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This post is about an issue that I've covered before - the issue of unnecessary medical tests and care, which has been documented by many, especially Dr. H. Gilbert Welch (here and here). In the past I've focused on research documenting physical and emotional harms resulting from overuse of some medical tests and procedures, especially some types of cancer screening, but today's post is about the financial harms of unnecessary medical tests and procedures.

We're talking about medical tests or services that are overused, perhaps done "routinely" when there are no symptoms or real reasons to do the test. The cost of unnecessary tests and services can be financially devastating to the person receiving the bill(s). But this "waste" has also been estimated  at $765 billion a year by the National Academy of Medicine. This is about a fourth of all the money spent each year on health care! Wow. The following article by Marshall Allen is co-published on both ProPublica and NPR. Excerpts from NPR:

Unnecessary Medical Care: More Common Than You Might Imagine

It's one of the intractable financial boondoggles of the U.S. health care system: Lots and lots of patients get lots and lots of tests and procedures that they don't need. Women still get annual cervical cancer testing even when it's recommended every three to five years for most women. Healthy patients are subjected to slates of unnecessary lab work before elective procedures. Doctors routinely order annual electrocardiograms and other heart tests for people who don't need them.

That all adds up to substantial expense that drives up the cost of care for all of us. Just how much, though, is seldom tallied. So, the Washington Health Alliance, a nonprofit dedicated to making care safer and more affordable, decided to find out. The group scoured the insurance claims from 1.3 million patients in Washington state who received one of 47 tests or services that medical experts have flagged as overused or unnecessary. What the group found should cause both doctors, and their patients, to rethink that next referral. In a single year:

  • More than 600,000 patients underwent a treatment they didn't need, treatments that collectively cost an estimated $282 million.
  • More than a third of the money spent on the 47 tests or services went to unnecessary care.
  • 3 in 4 annual cervical cancer screenings were performed on women who had adequate prior screenings – at a cost of $19 million.
  • About 85 percent of the lab tests to prep healthy patients for low-risk surgery were unnecessary — squandering about $86 million.
  • Needless annual heart tests on low-risk patients consumed $40 million.

Susie Dade, deputy director of the alliance and primary author of the report released Thursday, said almost half the care examined was wasteful. Much of it comprised the sort of low-cost, ubiquitous tests and treatments that don't garner a second look. But "little things add up," she said. "It's easy for a single doctor and patient to say, 'Why not do this test? What difference does it make?'"

ProPublica has spent the past year examining how the American health care system squanders money, often in ways that are overlooked by providers and patients alike. The waste is widespread – estimated at $765 billion a year by the National Academy of Medicine, about a fourth of all the money spent each year on health care.

Dr. H. Gilbert Welch, a professor at The Dartmouth Institute who writes books about overuse, said the findings come back to "Economics 101." The medical system is still dominated by a payment system that pays providers for doing tests and procedures. "Incentives matter," Welch said. "As long as people are paid more to do more they will tend to do too much."

There have been many posts on this blog about diet, fiber, microbes, and the association of diet with various diseases, such as cancer. A recent journal article by M. Song and A. Chan reviewed studies that looked at the link between diet, gut microbes (the gut microbiota or gut microbiome), and colorectal cancer (what we typically call colon cancer).

In summary, research from the last 20 years has found that diet and colorectal cancer (CRC) go hand in hand, and that diet determines the microbes (microbiota) living in the gut - that is, what you feed the microbes determines what microbes will live and thrive in the gut. Also, certain microbes in the gut are linked to inflammation and cancer formation, and others to its prevention. In other words, there is potential to prevent colorectal cancer with certain diets, and to increase the odds of colorectal cancer with other diets.

What are main dietary factors linked to colorectal cancer? Western diet (lots of processed foods, red and processed meat, low in fiber, refined grains), low levels of dietary fiber, low intake of omega-3 fatty acids from seafood (or fish oil), and obesity. The researchers point out that a Western diet is associated with gut dysbiosis (microbial imbalance), loss of gut barrier integrity, and increased levels of inflammation. What should one do? Basically think to yourself: "I need to feed the beneficial microbes in my gut, so I need to eat lots of fruits, vegetables, whole grains, and seafood (omega-3 fatty acids)" - this is what the researchers call a "prudent pattern diet". And try to maintain a normal weight. Some excerpts from Current Colorectal Cancer Reports:

Diet, Gut Microbiota, and Colorectal Cancer Prevention: a Review of Potential Mechanisms and Promising Targets for Future Research

AbstractDiet plays an important role in the development of colorectal cancer. Emerging data have implicated the gut microbiota in colorectal cancer. Diet is a major determinant for the gut microbial structure and function. Therefore, it has been hypothesized that alterations in gut microbes and their metabolites may contribute to the influence of diet on the development of colorectal cancer.We review several major dietary factors that have been linked to gut microbiota and colorectal cancer, including major dietary patterns, fiber, red meat and sulfur, and obesity

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the fourth leading cause of cancer death in the world. Over the past few decades, numerous epidemiologic studies have identified a range of dietary factors that may potentially promote or prevent CRC. Likewise, increasing evidence has implicated the gut microbiota in CRC development. Biological plausibility is supported by habitation of numerous gut microbes in the large intestine and the functional importance of the gut microbiota in maintenance of the gut barrier integrity and immune homeostasis, the disruptions of which are among the most important mechanisms in colorectal carcinogenesis. Given the critical role of diet in the configurations of gut microbial communities and production of bacterial metabolites, it has been proposed that diet may influence CRC risk through modulation of the gut microbial composition and metabolism that in turn shape the immune response during tumor development.

Although gut bacterial abundance may respond rapidly to extreme changes in diet, predominant microbial community membership is primarily determined by long-term diet, and substantial inter-individual variation persists despite short-term dietary change. .... Thus, this review focuses on the dietary factors that have strong mechanistic support, including dietary pattern, fiber, red meat and sulfur, and omega-3 fatty acid. Given the close link between diet and obesity and the predominant role of obesity in CRC as well as the substantial data linking the gut microbiome to obesity, we also include obesity at the end of the review.

DIETARY PATTERNS: Convincing data indicate that a “Western dietary pattern,” characterized by high intake of red or processed meat, sweets, and refined grains, is associated with higher risk of colorectal neoplasia; in contrast, diets that are rich in fruits, vegetables, and whole grains (“prudent pattern diet”) are associated with lower risk of CRC. Western diets are associated with gut dysbiosis (microbial imbalance), loss of gut barrier integrity, increased levels of inflammatory proteins, and dysregulated immune signatures.

A potential role of the gut microbiota in mediating the dietary associations with CRC risk is suggested by the dramatic difference of the gut microbial structures between populations consuming different diets. Rural Africans, whose diet is high in fiber and low in fat, have a strikingly different gut microbial composition than urban Europeans or African Americans consuming a Western diet, which parallels the lower CRC rates in Africa than Western countries. For example, the African gut microbiota is characterized by a predominance of Prevotella genus that are involved in starch, hemicellulose, and xylan degradation, whereas the American microbiota is predominated by Bacteroides genus with a higher abundance of potentially pathogenic proteobacteria, such as Escherichia and Acinetobacter. .... Moreover, a crossover study indicates that switching African Americans to a high-fiber, low-fat diet for 2 weeks increases production of SCFAs, suppresses secondary bile acid synthesis, and reduces colonic mucosal inflammation and proliferation biomarkers of cancer risk.

Fiber: Numerous prospective studies have linked higher fiber intake to lower risk of CRC. The most recent expert report from the World Cancer Research Fund and the American Institute for Cancer Research in 2011 concludes that evidence that consumption of foods containing dietary fiber protects against CRC is convincing. Besides systemic benefits for insulin sensitivity and metabolic regulation, which have been implicated in colorectal carcinogenesis, fiber possesses gut-specific activities, such as diluting fecal content, decreasing transit time, and increasing stool weight, thereby minimizing exposure to intestinal carcinogens.

Moreover, soluble fiber can be fermented by bacteria in the lumen of the colon into SCFAs [short-chain fatty acids], including butyrate, acetate,and propionate. Higher fiber intake has been shown to enrich butyrate-producing bacteria in the gut, such as Clostridium, Anaerostipes, Eubacterium, and Roseburia species, and increase production of SCFAs. SCFAs have been suggested as the key metabolites linking the gut microbes to various health conditions, especially CRC

Red Meat and Sulfur: There is convincing evidence that red and processed meats are associated with increased risk of CRC. Recently, the Int. Agency for Research on Cancer has classified processed meat as a carcinogen to humans. Mechanisms underlying the pro-cancer effects of red or processed meats include heme iron, N-nitroso compounds, or heterocyclic amines, and hydrogen sulfide production. Hydrogen sulfide has been implicated in inflammatory disorders associated with risk of CRC, such as ulcerative colitis, and directly with CRC.

