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First researchers talked about second-hand cigarette smoke, but now there is a concern with third-hand smoke. From Science Daily:

Major 'third-hand smoke' compound causes DNA damage and potentially cancer

Leftover cigarette smoke that clings to walls and furniture is a smelly nuisance, but now research suggests that it could pose a far more serious threat, especially to young children who put toys and other smoke-affected items into their mouths. Scientists reported today that one compound from this "third-hand smoke," which forms when second-hand smoke reacts with indoor air, damages DNA and clings to it in a way that could potentially cause cancer.

Bo Hang, Ph.D., who presented the research, said that although the idea of third-hand smoke made its debut in research circles just a few years ago in 2009, evidence already strongly suggests it could threaten human health.

"The best argument for instituting a ban on smoking indoors is actually third-hand smoke," said Hang, a scientist at Lawrence Berkeley National Laboratory (LBNL).

Researchers have found that many of the more than 4,000 compounds in second-hand smoke, which wafts through the air as a cigarette is smoked, can linger indoors long after a cigarette is stubbed out. Based on studies led by Hugo Destaillats, also at LBNL, these substances can go on to react with indoor pollutants such as ozone and nitrous acid, creating brand-new compounds, some of which may be carcinogenic.

One of those compounds goes by the acronym NNA. Hang's research has shown that NNA, a tobacco-specific nitrosamine, locks onto DNA to form a bulky adduct (a piece of DNA bound to a cancer-causing chemical), as well as other adducts, in lab test tubes. Other large compounds that attach to DNA tend to cause genetic mutations. NNA also breaks the DNA about as often as a related compound called NNK, which is a well-studied byproduct of nicotine and a known potent carcinogen. This kind of DNA damage can lead to uncontrolled cell growth and the formation of cancerous tumors.

The biggest potential health risk is for babies and toddlers, he noted. As they crawl and put their hands or toys in their mouths, they could touch, swallow or inhale compounds from third-hand smoke. Their small size and early developmental stage make them more vulnerable than adults to the effects of environmental hazards.

Although many public places prohibit smoking, Hang noted that people can still smoke in most rental apartments and private residences -- and smoking remains a huge public health issue. In 2011, nearly 44 million American adults reported smoking cigarettes, which ranks as the leading cause of preventable death in this country. And 34 million people smoke every day, according to data from the Centers for Disease Control & Prevention.

So far, the best way to get rid of third-hand smoke is by removing affected items, such as sofas and carpeting, as well as sealing and repainting walls, and sometimes even replacing contaminated wallboard, he explained. Replacing furniture can be pricey, but Hang said vacuuming and washing clothes, curtains and bedding can also help.

Article about the growing body of research supporting exercise in the treatment of depression. From The Atlantic:

For Depression, Prescribing Exercise Before Medication

Depression is the most common mental illness—affecting a staggering 25 percent of Americans—but a growing body of research suggests that one of its best cures is cheap and ubiquitous. In 1999, a randomized controlled trial showed that depressed adults who took part in aerobic exercise improved as much as those treated with Zoloft. A 2006 meta-analysis of 11 studies bolstered those findings and recommended that physicians counsel their depressed patients to try it. A 2011 study took this conclusion even further: It looked at 127 depressed people who hadn’t experienced relief from SSRIs, a common type of antidepressant, and found that exercise led 30 percent of them into remission—a result that was as good as, or better than, drugs alone.

Though we don’t know exactly how any antidepressant works, we think exercise combats depression by enhancing endorphins: natural chemicals that act like morphine and other painkillers. There’s also a theory that aerobic activity boosts norepinephrine, a neurotransmitter that plays a role in mood. And like antidepressants, exercise helps the brain grow new neurons.

But this powerful, non-drug treatment hasn’t yet become a mainstream remedy. In a 2009 study, only 40 percent of patients reported being counseled to try exercise at their last physician visit.

Instead, Americans are awash in pills. The use of antidepressants has increased 400 percent between 1988 and 2008. They’re now one of the three most-prescribed categories of drugs, coming in right after painkillers and cholesterol medications.

After 15 years of research on the depression-relieving effects of exercise, why are there still so many people on pills? The answer speaks volumes about our mental-health infrastructure and physician reimbursement system, as well as about how difficult it remains to decipher the nature of depression and what patients want from their doctors.

