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Author: Sima

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Published on 8 Comments on Health Reasons to Avoid Fragrances, Air Fresheners, Dryer Sheets

Did you ever wonder about all the consumer products that have fragrances in them and whether they are safe to use? Think of all the fragrances in personal care products and perfumes, in air fresheners, scented soaps, cleaning products, scented candles, even laundry detergents, and scented dryer sheets.

Fragrances are made up of many synthetic chemicals - with the "fragrance" in a product typically being a mixture of 50 to 300 chemicals. They are considered an important source of indoor air pollution and can have negative health effects on humans, especially developing fetuses and children. Fragrances are added to products to achieve a desired scent or mask other scents in the product. Air fresheners do not clean or freshen the air, but actually add chemicals to the air to mask other odors. Manufacturers are NOT required to disclose all the ingredients or chemicals in the products, and don't have to disclose any ingredients in any chemical mixture called "fragrance".

The few studies looking at health effects have found negative health effects, including on the lungs, respiratory effects, asthma, allergies, headaches, skin irritation, sensory irritation, hormonal effects, central nervous system effects, and inflammation. But more negative health effects are possible, especially because many of the chemicals are carcinogenic (cancer causing). We inhale the chemicals or absorb them through the skin, and from there they travel throughout the body - which is why they can be measured in the blood or urine.

Reading the studies that look at the chemicals emitted from scented products that people use every day can be overwhelming. Many of the studies specifically look at VOCs (volatile organic compounds) that the products emit, because these can affect air quality and human health. A big difficulty is that humans are exposed to mixtures of chemicals daily from many products, and the effects may take years to manifest themselves (such as cancer). 

Bottom line: avoid, avoid, avoid fragranced or scented products if possible. Do not use scented detergent or dryer sheets (not necessary), do not use air fresheners (either in the home, workplace, or car), do not use incense or scented candles (post on scented candles). Read labels. Opening windows is the best way to air out a house or apartment. Studies find that fragrances labeled "organic", "natural", "green", or "with essential oils" basically emit the same toxic chemicals into the air (view such labels as marketing or "greenwashing") - therefore avoid those also.

Air fresheners are consumer products used in homes or in restrooms that typically emit fragrances,  including incense, scented candles, aerosol liquid wick and electric diffusers, and gels. Depending on which air freshener is used (and including those labeled "all natural"), they emit varying levels of allergens and toxic air pollutants (and which can also combine to produce other pollutants - "secondary pollutants"): acetone, aldehydes, benzene, toluene, formaldehyde, terpenes, styrene, esters, phthalates (which are hormone disrupting chemicals), limonene, and also ultrafine particles. None of these toxic chemicals are listed on the product labels. Typically, a fragrance is listed simply as “fragrance,” even though each fragrance can contain hundreds of individual chemicals. Only this past year has one company (Glade) started posting online (but not on the packages) some of the many chemicals used in its scented products.  ...continue reading "Health Reasons to Avoid Fragrances, Air Fresheners, Dryer Sheets"

Published on Leave a comment on A New Tree of Life That’s Mainly Bacteria

In 1837, Charles Darwin sketched a simple tree of life (shown left) to illustrate the idea that all living things share a common ancestor. Ever since then, scientists have been adding names to the tree of life, including a massive effort of 2.3 million named species of animals, plants, fungi and microbes in 2015. A tree of life is a visual hypothesis of how scientists think species are related to one another, so it has been evolving over the years as more information is learned and species discovered.

Now a group of 17 researchers have sketched out a radically different tree of life. It has two main trunks—one full of bacteria and another comprised of archaea, a group of single-celled microbes that run on very different biochemistry. The eukaryotes—the domain that includes all animals, fungi, and plants—are crowded on a thin branch coming off the archaeal trunk. About half of these bacterial branches belong to a supergroup, which was discovered very recently and is currently known as the candidate phyla radiation. Within these branches are numerous species that we’re almost completely ignorant about, and they’ve never been isolated or grown in a lab (with one exception called TM7). In fact, this supergroup of bacteria and “other lineages that lack isolated representatives clearly comprise the majority of life’s current diversity,” write researchers Hug and Banfield. Wow. From Science Daily:

Wealth of unsuspected new microbes expands tree of life

Scientists have dramatically expanded the tree of life, which depicts the variety and evolution of life on Earth, to account for over a thousand new microscopic life forms discovered over the past 15 years. The expanded view finally gives bacteria and Archaea their due, showing that about two-thirds of all diversity on Earth is bacterial -- half bacteria that cannot be isolated and grown in the lab -- while nearly one-third is Archaeal.

