The author wrote, "In the end, admitting that most cancers have natural causes rightly shifts the focus on cancer prevention away from individual consumers. That's a good thing, since in the end, you can't always shop your way to becoming cancer-free."

I found this to be an oddly-worded conclusion. Of course you "can't always." There is no such thing as zero risk. But why de-emphasize the role of consumers in selecting products which reduce risk?

I also take issue with the author's conflating"environmental causes" with "natural causes." They are not synonyms. The environment contains everything to which we are exposed. Only some of that is natural; the rest is there because human activity put it there.

Cancer rates have been climbing steeply since the beginning of the industrial age. If cancer is explainable mostly as a product of environmental mutagenic factors (a point with which I agree), than humans are being exposed to far more of them. The cancer rates are nothing less than astonishing today: almost 1 in 2 for American males, and more than 1 in 3 for females, will contract cancer in their lifetimes. Longevity can explain some part of the rise, but even childhood cancers are up markedly. Something in our environment has changed.

What?

More viruses? Unlikely. Although we can expect specific pathogens to wax and wane (such as HPV) and have an influence, pathogens are unlikely to be driving all cancers up uniformly. Is the sun suddenly putting out more ultraviolet radiation? No. Magnetic fields? A statistically minor factor in cancer. Bovine growth hormone? Hormone Replacement Therapy? Hormones probably accelerate a cancer once it gets started, but there's little evidence hormones actually cause cancer.

No, the most likely explanation is the thousands of toxins produced by industry today that did not exist a century ago. And while many of these toxins are now in the atmosphere, dust, and ground water, and thus pretty much unavoidable, a great deal of it is actually contained within products which we purchase and use.

We paint our lips with cancer-causing chemicals. Brush our teeth and gums with cancer-causing toothpaste. Glug cancer-causing diet soft drinks. Buy furniture and house trailers which exude cancer-causing chemicals into the air we breath. Wash up with carcinogenic soap, wipe down the counter with carcinogenic cleanser, spray our flower beds with carcinogenic chemicals, store food in containers that leak carcinogens. These and thousands of other industrial products contain known carcinogens.

Some we can avoid through informed consumer choices.

There are other factors, such as genetics and diet. But the conclusion reached by the author is unsupported and unsupportable. Minimizing exposure to carcinogenic toxins means being a careful consumer. You can shop your way to a lower (but not zero) risk.

Better regulation of industrial practices would help, too.

I'm sorry, but I have to say this: I consider the author of this article to have been irresponsible. Following his advice would bring harm to some who, given better advice, might have avoided it.

Something that is missing from all of these discussions on the cause of cancer is age. Yes, young people do get cancer, but the greatest number of diagnosis of cancer are in the older population and we have a burgeoning aging population. Therefore more people will, sooner or later, be diagnosed with some form of cancer. We can point our fingers at many environmental causes of cancer and yes, it may play a part in the start of cancer in an individual, but there are also genetic and other components at play also. We can't exist in a vaccuum, free from all contact with our world and our ancestry. It is a part of living and a part of our dying. And we our mortal.

mellowing - so what is your point? What a fatalistic statement! Cancer is a hideous and horrible disease, at any age. It is not something you want to die of. And the cancers that have typically afflicted older people are showing up more frequently in younger people. Prostate and breast cancers are definitely coming earlier.

We live in a chemical stew of unregulated substances. The western world, especially the U.S., is conducting a giant experiment, and we are the rats. The EPA was forbidden to test hundreds of chemical in use at its inception as a "compromise" to industry's resistance. Since then, I think only about 7 have been baned. That is astounding. Our regulations are so lax that even if we stop producing products with these elements, foreign producers send their surpluses in products meant for us, e.g. the lead toys from China.

There are other parts of the world that do not have our cancer rates. Therefore, one must ask, why is that? There could be several answers. T. Collin Campbell in The China Study has concluded it is diet. But to not ask the question and assume that since we are living longer that we are naturally getting more cancers is not an acceptable response. Even if that were true, which I don't think is, we need to find ways to avoid cancer even in older people, because dying from being eaten from the inside is not pleasant.

