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Published on Leave a comment on Time For Doctors To Prescribe Exercise

We all know that exercise is beneficial for health. Research suggests that exercising out in nature is best for several varied reasons -  including that it lowers markers of inflammation, and that it's good for our gut microbiome (community of gut microbes). The following excerpts are written by Dr. John La Puma encouraging other doctors to prescribe exercise for their patients and why.

An important message of his is that exercise is more important than a drug prescription for a number of conditions, including diabetes prevention, reducing the risk of recurrence of several cancers (he mentions breast cancer, but it also holds for prostate cancer). While exercising and walking out in nature may be best, any exercise anywhere is better than no exercise. (Other posts on exercise as prescription medicine are here and here; and check the category exercise for all exercise research posts).

From Medscape: Rx: Exercise Daily -- Outdoors. Doctor's Orders

With dazzling Olympic feats on display all summer, too many of my patients are still literally immobilized. Medically, sitting too long shuts off the enzyme lipoprotein lipase. In people who are sedentary, the enzyme doesn't break down fat to create energy, like it should. But medical prescription for exercise has lagged even the slowest runner. Why? Some reasons are time, training, and money. Time especially is a scarce commodity: The average clinician visit lasts just 20 minutes. Fitness is a shamefully small part of medical training. And as doctors, we don't get paid for discussing exercise, let alone monitoring a prescription and assessing the response. 

Finally, there are practical reasons. Clinicians find it difficult to persuade patients that exercise is more effective than medication for any number of conditions, including stroke recovery, diabetes prevention, and treatment of low back pain. Regular exercise reduces the risk for recurrent breast cancer by approximately 50%. Given all these reasons, it's easy to see why fitness prescriptions are seldom more than an afterthought. Yet even without formally prescribing the frequency, intensity, time, and type of exercise, clinicians can speak with patients and families about fitness in inspiring, life-changing ways.

Because clinicians have a secret weapon to use that most people don't even know about—location. Exercising in nature (in sight of and preferably near water or greenery, whether a deserted beach or an urban park) is better. Walking city streets and the office itself can be harder on your health than you think. In both environments, your attention is demanded and directed—sometimes by digital interruptions, sometimes by vehicles, toxins, or duties. In nature, your attention is drawn, not pushed, to a variety of often unexpected but not unpleasant sounds, colors, aromas, textures, and forms.

A recent Stanford study of nature therapy showed significantly reduced rumination after a 90-minute walk in nature, compared with a 90-minute walk through an urban environment. On MRI, "nature walkers" showed lower activity in an area of the brain linked to risk for mental illness, the subgenual prefrontal cortex, compared with "urban walkers." In other words, nature offers a sense of something bigger than ourselves on which to focus. MRIs show the way the brain changes when that sense occurs to us.

Exercising in nature may improve a person's immune system by enriching the diversity in the microbiota. Microbiota buffer the immune system against chronic stress-related disease. They appear to act as a hormone-producing organ, not simply a collection of beneficial bacteria. Microbiota are sensitive and responsive to physical environmental changes as well as dietary ones. So, exercise in nature may favorably boost microbiota.

And finally, exercise in nature is clinically preferred and calming. A Norwegian study showed that exercise in nature and in view of nature improves both mood and diastolic blood pressure vs exercise without nature. A Chinese study showed higher energy levels, and lower levels of interleukin-6 and tumor necrosis factor (both markers of inflammation), in a forest walking group compared with an urban exercising group. A British study showed significantly improved mood and self-esteem with "green" exercise, with the largest benefits from 5-minute engagements. Five minutes!

Of course, there are areas in our country and world in which it is dangerous to walk, never mind exercise. It may not be as easy to generate sweat and intensity with outdoor exercise as it is with indoor exercise. It may be stormy, or baking hot, or otherwise harsh outside, and the cool recesses of one's own bedroom or the gym may be just perfect for you today. And with the 2013 total cost of inactivity estimated at $24.7 billion for the United States, and with the public sector bearing almost one half of that expense, any exercise anywhere is better than none.  Yet physicians have a therapeutic tool few others in our culture wield—a prescription pad—and we have every patient's attention, at least for a few minutes. Patients try harder when doctors advise them about fitness. 

