Have you ever wondered whether you should be on low fat or high fat? What is cholesterol and is it good or bad for your health? Should we all be on cholesterol-lowering drugs, statins? Do you wonder when these messages change and who to believe? Well, my guest today is Dr Ross Walker, an internationally renowned cardiologist, he’s written over seven books, he’s got his own weekly national radio program called Healthy Living…..and he’s also my cardiologist.
Not only does he answer these confusing questions but he also talks about his five keys to eliminating 70 percent of all chronic degenerative diseases. He demystifies cholesterol, statins and diagnostic cardiology tests. Dr Ross Walker gets to the heart of the matter.
Dr. Ron Ehrlich: Hello, and welcome to Unstress, with Dr Ron Ehrlich. Have you ever had any confusing health messages? Have you ever wondered whether you should be on low fat or high fat? And do you always wonder when these messages change and who to believe? Well, my guest today is Dr Ross Walker. Now, apart from being an internationally renowned cardiologist, he’s written over seven books, he’s got his own two hour weekly national radio program called Healthy Living. We’ll have links to all that.
He describes himself, and I love this term, an integrative cardiologist. Can’t quite get him to say holistic, but he is integrative. And you’ll hear what that just means. He’s actually my own cardiologist. Happens to be an old-school friend of mine. A font of great wisdom and a great conversation. But, Ross talks his five keys to eliminating 70 percent of all chronic degenerative diseases.
He’s going to share those with us. The whole story about cholesterol, you know what? I mean, honestly, cholesterol’s an important part of every single cell in our body and, as Ross will point out, a whole lot more than that. So, we’re going to clear up that myth. I mean, this whole business about fats, okay, you’ve heard it before, but how about hearing it from a cardiologist?
So, I hope you enjoy this conversation with Dr Ross Walker. Welcome to the show, Ross.
Dr. Ross Walker: Oh, thanks Ron. Pleasure to be here.
Dr. Ron Ehrlich: Now, Ross, you describe yourself as an integrative cardiologist?
Dr. Ross Walker: Yeah. I think that’s the best way to do it. See, what I believe in is combining the best bits of orthodox medicine, or allopathic medicine, with the best bits of complementary medicine. You see, the concern I have is there are people who are at extremes at either side, people who believe that if you can’t fix it with a script pad or a scalpel, then it doesn’t work, but then you’ve got other people in the complementary medical world who thinks that anyone in orthodox medicine sits at the right hand of the devil.
And anyone with any common sense knows that that’s nonsense, that both sides are nonsense. You’ve got to work as the Buddhists say, follow the middle path. Go somewhere in the middle, which is combining the best bits of both, which is what I think I do.
Dr. Ron Ehrlich: Yeah, I think that’s what I do, too. I wouldn’t use the word holistic, would you, Ross? Or is that a …
Dr. Ross Walker: Oh, you can use the word holistic, if you like. Some people like holistic. I prefer integrative.
Dr. Ron Ehrlich: Integrative. I like it, too. Now listen, after all this time, we’ve been following all the advice that we should be, what we should be eating, and all of that. How come heart disease and cardiovascular disease is still number one? What’s the story there? What are we doing wrong?
Dr. Ross Walker: Because people aren’t good at doing exactly what you said. If we all followed the five keys of being healthy, and I’ll summarize them quickly, because we spoke about this on numerous occasions, before. But the five keys to being healthy is to have no addictions. You cannot be healthy and smoke, drink too much grog, or snort cocaine. Number two is to have good quality sleep. So, seven to eight hours of good quality sleep every night is as good for your body as not smoking.
Number three, and this is one of the keys, eat less, and eat more naturally. That’s all you need to know about diet. All this nonsense about low fat foods, stuff that’s masquerading in a box as food, I mean, we all know that’s rubbish. We don’t need to follow low fat principles. We need good quality fats, we need good quality proteins, and we need good quality carbs. The best quality carbs on the planet are things called fruit and vegetables. So, it’s eat less and eat more naturally. That’s all you need to know about nutrition.
Number four, second best drug on the planet, three to five hours every week of some form of testing exercise that should be about two-thirds cardio and a third resistance training. And finally, the best drug on the planet’s happiness.
