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CANCER FIGHTER
March 18, 1998The NewsHour with Jim Lehrer Transcript |
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A recent study has found that Vitamin E helps reduce the risk of prostate cancer by one-third and cuts the death rate by 41 percent. Others studies have suggested that Vitamin E can help fight heart disease. Elizabeth Farnsworth and guest discuss the reports' findings.
A RealAudio version of this segment is available.
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ELIZABETH FARNSWORTH: A study in Finland suggesting that Vitamin E pills reduced the risk of prostate cancer in a group of male smokers is just the latest in a series of successes for Vitamin
E. Other studies have reported it may help fight heart disease, slow the progression of Alzheimer's Disease, reduce the risk of cataracts, and boost the immune system of the elderly. For more, we turn now to Jeffrey Blumberg, a nutritional biochemist who studies Vitamin E at Tufts University. Thanks for being with us.
JEFFREY BLUMBERG, Tufts University: Thank you.
ELIZABETH FARNSWORTH: Mr. Blumberg, tell us about the study in Finland. What was it looking at, and what did it discover?
The study's findings.
JEFFREY BLUMBERG: Well, scientists from the National Cancer Institute, working together with scientists in Finland, studied 30,000 male smokers in Finland and found that those who took a Vitamin E capsule every day for five to eight years had a 30 percent reduction in a number of cases of prostate cancer and a 40 percent reduction in the number of deaths from prostate cancer. And this is really exciting because in this country we expect about 40,000 men to die from prostate cancer this year.
ELIZABETH FARNSWORTH: This was not the first study, was it, that showed these kinds of results with prostate cancer?
JEFFREY BLUMBERG: No. There have been a number of studies that show that high intakes of Vitamin C--excuse me--high intakes of Vitamin E are associated with reduced risk of many forms of cancer. Some recent studies have also shown that in smokers with low levels of Vitamin E in their blood have high rates of prostate cancer. So this new finding is consistent with earlier evidence.
ELIZABETH FARNSWORTH: What is Vitamin E? Where does it come from?
JEFFREY BLUMBERG: Vitamin E is found in our food. We find it in oils like salad dressings and in nuts and in grains, and, of course, we also find it in dietary supplements. It's an essential anti-oxidant nutrient. If you--
ELIZABETH FARNSWORTH: Let me interrupt you. What is an anti-oxidant?
Oxygen - the dangerous friend.
JEFFREY BLUMBERG: Well, you just have to appreciate that oxygen is a dangerous friend. When it's metabolized in our body, it generates compounds called free radicals, and these are highly toxic molecules that can damage the cell; they can damage our own DNA; and we think lead to things such as cancer.
ELIZABETH FARNSWORTH: So is that--is that the working theory right now, that Vitamin E somehow mitigates the effect of this--these--the free radicals?
JEFFREY BLUMBERG: Absolutely. We think that the anti-oxidant mechanism of Vitamin E helps to slow down the rate of cancer development and perhaps even the initiation of cancer by free radicals.
ELIZABETH FARNSWORTH: Why--how much Vitamin E were people taking in the Finnish study, and how does that compare with how much I would get naturally just from eating certain oils and peanuts and things like that?
JEFFREY BLUMBERG: The Finnish study used a dose of 50 international units or IU's of Vitamin E a day. A typical American diet would provide ten to fifteen IU's per day, and a standard multi-vitamin provides about 30 IU's per day.
ELIZABETH FARNSWORTH: All right. Let's move on to some of these other effects of Vitamin E. Tell us about the studies--what do the studies show about heart disease.
"...the data really is somewhat equivocal--some studies show that Vitamin E can reduce the risk of different forms of cancer, and other studies are not quite so positive...."
JEFFREY BLUMBERG: Well, in contrast to the studies about Vitamin E and cancer, which despite this very exciting new study, the data really is somewhat equivocal--some studies show that Vitamin E can reduce the risk of different forms of cancer, and other studies are not quite so positive--but with heart disease, studies have very consistently shown that Vitamin E is associated with a very significant reduction in the risk of heart disease.
ELIZABETH FARNSWORTH: How would that work? It seems so different from prostate cancer. What's the theory here?
JEFFREY BLUMBERG: Well, once again, free radicals come into play. When we think about many of the chronic diseases associated with aging, it looks like they're rusting diseases. These free radicals, created by oxygen metabolism, damage different components in a cell. In the case--
ELIZABETH FARNSWORTH: And over time, is that the idea, that as we age, there's all this oxygen being produced that's damaging our cells?