Published on Leave a comment on What’s In Your Household Dust?

Ten chemicals suspected or known to harm human health are present in more than 90% of U.S. household dust samples, according to a new study. The research adds to a growing body of evidence showing the dangers posed by exposure to chemicals we are exposed to on a daily basis. The chemicals come from a variety of household goods, including toys, cosmetics, personal care products, furniture, electronics, nonstick cookware, food packaging, floor coverings, some clothing (e.g., stain resistant), building materials, and cleaning products. How do the chemicals get into the dust? The chemicals can leach, migrate, abrade, or off-gas from the products, which winds up in the dust and  results in human exposure. (That's right:  vacuum a lot and wash your hands a lot, and try to avoid or cut  back use of products with these chemicals,)

What was found in the dust? The main chemicals were: phthalates — a group of chemicals that includes DEP, DEHP, DNBP and DIBP (these were present in the highest concentrations),  highly fluorinated chemicals (HFCs), flame retardants (both old and newer replacement ones), synthetic fragrances, and phenols. These chemicals are known to have various adverse health effects, including endocrine disruption, cancer, neurological, immune, and developmental effects. (See posts on endocrine disruptors and flame retardants) Studies typically study one chemical at a time, but household dust contains MIXTURES of these chemicals with effects unknown. How does it get into us? Inhalation, ingestion, and through skin contact. And while the levels we are exposed to may be low, research is showing that even low level exposure can have adverse health effects. From Medical Xpress:

Potentially harmful chemicals widespread in household dust

Household dust exposes people to a wide range of toxic chemicals from everyday products, according to a study led by researchers at Milken Institute School of Public Health at the George Washington University. The multi-institutional team conducted a first-of-a-kind meta-analysis, compiling data from dust samples collected throughout the United States to identify the top ten toxic chemicals commonly found in dust. They found that DEHP, a chemical belonging to a hazardous class called phthalates, was number one on that list. In addition, the researchers found that phthalates overall were found at the highest levels in dust followed by phenols and flame retardant chemicals....."The findings suggest that people, and especially children, are exposed on a daily basis to multiple chemicals in dust that are linked to serious health problems." ...continue reading "What’s In Your Household Dust?"

Published on Leave a comment on Reading Books Linked To Living Longer

 Image result for books wikipedia There are some things we can do that are linked to living longer, such as not smoking and exercising regularly, but could reading books also have such an effect? A study published in the journal Social Science and Medicine concludes that those who regularly read books add several years to their lives. They found this effect in both men and women, found that reading books are "protective regardless of gender, wealth, education", but the effect holds only for books and not magazines and newspapers. Since surveys show that 87% of book readers read fiction, then it is likely that most of the book readers were reading fiction.

In the long-term (12 years) study of 3,635 people, the researchers found that those that read books for more than 3.5 hours per week lived on average two years longer than non-readers, and that there was a dose-response effect (the more one reads, the better). This appeared to be linked to cognitive enhancement rather than any other associated factor, such as age, sex, education, race, health, wealth, etc. The research team from the Yale University School of Public Health divided their subjects into three groups: those who didn’t read at all, those who read for 3.5 hours per week or less, and those who read for more than 3.5 hours per week. They found that the occasional readers were 17 percent less likely to die during the follow-up period than those who did not. This beneficial effect of reading was only linked to books, and not other forms of reading material such as magazines or newspapers. From the journal Social Science and Medicine:

A chapter a day: Association of book reading with longevity

This study examined whether those who read books have a survival advantage over those who do not read books and over those who read other types of materials, and if so, whether cognition mediates this book reading effect. The cohort consisted of 3635 participants in the nationally representative Health and Retirement Study who provided information about their reading patterns at baseline.....based on survival information up to 12 years after baseline. A dose-response survival advantage was found for book reading by tertile.....Book reading contributed to a survival advantage that was significantly greater than that observed for reading newspapers or magazines. Compared to non-book readers, book readers had a 23-month survival advantage at the point of 80% survival in the unadjusted model. A survival advantage persisted after adjustment for all covariates (HR = .80, p < .01), indicating book readers experienced a 20% reduction in risk of mortality over the 12 years of follow up compared to non-book readers. Cognition mediated the book reading-survival advantage. These findings suggest that the benefits of reading books include a longer life in which to read them.

