Antioxidants - Hype versus Reality

[r2473]

The term "antioxidant" has become a marketing term synonymous with healthful. Does the hype really hold up to reality?

Do many of us actually understand anything about oxygen free radicals? How are they produced? What do they do inside our body (both harmful and beneficial effects)? What does our immune system do with them? How are they normally dealt with in healthy people?

-Will that green tea, Acai, Noni, blueberry, or pomegranate juice help you live longer and healthier?

-What are high doses of anti-oxidants and anti-oxidant supplements supposed to do anyway?

-What diseases do they prevent?

-Do they help cure diseases?

-Do they slow (or even reverse) the effects of the aging process?

-Have antioxidant supplements proven beneficial? How? Do we see reduced instances of cancer in people that have taken anti-oxidant supplements?

-Fruits and vegetables contain anti-oxidants. I believe there is evidence that eathing them helps prevent cancer and improves longevity. Is it the anti-oxidants in fruits and vegetables or something else?

Well, what is your opinion on the whole "anti-oxidant" craze. Its been around now for over 20 years. What does science have to say so far? Is it hype or reality?

 

[r2473]

The science doesn't look as promising as first thought anyway.

Steven Novella is an academic neurologist at Yale and has an interesting site called "Science-Based Medicine". Always interesting to see what the science is really showing instead of the marketing:

http://www.sciencebasedmedicine.org/index.php/antioxidant-hype-and-reality/

 

[ollinger]

1) no adequate evidence of benefit.
2) if there were, no evidence that the benefit is due to an antioxidation effect.
3) no evidence that substances which may have antioxidation effects in vitro have the same effect in vivo. this is especially relevant since genetic material thought to be damaged by oxidation is mostly intranuclear, and many substances do not penetrate the cell nucleus.
4) not known if, for example, you'd have to take an antioxidant continuously to benefit from it. one of the lessons learned from cancer chemotherapy is that you can give the right stuff but if you're not giving it at the right times, it's worthless.

 

[WildVolley]

Well, we can say at this point that we don't fully understand the benefits and costs of various anti-oxidants.

We do know that diseases of deficiency develop, such as scurvy, when consuming very low levels of antioxidants. However, we don't know what the optimal level yet is. A lot of the hype was from Pauling who thought it could be used to treat both cancer and heart disease.

In any case, I will keep eating fruits and vegetables which are high in anti-oxidants because I feel better when I have them in my diet. I will keep supplementing vitamin C because 1) it is very inexpensive and 2) I haven't experienced any noticeable negative side-effect. If credible evidence shows that it is harming me, then I'll stop using it. I won't be dumping a lot of money into super expensive Acai berry drinks or the like unless I really enjoy how they taste. I prefer to eat fruit than to drink juices.

I reason the same way at the moment about vitamin D. Crude correlation studies are showing that it might help fight cancers and the like. I enjoy being out in the sun. So I take my shirt off and get more of a tan these days.

 

[Bartelby]

People who think a diet of antioxidants could prevent or cure a thing like cancer are by definition seriously deluded.

Everyone however is concerned to eat well in the hope that this will make them feel well and not cause any harm.

All the foods mentioned are probably beneficial regardless of the veracity of the antioxidant thesis.

The problem is the way these products are reported and advertised, which is nothing short of obscene and untruthful.

Even science reporting and advertising can be extremely dubious with universities and institutes hyping claims to the media for steps toward a cure that is still decades in the making.

 

[Power Player]

I am not sure, but I try and eat blueberries a lot regardless.

They are delicious.

 

[charliefedererer]

Hype > Reality

 

[Posture Guy]

Bartelby....are you asserting that there is no linkage whatsoever between diet and disease processes like cancer?

 

[ollinger]

Linkages between specific dietary factors and cancer are in fact extremely difficult to establish because of dietary overlaps. For example, suggesting that red meat may cause colon cancer is nearly impossible to say because people who eat lots of red meat also typically have high fat diets, so is it the meat or other fats that cause cancer? The kinds of carefully controlled studies needed are almost impossible to do -- how do you carefully control what a large number of people eat for many years? Also, some cancers don't seem to manifest for 10 to 20 years after the first cell goes awry, so you'd have to follow subjects for decades to do such research. The clearest link I've ever seen in a carefully done study was the one that showed you can reduce your risk of colon cancer by nearly fifty percent if you take two aspirin every day.