Omega-3 Fatty Acid: Marine omega-3 polyunsaturated fatty acid, including eicosapentaenoic acid, docosahexaenoic acid, and docosapentaenoic acid, possesses potent anti-inflammatory activity and may protect against CRC. Fish oil, a rich source of omega-3 fatty acid, is the most popular natural product used by US adults. Substantial data support the beneficial effect of omega-3 fatty acid on CRC prevention and treatment.

Dietary fat composition is a major driver of the gut microbial community structure. Compared to other types of fat, omega-3 fatty acid have been associated with higher intestinal microbiota diversity and omega-3 fatty acid-rich diet ameliorates the gut dysbiosis induced by omega-6 polyunsaturated fatty acid or antibiotics.

Obesity: Since the 1970–1980s, the prevalence of obesity has markedly increased worldwide. The obesity epidemic is believed to be largely driven by global westernization characterized by overconsumption of easily accessible and energy-dense food and a sedentary lifestyle. Obesity is an established risk factor for CRC and several other cancers. Possible mechanisms include increased insulin levels and bioavailability of insulin-like growth factor 1, altered secretion of adipokines and inflammatory cytokines, and changes in sex hormone levels.

A new study's results actually made me ask - this was a surprise? Of course more fit people have lower levels of chronic inflammation and smaller waist size, no matter their Body Mass Index (BMI) - which includes their weight. And the reverse is also true (lower fitness levels are associated with greater waist size and higher levels of chronic inflammation, no matter the BMI). Which means that being fit, no matter the weight, has health benefits. From Medical Xpress:

Low fitness is associated with larger waist size and higher degree of inflammation

Low fitness is associated with a larger waist size and a higher degree of inflammation, according to a study published January 17, 2018 in the open-access journal PLOS ONE by Anne-Sophie Wedell-Neergaard from the University of Copenhagen, Denmark, and colleagues.

Waist circumference can indicate the amount of excess fat found around the abdomen and previous studies have shown excess abdominal fat may increase the risk of chronic system inflammation and metabolic diseases. The authors of the present study sought to investigate the association between fitness and waist circumference as well as the association between fitness and low-grade inflammation, and whether there was a correlation with Body Mass Index (BMI).

The researchers analyzed the previously collected data of 10,976 individuals from The Danish National Health Examination Survey 2007-2008. These individuals took a maximal oxygen uptake (VO2max) test to assess their physical fitness. Their waist circumference, weight and height were measured, and blood samples were taken to measure their level of C-reactive protein, a nonspecific biomarker of low-grade inflammation.

The researchers found that higher levels of fitness were associated with a smaller waist circumference and a lower degree of inflammation independently of BMI. The researchers acknowledge that there are possible limitations that may affect the findings of the study, but overall the results suggest that increased fitness has the potential to reduce abdominal fat mass and inflammation which may improve metabolic health irrespective of BMI

There are health benefits to babies from being breastfed, including that breast milk contains hundreds of microbial species which are transmitted to the baby. There are also health benefits to the mother, including a lower risk of breast cancer and ovarian cancer. In addition, a multicenter study in the United States found that breastfeeding lowers the mother's risk of type 2 diabetes over the next 30 years - by up to 47%.

In general: the study found that the longer a woman breastfeeds, the lower her risk of developing type 2 diabetes. Thus one can say that breastfeeding has a "protective" effect for type 2 diabetes. From Medical Xpress:

Thirty-year study shows women who breastfeed for six months or more reduce their diabetes risk

In a long-term national study, breastfeeding for six months or longer cuts the risk of developing type 2 diabetes nearly in half for women throughout their childbearing years, according to new Kaiser Permanente research published Jan. 16 in JAMA Internal Medicine. "We found a very strong association between breastfeeding duration and lower risk of developing diabetes, even after accounting for all possible confounding risk factors," said lead author Erica P. Gunderson, PhD, MS, MPH, senior research scientist with the Kaiser Permanente Division of Research.

Women who breastfed for six months or more across all births had a 47 percent reduction in their risk of developing type 2 diabetes compared to those who did not breastfeed at all. Women who breastfed for six months or less had a 25 percent reduction in diabetes risk.