While most sedentary behaviors are well-established risk factors for mortality in older individuals (Wullems et al., 2016; de Rezenade et al., 2014, Katzmaryk & Lee, 2012; Muennig, Rosen, & Johnson, 2013), previous studies of a behavior which is often sedentary, reading, have had mixed outcomes....We speculated that books engage readers’ minds more than newspapers and magazines, leading to cognitive benefits that drive the effect of reading on longevity. 

Reading books tends to involve two cognitive processes that could create a survival advantage. First, it promotes "deep reading,” which is a slow, immersive process; this cognitive engagement occurs as the reader draws connections to other parts of the material, finds applications to the outside world, and asks questions about the content presented (Wolf, Barzillai, & Dunne, 2009). Cognitive engagement may explain why vocabulary, reasoning, concentration, and critical thinking skills are improved by exposure to books (Stanovich, West, & Harrison, 1995; Stanovich & Cunningham, 1998; Wolf, Barzillai, & Dunne, 2009). Second, books can promote empathy, social perception, and emotional intelligence, which are cognitive processes that can lead to greater survival (Bassuk, Wypij, & Berkmann, 2000; Djikic, Oatley, & Moldoveanu 2013; Kidd & Castano 2013; Shipley, Der, Taylor, & Deary 2008; Olsen, Olsen, Gunner-Svensson, & Waldstrom, 1991).

The final sample consisted of 3635 individuals that were followed over 34,496 person years, with 27.4% of the sample dying during an average 9.49 years of follow-up. Consistent with the older population, the sample was predominantly (62%) female.....The average time spent reading per week was 3.92 hours for books and 6.10 hours for periodicals. The two types of reading were not strongly correlated, and 38% of the sample (n=1390) read only books or only periodicals; this allowed them to be treated as separate constructs.....Cognitive engagement was assessed with total cognitive score (available in the supplemental Imputation of Cognitive Function Measures) which is a summary variable based on 8 items, including immediate recall, delayed recall, serial 7s, backwards count from 20, object naming, President naming, Vice President naming, and date naming.

A 20% reduction in mortality was observed for those who read books, compared to those who did not read books. Further, our analyses demonstrated that any level of book reading gave a significantly stronger survival advantage than reading periodicals.....The mediation analyses showed for the first time that the survival advantage was due to the effect that book reading had on cognition....This finding suggests that reading books provide a survival advantage due to the immersive nature that helps maintain cognitive status.

Published on Leave a comment on Avoid Lavender and Tea Tree Oils In Personal Care Products?

Over the years I have read about some oils, especially lavender and tea tree oils,  as having hormone altering (endocrine disrupting) effects when used over prolonged periods of time or when someone is "chronically exposed". Especially worrisome was the possible estrogenic effects of lavender oils in shampoos, lotions, and soaps on developing children - especially boys (prolonged use leading to the development of breasts in some boys!). I just read a recently published journal study (with very interesting comments at the end), and an article in WebMD about this same topic. The condition of early breast development is called prepubertal gynecomastia in boys and thelarche in girls.

As you can imagine, the industry (Australian Tea Tree Industry Association and Research Institute for Fragrance Materials Inc) calls such research  "poor science". Of course industry sponsored "research" never ever finds any problems (because any "problems" would impact the big $$ from the sale of those products). In fact, I would be skeptical of any industry sponsored research in this area - it is not truly independent, unbiased research if they "have to" and "want to" find no problems. So when you do read industry research, also read the rebuttals by independent scientists and doctors.

