DAVID AGUS: Right. SALMAN KHAN: And so what is inflammation? It isn't just swollen and redness. I mean, the football player isn't getting swollen and red, or is he? DAVID AGUS: So inflammation is when your body senses danger. So when something is wrong, whether it be an infection, whether it be trauma in the case of football players, whether it be a cold, your body senses danger and sends in its frontline soldiers, which are the immune cells, in order to fight whatever's causing it. So if it's trauma, the immune cells go in there and they help rebuild the tissue that's damaged. If it's a bacteria, they go in there and they try to take away the bacteria so you can get over that cold or that flu. And so that whole process we call inflammation. SALMAN KHAN: I see. DAVID AGUS: It's a danger process. SALMAN KHAN: So it's the immune cells going to the sign of danger to either fight the danger itself or repair the aftermath-- DAVID AGUS: Yup. SALMAN KHAN: --of the danger. So that sounds like a good thing. DAVID AGUS: It's an awesome thing. The problem is, your body, all of us, we care about what happens today, not down the road. SALMAN KHAN: Right. DAVID AGUS: And this is one of the take home points that astonished me when I start to think about it, is that nature, evolution, selects out, for who has good kids. And that's what evolution is about. It's about having children. We call progeny. SALMAN KHAN: Right DAVID AGUS: It's not about what happens when you're 80 years old or 90 years old. And so inflammation is fantastic about dealing with today's ramifications. The problem is if you get the flu today, your risk of cancer and heart disease a decade or two decades from now are up. SALMAN KHAN: If I get the flu once? DAVID AGUS: If you get the flu once. SALMAN KHAN: Really. DAVID AGUS: So those five, six days-- SALMAN KHAN: You're worrying me. DAVID AGUS: --when you feel horrible, your inflammation is through the roof. That's having ramifications down the road. SALMAN KHAN: Right. I mean this is already getting a little scary for me because I've had the flu. So I already feel a little worried about my cancer risk. DAVID AGUS: I can tell by looking at you. [LAUGHTER] SALMAN KHAN: You can tell by looking at-- [LAUGHTER] And the symptoms that we get when we have the flu or a cold, these are actually-- it's not the virus that's-- the virus is causing the inflammation, which is causing the symptoms. DAVID AGUS: Yeah. And that's what's wild. Is that when you get a virus, your immune system attacks it and you get a fever. I still don't know why we get fevers. It's one of those things where the-- we call them the cytokines, which are proteins the immune cells make to send out and get more reinforcements and tell the body what to do. It causes a fever. Is a fever good? Is a fever bad? I don't know. We take Tylenol to lower a fever, but is that a good thing? Nobody really has looked at the long-term ramifications. They look at short term. But how does it affect a decade from now what's going to happen? We just don't know. SALMAN KHAN: Wow. Wow. And what you're saying is that the reason why we have inflammation is, yeah, something has happened to my body. I have some trauma, some injury. And you were saying this to me earlier, you might have to run away from a lion tomorrow. So fix Sal or fix David up right now, so that he can run away from the lion tomorrow. But in the wild, I might only live to 40 anyway. So why even worry about whether that person might get cancer if they get to 40 or 50, once they're past the age of reproduction. DAVID AGUS: Eactly. The body has to choose priorities. And the priority clearly is today rather than tomorrow. And so an amazing study was done in that we gave patients what we call a statin. So statins were drugs-- S-T-A-T-I-N. They were drugs that were developed because they blocked the synthesis of cholesterol. SALMAN KHAN: Right. DAVID AGUS: And we thought people with higher cholesterol, particularly the bad one called LDL, those people have a higher incidence of heart disease. So if we block the synthesis, we're going to affect heart disease. And what do you know, we did. A dramatic effect, we lowered the death from heart disease with these drugs. SALMAN KHAN: Right. So it seems like they worked. DAVID AGUS: They worked. Then a company, or a very clever group, did a trial where they gave people with normal cholesterol these drugs. And they had a dramatic effect in that it delayed heart attack and stroke by almost a dozen years. SALMAN KHAN: Wow. DAVID AGUS: And it reduced the incidence of cancer by about 40%. SALMAN KHAN: So cancer, something-- I mean we don't associate cholesterol-- DAVID AGUS: Totally different. SALMAN KHAN: Wow. DAVID AGUS: So it turns out these drugs, which were the biggest drug in terms of sales we've ever had, worked by lowering inflammation. So their effect in heart disease wasn't by lowering cholesterol. It was predominantly by lowering inflammation. SALMAN KHAN: Right. Right. DAVID AGUS: And the effect on cancer was by lowering inflammation. In fact, do you remember when the swine flu came out a couple years ago? SALMAN KHAN: Right. Right. DAVID AGUS: So if you got the swine flu, the only thing that protected you from your lungs collapsing