 

[Posture Guy]

ollinger...I completely agree.

the data I find most compelling is on the flip side. It's not scientific, but I find it compelling nonetheless. There are tens of thousands of stories of people with terminal cancers who reversed their disease processes after making significant dietary changes.

but I agree, it's almost impossible to do traditional scientific studies on diet. You can't do double blind placebo studies on diet.

it's a muddy water, to be sure, but I think there are few researchers in the field who would assert that dietary choices play no role in either the causation or reversal of various disease processes.

 

[ollinger]

On the whole, I'd agree it's likely that what we eat (breathe) has a role in causing cancers and other illnesses.

 

[Posture Guy]

I'd also add what we apply. Most personal care products are replete with petrochemicals. Some of the stuff in things like shampoo, toothpaste, soap and anti perspirant or deodorant is downright scary.

 

[r2473]

I'd also add what we apply. Most personal care products are replete with petrochemicals. Some of the stuff in things like shampoo, toothpaste, soap and anti perspirant or deodorant is downright scary.

Are you French, British, or Armenian?

 

[GuyClinch]

Cancer ultimately is a product of celluar metabolism. Sooner or later human beings will get it because unlike some other lessor species of the animal kingdom - we don't have adequate anti-cancer mechanisms built in.

Enviromental components do play a factor (witness the effects of smoking) but even if you elimated every reasonable cause of cancer - you will eventually still get it if you live long enough..

Sooner or later one of the cells goes bad - and replicates out of control. Think of it like a car engine. Sure if you change the oil - warm it up properly etc. You can get one that lasts an incredibly long time. But sooner or later they do fail. It's because the engine has no self repair mechanism. I think anti-oxidants might help but remember the cell needs oxygen to run. The very aspect of being alive is damaging to cells.

The only real way to fix this problem is with some kind of nano-technology or bio engineering. Not sure any of us will live long enough to see that. Even 50 years doesn't seem to be nearly enough time.

 

[El Diablo]

^^^ Ummm, what are you talking about?? Cancer has been found to occur in nearly every animal it's been looked for in.

 

[GuyClinch]

They all get it - but many of the lessor animals can self-repair the cancer before it gets out of control. Some animals that are thought to be able to live forever include horseshoe crabs, lobsters and Jellyfish.

These animals don't suffer from the celluar damage and aging associated with 'old age' in humans. Hence the car engine analogy..

 

[GuyClinch]

10 characters

 

[El Diablo]

Ummm, no. There are reports of lobsters living a hundred years, but that's quite unusual. "Live forever." You need to offer some decent scientific references here because I don't find any sense in anything you say.

 

[LuckyR]

It makes complete sense that free radicals lead to damage then to disease. It also makes sense, but has largely been unproven, (though many have tried) that anti oxidant use would prevent such disease. Perhaps, free radicals are so reactive that they do their damage before they can run into an anti oxidant (and become detoxified).

 

[Talker]

It makes complete sense that free radicals lead to damage then to disease. It also makes sense, but has largely been unproven, (though many have tried) that anti oxidant use would prevent such disease. Perhaps, free radicals are so reactive that they do their damage before they can run into an anti oxidant (and become detoxified).

True, some damage will be done regardless sometimes causing mutations.
No one knows the exact mutation that will cause problems, like cancer, so we are stuck with probabilities of outcome.

So increase the antioxidant levels and increase the chance of getting the free radical neutralized that will make the mutation(s).

 

[ollinger]

The problem remains that nearly all our important genetic material subject to mutations is in the relatively inaccessible nucleus of the cell, while the metabolic machinery where antioxidants generally have access is in the cytoplasm, outside the nucleus. So it's extremely unlikely that something you ingest is going to prevent genetic mutations (theoretically caused by free radicals), the same problem that has plagued cancer researchers for countless decades.

 

[Bartelby]

Diet is what we should eat to feel well and what he should not eat or at least indulge in less. Medicine contributes to our knowledge of this, but much is still unclear.

Medical issues like cancer are a different order of complexity. It has ties to lifestyle, but goes far beyond such factors. So to think a food will protect against a disease is magical thinking.