Bottom line: No matter the age, avoid prolonged use of lavender and tea tree oil in personal care products, including "aromatherapy" -  especially important for children and pregnant women. The good news is that the development of breasts in young children is reversible when use of the product is stopped. But better to avoid such products (including Agua de Violetas) on children in the first place. Instead use unscented personal care products.

From WebMD:  Are Tea Tree and Lavender Oils Safe for Kids?

Tea tree and lavender essential oils are popular ingredients in personal care and household products, including many aimed at children. But can the ingredients, often promoted as “natural” alternatives, trigger abnormal breast growth in boys and girls? A few small studies suggest that frequently using lotions, shampoos, styling gels, and even a certain cologne containing lavender and tea tree oils may cause breast growth in boys, also known as gynecomastia, along with breast growth in girls as young as 4 or 5. 

Other studies have not reached the same conclusions, and the cases appear to be rare. In addition, scientific research into most natural products is scant. The FDA doesn’t oversee essential oils unless they are intended for use in a drug, making it challenging to know how safe and effective these products are....Lavender and tea tree oils are among the most commonly used essential oils used. Although research is inconclusive, lavender is often used for aromatherapy and calming lotions, while tea tree oil is promoted for acne, nail fungus, and other skin conditions. 

...continue reading "Avoid Lavender and Tea Tree Oils In Personal Care Products?"

Published on Leave a comment on Selenium, Retinoic Acid, and Cancer Risk

Image result for meat, fish, eggs It is important to eat a varied diet for health, one that focuses on the food groups (and no - cookies and cake are not necessary foods). The first study looks at liver cancer risk and selenium - which is found in fish, shellfish, meat, milk, eggs, and certain South American nuts, such as Brazil nuts. The second article focuses on colorectal cancer and retinoic acid, a compound derived in the body from vitamin A. Vitamin A rich foods can provide you with retinoic acid, such as the lungs, kidneys, and liver of beef, lamb, pork. Also poultry giblets, eggs, cod liver oil, shrimp, fish, fortified milk, butter, cheddar cheese and Swiss cheese. Red and orange vegetables and fruits such as sweet potatoes, squash, carrots, pumpkins, cantaloupes, apricots, peaches and mangoes all contain significant amounts of beta-carotene, thus retinoids. Note that research generally has found health benefits from real foods, not from supplements.

From Science Daily:  Selenium status influence cancer risk

As a nutritional trace element, selenium forms an essential part of our diet. Researchers have been able to show that high blood selenium levels are associated with a decreased risk of developing liver cancer. Selenium (Se) is found in foods like fish, shellfish, meat, milk and eggs; certain South American nuts, such as Brazil nuts, are also good sources of selenium. It is a trace element that occurs naturally in soil and plants, and enters the bodies of humans and animals via the food they ingest. European soil has a rather low selenium concentration, in comparison with other areas of the world, especially in comparison to North America. Deficiencies of varying degrees of severity are common among the general population, and are the reason why German livestock receive selenium supplements in their feed.

While in Europe, neither a selenium-rich diet nor adequate selenium supplementation is associated with adverse effects, selenium deficiency is identified as a risk factor for a range of diseases. "We have been able to show that selenium deficiency is a major risk factor for liver cancer," says Prof. Dr. Lutz Schomburg of the Institute of Experimental Endocrinology, adding: "According to our data, the third of the population with lowest selenium status have a five- to ten-fold increased risk of developing hepatocellular carcinoma -- also known as liver cancer."....Previous studies had suggested a similar relationship between a person's selenium status and their risk of developing colon cancer, as well as their risk of developing autoimmune thyroid disease. (Original study)

From Science Daily: Retinoic acid suppresses colorectal cancer development, study finds

Retinoic acid, a compound derived in the body from vitamin A, plays a critical role in suppressing colorectal cancer in mice and humans, according to researchers at the Stanford University School of Medicine. Mice with the cancer have lower-than-normal levels of the metabolite in their gut, the researchers found. Furthermore, colorectal cancer patients whose intestinal tissues express high levels of a protein that degrades retinoic acid tend to fare more poorly than their peers.