Much of this microbial diversity remained hidden until the genome revolution allowed researchers like Banfield to search directly for their genomes in the environment, rather than trying to culture them in a lab dish. Many of the microbes cannot be isolated and cultured because they cannot live on their own: they must beg, borrow or steal stuff from other animals or microbes, either as parasites, symbiotic organisms or scavengers.

The new tree, to be published online April 11 in the new journal Nature Microbiology, reinforces once again that the life we see around us -- plants, animals, humans and other so-called eukaryotes -- represent a tiny percentage of the world's biodiversity.

"Bacteria and Archaea from major lineages completely lacking isolated representatives comprise the majority of life's diversity," said Banfield.....According to first author Laura Hug,... the more than 1,000 newly reported organisms appearing on the revised tree are from a range of environments, including a hot spring in Yellowstone National Park, a salt flat in Chile's Atacama desert, terrestrial and wetland sediments, a sparkling water geyser, meadow soil and the inside of a dolphin's mouth. All of these newly recognized organisms are known only from their genomes.

One striking aspect of the new tree of life is that a group of bacteria described as the "candidate phyla radiation" forms a very major branch. Only recognized recently, and seemingly comprised only of bacteria with symbiotic lifestyles, the candidate phyla radiation now appears to contain around half of all bacterial evolutionary diversity.

Charles Darwin first sketched a tree of life in 1837 as he sought ways of showing how plants, animals and bacteria are related to one another. The idea took root in the 19th century, with the tips of the twigs representing life on Earth today, while the branches connecting them to the trunk implied evolutionary relationships among these creatures.....Archaea were first added in 1977 after work showing that they are distinctly different from bacteria, though they are single-celled like bacteria. A tree published in 1990 by microbiologist Carl Woese was "a transformative visualization of the tree," Banfield said. With its three domains, it remains the most recognizable today.

With the increasing ease of DNA sequencing in the 2000s, Banfield and others began sequencing whole communities of organisms at once and picking out the individual groups based on their genes alone. This metagenomic sequencing revealed whole new groups of bacteria and Archaea, many of them from extreme environments, such as the toxic puddles in abandoned mines, the dirt under toxic waste sites and the human gut. Some of these had been detected before, but nothing was known about them because they wouldn't survive when isolated in a lab dish.

For the new paper, Banfield and Hug teamed up with more than a dozen other researchers who have sequenced new microbial species, gathering 1,011 previously unpublished genomes to add to already known genome sequences of organisms representing the major families of life on Earth.....The analysis, representing the total diversity among all sequenced genomes, produced a tree with branches dominated by bacteria, especially by uncultivated bacteria. A second view of the tree grouped organisms by their evolutionary distance from one another rather than current taxonomic definitions, making clear that about one-third of all biodiversity comes from bacteria, one-third from uncultivable bacteria and a bit less than one-third from Archaea and eukaryotes. (Original article and diagrams.)

This is a new and expanded view of the tree of life, with clusters of bacteria (left), uncultivable bacteria called 'candidate phyla radiation' (center, purple) and, at lower right, the Archaea and eukaryotes (green), including humans.
Credit: Graphic by Zosia Rostomian, Lawrence Berkeley National Laboratory

Published on Leave a comment on Chocolate, Cognitive Function, and Athletic Performance

Image result for dark chocolate Two new studies finding benefits from chocolate consumption: dark chocolate boosting athletic performance (in cycling), and long-term chocolate consumption (several times a week for many years) linked to better cognitive function. From Medical Xpress:

Eating chocolate improves cognitive function, study finds

People who ate chocolate at least once a week performed better on multiple cognitive tasks, compared to those who ate chocolate less frequently, according to a new study by researchers at the University of Maine, University of South Australia and Luxembourg Institute of Health that has garnered international attention. 

With age, education, gender, age and race controlled, cognitive tasks were related to following domains, each measured by multiple tests: Visual-Spatial Memory and Organization, Working Memory, Abstract Verbal Reasoning, Scanning and Tracking, and overall cognitive functioning. The 968 participants ages 23–98 in the study came from the Maine-Syracuse Longitudinal Study, directed by Elias, which has tracked more than 1,000 people over 35 years.

The researchers hypothesized that regular intake of cocoa flavanols may be one of several mechanism explaining the cognitive benefits of chocolate. In addition, compared to those who never or rarely ate chocolate, those who ate chocolate weekly had higher total and LDL cholesterol, but lower glucose levels. Hypertension and Type 2 diabetes also were lower in regular chocolate consumers than in nonconsumers. 

