A new study shows a link between a nutrient found in red meat and heart disease. L-carnitine, found in red meat and also a popular supplement, is being tied to heart disease. Dr. Nathan Laufer of the Heart & Vascular Center of Arizona will talk about the new findings.
Ted Simons: A new study shows a nutrient found in red meat is tied to an increased risk for heart disease. For more on just how far this connection goes is Dr. Nathan Laufer, founder and medical director of the Heart and Vascular Center of Arizona. Good to have you here. Thanks for joining us.
Dr. Nathan Laufer: Thanks for having me.
Ted Simons: Let's start by just figuring out what is -- is it L-carnitine?
Dr. Nathan Laufer: It's L-carnititne which is made from and amino acid called Lysine. It's found in significant amounts in red meat, lesser amounts in dairy products, but we have been concerned for many years as cardiologists about excess consumption of red meat. We always thought that it was the cholesterol and high fat in the red meat that was linked to coronary artery disease but this new study links carnitine as well.
Ted Simons: Take us exactly into how it increases cardiovascular risk.
Dr. Nathan Laufer: It's absorbed when red meat is ingested is broken down by bacteria in the gut. That bacteria will then form a substance, the short version is called tMAO. That helps cholesterol land inside the plaque and helps create plaque rather than just flying through the arterial warm and being absorbed by the liver.
Ted Simons: It hits your gut, gut has bacteria in there, it forms this tMAO thing, and the cholesterol decides to stay.
Dr. Nathan Laufer: It gets sticky and decides to sit and stay, gets absorbed in the wall and that's the beginning of atherosclerosis.
Ted Simons: We were trying to figure out what was making that cholesterol sit and stay.
Dr. Nathan Laufer: That's right. There are numerous risk factors. It's also used in supplements and weight building and muscle bulking. But there are several other risk factors. The one we can't do anything about obviously is the genetic risk factor, about but those that are reversible are smoking, high blood pressure, lack of exercise, risk factors we can certainly do something about. The exercise, for example, will raise the good cholesterol and good cholesterol takes cholesterol out of the plaque and brings it back to the liver.
Ted Simons: For those of us who do exercise, you keep telling yourself it's a good thing. How is it good? Does it add more veins, more arteries? Does it clear out the arteries? What does exercise do to help your heart?
Dr. Nathan Laufer: Excellent question. The first you mentioned is does exercise clear out the arteries. The answer is no, but it's an excellent preventer of plaque buildup. The more you do the higher the HDL, the good cholesterol. It doesn't do that much to lower the bad cholesterol, which is the cholesterol that lands inside the plaque and creates plaque, but by building up the good cholesterol it can decrease the amount of plaque formation. That's one thing. The other thing is that people who exercise tend to be more conscious of their health in general and have a more balanced diet.
Ted Simons: The idea of the good cholesterol, though, HDL, if that stuff is siting there and staying there and you start exercising, that stuff still stays there.
Dr. Nathan Laufer: That stuff still stays there unless you're a monkey. Studies done in monkeys that were Fed high cholesterol diets for five years developed atherosclerosis. If then all the cholesterol was taken out of their diet and they were fed a vegetarian diet, five years later you could show some regression of this cholesterol buildup. But whether we show regression or not, the fact that we can stabilize the plaque and stop progression is very important.
Ted Simons: You brought along a kind of a poster or something there of what actually is happening in the artery. It's basically -- it really -- again, you could have that artery and you could start running marathons you'll still have that artery.
Dr. Nathan Laufer: Correct. That was the problem with Jim Fixx from, years ago, who believed exercise is good for you to the exclusion of medication. It is good for you and maybe prolonged his life somewhat but not to the exclusion of medication. If you look in the middle of the artery you'll see the beginnings of a plaque that's formed. To the right you'll see a severe atherosclerosis plaque. If you can start exercising, mod fight your diet, start a Mediterranean type diet you may stop the progress. If you are little with the middle segment of that you can live many years.
Ted Simons: Mediterranean diet? What are we talkin' about here? We're not talking linguine, are we?
Dr. Nathan Laufer: No. We're talking about a low carbohydrate diet. A diet from southern Italy, for example, which is rich in fish, chicken, fruits, vegetables and olive oil there was a study that just came out last month that showed that Mediterranean diet plus a little bit of olive oil or some nuts such as walnuts, high in antioxidants, actually can decrease the cardiovascular mortality by 30 to 50% compared to just low fat diet.
Ted Simons: Okay. Have a glass or two of wine, eat grapes, do the Mediterranean diet, douse myself in olive oil, eat fish, I take an aspirin or two. Again, is that artery going to always look like that?
Dr. Nathan Laufer: That artery will look like the artery you started with when you started this diet. You will decrease further progression. Even if you delay progression, say you don't decrease progression but can delay it 20 or 30 years, instead of having it progress in two to five years, you've still done some good.
Ted Simons: We have another graphic here. This is a straight on view of the artery. Again, this is basically -- if you got it, you got it. How do you know you got it? Are there warning signs? We hear so much about sudden heart attacks out of the blue. If you have that, how out of the blue is this?
Dr. Nathan Laufer: That's another excellent question. First if you look at the yellow, that's the plaque inside the artery which is in pink. That little spot you see in red, that's a clot that's formed inside the plaque. We don't really care that people have plaques. Most people don't care if they have atherosclerosis. They care if they die of heart attack. Is atherosclerosis a predictor of heart attacks? That's the $64,000 question. Cardiologists are not very good at predicting heart attacks. We're very good at finding plaque buildup in the artery but does that lead to heart attack? Turns out if you lower your blood cholesterol whether you have a 70% or 20% plaque you have the same risk of having a heart attack. The problem is the 20% plaque will not show up on the stress test. If we did an angiogram where we put dye into the artery we would not do anything if we just saw 20% plaque. That patient has the same risk as a person with a 70, 80 or 90% plaque at having that plaque tear and cause a clot to form. The best predictor is lowering the cholesterol level. Then that plaque will scar down and be less like Jell-o and less likely to tear and form a firmer plaque that won't tear. That is probably the best predictor of whether you'll have a heart attack is what your cholesterol level is.
Ted Simons: Before we go, the study, what does that tell us, eat less red meat, eat no red meat?
Dr. Nathan Laufer: Less red meat. Less. Maybe four to eight ounces less than once a week. People who ate just a little red meat had less bacteria in their gut to work with that carnatine and form tMAO and were less likely to have cholesterol deposits in their plaque.
Ted Simons: Great stuff, doctor. I'm glad we had you on. Good to have you here.
Dr. Nathan Laufer: Thank you.
Dr. Nathan Laufer:Heart & Vascular Center of Arizona