Now, those five key principles, together, reduce your risk for all diseases 70-80 percent, cardiovascular disease 83 percent. But the point is, most people fall down in at least one of those areas, and that’s why we’re still seeing rampant heart disease. In fact, these days, 70 percent of heart disease is due to people who have the insulin resistance gene. And the insulin resistance gene occurs in 30 percent of Caucasians, 50 percent of Asians, and almost 100 percent of people with darker skin.
If you’ve got that gene, and you live in the modern society, do it falling down in one of those areas I spoke about, it still increases your risk for heart disease. The other 20 percent, Ron, and this will come as no shock to you, it is to pick the wrong relatives who’ve given you this high lipoprotein(a). So, 90 percent of heart disease is due to either insulin resistance or lipoprotein(a), and the other 10 percent is due to a whole lot of other things.
But so, we’re seeing rampant heart disease. The number one cause of death and disability, around the world, cardiovascular disease. One person in Australia dies every 12 minutes from some form of cardiovascular disease. The second commonest cause of death and disability is cancer. The third commonest cause of death and disability is western healthcare.
Dr. Ron Ehrlich: Yes. That’s right, isn’t it? The use of prescription drugs, as prescribed.
Dr. Ross Walker: Oh, it’s not just prescription drugs. It’s unnecessary procedures, it’s doing the wrong operation on the wrong person, it’s the superbugs that are killing people, it’s things like unnecessary antibiotics. But in America, every year, there are over 100,000 deaths from the appropriate prescription of pharmaceutical drugs. And no one would disagree the person shouldn’t have taken the drug, but we’re talking about people dying as a consequence of prescribed drugs.
And this is what irritates me when I hear these brain-dead conservatives in medicine, who are criticizing complementary medicine. Fix up the problem in your own backyard, before you criticize people who are practicing good complementary medicine. I always think that’s where integrated medicine is important.
Dr. Ron Ehrlich: Yes, and well, we won’t go into the group — we could, easily — who call themselves “friends of science”. I think what we really need is scrutineers of science, and not really friends. But going back to that insulin resistance, I mean, this gets back to this sugar versus fat being the demon. You mentioned good fats. Tell our listeners what good fats are.
Dr. Ross Walker: Oh, look. I think good fats are anything apart from trans ftrsnats. Trans fats are the synthetic fats that you get from either the hydrogenation of vegetable oils, causing trans fatty acids, or the interesterification of fats, which is another technique they use so they can put on the side of the box, “no trans fats.” They just use interesterification. It’s just another con job. But it’s all synthetic fats.
And what the synthetic fats do, the reason they’re in food is to thicken and harden the food. So, when those synthetic fats get into our body, they thicken and harden our cell membranes, to make them brittle and easy to be broken down. So, this whole demonization of saturated fat, anyone who continues to say, “You’ve got to reduce your saturated fat in your diet,” is not looking at the current science. A few months ago, a study called the PURE study came out. The PURE study was done by Salim Yusuf, who is one of the top epidemiologic researchers in the world, from Canada.
This study looked at just over 135,000 people, 18 countries, followed for about seven and a half years, and found — wait for this one — those people who had the highest carbohydrate intake … and we’re not talking about fruits and vegetables here, we’re talking about the processed carbs, so what I call white death, so white bread, white rice, pasta, potatoes, any form of sugar … so, those who had the highest carbohydrate intake had a 28 percent increased risk for death, 28 percent increased risk for death.
Those who had the highest fat intake, across the board, had a 23 percent reduction in death rates, 23 percent reduction. Those who had the highest saturated fat intake had a four to eight percent reduction. When I hear people saying saturated fat’s bad for you, where’s the damn evidence, because it isn’t there. For example, study of 15,000 people, sorry, got it wrong. 30,000 people, over 15 years in Europe looked at people’s intakes of different foods and found that those who had the highest intake of high fat dairy had a 23 percent reduction in Type 2 diabetes.
So, let’s forget about all this fat nonsense, about how fat is bad for you. Fat does not cause coronary artery disease. It’s complete nonsense, and anyone who says that just doesn’t understand science.
Dr. Ron Ehrlich: Well, Ross, music to my ears. And of course, the whole point about insulin resistance is this skyrocketing thing called diabetes, and that makes things very unstable, doesn’t it?