From Medical Xpress: Eating dark chocolate as a daily snack could help boost athletic performance, study suggests

Dark chocolate has already been hailed for its positive effects on cardiovascular health – and now a study undertaken at London's Kingston University has found the tasty treat could help give sports enthusiasts an extra edge in their fitness training. A team led by postgraduate research student Rishikesh Kankesh Patel discovered that dark chocolate provides similar benefits to beetroot juice, now taken regularly by elite athletes after studies showed it can improve performance. "Beetroot juice is rich in nitrates, which are converted to nitric oxide in the body. This dilates blood vessels and reduces oxygen consumption – allowing athletes to go further for longer," Mr Patel explained.

The Kingston University team wanted to find out whether dark chocolate could provide a similar boost, as it contains a substance called epicatechin – a type of flavanol found in the cacao bean, that also increases nitric oxide production in the body.

To test the theory, Mr Patel carried out a study with a group of nine amateur cyclists.....After undergoing initial fitness tests to establish a baseline for comparison, the participants were then split into two groups. The first group was asked to replace one of its normal daily snacks with 40 g of a dark chocolate known to be rich in flavanols for a fortnight, while the other participants substituted 40 g of white chocolate for one of their daily snacks as a control.

The effects of the athletes' daily chocolate consumption were then measured in a series of cycling exercise tests in the sports performance laboratory at the University's Penrhyn Road campus....The study, which has now been published in the Journal of the International Society of Sports Nutrition, found that after eating dark chocolate, the riders used less oxygen when cycling at a moderate pace and also covered more distance in a two-minute flat-out time trial.

Published on Leave a comment on Some Popular Medicines Have Negative Brain Effects

Another study showing big problems with anticholinergics, which are in many popular medicines - both non-prescription and prescription (e.g., Chlor-Trimeton, Benadryl, Tavist, Dimetapp). An earlier study with older adults found a dose-response link with dementia, but the current study explored this issue further. They followed 2 groups of  "cognitively normal older adults" in their early 70s for several years: those who took anticholinergic medicines and those who did not take anticholinergic medicines. They found that those who took anticholinergic medicines had reduced brain volume (brain shrinking) and cognitive decline (when compared to those who did not take anticholinergic medicines). The researchers summarized their findings as the "use of anticholinergic medication was associated with increased brain atrophy and dysfunction and clinical decline". This finding was greatest for those taking drugs with the most anticholinergic activity.

See a list of anticholinergic medicines  from the Aging Brain Program of the Indiana University Center for Aging Research. Definitely try to avoid medicines with a score of 2 (medium effect) or 3 (high effect), but I would even be cautious about score 1 (low effect) medicines - use all medicines only as long as absolutely needed. My one very important question is: If these effects are found in older adults, what do anticholinergics do to younger brains, especially the developing brains of children? From Medical Xpress:

Brain scans link physical changes to cognitive risks of widely used class of drugs

Older adults might want to avoid a using class of drugs commonly used in over-the-counter products such as nighttime cold medicines due to their links to cognitive impairment, a research team led by scientists at Indiana University School of Medicine has recommended. Using brain imaging techniques, the researchers found lower metabolism and reduced brain sizes among study participants taking the drugs known to have an anticholinergic effect, meaning they block acetylcholine, a nervous system neurotransmitter.

Previous research found a link between between the anticholinergic drugs and cognitive impairment and increased risk of dementia.....Drugs with anticholinergic effects are sold over the counter and by prescription as sleep aids and for many chronic diseases including hypertension, cardiovascular disease, and chronic obstructive pulmonary disease. A list of anticholinergic drugs and their potential impact is at http://www.agingbraincare.org/uploads/products/ACB_scale_-_legal_size.pdf.

Scientists have linked anticholinergic drugs and cognitive problems among older adults for at least 10 years. A 2013 study by scientists at the IU Center for Aging Research and the Regenstrief Institute found that drugs with a strong anticholinergic effect cause cognitive problems when taken continuously for as few as 60 days. Drugs with a weaker effect could cause impairment within 90 days.

The current research project involved 451 participants, 60 of whom were taking at least one medication with medium or high anticholinergic activity. The participants were drawn from a national Alzheimer's research project....and the Indiana Memory and Aging Study. To identify possible physical and physiological changes that could be associated with the reported effects, researchers assessed the results of memory and other cognitive tests, positron emission tests (PET) measuring brain metabolism, and magnetic resonance imaging (MRI) scans for brain structure.

The cognitive tests revealed that patients taking anticholinergic drugs performed worse than older adults not taking the drugs on short-term memory and some tests of executive function, which cover a range of activities such as verbal reasoning, planning, and problem solving. Anticholinergic drug users also showed lower levels of glucose metabolism—a biomarker for brain activity—in both the overall brain and in the hippocampus, a region of the brain associated with memory and which has been identified as affected early by Alzheimer's disease. The researchers also found significant links between brain structure revealed by the MRI scans and anticholinergic drug use, with the participants using anticholinergic drugs having reduced brain volume and larger ventricles, the cavities inside the brain.