 

[snoopy]

This seems related to the discussion:

http://online.wsj.com/article/SB10001424052970204621904577014011448483058.html?mod=e2fb

 

[WildVolley]

So to think a food will protect against a disease is magical thinking.

Much too strong of an assertion. In many cases food has been able to protect against disease. For instance, it was common knowledge that citrus cured scurvy long before the actual mechanism of the disease was understood. Some doctors still denied that scurvy was a disease of deficiency and believed it was infectious long after it was successfully treated with food. If you know the history of pellagra (a disease caused by a chronic lack of niacin) you'll know that after Goldberger had demonstrated it could be cured by food alone, he was still accused of being wrong and many doctors insisted it was an infectious disease.

My point isn't that all diseases may be cured by diet, just that hypothesizing that a disease might be cured by food isn't a good example of magical thinking, even if it is incorrect.

 

[Posture Guy]

There is ample research that many foods have clinically documented protective or even curative effects against a variety of disease processes. To say that food cannot protect against disease is just flat incorrect. There is no knowledgeable researcher in the field who would agree with that statement.

 

[r2473]

People with a diet high in fruits and vegetables seem to be overall healthier. Why exactly this is isn't clear (though opinions abound).

It's fairly clear that using supplements to supply vitamins and nutrients instead of fruits and vegetables is not an effective substitute. The reason for this isn't clear either.

It is also clear that people who get regular exercise are overall healthier.

It's fun to talk about the myriad "fringe" issues relating to health and nutrition. But the fundamentals never change. If you simply structure a lifestyle that includes a habitual adherence to these few fundamentals, you can basically ignore the other stuff.

You can also enjoy your deviations from the fundamentals guilt free. Your body will always "remember" what you normally do. Not what you occasionally do.

 

[sureshs]

People with a diet high in fruits and vegetables seem to be overall healthier. Why exactly this is isn't clear (though opinions abound).

Because they have a great sheet in the morning from all the fiber.

 

[XFactorer]

r2473, I'm glad you brought this up. The other day I was watching the stupid ads for PomWonderful and one of the selling points of the juice is that it is 'backed by modern science.' Not sure what science they're looking at since the science doesn't seem to indicate we need extra antioxidants we don't already get in regular foods.

"And what we've found by testing antioxidant supplements is that they do not provide any of the claimed benefits, such as preventing cancers or heart disease. Yes they're good, and your body needs them, but there is no reason to supplement with them. In fact, one large 2007 study published in the Journal of the American Medical Association found that supplementation does more harm than good."

-Brian Dunning, Skeptoid.com
http://skeptoid.com/episodes/4243

As for Steven Novella... listen to his podcast, the Skeptic's Guide to the Universe. They discuss a lot of science news on that podcast and pop culture myths (like antioxidants). He's a very articulate, knowledgeable person.

 

[Posture Guy]

r2473, I'm glad you brought this up. The other day I was watching the stupid ads for PomWonderful and one of the selling points of the juice is that it is 'backed by modern science.' Not sure what science they're looking at since the science doesn't seem to indicate we need extra antioxidants we don't already get in regular foods.

"And what we've found by testing antioxidant supplements is that they do not provide any of the claimed benefits, such as preventing cancers or heart disease. Yes they're good, and your body needs them, but there is no reason to supplement with them. In fact, one large 2007 study published in the Journal of the American Medical Association found that supplementation does more harm than good."

-Brian Dunning, Skeptoid.com
http://skeptoid.com/episodes/4243

As for Steven Novella... listen to his podcast, the Skeptic's Guide to the Universe. They discuss a lot of science news on that podcast and pop culture myths (like antioxidants). He's a very articulate, knowledgeable person.

I'm not arguing for or against consumption of their product, but there are a LOT of studies out there showing some potential health benefits from the consumption of pomegranate juice. Here's one from the POM web site:

http://www.pomwonderful.com/media/p...am_ClinNutr_PJ_Consump_3Years_Carotid_021.pdf

it's easy to find a lot of them out there.

 

[Posture Guy]

here's another study showing promise for men with prostate cancer:

http://clincancerres.aacrjournals.org/content/12/13/4018.full

and another one with respect to heart disease:

http://pomwonderful.com/media/pdf/health/HH_2005_Sumner_AmJCardio_PJ_Consump_Myocard_024.pdf

 

[XFactorer]

I'm not arguing for or against consumption of their product, but there are a LOT of studies out there showing some potential health benefits from the consumption of pomegranate juice. Here's one from the POM web site:

http://www.pomwonderful.com/media/p...am_ClinNutr_PJ_Consump_3Years_Carotid_021.pdf

it's easy to find a lot of them out there.