Dr. Ross Walker: Yeah. Look, Ron, diabetes is like cancer of the blood vessels. So, once you become diabetic, you’re in trouble, because you get this accelerated atherosclerosis, accelerated build-up of fat in the arteries. And so, what happens is that the sugar in your bloodstream from the diabetes combines with the bad fats, and combines with protein, to cause these things called advanced glycosylated end products. So you end up with, almost like little bits of toffee apple in your arteries.
The diabetics are really the canaries in the coal mine, but it’s not just the diabetics, it’s also the pre-diabetics. And if you’ve got this insulin resistance gene, as I said, 30 percent of Caucasians have it, it’s very easy to get diabetes, to get blood pressure, to put up not just your cholesterol, but your triglycerides, and put down the HDL, the so-called good cholesterol. It actually isn’t, but this is just the pattern you look for in the bloodstream, and fat around the belly.
So, the fat around the belly, which we spoke about on a number of occasions, abdominal obesity, that is the bad fat. So, like a lot of women are concerned about the fat on the backside or on the thighs, and it might not look good in terms of what they’re thinking, but it doesn’t hurt them. What hurts is abdominal fat, and fat around the throat, because that increases your risk for sleep apnoea, which is certainly in your area.
By the way, I just read through your magnificent new book, so anyone who’s listening should get Ron’s book. It’s magnificent.
Dr. Ron Ehrlich: Ah, Ross. And I didn’t even pay you to say that. I mean, you’re a dear. Thank you so much.
Dr. Ross Walker: Can you just tell everyone what it’s called? Thank you.
Dr. Ron Ehrlich: It is called A Life Less Stressed: The Five Pillars of Health and Wellness.
Dr. Ross Walker: It’s a beautifully researched book. It’s really easy to read. So, anyone who’s listening, Ron did not ask me to do this. You go out and buy his book. It’s magnificent. Sorry, mate. Keep going.
Dr. Ron Ehrlich: No-no-no. Ross, you and I go back so long, let’s not even go there. Actually, we should. But I think I worked it out just before we came on air. And I think when we were at school together, that was almost 45 years ago, or more even. I digress. I digress. I get all nostalgic, when I talk to you. But it’s back to those fats, isn’t it? I mean, the demonization of the fats has pushed us into this … Well, I know you don’t like the … but, high carb. Well, high carb, and that’s led to these people who are predisposed to diabetic actually becoming diabetic, and the whole range of problems.
Dr. Ross Walker: And also, since we’ve become obsessed with dieting over the last 20 or 30 years, we’ve got fatter. I read a book 10 years ago, called Diets Don’t Work.
Dr. Ron Ehrlich: I was going to ask you about that.
Dr. Ross Walker: Yeah, well they don’t work because people go on a diet like they go on a holiday. Recently on my show, I interviewed a fellow called Dr Nick Fuller, who’s a professor at University of Sydney, an expert in obesity. And he agrees with me entirely, diets don’t work. What you’ve got to do is … And I think I’d certainly advise to go get his book, as well. It’s called Interval Weight Loss. And he says you’ve got to really trick your body.
It’s a bit like the 5:2 Diet, where you trick your metabolism into thinking that you’ve changed for a day, but you go back to another way of eating. And so your body can never get used to it. So you then lose weight, because you’re tricking your body into changing your metabolism. Whereas, if you go onto a diet, your body then just goes into starvation mode, and just holds onto the fat. So, it’s crazy to even think about dieting. Dieting is ridiculous.
Dr. Ron Ehrlich: Well, I think the idea of three meals a day is another one that, when in human history was three meals a day a normal part of life?
Dr. Ross Walker: Oh, it’s only been recently. People come to me and say, “But don’t I get starving at 10:30?” Get over it! There’s nothing wrong with a bit of hunger. Hunger doesn’t hurt you. We were designed to wander in the jungle with a spear for 30, 40 years. You’d kill the beast, you’d eat the beast. You’d store a bit of fat in your belly, which is where the insulin resistance came into it, because people who are insulin resistant are much better hunter-gatherers than people who aren’t. So you can store the fat for a day or two, until the next big feed. But what do we do? Breakfast, lunch, dinner, we sit on our bums all day, and you wonder why we’re still getting rampant cardiovascular disease. It’s obvious.
Dr. Ron Ehrlich: Yeah. Yeah. Now listen, I can’t help but ask this question, because you are a cardiologist. You know, we’ve heard cholesterol. It’s actually an integral part of our body. Remind our listeners of what cholesterol actually does.