Published on Leave a comment on Noninvasive Thyroid Cancer Is No Longer Cancer

For the first time ever, one type of cancer has been reclassified as a non-cancer. An international panel of pathologists and clinicians has reclassified a type of thyroid cancer to reflect that it is noninvasive and has a low risk for recurrence.The panel renamed encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). There has been concern for a while of the costs (financial, physical, and mental) of the overdiagnosis and overtreatment for something that won't spread (it's "indolent" and "low-risk").

There have been discussions for some time now in the medical community regarding the move away from the word "cancer" in the description of early stages of both breast and prostate cancer. In 2013, a medical team sanctioned by the National Cancer Institute proposed that a number of premalignant conditions, including ductal carcinoma in situ and high-grade prostatic intraepithelial neoplasia, should no longer be called "cancer." Instead, the conditions should be labeled something more appropriate, such as indolent lesions of epithelial origin (IDLE), the group suggested. " Use of the term 'cancer' should be reserved for describing lesions with a reasonable likelihood of lethal progression if left untreated," the group said at the time.

From Futurity: NONINVASIVE THYROID ‘CANCER’ ISN’T CANCER

The reclassification of a noninvasive type of thyroid cancer that has a low risk of recurrence is expected to reduce the fears and the unnecessary interventions that come with a cancer diagnosis, experts say. The incidence of thyroid cancer has been rising partly due to early detection of tumors that are indolent or non-progressing, despite the presence of certain cellular abnormalities that are traditionally considered cancerous, says senior investigator Yuri Nikiforov, professor of pathology at the University of Pittsburgh.

“This phenomenon is known as overdiagnosis,” Nikiforov says. “To my knowledge, this is the first time in the modern era a type of cancer is being reclassified as a non-cancer. I hope that it will set an example for other expert groups to address nomenclature of various cancer types that have indolent behavior to prevent inappropriate and costly treatment.”

In particular, a tumor type known as encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) has increased in incidence by an estimated two- to three-fold over the past 20 to 30 years and makes up 10 to 20 percent of all thyroid cancers diagnosed in Europe and North America. Although studies have shown EFVPTC is not dangerous, it is typically treated as aggressively as other types of thyroid cancer. At the recommendation of the National Cancer Institute, the panel sought to revise the terminology and to see if the word “cancer” could be dropped from its name.

As reported in JAMA Oncology, two dozen experienced pathologists from seven countries and four continents independently reviewed 268 tumor samples diagnosed as EFVPTC from 13 institutions....In a group of more than 100 noninvasive EFVPTCs, there were no recurrences or other manifestations of the disease at a median follow-up of 13 years. They decided to rename EFVPTC as “noninvasive follicular thyroid neoplasm with papillary-like nuclear features” or NIFTP. The new name cites key features to guide pathologists in diagnosis, but omits the word “cancer,” indicating that it need not be treated with radioiodine or other aggressive approaches.

“We determined that if NIFTP is carefully diagnosed, the tumor’s recurrence rate is extremely low, likely less than 1 percent within the first 15 years,” Nikiforov says. “The cost of treating thyroid cancer in 2013 was estimated to exceed $1.6 billion in the US. Not only does the reclassification eliminate the psychological impact of the diagnosis of ‘cancer,’ it reduces the likelihood of complications of total thyroid removal, and the overall cost of health care.”

Published on Leave a comment on Butter Is No Longer Taboo

This is huge. Decades long advice dietary advice to Americans was wrong. New research finds that the medical advice to replace saturated fat in the diet with vegetable oils rich with linoleic acid lowers cholesterol, but does not lead to a lower risk of death from coronary heart disease or other causes. It may even lead to increased rates of death from coronary heart disease, and cardiovascular disease (2013 study). Vegetable oils rich in linoleic acid are corn oil, sunflower oil, safflower oil, cottonseed oil, and soybean oil.

Other recent articles written on this topic have pointed out that research evidence opposing the prevailing medical view of what is "heart healthy" (low-fat foods, and substitute vegetable oil for butter) was suppressed for decades and the researchers ridiculed. In the past few years a number of other studies have found health benefits from whole fat foods (such as high-fat dairy foods) and not from low-fat or zero fat foods or vegetable oils. From Medical Xpress:

Researchers unearthed more evidence that replacing butter with vegetable oils does not decrease risk of heart disease

A research team led by scientists at the UNC School of Medicine and the National Institutes of Health has unearthed more evidence that casts doubt on the traditional "heart healthy" practice of replacing butter and other saturated fats with corn oil and other vegetable oils high in linoleic acid. The findings, reported today in the British Medical Journal, suggest that using vegetable oils high in linoleic acid might be worse than using butter when it comes to preventing heart disease, though more research needs to be done on that front.

