Tag Archive for: cancer risk

Three Ways to Really Reduce Your Cancer Risk

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In the last Memo before Spring Break, I said I’d cover ways to reduce your risk of getting cancer that really work. Every cancer website has lists, ranging from 10 to 15 recommendations. I’m going to give you my top three ways to reduce the risk of cancer of the items you can control. You can’t control your age or your genetic risk factors, but there are many elements of your health you can control if you work at them.

I’m not including smoking cigarettes or other tobacco products. That’s a no-brainer and shouldn’t even be mentioned, because no one should smoke. (I’m not saying that from my perch on Mount Olympus; I smoked when I was young and foolish, and quitting was one of the best decisions I ever made.)

Dr. Chet’s Top Three Ways to Prevent Cancer

  1. Eat more vegetables and fruits every day and the wider the variety, the better. They don’t have to be organically farmed; you just have to eat eight to ten servings per day. That seems like a lot, and I’m not perfect at it, but you get a new chance every day. Here’s a tip: weigh your produce instead of measuring it. Find out what constitutes a serving in grams or ounces. You may find out that a large banana is actually two servings. Do supplements matter? Yes, but the important point is to eat the fruits and veggies first, then add a multivitamin as backup.
  2. Exercise for 30 to 45 minutes per day. The fitter you are, the lower your risk of cancer. It doesn’t all have to be aerobic; yoga and strength training count as well.
  3. Reduce your weight until you achieve as close to a normal BMI (under 25) as you can; you’ll find all the info you need in the Body Mass Index article on the Health Info page at drchet.com, including how to adjust your target for your body type. We talked about caloric restriction in February, and that’s a way to slowly reduce your weight. My theory is that the older you are, the more movement matters, so if you are doing well at Numbers 1 and 2, you’re well on your way to accomplishing Number 3.

Those may sound very familiar: Eat less. Eat better. Move more. The reason these are my top three is that they reduce inflammation in different ways.

On Thursday, I’m going to cover a study on the relationship between a test for inflammation and cancer.

What are you prepared to do today?

        Dr. Chet

Artificial Sweeteners and Cancer: The Bottom Line

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In the paper on artificial sweeteners and cancer risk that I covered on Tuesday, the researchers made it clear that although the study was done well, cause and effect cannot be determined. They also acknowledge that because 80% of the subjects were women, the results couldn’t be applied to the entire French population, let alone the population of any other country. What it could mean is that artificial sweeteners in combination with other dietary, environmental, or genetic factors could contribute to cancer development.

Here are some other issues with the data and the analysis:

  • They did not test the subjects for cancer before the study. They eliminated several thousand people for already having had cancer, but they didn’t check for present cancers that hadn’t reached the point where they could be diagnosed. That would have added to the complexity, but it was possible.
  • They didn’t seem to ask when the subjects began using artificial sweeteners. The mean age was 42 at the beginning of the study, so subjects might have been using them for decades; some may have been using them for only a few days. Most cancers take years to develop, so the possible link between artificial sweeteners and cancer is probably zero in people who’ve used them a short time. The real question is whether long-term users had a higher risk.
  • I would like to have seen scattergrams of artificial-sweetener intake along with fruit-and-vegetable intake on rates of cancer. In other words, could the increase in fruits and/or vegetables reduce the impact of artificial sweeteners? Fiber intake, exercise, and BMI could also have been plotted against artificial-sweetener consumption. They accounted for these statistically, but seeing what happens when plotted could show how behavioral changes might help neutralize the artificial sweeteners.
  • One thing they didn’t is factor in is use of animal products (except dairy) and the risk of cancer—the only factors accounted for were weight-loss, a healthy diet, and a Western diet. All the studies I’ve seen assess meat intake and cancer, especially processed meat.

The Bottom Line

Take this study for what it is: an indicator that there are numerous potential causes of cancers. Clinical trials can determine cause and effect if the studies are well designed. This study did a wonderful job of measuring the intake of artificial sweeteners; they just didn’t take it all the way in analyzing the data they collected.

So what should you do? If you use artificial sweeteners, that’s fine. If you prefer not to or want to cut down, that’s fine as well. There’s nothing from this study that indicates there’s anything to fear. Paula and I both use artificial sweeteners, we’ll continue to use them, and we won’t worry about them at all.

I still believe that obesity is a greater risk, not just for cancer but for many other health issues; if artificial sweeteners help you reduce or maintain your weight, I’d say the scale tips toward using them.

We’re taking next week off for spring break, so I’ll see you back here April 12. Then we’ll look at what science shows you can do to really limit your risk of cancer.

What are you prepared to do today?

        Dr. Chet

Reference: https://doi.org/10.1371/journal.pmed.1003950

Do Artificial Sweeteners Increase Cancer Risk?

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Last week, my health news feed filled up with headlines that almost all sounded like this: “Artificial Sweeteners Linked to Higher Cancer Risk!” This isn’t the first study to suggest that relationship and it won’t be the last. This French epidemiological study of over 100,000 subjects collected data for more than seven years. One of the things I almost always criticize is data collection using food frequency questionnaires. Not this time.

The subjects completed at least two food diaries per year. Portions were assessed by comparing with pictures of portions sizes. What they did particularly well is to list all the foods that contained artificial sweeteners, including all brand names; then they tested most of the foods in the lab to verify the presence of artificial sweeteners. Researchers collected as many confounding variables as they could to account for everything that contributes to cancer.