and going on what we call a ventilator, a breathing machine, was being on one of these statins. SALMAN KHAN: Because it would stop the inflammation. Because the swine flu people were dying from is the inflammation going nuts. DAVID AGUS: Yeah. SALMAN KHAN: This is fascinating. So the people who are dying of heart disease, is it necessarily the cholesterol that's killing them? Or is the inflammation that's causing cholesterol? DAVID AGUS: Well, I think it's this chicken and the egg phenomenon. That's it. The inflammation allows cholesterol to deposit-- SALMAN KHAN: I see. DAVID AGUS: --and they together. SALMAN KHAN: I see. I see. So it's really the statin affects inflammation, which then reduces cancer by stopping the inflammation and stopping the-- DAVID AGUS: Exactly. SALMAN KHAN: --cholesterol. DAVID AGUS: One of those problems we have a biology, in medicine, it's what you can measure. And so I can measure cholesterol. SALMAN KHAN: Right. DAVID AGUS: I don't really know how to measure inflammation well. So while we can make these association in big studies when we look back, if I had a metric, if I had a blood test or something to look at for inflammation, I can optimize things. SALMAN KHAN: Can you not measure just the amount of cytokines and other inflammatory type of things that become increased in your-- does it happen? DAVID AGUS: You're right. But are different types of inflammation. So some inflammation can be good, some can be bad. Some can be really causal. Some could be a little bit causal. And so we're putting them all into one basket now, which is inflammation. The key is to start to tease them out and be able to modulate them. You can develop a drug. But then you have to optimize it for a particular purpose. SALMAN KHAN: Right. Right. DAVID AGUS: So these were optimized to lower cholesterol. And they do that very well. They also lower inflammation and they work beautifully in that regard. But how do we optimize that going forward? What it also means is that when you look at your lifestyle and my lifestyle, we have to limit inflammation. So what are the easy ways to do that? One is, which I think should be mandatory things, like the flu shot. SALMAN KHAN: Right. DAVID AGUS: So again, the flu shot will certainly delay you from having or prevent from having bad flu. SALMAN KHAN: That's good today and good today and tomorrow. DAVID AGUS: And tomorrow-- SALMAN KHAN: Yeah, yeah, yeah, yeah. DAVID AGUS: --because it limits heart disease and cancer down the road. That SALMAN KHAN: I had no clue that the flu-- I thought it was just a nice thing, avoid a week of sneezing, and you know. But the flu shot, you can actually reduce your cancer-- DAVID AGUS: And heart disease down the road. And we have to think long term as a society. SALMAN KHAN: What about statins? I mean it seems like-- these are drugs like Lipitor and Crestor. I mean would you-- I mean no one should take our medical advice based on a thing in video. DAVID AGUS: Right. SALMAN KHAN: I mean are people taking it just for heart disease or are people taking it more broadly now? DAVID AGUS: Listen. I mean I'm a believer that these drugs have such a profound effect on cancer, heart disease, stroke, potentially Alzheimer's, that you should consider taking it to prevent these diseases. And again, we're giving no recommendations. But what I say is you, your parents, they should talk about it with their doctor. And so why shouldn't I be on this drug? SALMAN KHAN: Right. And there are some side effects. But they're easy to test for. DAVID AGUS: Test for, and then they're reversible. SALMAN KHAN: Right. OK. So you're not going too-- DAVID AGUS: So with anything, you got to do a risk and a benefit. SALMAN KHAN: Right. DAVID AGUS: And you have to look at you and say am I high risk for X, Y, and Z? If you are, what can prevent or delay it? The name of the game is not treating disease, it's preventing disease. SALMAN KHAN: Right. Right. Now, this is fascinating. Well, I might talk to my wife about getting some-- well, no advice here. Everyone should talk to their doctor. DAVID AGUS: By the way, another great medicine to reduce inflammation is called aspirin. SALMAN KHAN: Aspirin, I've heard of that. DAVID AGUS: Yeah. It's a hell of a drug. Again, there are side effects to aspirin. It can affect bleeding. But at the same time, it's a dramatic effect by lowering inflammation. SALMAN KHAN: Right. And that is its main side effect. I mean it's this age-old drug. It's a blood thinner. So if you get a cut or you bleed while you're taking aspirin, you might bleed more. DAVID AGUS: Right. Blood thinner is a funny term. I'm not quite sure what it means. I keep taking paint thinner when you see it. SALMAN KHAN: Right. That's kind of how I imagine it. DAVID AGUS: It binds to the platelets and blocks them from activating. It stops them from working really well. SALMAN KHAN: So it's more anticlotting. DAVID AGUS: Right. And platelets are one of the key components of clotting. And they certainly affect it. SALMAN KHAN: Right. So your blood will have the same viscosity. It just won't clot as easily. DAVID AGUS: Exactly. And you could certainly paint a wall with either one. SALMAN KHAN: That's a little morbid. All right. Well, thanks a bunch.