Dr. Ross Walker: Okay. Cholesterol is actually a steroid, it’s not a fat. So, a lot of people will be surprised about that one. It’s the basic steroid ring for most of our hormones. So, the cortisone based hormones, all of the sex hormones, are based around the steroid ring. So, we need cholesterol. Cholesterol is a vital part of our cell membranes.
So, in a healthy person, our cell membranes, the covering of our cells, the protective coating that protects us against outside toxins, should be 75 percent fat, of which a lot of that’s cholesterol. Which is why I don’t like fat soluble statins, because they rip the cholesterol out of your membranes. Lipitor and Zocor or Atorvastatin, Simvastatin, are the fat soluble statins. I don’t use them at all, because they rip the cholesterol out of the membranes and make the membranes leaky and permeable.
So, we need cholesterol, we need fat. And here’s where everyone’s getting it wrong. LDL cholesterol is said to be the bad cholesterol, and it isn’t. HDL cholesterol is said to be the good cholesterol, and it isn’t. They’re both divided into subcomponents, and the major subcomponents are what we call small, dense LDL cholesterol and large, buoyant LDL cholesterol. Small, dense LDL cholesterol is the proatherogenic cholesterol that puts muck in your arteries.
So, I’ll give you a great example, here. I’ve got a 36-year-old patient who, at age 36 has already had three stents in his arteries. 36 years old. The only abnormality he has in his bloodstream. He doesn’t have lipoprotein delay, his cholesterol profile is normal, the only abnormality in his bloodstream is he’s got a very high level of small, dense LDL, which I measured in subfractions, which most doctors don’t do, routinely. So, I’m hammering his small, dense LDL, so he doesn’t have to have any more stenting or bypass surgery.
And this is where we’ve got to target our therapy. Large LDL, what that does do is build healthy cell membranes, as I mentioned before. It improves blood-brain barrier, which is a fatty membrane. It improves cell to cell communication, the basic steroid ring, as I said. It’s important for basal metabolism, vitamin D metabolism. So, we need large LDL. Also, when we’re talking about HDL, large HDL is also protective. That rips the cholesterol out of the arterial walls, whereas small HDL is pro-inflammatory, so that makes the whole atherosclerotic process worse. So, just looking at a cholesterol profile doesn’t tell you much.
I received an email this morning, that I was reading, from a longstanding patient of mine. She’s got familial hypocholesterolaemia, where her cholesterol sits well above eight. And her GP is desperate to put her on a cholesterol lowering pill, wants to go see one of Sydney’s cholesterol experts, to get her cholesterol lowered. She’s a woman in her late 50s. Her coronary calcium score is zero. She has nothing in her arteries.
Now, a study that was done in the Journal of the American College of Cardiology, November, 2015, followed 5000 Yanks for 10 years, over the age of 50, and found that 77 percent of the people in the trial fit in the U.S. criteria to be on a statin to lower their cholesterol. But half of that 77 percent had a zero-calcium score. Their heart attack rate over the 10 years was so low that the conclusion of the trial was, if you’ve got a zero-calcium score, you do not need a statin. You can ignore your cholesterol level.
Now, I’m not saying just have a one-off zero calcium score. I do them every five years for people low calcium scores. Once you get a high calcium score, or you have coronary disease, you can forget about ever having it done again, because you need aggressive management. But we’ve got to stop this throwing around of cholesterol lowering pills like lolly water.
The only people who need a cholesterol lowering pill are people who’ve had established heart disease, stent, heart attack, bypass, or they have significant coronary atherosclerosis seen on a coronary calcium score. If your coronary calcium score is low, or zero, you can forget about your cholesterol.
Dr. Ron Ehrlich: Well, Ross. I remember the last time you said that to me, I went off and got my coronary calcium CT score, and it wasn’t good. It wasn’t good. I mean, a lot of my listeners will be following some of my own other health stories, and I’ve certainly got a whole new respect for family history. So, you know …
Dr. Ross Walker: Yeah, well you’ve got a high life approach. Let me tell you a story, and this is not speaking out of school, because this man actually published this in his website. One of my best mates is a guy called Peter Switzer. Now, a lot of people would know Peter Switzer from Switzer Business on Sky News. And I’m on his show once a month. He is, as I said, one of my best mates. He’s in his mid-60s. And I’ve said, “Pete, look. You’re long overdue for a coronary calcium score and a check-up with me. Your father died at 53 of heart disease. You’ve got to come in.”