"The intestine is constantly bombarded by foreign organisms," said Edgar Engleman, MD, professor of pathology and of medicine. "As a result, its immune system is very complex. There's a clear link in humans between inflammatory bowel disease, including ulcerative colitis, and the eventual development of colorectal cancer. Retinoic acid has been known for years to be involved in suppressing inflammation in the intestine. We wanted to connect the dots and learn whether and how retinoic acid levels directly affect cancer development."

"We found that bacteria, or molecules produced by bacteria, can cause a massive inflammatory reaction in the gut that directly affects retinoic acid metabolism," said Engleman. "Normally retinoic acid levels are regulated extremely tightly. This discovery could have important implications for the treatment of human colorectal cancer."

Further investigation showed that retinoic acid blocks or slows cancer development by activating a type of immune cell called a CD8 T cell. These T cells then kill off the cancer cells. In mice, lower levels of retinoic acid led to reduced numbers and activation of CD8 T cells in the intestinal tissue and increased the animals' tumor burden, the researchers found. "It's become very clear through many studies that chronic, smoldering inflammation is a very important risk factor for many types of cancer," said Engleman.

Published on Leave a comment on Stopping All Exercise and Blood Flow In the Brain

What happens to your brain when you stop exercising? The results of this Univ. of Maryland study should be a wake up call for those who are not quite convinced of exercise's health benefits to the brain. The researchers examined cerebral blood flow in athletes (ages 50-80 years, who were recruited from running clubs) before and after a 10-day period during which they stopped all exercise. Using MRI brain imaging techniques, they found a significant decrease in blood flow to several brain regions important for cognitive health, including the hippocampus, after they stopped their exercise routines.

As the researchers pointed out: "...the take home message is simple -- if you do stop exercising for 10 days, just as you will quickly lose your cardiovascular fitness, you will also experience a decrease in blood brain flow." The only good news was that there were no differences on cognitive measures both before and after stopping exercise for 10 days. From Science Daily:

Use it or lose it: Stopping exercise decreases brain blood flow

We all know that we can quickly lose cardiovascular endurance if we stop exercising for a few weeks, but what impact does the cessation of exercise have on our brains? New research led by University of Maryland School of Public Health researchers examined cerebral blood flow in healthy, physically fit older adults (ages 50-80 years) before and after a 10-day period during which they stopped all exercise. Using MRI brain imaging techniques, they found a significant decrease in blood flow to several brain regions, including the hippocampus, after they stopped their exercise routines.

"We know that the hippocampus plays an important role in learning and memory and is one of the first brain regions to shrink in people with Alzheimer's disease," says Dr. J. Carson Smith, associate professor of kinesiology and lead author of the study, which is published in Frontiers in Aging Neuroscience in August 2016. "In rodents, the hippocampus responds to exercise training by increasing the growth of new blood vessels and new neurons, and in older people, exercise can help protect the hippocampus from shrinking. So, it is significant that people who stopped exercising for only 10 days showed a decrease in brain blood flow in brain regions that are important for maintaining brain health."

The study participants were all "master athletes," defined as people between the ages of 50 and 80 (average age was 61) who have at least 15 years history of participating in endurance exercise and who have recently competed in an endurance event. Their exercise regimens must have entailed at least four hours of high intensity endurance training each week. On average, they were running 36 miles (59 km) each week or the equivalent of a 10K run a day! Not surprisingly, this group had a V02 max (maximum volume of oxygen) above 90% for their age. This is a measure of the maximal rate of oxygen consumption of an individual and reflects their aerobic physical fitness.

Dr. Smith and colleagues measured the velocity of blood flow in brain with an MRI scan while they were still following their regular training routine (at peak fitness) and again after 10 days of no exercise. They found that resting cerebral blood flow significantly decreased in eight brain regions, including the areas of the left and right hippocampus and several regions known to be part of the brain's "default mode network" -- a neural network known to deteriorate quickly with a diagnosis of Alzheimer's disease. This information adds to the growing scientific understanding of the impact of physical activity on cognitive health.