This latest evidence comes from an analysis of previously unpublished data of a large controlled trial conducted in Minnesota nearly 50 years ago, as well as a broader analysis of published data from all similar trials of this dietary intervention. The analyses show that interventions using linoleic acid-rich oils failed to reduce heart disease and overall mortality even though the intervention reduced cholesterol levels. In the Minnesota study, participants who had greater reduction in serum cholesterol had higher rather than lower risk of death.

Along with corn oil, linoleic acid-rich oils include safflower oil, soybean oil, sunflower oil, and cottonseed oil. The belief that replacing saturated fats with vegetable oils improves heart health dates back to the 1960s, when studies began to show that this dietary switch lowered blood cholesterol levels. Since then, some studies, including epidemiological and animal studies, have suggested that this intervention also reduces heart attack risk and related mortality. In 2009, the American Heart Association reaffirmed its view that a diet low in saturated fat and moderately high (5-10 percent of daily calories) amounts of linoleic acid and other omega-6 unsaturated fatty acids probably benefits the heart.

However, randomized controlled trials - considered the gold standard for medical research - have never shown that linoleic acid-based dietary interventions reduce the risk of heart attacks or deaths. The largest of these trials, the Minnesota Coronary Experiment (MCE), was conducted by researchers at the University of Minnesota between 1968 and 1973. It enrolled 9,423 patients in six state mental hospitals and one state-run nursing home.....The investigators reported then that a switch to corn oil from butter and other saturated fats did lower cholesterol levels but made no difference in terms of heart attacks, deaths due to heart attacks, or overall deaths.....But they also found that.... the corn oil group had almost twice the number of heart attacks as the control group.

In a much-cited study published in 2013, however, Ramsden, Zamora and colleagues were able to recover unpublished data from a smaller trial, the Sydney Diet Heart Study, and there they also found more cases of heart disease and death among patients who received a linoleic acid intervention (safflower oil), compared to controls.

Why linoleic acid-containing oils would lower cholesterol but worsen or at least fail to reduce heart attack risk is a subject of ongoing research and lively debate. Some studies suggest that these oils can - under certain circumstances - cause inflammation, a known risk factor for heart disease. There is also some evidence they can promote atherosclerosis when the oils are chemically modified in a process called oxidation.

Published on Leave a comment on Fast Food and Exposure to Phthalates and BPA

There is increasing concern over phthalates and BPA and their effects on human health. It turns out that a big source of phthalates (which are known endocrine disruptors) in humans may be fast food.

A new study looked at fast food consumption by  8877 people and found that those who reported eating more of it in the past 24 hours had urinary phthalate levels as much as 40 percent higher than those who had eaten no fast food in the 24 hours before testing. In fact, it was a dose-response relationship between fast food intake and exposure to phthalates - the more fast food, the higher the level of phthalates.

The researchers did not find an association between total fast food consumption and BPA. However, they did find an  association between fast food meat intake and BPA,  which corresponds to the small but growing evidence from other studies suggesting that hamburgers may be a source of BPA exposure.

These findings are of concern to all of us because phthalates and bisphenol A (BPA) are widely used industrial chemicals that may adversely impact human health. Studies detect phthalates in 98% of the US population. They are found in a wide variety of products (including plastics and personal care products), and can enter the human body via ingestion, inhalation, and absorption through the skin.

How are we exposed to them in fast food? Phthalates and BPA are typically found in food packaging and some leaches out into food. Some can also leach into food from dairy product tubing, in lid gaskets, food preparation gloves, conveyor belts, etc. Thus we ingest phthalates and BPA when we consume processed or packaged food. Fast food may be an especially important source of exposure to phthalates and BPA because it is highly processed, packaged, and handled.

Studies have demonstrated that the phthalates DEHP and DiNP are endocrine (hormone) disruptors, and that human exposure has been associated with adverse reproductive, neurobehavioral, and respiratory health effects. BPA is also an endocrine disruptor. We are all being exposed numerous ways, but the lower the levels, the better.

The good news is that once in the body, phthalates and BPA are quickly metabolized and excreted in urine, with elimination half-lives of less than 24 hours. Thus you can quickly reduce the levels in your body. And you should try.

From Science Daily: Fast food may expose consumers to harmful chemicals called phthalates

People who reported consuming more fast food in a national survey were exposed to higher levels of potentially harmful chemicals known as phthalates, according to a study published by researchers at Milken Institute School of Public Health (Milken Institute SPH) at the George Washington University.