Dr. Gunderson and colleagues analyzed data during the 30 years of follow up from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a national, multi-center investigation of cardiovascular disease risk factors that originally enrolled about 5,000 adults aged 18 to 30 in 1985 to 1986, including more than 1,000 members of Kaiser Permanente Northern California.The new findings add to a growing body of evidence that breastfeeding has protective effects for both mothers and their offspring, including lowering a mother's risk of breast and ovarian cancer.

The long-term benefits of breastfeeding on lower diabetes risk were similar for black women and white women, and women with and without gestational diabetes. Black women were three times as likely as white women to develop diabetes within the 30-year study, which is consistent with higher risk found by others. Black women enrolled in CARDIA were also less likely to breastfeed than white women.

"The incidence of diabetes decreased in a graded manner as breastfeeding duration increased, regardless of race, gestational diabetes, lifestyle behaviors, body size, and other metabolic risk factors measured before pregnancy, implying the possibility that the underlying mechanism may be biological," Gunderson said. Several plausible biological mechanisms are possible for the protective effects of breastfeeding, including the influence of lactation-associated hormones on the pancreatic cells that control blood insulin levels and thereby impact blood sugar.

This study included 1,238 black and white women who did not have diabetes when they enrolled in CARDIA, or prior to their subsequent pregnancies. Over the next 30 years, each woman had at least one live birth and was routinely screened for diabetes under the CARDIA protocol, which included diagnostic screening criteria for diabetes. Participants also reported lifestyle behaviors (such as diet and physical activity) and the total amount of time they breastfed their children.

 Breastfeeding a baby. Credit: Wikipedia Commons, Anton Nossik.

A recent study by a team of researchers from France and Denmark highlighted the point that all medicines have side-effects, even though we may not realize it for years. Ibuprofen is a great non-prescription pain reliever - a nonsteroidal anti-inflammatory drug (NSAID), but it should be taken only when needed. Ibuprofen is found in such commonly used medicines as Advil and Motrin. The researchers found that ibuprofen has antiandrogenic effects (alters or disrupts the endocrine system) which results in a temporary condition called "compensated hypogonadism" when taken for extended periods by healthy young men (in the study 600 mg was taken daily for 6 weeks).

The researchers stress that this "depression of important aspects of testicular function, including testosterone production" was temporary from short term use, but they were concerned with those who take it daily for longer periods, such as athletes. They wondered whether this could be contributing to lowered sperm levels and the drops in male fertility that we are seeing in western developed countries. [Note that ibuprofen use has also been linked to a higher risk of cardiac arrest.] From Medical Xpress:

Taking ibuprofen for long periods found to alter human testicular physiology

A team of researchers from Denmark and France has found that taking regular doses of the pain reliever ibuprofen over a long period of time can lead to a disorder in men called compensated hypogonadism. In their paper published in Proceedings of the National Academy of Sciences, the group describes their study, which involved giving the drug to volunteers and monitoring their hormones and sperm production.

To learn more about the possible impacts of the popular anti-inflammation drug Ibuprofen on male fertility when taken for long periods of time, the researchers asked 31 men between the ages of 18 and 35 to take 600 milligrams (three tablets) a day of the drug for six weeks. Other volunteers were given a placebo. Over the course of the study, the volunteers were tested to see what impact the drug had on their bodies.

The researchers report that just two weeks into the study, they found that all of the volunteers had an increase in luteinizing hormones, which the male body uses to regulate the production of testosterone. The increase indicated that the drug was causing problems in certain cells in the testicles, preventing them from producing testosterone, which is, of course, needed to produce sperm cells. They further report that the change caused the pituitary gland to respond by producing more of another hormone, which forced the body to produce more testosterone. The net result was that overall testosterone levels remained constant, but the body was overstressing to compensate for the detrimental impact of the Ibuprofen—a state called compensated hypogonadism.

The researchers note that while compensated hypogonadism can cause a temporary reduction in the production of sperm cells, reducing fertility, it is generally not cause for alarm. What is more of a concern, they note, is using the drug for longer periods of time. It has not been proven yet, but the researchers suspect such use, as is seen with some professional athletes or others with chronic pain issues, might lead to a condition called overt primary hypogonadism, in which the symptoms become worse—sufferers report a reduction in libido, muscle mass and changes in mood. Additional studies are required, they note, to find out if this is, indeed, the case. [Original study.]