Ick! Rule of thumb [for myself] is to never look at the data/studies the company presents you. I use scholar.google.com or pubmed.org to search for studies.

 

[XFactorer]

The 2007 meta-analysis of antioxidants in randomized-controlled trials (referenced in the Dunning article) basically put it, we don't need to worry about going out to get extra antioxidants, we already have enough in our regular Western diets.

I'd say to buy the juice because it tastes good and you like it. But don't buy it because the company tries to paint the picture that you need 10 pomegranates' worth of juice in a day or your lack of antioxidants will be the death of you. (Ok, that's a little extreme)


http://books.google.com/books?hl=en...: Systematic review and meta-analysis&f=false

 

[Posture Guy]

well if the study is independently performed, I don't much care regarding the mechanism used to make me aware of the data. The question is the integrity and findings of the study itself.

there is a LOT of data suggesting that pomegranate juice has a strong cardio-protective benefit. My thinking is this is less a result of anti-oxidants and more because of the ability of this substance to raise nitric oxide levels, thus improving endothelial function/vascular reactivity. Probably a similar mechanism to findings of heart health benefits from raw cacao, which I also believe is linked to nitric oxide levels.

 

[ollinger]

^^ both studies are of questionable value. The first looks primarily at PSA levels, a measure that made the front page of The New York Times a few weeks ago as being of far less value than we had thought, and there was a recommendation that it no longer be used as a primary indicator. The rest of the data looks at in vitro rather than in vivo measures, often unreliable in oncology research (lots of things work in vitro but not in vivo).
The second study has randomization problems. Comparing the active and placebo groups, six crucial measures (diastolic BP, cholesterol levels, HDL levels, triglyceride levels, glucose levels, and hemoglobin A1C levels) are all slightly in favor of the juice group rather than the placebo group. The levels INDIVIDUALLY do not differ to a statistically significant level but the authors do not do the necessary analysis when many factors TOGETHER all point in one direction.

 

[Posture Guy]

ollinger...good points. Data could hold value, and perhaps not.

funny timing, just got an email yesterday with a link to a new study on this subject:

http://www.lef.org/newsletter/2011/...ascular-Risk-Factors-in-Dialysis-Patients.htm

Friday, November 11, 2011. A presentation at the American Society of Nephrology's Annual Kidney Week, held November 8-13, 2011 in Philadelphia, revealed the finding of Lilach Shema, PhD and colleagues at Western Galilee Hospital in Israel of a benefit for pomegranate juice in the prevention of increased heart disease risk factors in patients undergoing hemodialysis for kidney failure.

In a U.S. government-funded study, 101 dialysis patients were randomized to receive approximately 3.5 ounces pomegranate juice or a placebo three times per week for one year. Blood pressure, antihypertensive drug use, serum lipids, and carotid artery intima media thickness (which measures atherosclerotic plaque in the arteries) were assessed before and after the treatment period.

At the study's conclusion, 22 percent of those who received pomegranate juice reported using fewer antihypertensive medications, compared with 7.7 percent of the placebo group. Similarly, 12.2 percent of those who consumed pomegranate juice reported using more antihypertensive drugs compared to 34.6 percent of those who received a placebo. Blood pressure, triglycerides and high density lipoprotein cholesterol levels improved over time among those who received pomegranate juice, but not in those who received a placebo.

While atherosclerosis increased in half of subjects who received a placebo, just 5 percent of those who received pomegranate experienced an increase and 25 percent had a decrease. No placebo patients experienced improvements.

"Pomegranate juice consumption attenuates traditional cardiovascular risk factors," the authors write. They conclude that pomegranate may help reduce the high incidence of morbidity and mortality observed in hemodialysis patients.

 

[XFactorer]

well if the study is independently performed, I don't much care regarding the mechanism used to make me aware of the data. The question is the integrity and findings of the study itself.

Mmmm... given the chance to cherry pick your own study, you'd pick a study to support your own views. All you have to do is make sure you find a study that says what you want that you have no ties with! Right?