I have to disagree with the crowd that equates increased cancer incidence with "industrial carcinogens". The reality is that the increased incidence of cancer is multifactorial, but owes mainly to the fact that a) people are living longer due to improved hygiene, vaccination, antibiotics, etc b) a dramatic increase in screening for cancers c) the high prevalence of heavy-duty smoking due to the mass manufacture of cigarettes and d) a greater medical understanding of cancers per se.

Why? The answer to a) is straightforward. A hundred years ago people were "lucky" to live long enough to develop cancer or cardiovascular diseases. Many people died from preventable or treatable infections like pneumonia, meningitis, wound infections, sepsis, tuberculosis etc.All of these are now prevented with vaccines, hygiene and antibiotics. That doesn't even begin to mention the epidemics of cholera, plague, influenza, etc. that wiped out millions of people at a time. This table demonstrates an interesting inverse relationship between infectious causes of death (TB, influenza, pneumonia) and malignant causes. Futher, whereas overall life expectancy in 1900 was 47 years, today it is 78 years.(Note, Adobe Acrobat is required, go to Table 27). Therefore, while not directly causal, we live in an age where we are "fortunate" to live long enough to die from cancer. Not to be callous, but we all can't live forever, and to put it bluntly, you have to die of something. So while I agree that dying of cancer can by ugly, so is death from tuberculosis (coughing blood), stroke (debilitating), heart disease (difficulty breathing), lung disease (ditto), etc.

For b) we now have screening tests for a great number of cancers such as breast, prostate, colon, and so the higher incidence is significant for the fact that more cancers are detected, not that there is necessarily more cancer. Frankly, when people died 100 years ago, it wasn't always clear why.

For c) it was understood 50 years ago that smoking leads to an inordinate number of cancers, and yet, worldwide approximately one in 3 people smoke. In fact, smoking contributes not only to cancer, but also to cardiovascular disease, emphysema, and other cancers. That ranks it as the #1 offensive carcinogen.

Finally, many diseases that were unknown years ago have only recently become diagnosable, identifiable and (potentially) treatable. For example, while Peyton Rous discovered the first viral association with cancer about 90 years ago, it took many more years before the associations between human viruses and cancer were discovered. Likewise, it was only recently that gastritis and gastric cancer were attributed mainly to H. pylori. Therefore, while it may seem like we have more cancer today, in fact, people are living longer, healthier lives.

Last but not least, I take issue with the author for not addressing the two greatest offenders from a cancer standpoint, namely, smoking and alcohol. I am by no means a teetotaler, but a close reading of worldwide mortality figures shows the damage: ischemic heart disease (1), cerebrovascular disease (2), COPD (5), tuberculosis (7), cancer of trachea/bronchus/lung (9), hypertensive heart disease (13), stomach cancer (15), cirrhosis of the liver (16) and liver cancer (19) can all be partly attributed to either smoking or drinking.

Sorry Crowe, I have been working in the health care field for over 50 years and have dealt with life and death issues all of those years. Where is proof that prostate and breast cancer is occurring at an earlier age. The difference today and in the past is there is earlier diagnosis of many of these cancers. Women died of breast cancer 50 years ago-100 years ago, as they are today. Testicular cancer is a greater problem than prostate cancer in a young male.

Apparently you don't know a whole lot about changes in the body as we get older, including a weakened immune system which increases our risk for cancer. There are older people out there who smoke or chew tobacco into a very late age and don't develop cancer. There are those who are in their forties and die from lung cancer. Oncogenes play a part in the big scheme of things.

And yes, as I said earlier, we are mortal, whether you like it or not. And who said death was pleasant? Every watch someone die with advanced emphysema or other major disorders of the lungs? And than there is congestive heart failure and so I could go on. Cancer is just a part of the whole picture and again, we are mortal.

Blaming cancer on everything "artificial" that exists in the environment is something I've been hearing all my life. There's a simple reason why it exists, and why the media tends to focus on "consumer oriented" cancers.