A recent study's results give hope to those who haven't really exercised or been physically active as they've gone through middle-age (it's viewed as "sedentary aging") and wonder if this dooms them in some way. Is it too late to get benefits from starting to exercise now? Studies show that being sedentary (that is, not being physically active or exercising weekly) and in "poor physical fitness" in middle-age is a risk factor for later heart failure. This is because a consequence of "sedentary aging" is stiffness of the heart, specifically the left ventricle (thus a loss of "cardiac plasticity").

But the study found that after 2 years of an exercise program in (formerly) sedentary middle-aged adults, they improved their maximal oxygen uptake, decreased the heart's stiffness, and improved overall fitness. All good, even though it was a small study (only 53 people completed the study). So the bottom line is: No, it's not too late to start exercising. The heart has elasticity and can remodel itself if the exercise is started before age 65 and is done 4 to 5 times a week. The adults studied were both male and female, between the ages of 45 and 64,  and exercised or were physically active for a total of 150 to 180 minutes a week, which meant at least 30 minutes 4 or 5 times a week.

Looking at the study's exercise regimen, it's clear that a variety of exercises or physical activities (low, moderate, and high intensity) is necessary. Some of the time one should be active or exercise to a point of breaking a sweat and feeling the heart pump. This meant that over time the participants increased their exercise frequency, duration, and intensity. Think about it - as you get more fit, it takes more to get your heart pumping and to break a sweat, and you can handle more exercise. 

Unfortunately the "control group", who did a combination of yoga, balance, and strength training 3 times a week for 2 years did not show improvements in heart plasticity, maximal oxygen uptake, or in overall fitness.Yikes. Sooo...the study clearly shows it is worth getting off your butt and making the effort to exercise. Perhaps view it as brushing your teeth - a daily nuisance, but necessary for health. The researchers themselves stated "Exercise is medicine." From Science Daily:

Proper exercise can reverse damage from heart aging

Exercise can reverse damage to sedentary, aging hearts and help prevent risk of future heart failure -- if it's enough exercise, and if it's begun in time, according to a new study by cardiologists at UT Southwestern and Texas Health Resources. To reap the most benefit, the exercise regimen should begin by late middle age (before age 65), when the heart apparently retains some plasticity and ability to remodel itself, according to the findings by researchers at the Institute for Exercise and Environmental Medicine (IEEM), which is a collaboration between UT Southwestern Medical Center and Texas Health Presbyterian Hospital Dallas.

And the exercise needs to be performed four to five times a week. Two to three times a week was not enough, the researchers found in an earlier study..... The regimen included exercising four to five times a week, generally in 30-minute sessions, plus warmup and cool-down: One of the weekly sessions included a high-intensity 30-minute workout, such as aerobic interval sessions in which heart rate tops 95 percent of peak rate for 4 minutes, with 3 minutes of recovery, repeated four times (a so-called "4 x 4"). Each interval session was followed by a recovery session performed at relatively low intensity. One day's session lasted an hour and was of moderate intensity. (As a "prescription for life," Levine said this longer session could be a fun activity such as tennis, aerobic dancing, walking, or biking.) One or two other sessions were performed each week at a moderate intensity, meaning the participant would break a sweat, be a little short of breath, but still be able to carry on a conversation -- the "talk test.".... One or two weekly strength training sessions using weights or exercise machines were included on a separate day, or after an endurance session.

The more than 50 participants in the study were divided into two groups, one of which received two years of supervised exercise training and the other group, a control group, which participated in yoga and balance training.A t the end of the two-year study, those who had exercised showed an 18 percent improvement in their maximum oxygen intake during exercise and a more than 25 percent improvement in compliance, or elasticity, of the left ventricular muscle of the heart, Dr. Levine noted. He compared the change in the heart to a stretchy, new rubber band versus one that has gotten stiff sitting in a drawer. Sedentary aging can lead to a stiffening of the muscle in the heart's left ventricle, the chamber that pumps oxygen-rich blood back out to the body, he explained.

"When the muscle stiffens, you get high pressure and the heart chamber doesn't fill as well with blood. In its most severe form, blood can back up into the lungs. That's when heart failure develops," said Dr. Levine, who holds the S. Finley Ewing Chair for Wellness at Texas Health Dallas and the Harry S. Moss Heart Chair for Cardiovascular Research. Earlier research by UT Southwestern cardiologists showed that left ventricular stiffening often shows up in middle age in people who don't exercise and aren't fit, leaving them with small, stiff chambers that can't pump blood as well[Original study.]