I eventually convinced him to come in a couple of months ago. He was in atrial fibrillation when he arrived, didn’t even know it. Got him out of atrial fibrillation, put him on the treadmill. And his heart at rest, on the echo, didn’t look that good, but at the end of exercise was dreadful. No symptoms. Put him into the hospital, severe triple-vessel disease, had bypass surgery. He’s now fine, but he probably would have died in the next few months.
Dr. Ron Ehrlich: Well, tell our listeners that you’ve mentioned the coronary calcium CT score, because a lot of our listeners would be exposed to the idea of getting an angiogram. And, what’s the difference? I mean, why …
Dr. Ross Walker: Okay. Look, as you well know from a bit of personal experience, I completely object to the intravenous CT coronary angiogram as a screening test for heart disease. It is not a screening test. It does not give you any extra prognostic information, over the simple coronary calcium score, which is done with a CT scan, no dye, no injections, just measures how much muck you’ve got in your arteries.
Now, the difference between the two tests is that, firstly as I said, A, there’s no extra prognostic information by the invaded, intravenous dye test, but you are being exposed to dye, that potentially you could have an allergic reaction to. These tests can be, with certain machines, up to 300 chest x-rays of radiation, as opposed to the four or five with the coronary calcium score. So, you glow in the dark for three days after you’ve had the test. And also, the intravenous CT coronary angiogram makes your wallet $500 lighter.
So, there is no indication, whatsoever, to use the coronary CT angiography, the intravenous test, as a screening test for heart disease. There is strong indication, in my view, that all males at 50, or females at 60, should have a routine coronary calcium score, if they don’t have established heart disease. So, my 36-year-old patient with the stents in his arteries, waste of time. There’s no point doing it. But for somebody who, say is, a male who has just hit 50. Maybe his father had a heart attack at 75, or somebody in the family is on a cholesterol lowering pill and his cholesterol’s nudging up, have the coronary calcium score. You know, exactly where you are.
Dr. Ron Ehrlich: Yep. And you, I remember once saying to me, and it still rings in my ear, and it’s why I’m not reading it, said anything over 400, don’t read Tolstoy.
Dr. Ross Walker: Yeah, that’s right. Keep away from Tolstoy. No, let’s don’t read Tolstoy without treatment. But the point is, Pete Switzer’s coronary calcium score was, I think, 476. But if you have it and you get something done about it, well then, I mean Pete will live another 40 years, now he’s had an excellent operation. He’ll be on appropriate therapy. You’ll live for another 40 years, as well, because you’re under my care. So, there you go.
Dr. Ron Ehrlich: Thanks, Ross. Now, listen. What do you think are some of the biggest challenges people face today, when they’re dealing with their health. I mean, you’ve identified the five things, but what’s standing in the way of people getting on with it?
Dr. Ross Walker: I just think, life. I think the biggest challenge these days is our modern society. And so, this is a really interesting thing. We all think that, with all these extra luxuries we have on the planet, that life’s so much easier. But, it’s interesting that people in their 20s and 30s say, “I’ll go and I’ll work really hard for the next 10 years, then I’ll retire.” But, when they hit their mid-30s or 40s, they’ve now got the mortgage and the two cars, because you have to have two cars. And they’ve got to have their smashed avocados and their double shot lattes every day. And all of those things become expensive.
And also, if you think about it, when you and I were kids, we were at school, anything at all like that. If you wanted to make some comments to somebody, you would write them a letter. That letter would be posted. The person would get the letter two or three days later, and you might get an answer a week or so later. And you would only write something down if it was really important.
These days, people will have a thought in their head, put it on social media, send an email to someone, expect a result in five seconds. If they don’t get the message back straightaway, they’re all upset. And so, what we’re getting, these rubbish emails. We might get 10, 20, 30, 50, 100 a day, and some of them have to be dealt with. It’s just, it’s wasting our time on nonsense.
And all of this stress is creating stress for everyone. Everyone’s just time poor, they’re stressed, they’re unhappy with their lives. They’re not putting their everything to where they should be putting their everything. So, I think that’s the biggest challenge associated with today’s life. It’s just, it’s too much for too many people.