People need to blame something for their problems. That's all there is to it. They need something concrete to point at, to shout at, and to rebel against. It makes them feel like they have at least some control over what's going to happen to them. It doesn't even matter that it isn't true, many of them know that, too, at some level.

"Cleansing" diets, veganism, organic diets, colonics and other so-called "detoxifying" treatments cost hundreds of millions of consumer dollars every year, and none of them work to prevent cancer. Some are dangerous to the point of being life-threatening, but people still subject themselves to this expensive nonsense, just so they can feel like they're doing something.

Everyone would be far better off if they just listened to the timeless advice that they've been ignoring from their doctors for decades. Eat a balanced diet, exercise, don't smoke, don't drink too much alcohol, sleep as much as you need to and get regular checkups. That's all anyone needs, but I guess it just seems too simple.

mellowing - first, let me thank you and congratulate you for your work in the medical field. I know from first hand experience what terrific people work in these jobs.

However, just because you do work there doesn't mean you know about health in a broad sense. I have a friend who is a professor of nursing and went through breast cancer. She is rethinking everything she thought she knew now that it has come to her. My doctors are wholly uninterested in the causes of cancers. And many medical people I've had contact with are in very poor health themselves, for whatever reasons.

All of your points are well taken. However, there is one point I made you didn't address which I think is critical in thinking about cancer: the rates and types of cancer are significantly different in various parts of the world. Those differences are not apparently genetic because when people migrate to other regions, they tend to take on the statistical rates and types of the new area. That at least implies there is some kind of diet or lifestyle or environmental influence that supercedes genetics. Not only should we be studying that, but we are, and the findings are rather stunning.

I certainly know about the changes in the body as aging occurs, although not in the same way as you do. I also know that good health is possible to a very advanced age. Dieing is inevitable, and no one is suggesting that we can avoid it. But I would think everyone would want as many years as possible of vibrant, healthy living. We just have to be willing to go where the studies and research lead us, even if it makes us question some of our assumptions about "normal" life.

Clearly, many people are unwilling to make any life changes that might enhance their health. I am baffled as to why. We know a LOT about smoking, yet people still smoke and it is still legal to sell cigarettes. We know a lot about many chemicals, yet there is always resistance to definitively doing anything about eliminating them. We know a lot about the effects of poor diets, yet increasing numbers of people gorge themselves on the most awful "food" imaginable and wonder how they get fat and diseased.

It is easier to just focus on treatment. I, however, want to understand what I can do to take responsibility for my health. I want to know what lurks in my environment so I can avoid the risks. I don't want to just stuff my mouth with what tastes good with no thought to what it is doing to my body. To know these things, I depend on scientists doing sound studies and good research. I have to trust someone, and I trust less and less the industries and politicians who keep pouring soothing words on us while we discover, oh so slowly, that they have been lying to us.

This article seems to be suggesting, as have some of the posters, that we just shouldn't worry about it. There aren't really any threats out there. The natural world, or aging process can account for most of it.

I don't think so.

Crowe,

You have made a number of valid points. All I am trying to say is that there are a lot of variables and yes, we need to take control of our health, that is be proactive instead of reactive. But bad things do happen, some out of our control. As far as exposing ourselves to toxins i.e. tobacco, too much sun, alcohol, pollution, some things we can control, other things we try to minimize.

A problem that I have seen and continue to see is too many people want a quick fix. "Give me a pill" is a common mantra, instead of changing behaviors.

We continue to live in our environment, and unless your are willing to become a Robinson Caruso, you will have to live with a certain amount of risk. I myself prefer to have a quality of life versus that of quantity (although I am getting up there in years) and choose to live in a very rural state. My husband and I raise a lot of our own food and are very active. Will this keep us healthier than those of you in the middle of the cities where industrial pollution is an issue? I don't know. But we are both quite healthy at this point except for "wearing out" issues.

Sorry to hear about your friend who was a professor of nursing. I retired from teaching nursing about a year ago. I wish her well.