After the statistical analysis, the overall hazard ratio demonstrated a 13% increase in the risk of cancer. Aspartame and acesulfame potassium were the artificial sweeteners with the highest hazard ratio among all those tested. Based on this information, do we need to avoid artificial sweeteners or at least lower the amounts we consume? I’ll talk about that Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: https://doi.org/10.1371/journal.pmed.1003950

B6, B12, and Lung Cancer

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The overwhelming message from the study I’ve been reviewing this week: don’t smoke cigarettes. Period. That’s the true cause of most cases of lung cancer. There was no increase in lung cancer in subjects taking high doses of B6 or B12 who never smoked or in those who quit more than 10 years before the study began. While the increased risk applied only to men, women shouldn’t smoke either: 44% of those who got lung cancer were women.

For those men who still insist on smoking or quit less than ten years ago, is there anything to be concerned about if you megadose on B6 or B12? It’s hard to know for sure.

I spoke with the primary author via email. Dr. Ted Brasky and I have battled over omega-3s in the past but minor disagreements in methodologies aside, he is a top-notch researcher. He doesn’t think the B vitamins cause cancer. What he thinks may be happening is that the carcinogens in cigarette smoke cause damage to lung cell DNA, and the excess B vitamins may be enhancing the initiation of cancer. I agree with him.

The question is why might this be happening? The lack of B vitamins seems to reduce the DNA repair process, so increasing to normal levels seems to help. But overdoing it may not be beneficial. Some smokers are taking high-stress B supplements with hundreds or thousands of micrograms of B12. Those are the smokers who could be at risk.

There are two explanations that make sense to me. First, there may be a mutation in the gene that manufactures the enzyme methylenetetrahydrofolate reductase, the enzyme that helps convert homocysteine to methionine. That enzyme requires B12, but perhaps it malfunctions and the B12 becomes toxic to the cells damaged by smoking.

The second explanation comes from the article itself. When trying to explain the factors that could impact this relationship between smoking and vitamin intake, researchers suggest there may be a difference in the absorption, utilization, or distribution of the vitamins. In other words, some people may absorb more vitamin B6 or B12 than others, resulting in a higher circulating amount and thus more available for cells to use. In normal conditions that may be fine but with smoking-induced damage, it may not. The fact is we just don’t know at this time.

 

The Bottom Line

Back to addressing those headlines. If you don’t smoke, there is no problem based on this study. If you do smoke, taking a multivitamin, a B-complex with reasonable amounts of B vitamins, or using energy drinks should present no problem: the study showed no increases with the amounts found in those types of products. If you do smoke, until there is research to clarify the actual cause, limit your intake of high-stress Bs or megadoses of vitamins B6 and B12.

Or maybe the best idea is to just quit smoking. I know it’s hard; I smoked back when I was young and thought myself immortal. You have my sympathy, but my advice is to quit any way you can.

What are you prepared to do today?

Dr. Chet

 

Reference: J Clin Oncol. DOI: https://doi.org/10.1200/JCO.2017. 72.7735

Behind the Misleading B Vitamin Headlines

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Headlines are designed to be provocative. With so many sources of news to choose from, something must get you to click on that link. The problem is when the articles and posts are misleading and, in some cases, just wrong. There were primarily two things wrong about the two online articles I cited in Tuesday’s Memo. I could have picked just about any articles about the study but these were the highest profile.

First, the headlines and the body of the text in both articles implied that the increased risk applies to everyone who uses high doses of vitamins B6 and B12. That’s false. There were so few cases of lung cancer in non-smokers, they saw no reason to analyze that data. Either that’s outright deception or the reporters didn’t read the study.

Second, the word “cause” was used in some headlines, and that’s just false. This was an observational study; the original data on supplement use was collected at the beginning, and then the researchers observed the health of the subjects via a centralized medical database. That type of study shows there’s a link of some kind but cannot show cause and effect.

What did the study actually say and what did the study author say about the results? I’ll let you know on Saturday.

One more thing: we try to make our Memo headlines grab your attention by using key words or asking an intriguing question. That’s part of the business of online information. But if we ever have a headline that’s truly misleading, I expect you to call me on it. Being reliable, trustworthy, and factual are our goals.

What are you prepared to do today?

Dr. Chet

 

Reference: J Clin Oncol. DOI: https://doi.org/10.1200/JCO.2017. 72.7735

 

Do Vitamins B6 and B12 Cause Cancer in Men?

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The headline in The Atlantic said: “Vitamin B6 and B12 Supplements Appear to Cause Cancer in Men.” The Huffington Post said: “Men: Taking Vitamins B6 and B12 Could Increase Your Risk of Lung Cancer.” There were few news sources that didn’t pick up this provocative headline. As you might expect, I started to get questions about the study almost immediately from people who take B vitamins and who drink energy drinks. Exactly what is going on? That’s what we’ll examine in this week’s Memos. Today we’ll take a look at the study.

The Vitamin and Lifestyle study (VITAL) collected information from over 77,000 men and women in western Washington State. The subjects were 50 to 76 when data collection began in 2000–2002. Participants completed a detailed questionnaire on supplement use, a food frequency questionnaire for diet, and a lifestyle questionnaire focusing on risk factors for cancer. The focus was to recruit supplement users.

In an analysis of the data on smoking patterns and the use of folic acid and vitamins B6 and B12, researchers found that men who smoked while taking high amounts of vitamin B6 and B12 had a significantly increased risk of lung cancer. The same results were not found in women.

Those are the results. We’ll take a closer look at the accuracy of the headlines on Thursday.

What are you prepared to do today?

Dr. Chet

 

Reference: J Clin Oncol. DOI: https://doi.org/10.1200/JCO.2017. 72.7735