JEFFREY BLUMBERG: Exactly. In some cases, that damage happens to our genetic material and can lead to cancer. In the case of heart disease that damage is occurring to cholesterol, particularly the low density lipoprotein are bad cholesterol, and when that bad cholesterol gets oxidized, we think that that's really the key event that leads to the progression of heart disease.
ELIZABETH FARNSWORTH: And did the study show that Vitamin E helped with repeat heart attacks, or first heart attacks, or was there no distinction?
JEFFREY BLUMBERG: Well, studies have shown both, but most recently, a clinical trial conducted in Britain showed that people who had had one heart attack and then were given Vitamin E had a 77 percent lower risk of a repeat heart attack. Other studies of an observational nature showed that people who use Vitamin E supplements have about a 40 percent lower risk of even developing a first heart attack.
ELIZABETH FARNSWORTH: Now, what about the way that it helps the immune system of people over the age of 65, this was actually research you were very much involved in, right?
Vitamin E and heart disease.
JEFFREY BLUMBERG: That's right. And one thing we know, as people grow older, that their immune responses decline; they're just less vigorous. And when we gave Vitamin E supplements to healthy, active, older people, we found that the supplements significantly increased the vigor of their immune response, and we think that would lead to a decreased risk for infectious disease, and maybe cancer as well, because they have a more active immune response.
ELIZABETH FARNSWORTH: And finally with Alzheimer's, how has it helped with Alzheimer's, according to recent studies?
JEFFREY BLUMBERG: Well, a very recent study conducted a very carefully controlled clinical trial and found that people who received a very high dose--2,000 IU a day--of Vitamin E had a slower progression of their moderate Alzheimer's Disease. What happened was they were able to retain many of their activities of daily living and their admission into hospitals or other institutions was a lot slower than that of people who were taking a placebo.
ELIZABETH FARNSWORTH: It does sound like kind of a magic bullet. Is that the way you see it?
"...while Vitamin E does seem to help in many of these diseases, it's certainly not a magic bullet."
JEFFREY BLUMBERG: Oh, absolutely not. We know that both for cancer and heart disease and Alzheimer's Disease, there are many factors that contribute to these diseases, and while Vitamin E does seem to help in many of these diseases, it's certainly not a magic bullet. But it does represent possibly one inexpensive and effective intervention that may help contribute to a lower risk of many of these diseases. What you cannot do is expect any vitamin or any dietary supplement to offset adverse lifestyles. You can't smoke cigarettes, as they were doing in Finland, or be a heavy drinker and have a high fat/low fiber diet and expect a Vitamin E supplement to perform miracles.
ELIZABETH FARNSWORTH: And it can have some side effects, or not?
JEFFREY BLUMBERG: Vitamin E is remarkably safe even in very high doses. It is true that people who are taking blood-thinning medications, oral anti-coagulants, who take high doses of Vitamin E, may be at risk for a bleeding syndrome, but most all of the studies that have been done have shown Vitamin E to be remarkably safe.
JEFFREY BLUMBERG: Yes, I do.
ELIZABETH FARNSWORTH: I know that you're not a medical doctor, but there has been some skepticism about supplements. The American Heart Association, for example, said it's too early to recommend supplements. Do you think they're right, that there's not enough known?
JEFFREY BLUMBERG: I think there's a wide diversity of opinion in how much scientific evidence is needed before a medical recommendation can be made. I think that if you look at the totality of scientific evidence from observational studies in large populations, in clinical trials, animal studies, and recognizing the biological plausibility, that is, understanding how Vitamin E seems to be doing this work, the evidence is very compelling. I think we still need more scientific research to tell us what people really are going to benefit the most from Vitamin E, what dose is the best dose. So I think there's a great need for further research, but I think the research that we do have today is really very promising and very encouraging. It's quite compelling to appreciate that we may have a treatment that can really help us reduce our risk for many of the chronic diseases so common among older people--
heart disease and cancer, eye diseases, and even diseases of dementia, like Alzheimer's--that a simple, cheap, and safe intervention may really be helpful.
ELIZABETH FARNSWORTH: Well, Jeffrey Blumberg, thank you very much for being with us.
JEFFREY BLUMBERG: Thank you.
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