"People who ate the most fast food had phthalate levels that were as much as 40 percent higher," says lead author Ami Zota, ScD, MS, an assistant professor of environmental and occupational health at Milken Institute SPH. "Our findings raise concerns because phthalates have been linked to a number of serious health problems in children and adults."Phthalates belong to a class of industrial chemicals used to make food packaging materials, tubing for dairy products, and other items used in the production of fast food. Other research suggests these chemicals can leach out of plastic food packaging and can contaminate highly processed food.

Zota and her colleagues looked at data on 8,877 participants who had answered detailed questions about their diet in the past 24 hours, including consumption of fast food. These participants also had provided researchers with a urinary sample that could be tested for the breakdown products of two specific phthalates--DEHP and DiNP.

Zota and her colleagues found that the more fast food participants in the study ate the higher the exposure to phthalates. People in the study with the highest consumption of fast food had 23.8 percent higher levels of the breakdown product for DEHP in their urine sample. And those same fast food lovers had nearly 40 percent higher levels of DiNP metabolites in their urine compared to people who reported no fast food in the 24 hours prior to the testing. The researchers also discovered that grain and meat items were the most significant contributors to phthalate exposure. Zota says the grain category contained a wide variety of items including bread, cake, pizza, burritos, rice dishes and noodles.

In addition, the researchers also looked for exposure to another chemical found in plastic food packaging--Bisphenol A or BPA. Researchers also believe exposure to BPA can lead to health and behavior problems, especially for young children. This study found no association between total fast food intake and BPA. However, Zota and her colleagues found that people who ate fast food meat products had higher levels of BPA than people who reported no fast food consumption.

Published on Leave a comment on Eat More Fiber to Improve Your Gut Microbiome

Another article commenting that increasing the amount of dietary fiber eaten by people eating a typical Western diet (which is low in fiber) will improve their gut microbiome (community of microbes). Research is finding that the added dietary fiber is food (nutrition) for microbes in the gut, and eating additional fiber daily will help restore or increase bacterial diversity, which then should lead to health benefits. Note: Easy ways to increase dietary fiber are increasing intake of whole grains, legumes, nuts, seeds, fruits, and vegetables. Think of food writer Michael Pollan's advice: "Eat food. Not too much. Mostly plants."

Researchers feel that fiber intake needs to be increased to more than current dietary guidelines, and that beneficial effects to the microbiome starts to occur rapidly (within 2 weeks) of changing to a higher fiber diet. This post from January 21, 2016 discussed the Sonnenburg research on gut microbe depletion (from a low fiber diet), and this April 28, 2015 post discussed the O'Keefe research (changing the diet has big effect on colon cancer risk) - both studies are mentioned below. See the page Feeding Your Gut Microbes for more information. From Science Daily:

Can more fiber restore microbiome diversity?

Scientists are pushing to restore human health in Western countries by changing our diet to restore the microbial species lost over the evolution of Western diet. Researchers advocate for strategically increasing dietary fiber intake as one path forward in regaining microbial biodiversity.

Insufficient nutrients for our gut microbes have been linked to a loss of certain beneficial bacterial species in industrialized societies and are likely impacting our immunological and metabolic health, although more data is needed. For example, most Westerners consume half of the amount of dietary fiber recommended by dietary guidelines, which nutritionists refer to as the "fiber gap," which is a problem because dietary fiber is the primary source of nutrition (e.g., carbohydrates) accessible to gut bacteria in humans.

"The idea to boost fiber levels is not new," says Jens Walter of the University of Alberta, Canada. "However, depletion of the microbiome adds a new perspective to this low-fiber Western diet that we are currently eating." Earlier this year, Stanford University's Justin Sonnenburg found that mice fed a typical Western diet (high in fat and carbohydrates and low in fiber) transferred a lower diversity of beneficial microbial species to future generations. The re-introduction of the microbes' preferred fiber at that stage did not result in a return of some (good) species, indicating that extinctions had occurred in only a few generations.

Walter and co-author Edward Deehan, his PhD student, are concerned that a dramatic shift away from a diet similar to the one under which the human-microbiome symbiosis evolved is a key factor in the rise of non-communicable disorders like obesity. "There is a lot of epidemiological evidence that fiber is beneficial, and food products containing dietary fiber have FDA-approved health claims for both colon cancer and coronary heart disease. There is also quite a bit of clinical evidence (although it is less consistent)," Walter says. "The most pressing issue at the moment that neither consumption of fiber in society nor the doses used in clinical research are high enough."