I recently read a nice article discussing indoor air pollution, which can be worse than outdoor air, even that of cities. Yes, that's true! In past posts I've discussed problems (and health issues) with air fresheners, fragrances, incensedryer sheets, scented candles, synthetic rugs, "stain-proofing", and flame retardants in upholstery, but this article is about furniture and how it can emit various chemicals ("outgassing"), especially when new. Think of all the stains, glues, paints, etc. used in making furniture.

The article points out that when buying new furniture, can look to see if it is certified by Greenguard or SCS Global Services as having low or no emissions of  hazardous chemicals. Another thing to do is avoid particle boardengineered wood, or pressed wood (frequently emits formaldehyde, a carcinogen). But in the mean time - it's generally a good idea to frequently get fresh air in your residence by opening windows for a while. Excerpt's from E. Leamy's article in the Washington Post:

Your furnishings could be causing indoor air pollution

We feel safe in our homes, but that can be a false sense of security. The threat I’m talking about is something we can’t see: indoor air pollution. The air in our homes and workplaces can be more polluted than outdoor air in the most industrialized citiesaccording to the Environmental Protection Agency. The EPA says the problem is compounded by the fact that Americans spend 90 percent of their time indoors. Many different things can cause indoor air pollution, and they have a cumulative effect on our health.

Let’s look at one of those possible sources: our furnishings. Yes, your new carpet or cabinet could be subtly poisoning you with chemicals such as benzene, ethylene glycol or formaldehyde. It’s called “off-gassing.” Four of the top 10 chemicals emitted from furnishings are considered “acute” hazards, or irritants. “Poor indoor air quality can cause or contribute to the development of infections, lung cancer and chronic lung diseases such as asthma,” according to the American Lung Association.

How do researchers know that some furnishings emit harmful gaseous chemicals? Greenguard, a division of UL Environment, has developed a way of testing furniture to find out. In a ­generic-looking office park outside Atlanta, researchers heft furniture into giant, airtight chambers. .... Greenguard developed the testing method so manufacturers who wanted to sell low-emission furniture could prove their products were healthier. UL awards its Greenguard certification to furniture that emits low or no levels of hazardous chemicals

Manufacturers don’t have to state what chemicals they use in their furnishings. The EPA singles out engineered wood — otherwise known as particleboard — as being particularly prone to emitting formaldehyde, a probable carcinogen. UL Environment adds that products that are applied wet, such as glues and paints, often off-gas while they are curing. Sometimes a strong industrial odor is a good hint that a piece of furniture is emitting chemicals. If you develop a headache while inside a building where paints, stains or glues are being used, that’s another clue. 

However, it is possible to know whether harmful chemicals are not present, because more and more furnishings are being certified as having low emissions. Here are certifications you can look for and other steps you can take to reduce your exposure to indoor air pollution from your furnishings: 

1. Check certifications. Look for an indoor-air-quality certification, such as the one offered by Greenguard. Another firm that certifies low-emission furniture is SCS Global Services2. Air out. .... 3. Paint first. If you’re renovating your house, paint it and air it out before installing carpeting and curtains, because they can absorb chemical fumes from the paint..... 4. Buy used. Off-gassing diminishes over time, so buying older furniture can be better. ....5. Avoid particleboard. This material is also called pressed wood, engineered wood and MDF. The glues used to hold the material together often contain harmful chemicals such as formaldehyde. Alternatively, look for certified particleboard products. 6. Choose unscented. .... 7. Beyond furnishings. Other products frequently used in homes can also off-gas and cause indoor air pollution. 

For those who need convincing that lifestyle can contribute to development of cancer or its prevention, new medical research has once again supported the importance of lifestyle choices. A report from Australian researchers (with similar findings as a study in the US) stated: an estimated 38% of cancer deaths and 33% of cancer diagnoses could have been prevented with healthy lifestyle choices.