Published on Leave a comment on Endocrine Disruptors BPA, BPS, and Now BPSIP

Studies are accumulating evidence that the hormone disrupting effects of compounds BPA (bisphenol A) and BPS (the common substitute for BPA) have numerous negative health effects in humans, including reproductive disorders. But now a second BPA substitute - BPSIP - is also being found in humans, and may be even more persistent than BPA and BPS. This is because they're all chemically similar, and all three are endocrine disruptors. This article points out that they have slightly different effects, and when we are exposed to more than one of them (which we are), then the health effects will be even more worrisome.

Unfortunately these plasticizers are in products all around us, and so detected within almost all of us. They're in food packaging containers (and therefore in food), water bottles, can linings, toys, personal care products, thermal paper products such as cash receipts, etc. Canned foods are considered one of the most significant routes of human exposure to bisphenol A (BPA).

Other endocrine disruptors include phthalates - so read personal care product labels to avoid these. Another way to lower exposure to endocrine disruptors is to buy and store food not in plastic containers, but in glass containers or stainless steel. Don't microwave food in any sort of plastic containers. Avoid products with fragrances in them, including air fresheners. Avoid flexible vinyl (e.g. shower curtains). (For all posts on endocrine disruptors, and an article from National Institutes of Health.) From a research article by Liza Gross in PLOS Biology:

Wreaking Reproductive Havoc One Chemical at a Time

Bisphenol A (BPA), unlike DES, remained obscure until the 1950s, when chemists tapped it to make polycarbonate plastics and epoxy resins. BPA now tops the list of high-volume chemicals, and is found in numerous consumer products, including water bottles, food packaging containers and can linings, and thermal paper products like cash receipts and boarding passes (Fig 1). And because it can leach out of products, it’s been detected in the urine of nearly every person tested. It’s also been found in breast milk, follicular and amniotic fluid, cord blood, placental tissue, fetal livers, and the blood of pregnant women.  ...continue reading "Endocrine Disruptors BPA, BPS, and Now BPSIP"

Published on Leave a comment on Can Eating A Vegetarian Diet Lower Blood Pressure?

Can eating a vegetarian diet lower blood pressure? Both this review and other reviews of studies say YES, that those following vegetarian diets have a lower prevalence of hypertension. Overall, the mean prevalence of hypertension was 21% in those consuming a vegetarian diet and 29% in those consuming a nonvegetarian diet (the differences varied between studies).Those following a vegetarian diet also tended to have a healthier lifestyle. As the researchers point out: blood pressure medicine lowers blood pressure for one day, while lifestyle changes (diet, exercise, not smoking, limiting or avoiding alcohol) can lower blood pressure for life. From Medscape:

Vegetarian Diet: A Prescription for High Blood Pressure?

Hypertension is one of the most costly and poorly treated medical conditions in the United States and around the world. Consequences of hypertension include morbidity and mortality related to its long-term effects, which include stroke, myocardial infarction, renal failure, limb loss, aortic aneurysm, and atrial fibrillation, among many others. Although there is an armamentarium of medications to treat hypertension, we do little for prevention. In this review we examine the relationship between vegetarian and nonvegetarian diets and the prevalence of hypertension. 

Current nonpharmacologic treatments include: physical activity (≥ 30 minutes of moderate-intensity activity on most days of the week); smoking cessation; dietary modification (lower sodium, increased potassium; mainly plant-based foods; low-fat foods; reduced-fat dairy products; moderate amounts of lean unprocessed meats, poultry, and fish; and moderate amounts of polyunsaturated and monounsaturated fats, such as olive oil); weight reduction; management of stress; and limited alcohol consumption.