People living in non-industrialized societies have an average intake of fiber that is much higher than the low norms of Western societies. The authors note the recent work from the Stephen J.D. O'Keefe lab in Nature Communications in which modern African-Americans were given a traditional South-African diet that contained 55 grams of daily dietary fiber and had improved markers for colon cancer within two weeks.

Published on Leave a comment on Coffee, Colorectal Cancer, and Miscarriage

Coffee consumption overall seems to be beneficial to health in various ways, such as lowering the risk of colorectal cancer. But there are times one should limit how much one drinks, such as during the  preconception period for both the male and female, and also during pregnancy, to lower the risk of miscarriage.

From Science Daily: Coffee consumption linked to decreased risk of colorectal cancer

Researchers have found that coffee consumption, including decaf, instant and espresso, decreases the risk of colorectal cancer. Moreover, these benefits increase the more coffee you drink. The study examined over 5,100 men and women who had been diagnosed with colorectal cancer within the past six months, along with an additional 4,000 men and women with no history of colorectal cancer to serve as a control group. Participants reported their daily consumption of boiled (espresso), instant, decaffeinated and filtered coffee, as well as their total consumption of other liquids.....

The data showed that even moderate coffee consumption, between one to two servings a day, was associated with a 26 percent reduction in the odds of developing colorectal cancer after adjusting for known risk factors. Moreover, the risk of developing colorectal cancer continued to decrease to up to 50 percent when participants drank more than 2.5 servings of coffee each day. The indication of decreased risk was seen across all types of coffee, both caffeinated and decaffeinated.

Coffee contains many elements that contribute to overall colorectal health and may explain the preventive properties. Caffeine and polyphenol can act as antioxidants, limiting the growth of potential colon cancer cells. Melanoidins generated during the roasting process have been hypothesized to encourage colon mobility. Diterpenes may prevent cancer by enhancing the body's defense against oxidative damage. "The levels of beneficial compounds per serving of coffee vary depending on the bean, roast and brewing method," said first author Stephanie Schmit, PhD, MPH. 

Colorectal cancer is the third most common cancer that is diagnosed in both men and women in the United States, with nearly five percent of men and just over four percent of women developing the disease over their lifetime. The American Cancer Society (ACS) estimates that in the United States, over 95,000 new cases of colon cancer and 39,000 new cases of rectal cancer will be diagnosed in this year alone.

Both males and females should limit coffee consumption in the preconception period to no more than 2 caffeinated drinks daily to lower the female's risk of miscarriage. From Medscape:

Even Men Need to Cut Back on Coffee Before Pregnancy

Women already know they need to cut back on coffee during pregnancy, if not sooner, to lower the risk of miscarriage. But a new study suggests the men in their lives need to limit caffeine too. Pregnant women who had more than two caffeinated drinks a day while trying to conceive had a 74% higher risk of miscarriage than their peers who drank less coffee, tea, soda and energy drinks, the study found.

When their husbands and boyfriends had more than two caffeinated drinks a day during the preconception phase, however, these pregnant women ended up with almost the same increased risk of miscarriage they would get from drinking coffee or soda themselves...."We did not find drinking one to two daily caffeinated beverages to increase the risk of miscarriage." Scientists aren't sure how caffeine contributes to miscarriage, but it's possible it affects egg or sperm production, implantation of the fertilized egg, or the ability of the embryo to grow in the uterus.

To assess how lifestyle choices may influence miscarriage risk, Louis and colleagues followed 344 couples in Texas and Michigan through the first seven weeks of pregnancy....Overall, 98 women, or 28%, experienced a miscarriage during the study, as reported March 24 in the journal Fertility and Sterility. Women 35 or older had nearly double the miscarriage risk of younger women, the study found. When women took daily multivitamins, their miscarriage risk was 55% lower than for their peers who didn't do this.

One surprise in the study is that researchers didn't find an increased miscarriage risk associated with smoking or alcohol, however. This doesn't mesh with previous research, noted Dr. Jeffrey Goldberg, a reproductive health researcher at Cleveland Clinic in Ohio who wasn't involved in the study. 

Published on Leave a comment on Vitamin D Level Linked to Cancer Risk

 A number of recent studies looked at vitamin D and various diseases. All showed benefits of higher vitamin D levels in the blood: lower rates of cancer incidence, improved heart function in those with heart failure, lower rates of leukemia incidence, lower rates of breast cancer, and less aggressive breast and prostate cancer. However, one study found no benefits to vitamin D supplementation during pregnancy and the child's asthma risk. Older studies found low levels of vitamin D linked to higher risk of premenopausal breast cancer, and also to thicker melanomas at diagnosis (the thinner the melanoma, the better the prognosis).