Dr. Ron Ehrlich: And, I mean, you’re five tips, which I love, and I know you’ve written a book on that very subject. And we’re going to have links to your webpage, of course, because you’ve written how many books now, seven?
Dr. Ross Walker: Seven. Yes, seven books.
Dr. Ron Ehrlich: Seven books.
Dr. Ross Walker: Well, sort of eight, if you want to throw in another ebook I wrote, called How to Reverse Heart Disease, but seven that have been published in bookstores.
Dr. Ron Ehrlich: And, of course, you’ve got your weekly program on, where …
Dr. Ross Walker: The Talking Lifestyle Network, which goes throughout Australia. On Sunday nights, 6:00-8:00 on Sunday nights, so it’s 954 AM in Sydney. It’s the Magic Network in Brisbane and Melbourne. I can’t remember the numbers. I think it’s 884 in Brisbane, and 1126 in Melbourne.
Dr. Ron Ehrlich: We’ll have links to all.
Dr. Ross Walker: And Perth, Perth as well. So we through Australia, 6:00-8:00 on a Sunday night. Health Living, the show is called.
Dr. Ron Ehrlich: Yeah. Well, Ross, Thank you so much [00:22:30] for today. We always have a good chat, and always enjoy catching up. So, we’ll have links to your website, and your program [Walker Wellbeing]. And, until the next time, thank you.
Dr. Ross Walker: Hope to talk to you soon, mate.
Dr. Ron Ehrlich: So, fats are not the problem, which is something I identify in my book [you can download a FREE synopsis here]. You’ll hear it repeatedly on this podcast. I mean, we have to redress the balance. This is a theme, I’ve got to tell you now folks. This cholesterol story, this demonizing saturated fats story, is not going away any time soon. There are just too many reputations that are at stake, here. There are too many organizations that are making a great deal of money out of it. So, I think what we want to focus on is some independent advice, independent of pharmaceutical industry, independent of the food industry, et cetera.
So, that’s going to be a recurring theme, and it’s great to hear it from my cardiologist. And, of course, the whole cholesterol story, as well. And, when you read about it, when you discuss it, I’m telling you, talk about public health messages. I mean, there was a Harvard study, which looked at the evidence, as to whether statins were good for your health. Okay? Now, the key question in this study was, “Are statins, which lower cholesterol, good for your health?”
And, funnily enough, in this Harvard study they found that when industry did those studies, they were 20 times more positive than when independent studies were done. Well, of course, the statin industry’s not going to let that one lie, so they actually engaged the London School of Economics to do a study to test whether industry funded studies were as reliable or consistent as independent studies. And their conclusion was, there was no difference. So, talk about confusing health messages.
And I told you before, they’re not going to let this one go. But, when you read the fine print, in fact, when you read the methodology, the question that was asked in the first Harvard study was “Does cholesterol make a difference to a person’s health?” When that question was asked, the results were 20 times more positive for industry funded studies, than non-industry. But the LSE study, the London School of Economics study, asked the question, “Do statins lower cholesterol?” Now, no one is going to argue with that.
And so, industry funded studies and independent studies will all agree. But, as you will have got from this podcast, I hope, and that is cholesterol is really not the problem. It really depends. And the family history’s important. Let’s get that straight. So, that’s really important. And most importantly is the message that Ross shares with millions of people. I love those five tips.
And those five tips, just to recap were: no addictions; sleep, hey, we mention that a lot on our podcast; eat less, but eat more nourishing food, and processed food, of course, it’s a no-brainer; exercise, we’re going to do a whole lot of work on exercise; and happiness. Well, we’re going to focus more on thinking. Happiness is somewhat, can be illusion, you know, a bit hard to achieve sometimes. And if we get preoccupied by that … But happiness, and how we think about things is critically important. And with those five things, you’ve got at least a 70 percent chance of reducing all chronic disease. So, that’s pretty good.
Anyway, look. I hope you enjoyed it. Until next time, this is Doctor Ron Ehrlich. Be well.
This podcast provides general information and discussion about medicine, health, and related subject. The content is not intended and should not be construed as medical advice or as a substitute for care by a qualified medical practitioner. If you or any other person has a medical concern, he or she should consult with an appropriately qualified medical practitioner. Guests who speak in this podcast express their own opinions, experiences, and conclusions.