It is well known that hypertension is modulated by dietary influences. In this review we examine vegetarian, vegan, and nonvegetarian (omnivore) diets and prevalence of hypertension among these dietary populations. A vegetarian diet (ie, lacto/ovo-vegetarian) includes plant foods, dairy products, and eggs (excludes all meat, such as turkey, beef, poultry, seafood, bacon, etc.). A vegan diet is similar to vegetarian, except it further excludes dairy products and eggs (no animal or animal products). On the other hand, an omnivore diet (referred to as nonvegetarians throughout this study) includes both plant and animal foods and products.....The majority of studies included in this review addressed vegetarians and vegans as a single group (vegetarians), whereas others differentiated them. Vegetarian diets are known to be low in saturated fat and cholesterol, high in fiber, low in sodium, and high in potassium. These key elements have been shown to correlate with lower incidence of cancer, heart disease, and other chronic diseases, such as diabetes type II, hypertension, and hyperlipidemia.

The exact percentage of those following a vegetarian or vegan diet in the US is unknown; however, a 2014 study found that 221 of 11,399 adult respondents, from a group generally representing the demographics of the US, identified as vegan (0.5%), vegetarians (1.5%), or meat-eaters (98%). The prevalence of hypertension in the US in 2011 was roughly 33.8%.

The mean prevalence of hypertension in those consuming a vegetarian diet was 21% and 29% in those consuming a nonvegetarian diet. The overall prevalence of hypertension among vegetarians was 33% lower than nonvegetarian diets. These data support the hypothesis of a decreased prevalence of hypertension in those maintaining a vegan or vegetarian diet versus a nonvegetarian diet, in cross-sectional, cohort, and case-control studies, and in those consuming a vegan or vegetarian diet according to an experimental dietary change. The blood pressure benefit is noted to disappear in those reverting back to a nonvegetarian diet. 

Overall, these findings support previous reviews and meta-analyses of vegetarian and nonvegetarian diets and blood pressure. A recent meta-analysis that identified 39 studies with 21,915 participants concluded vegetarian diets were associated with a drop in mean systolic (-5.9 mm Hg) and diastolic (-3.5 mm Hg) blood pressures when compared with nonvegetarians. Other reviews had similar conclusions, showing that vegetarians have a lower blood pressure compared with nonvegetarians. Of the studies that included a vegan diet separate from other vegetarians (eg, lacto/ovo), the data show a significantly lower prevalence of hypertension when compared with nonvegetarians and other vegetarians. However, limited research has been conducted on strict, consistent vegan diets.

There are possible rationalizations for the observed associations between diet and hypertension. First, vegetarians have a lower rate of smoking tobacco. Smoking can increase blood pressure acutely and chronically over time.....Second, vegetarians tend to drink less alcohol compared with nonvegetarians. Alcohol, specifically ≥ 2 drinks/day, increases blood pressure by causing vasodilation, followed by a compensatory increase in blood pressure.....Further, vegetarians have a lower mean BMI when compared with nonvegetarians, which means a lower overall weight....Fourth, vegetarians tend to exercise more than nonvegetarians. Vegetarians reported a greater incidence of physical activity of ≥ 30 minutes of moderate to vigorous activity per day.

A limitation of this study is that it remains unclear whether vegetarians are more health conscious and therefore live healthier lives, or whether a predominant diet of fruits and vegetables is a basis for lower blood pressure.

Published on Leave a comment on The Longer Overweight, the Greater A Woman’s Cancer Risk

Yikes! A good reason to lose weight now rather than years from now, and the importance of not ignoring a weight gain (you know, over the years as the pounds slowly creep up). The researchers found that for every 10 years of being overweight as an adult, there was an associated 7% increase in the risk for all obesity-related cancers. The degree of overweight (dose-response) during adulthood was important in the risk of developing cancer, especially for endometrial cancer. This study just looked at postmenopausal women, so it is unknown if it applies to men. From Medscape:

Longer Duration of Overweight Increases Cancer Risk in Women

A longer duration of being overweight during adulthood significantly increased the incidence of all cancers that are associated with obesity, a new study in postmenopausal women has concluded. The large population-based study was published August 16 in PLoS Medicine.