Everyone agrees that sunshine is an excellent source of vitamin D, but there is still disagreement over what are the best daily vitamin D supplement dosages, or even what are optimal levels of vitamin D in the blood (measured as serum 25-hydroxyvitamin D or 25(OH)D). In 2010, the Institute of Medicine (IOM) concluded that levels lower than 12 ng/ml represented a vitamin D deficiency and recommended a target of 20 ng/ml, which could be met in most healthy adults (ages 19 to 70) with 600 International Units of vitamin D each day. Since then most researchers have argued for higher blood serum levels: most agreeing that over 30 ng/ml is best, while some advocating 50 ng/ml or more. But even what's too high (and could cause problems) is debated. Many vitamin D supporters now advocate taking 800 to 1,000 IUs of vitamin D daily (some say up to 4000 IUs daily is OK). Remember to look for vitamin D3 supplements, not D2.

This study found that higher levels of vitamin D (measured as serum 25(OH)D) are better, with 25(OH)D concentrations of at least 40 ng/ml best to reduce cancer risk (all types of cancer). From Medical Xpress: Higher levels of vitamin D correspond to lower cancer risk, researchers say

Researchers at University of California, San Diego School of Medicine report that higher levels of vitamin D - specifically serum 25-hydroxyvitamin D - are associated with a correspondingly reduced risk of cancer. The findings are published in the April 6, online issue of PLOS ONE.

Garland and his late brother, Frank, made the first connection between vitamin D deficiency and some cancers in 1980 when they noted populations at higher latitudes (with less available sunlight) were more likely to be deficient in vitamin D, which is produced by the body through exposure to sunshine, and experience higher rates of colon cancer. Subsequent studies by the Garlands and others found vitamin D links to other cancers, such as breast, lung and bladder.

The new PLOS ONE study sought to determine what blood level of vitamin D was required to effectively reduce cancer risk....The only accurate measure of vitamin D levels in a person is a blood test....Cancer incidence declined with increased 25(OH)D. Women with 25(OH)D concentrations of 40 ng/ml or greater had a 67 percent lower risk of cancer than women with levels of 20 ng/ml or less.

Garland does not identify a singular, optimum daily intake of vitamin D or the manner of intake, which may be sunlight exposure, diet and/or supplementation. He said the current study simply clarifies that reduced cancer risk becomes measurable at 40 ng/ml, with additional benefit at higher levels. "These findings support an inverse association between 25(OH)D and risk of cancer," he said, "and highlight the importance for cancer prevention of achieving a vitamin D blood serum concentration above 20 ng/ml, the concentration recommended by the IOM for bone health."

From Science Daily: Vitamin D improves heart function, study finds

A daily dose of vitamin D3 improves heart function in people with chronic heart failure, a five-year research project has found. The study involved more than 160 patients who were already being treated for their heart failure using proven treatments including beta-blockers, ACE-inhibitors and pacemakers.

Participants were asked to take vitamin D3 or a dummy (placebo) tablet for one year. Those patients who took vitamin D3 experienced an improvement in heart function which was not seen in those who took a placebo....In the 80 patients who took Vitamin D3, the heart's pumping function improved from 26% to 34%. In the others, who took placebo, there was no change in cardiac function.

Disappointing results. From Medscape: Vitamin D Disappoints: Prenatal Supplementation and Childhood Asthma

Two recent clinical trials examined maternal supplementation with vitamin D and postpregnancy offspring outcomes for asthma and wheezing....However, with respect to preventing asthma in offspring, there is no clear evidence for vitamin D supplementation in pregnant women.

From PLOS ONE: Vitamin D Deficiency at Melanoma Diagnosis Is Associated with Higher Breslow Thickness

Vitamin D deficiency at the time of melanoma diagnosis is associated with thicker tumours that are likely to have a poorer prognosis. Ensuring vitamin D levels of 50 nmol/L or higher in this population could potentially result in 18% of melanomas having Breslow thickness of <0.75 mm rather than ≥0.75 mm.

Reported in 2013. From Medical Express: Low vitamin D levels linked to high risk of premenopausal breast cancer

A prospective study led by researchers from the University of California, San Diego School of Medicine has found that low serum vitamin D levels in the months preceding diagnosis may predict a high risk of premenopausal breast cancer. The study of blood levels of 1,200 healthy women found that women whose serum vitamin D level was low during the three-month period just before diagnosis had approximately three times the risk of breast cancer as women in the highest vitamin D group. 

A 2011 meta-analysis by Garland and colleagues estimated that a serum level of 50 ng/ml is associated with 50 percent lower risk of breast cancer. While there are some variations in absorption, those who consume 4000 IU per day of vitamin D from food or a supplement normally would reach a serum level of 50 ng/ml.