And what were the lifestyle choices that are linked to cancer?  The researchers list 20 separate things (in 8 broad groups) that are known to cause or are linked to cancer. They are: tobacco smoke (smoking or second-hand smoke), dietary factors (low-intake of fruit, non-starchy vegetables, and dietary fiber; and high intake of red and processed meat), overweight/obesity, alcohol, physical inactivity, solar ultraviolet radiation, certain infections (they list 7 infections, such as human papillomavirus, hepatitis B, hepatitis C), and reproductive factors (lack of breastfeeding, menopausal hormone therapy use, combined oral contraceptive use). Note that they found that the #1 most important lifestyle factor is tobacco smoke - and it accounted for about 23% of all preventable cancer deaths in Australia. From Medscape:

One Third of Cancer Deaths Could Be Prevented by Lifestyle

As we head into the festive season, many are looking forward to the tradition of "Eat, drink, and be merry." But as another research paper shows that more than a third of cancer deaths could be prevented by lifestyle, maybe a qualifier should be added:"celebration in moderation." The latest statistics come from Australia, where researchers note that 44,004 cancer deaths occurred in 2013. But an estimated 38% of these deaths and 33% of cancer diagnoses could have been prevented with healthy lifestyle choices, says a research team led by Louise Wilson, MEpi, at the QIMR Berghofer Medical Research Institute and the University of Queensland, Brisbane.

These cancer diagnoses and deaths were seen in Australians of all ages and are directly attributable to 20 known modifiable risk factors within eight categories that are established causes of cancer, the study authors say. The report is published in the February 2018 issue of the International Journal of Cancer.

Smoking was the leading cause of preventable cancer death in Australia in 2013 and accounted for 23% of all cancer deaths. ...Three other categories of modifiable risk factors — poor diet, overweight/obesity, and infections — accounted for 5% of cancer deaths each. In a fifth category, alcohol-related cancer accounted for 2.4% of deaths. Physical inactivity factors were responsible for 0.8% of cancer deaths, overexposure to ultraviolet radiation for 3.2% of cancer deaths, and, in the eighth category, reproductive or hormonal factors were linked to 0.4% of cancer deaths.

In the diet category, risk factors include low intake of fruit, nonstarchy vegetables, and dietary fiber and high intake of red and processed meat. In the infection category, seven cancer-causing agents, including human papillomavirus (associated with cancer of the vulva, vagina, penis, anus, oral cavity, and oropharynx) and Helicobacter pylori (noncardia stomach cancer), are included. Lack of breastfeeding, use of menopausal hormone therapy, and use of combined oral contraceptive use (breast and cervical cancer) are listed as preventable risk factors in the reproductive category.

These findings are in keeping with other research on the role of modifiable lifestyle-related risk factors in cancer prevention. As previously reported by Medscape Medical News, results from a large cohort study in the United States led researchers to conclude that 20% to 40% of cancer cases and related mortality could be prevented by not smoking, maintaining a healthy weight, and exercising regularly. In another report, results from a national online survey undertaken by the American Society of Clinical Oncology showed that, like their Australian counterparts, most US adults don't know alcohol and obesity are major risk factors for cancer[Original study.]

A dividing lung cancer cell. Lung cancer is associated with smoking. Credit: National Institute of Health (NIH). 


The message is clear from a recent study: older adults should get out and move, move , move (brisk walking is fine) - to lower the risk of early death. The older women engaging in the most moderate to vigorous activity had a 65% lower risk of early death during an average follow-up period of 2.3 years (when compared to the women with the least exercise).

How much exercise did the groups get? The least active had 6.8 minutes per day of moderate to vigorous exercise, and the most active had about 68 minutes/day of moderate to vigorous physical activity. The women wore a Fitbit type of device (an accelerometer) that measured their movements. Moderate to vigorous exercise was any movement that got the heart rate up a bit, made them sweat a little - and which could be brisk walking.

The study was done with older women (in their 70s), but one would think it also applies to men. Note: all-cause mortality means death from any cause (death in general). From Medscape:

Intense Exercise Tied to 65% Lower Death Risk in Older Women

Older women who engaged in the greatest amount of moderate to vigorous physical activity, such as brisk walking, were found to have a 65% lower risk of all-cause mortality compared with women who performed the least amount of such exercise, a new study reports. The researchers examined women in their early 70s in the Women's Health Study (WHS) who wore a triaxial accelerometer for 7 days to measure physical activity. The findings, by Dr I-Min Lee (Brigham and Women's Hospital, Boston, MA) and colleagues, were published November 6, 2017 in Circulation.

It's been known for a long time that physical activity is associated with lower mortality rates, Dr Lee told | Medscape Cardiology.... Now that physical activity can be better measured using a research-grade triaxial accelerometer, the magnitude of the reduced risk of short-term death with recommended amounts of moderate to vigorous physical activity can be seen to be as strong as not smoking, Lee said. ... This study "reinforces the message that adults should strive to meet physical activity guidelines of 150 minutes of moderate or 75 minutes of vigorous exercise per week," Dr Alpa Patel (American Cancer Society, Atlanta, Georgia) who recently published a related article that showed benefits from walking told | Medscape Cardiology.