Dr Arnold and colleagues found that for every 10 years of being overweight as an adult, there was an associated 7% increase in the risk for all obesity-related cancers. The risk was highest for endometrial cancer (17%) and kidney cancer (16%). For breast cancer, the increased risk was 5%, but no significant associations were found for rectal, liver, gallbladder, pancreatic, ovarian, and thyroid cancer.

When the authors took into account the degree of excess weight over time, the risks were further increased, and there were "clear dose-response relationships," they note. Again, the risk was highest for endometrial cancer. For each additional decade spent with a body mass index (BMI) that was 10 units above normal weight, there was a 37% increase in the risk for endometrial cancer.

Study Details: The researchers used data from the huge American Women's Health Initiative (WHI) trial of postmenopausal women (aged 50 to 79 years at time of study enrollment). For this analysis, the team focused on a cohort of 73,913 postmenopausal women. During a mean follow-up of 12.6 years, 6301 obesity-related cancers were diagnosed. About 40% (n = 29,770) of women in the cohort were never overweight during their adult life....Women who were ever overweight were on average overweight for about 30 years, while those who were ever obese had been so for an average of 20 years. The authors found that the risk of being diagnosed with an obesity-related cancer rose for every 10 years of being overweight.

Published on Leave a comment on Exercise Can Lead To Misdiagnosis of Heart Disease

 The last post pointed out that the importance of high levels of physical activity or exercise in reducing the risk of 5 diseases. Now a study points out that all this exercise (starting at about 3 to 5 hours of exercise per week) can result in the heart becoming enlarged from all this exercise ("athlete's heart"), and that this is totally normal and healthy. The researchers also stressed that doctors should be aware that athlete's heart or "exercise-related cardiac remodeling" can occur not only in professional athletes, but also in those engaging in moderate levels of exercise, and that it not be misdiagnosed as heart disease. From Science Daily:

Regular exercise can lead to heart disease misdiagnosis

Scientists have shown that people who exercise for even a few hours each week can enlarge their hearts. This is a normal and beneficial response to exercise, but until now has only been recognised in athletes. The researchers say that doctors should now consider an individual's activity level before diagnosing common heart conditions.

"It's well known that the hearts of endurance athletes adapt in response to exercise, a phenomenon called 'athlete's heart'. This study is the first to show that healthy adults who do regular exercise may also develop enlarged hearts. As a result, there's a risk that some active adults could be misdiagnosed with heart disease," says Declan O'Regan, of the MRC Clinical Sciences Centre, based at Imperial College London, and one of the lead scientists on the research. The findings were published today in Circulation: Cardiovascular Imaging.

Scientists have not previously known the extent to which the hearts of healthy people adapt to the demands of moderate exercise. Over 1000 people took part in this study, making it one of the largest of its kind. Participants selected one of four possible categories that best represented their activity level over the past year, according to how many hours of exercise they did each week. Around one third of participants reported doing three to five hours of exercise, and the scientists found that one in five of these people had developed an enlarged heart as a result. Similar adaptations were seen in almost half of those who reported doing more than five hours of exercise.

The findings suggest that above a threshold of three hours, the more exercise you do, the more your heart is likely to adapt, and the more the exercise, the more pronounced the changes. "Going to the gym frequently increases the thickness of your heart muscle and the volume of your heart chambers, particularly the right ventricle. It's a completely normal, healthy response. It shouldn't be misdiagnosed as being heart disease," says O'Regan. These adaptations allow the heart to pump more blood, which helps to supply exercising muscles with the oxygen and nutrients they need. Changes to the heart's thickness and volume happen in tandem, and this distinguishes them from the changes seen in disease, which occur in isolation.

Today, doctors across the world use a standard of set values to see if the thickness and volume of a person's heart fall into the healthy or abnormal range. This helps to ensure consistency between different hospitals. According to O'Regan, the data that underpins these ranges comes from a relatively small study with people who were mainly sedentary. He says, "In this latest study, we looked at a much larger and broader group of people. We found that more people reported being active than had done in previous studies. Our recommendations reflect this growing participation in exercise.".....And this interesting research shows that even moderate physical activity is associated with changes in the heart's size and shape, which are visible on a cardiac MRI.