From 2011 to 2015, 18,289 of 29,494 living women (63%) in the Women's Health Study agreed to participate in the current study.... The remaining 17,708 women were mailed a research-grade triaxial accelerometer (ActiGraph GT3X+, ActiGraph Corp) and asked to wear it on their hips for 7 days (but to take it off when sleeping or swimming) and then mail it back. 

The women spent a median of 8.4, 5.8, and 0.5 hours/day being sedentary, doing light physical activity, and doing moderate to vigorous physical activity, respectively. "The least active quartile were doing 8 minutes a day of moderate to vigorous . . . physical activity," Lee said, which was typically "brisk walking, anything that gets your heart rate up a little bit, gets you to sweat a little bit." The most active quartile did about 68 minutes/day of moderate to vigorous physical activity. During an average follow-up of 2.3 years, 207 women died. The total amount of physical activity was inversely related to the risk of all-cause mortality during follow-up, after adjustment for age and time spent wearing the device. 

Two studies (one in mice and one in humans) from researchers at the University of Illinois found that no matter what your diet - exercise changes the gut bacteria in a beneficial way. And when you go back to a sedentary lifestyle, your gut microbes change again and beneficial microbes such as short chain fatty acids (SCFAs), especially butyrates, decline. The effect was more pronounced in lean sedentary adults (as compared to obese sedentary adults).

Beneficial microbes that increased with exercise in humans were species of Faecalibacterium, Roseburia, Lachnospira, Lachnospiraceae, and Clostridiales. Faecalibacterium prausnitzii has been discussed in earlier posts as a beneficial keystone species in the gut (here, here, and here). What kind of exercises did they do? They did three supervised 30 to 60 minute moderate to vigorous intensity aerobic/endurance exercise sessions per week for 6 weeks, and they could use a cycle ergometer (stationary bicycle) or treadmill each session.

Besides beneficial microbial changes, 6 weeks of exercising resulted in improved body composition (total lean body mass, decreased body fat, increased bone mineral density), and an improvement in cardiorespiratory fitness. These changes reversed in everyone when they went back to 6 weeks of a sedentary lifestyle. Bottom line: get out and move, move, move. Your gut microbes and your body will thank you. From Science Daily:

Exercise changes gut microbial composition independent of diet, team reports

Two studies -- one in mice and the other in human subjects -- offer the first definitive evidence that exercise alone can change the composition of microbes in the gut. The studies were designed to isolate exercise-induced changes from other factors -- such as diet or antibiotic use -- that might alter the intestinal microbiota.

In the first study, scientists transplanted fecal material from exercised and sedentary mice into the colons of sedentary germ-free mice, which had been raised in a sterile facility and had no microbiota of their own. In the second study, the team tracked changes in the composition of gut microbiota in human participants as they transitioned from a sedentary lifestyle to a more active one -- and back again.

Recipients of the exercised mouse microbiota also had a higher proportion of microbes that produce butyrate, a short-chain fatty acid that promotes healthy intestinal cells, reduces inflammation and generates energy for the host. They also appeared to be more resistant to experimental ulcerative colitis, an inflammatory bowel disease.

In the human study, the team recruited 18 lean and 14 obese sedentary adults, sampled their gut microbiomes, and started them on an exercise program during which they performed supervised cardiovascular exercise for 30-60 minutes three times a week for six weeks. The researchers sampled participants' gut microbiomes again at the end of the exercise program and after another six weeks of sedentary behavior. Participants maintained their usual diets throughout the course of the study. Fecal concentrations of SCFAs, in particular butyrate, went up in the human gut as a result of exercise. These levels declined again after the participants reverted to a sedentary lifestyle.

The most dramatic increases were seen in lean participants, who had significantly lower levels of SCFA-producing microbes in their guts to begin with. Obese participants saw only modest increases in the proportion of SCFA-producing microbes. The ratios of different microbes in the gut also differed between lean and obese participants at every stage of the study, the researchers said. "The bottom line is that there are clear differences in how the microbiome of somebody who is obese versus somebody who is lean responds to exercise," Woods said. " [Original study in humans.]