When it comes to non-drug remedies for depression, exercise is actually just one of several promising options. Over the past few months, research has shown that other common lifestyle adjustments, like meditating or getting more sleep, might also relieve symptoms. Therapy has been shown to work just as well as SSRIs and other medications. In fact, a major JAMA study a few years ago cast doubt on the effectiveness of antidepressants in general, finding that the drugs don't function any better than placebo pills for people with mild or moderate depression.

The half-dozen psychiatrists I interviewed said they’ve started to incorporate non-drug treatments into their plans for depressed patients. But they said they’re only able to do that because they don’t accept insurance. (One of the doctors works for a college system and only sees students.)

That’s because insurers still largely reimburse psychiatrists, like all other doctors, for each appointment—whatever that appointment may entail—rather than for curing a given patient. It takes less time to write a prescription for Zoloft than it does to tease out a patient’s options for sleeping better and breaking a sweat. Fewer moments spent mapping out jogging routes or sleep schedules means being able to squeeze in more patients for medications each day.

Another study discussing how physical activity reduces the risk of breast cancer for women of all ages and sizes. From Science Daily:

Regular physical activity reduces breast cancer risk irrespective of age

Practicing sport for more than an hour day reduces the risk of contracting breast cancer, and this applies to women of any age and any weight, and also unaffected by geographical location, according to research presented to the 9th European Breast Cancer Conference (EBCC-9). Compared with the least active women, those with the highest level of physical activity reduced their risk of breast cancer by 12%, researchers say.

Professor Mathieu Boniol, Research Director at the International Prevention Research Institute, Lyon, France, recently reported the results of a meta-analysis of 37 studies published between 1987 and 2013, representing over four million women. "These are all the studies looking at the relationship between physical exercise and breast cancer risk that have been published to date, so we are confident that the results of our analysis are robust," he said.

Although the results varied according to tumour type, the overall message was encouraging, the researchers say. However, in women taking hormone replacement therapy (HRT), the protective effect of exercise seemed to be cancelled out. But increased awareness of the side effects of HRT means that its use is decreasing in a number of countries, and this means that the beneficial effects of activity will most likely grow in the years to come. 

Physical activity is known to have a protective role in other cancers, as well as in disorders such as cardiovascular disease. Although the mechanisms for its effect are unclear, the results are largely independent of body mass index (BMI), so the effect must be due to more than weight control. And the age at which sporting activity starts also appears to be immaterial; the researchers found no indication that breast cancer risk would decrease only when physical activity started at a young age.

"Adding breast cancer, including its aggressive types, to the list of diseases that can be prevented by physical activity should encourage the development of cities that foster sport by becoming bike and walk-friendly, the creation of new sports facilities, and the promotion of exercise through education campaigns," said Prof Boniol. 

The United Nations has proclaimed today as the International Day of Happiness. In that spirit is the following article. From Science Daily:

Precise reason for health benefits of dark chocolate: Thank hungry gut microbes

The health benefits of eating dark chocolate have been extolled for centuries, but the exact reason has remained a mystery -- until now. Researchers have just reported that certain bacteria in the stomach gobble the chocolate and ferment it into anti-inflammatory compounds that are good for the heart.

"We found that there are two kinds of microbes in the gut: the 'good' ones and the 'bad' ones," explained Maria Moore, an undergraduate student and one of the study's researchers.

"The good microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate," she said. "When you eat dark chocolate, they grow and ferment it, producing compounds that are anti-inflammatory." The other bacteria in the gut are associated with inflammation and can cause gas, bloating, diarrhea and constipation. These include some Clostridia and some E. coli.

"When these compounds are absorbed by the body, they lessen the inflammation of cardiovascular tissue, reducing the long-term risk of stroke," said John Finley, Ph.D., who led the work. He said that this study is the first to look at the effects of dark chocolate on the various types of bacteria in the stomach. The researchers are with Louisiana State University.

The team tested three cocoa powders using a model digestive tract, composed of a series of modified test tubes, to simulate normal digestion. They then subjected the non-digestible materials to anaerobic fermentation using human fecal bacteria, according to Finley.

He explained that cocoa powder, an ingredient in chocolate, contains several polyphenolic, or antioxidant, compounds such as catechin and epicatechin, and a small amount of dietary fiber. Both components are poorly digested and absorbed, but when they reach the colon, the desirable microbes take over. "In our study we found that the fiber is fermented and the large polyphenolic polymers are metabolized to smaller molecules, which are more easily absorbed. These smaller polymers exhibit anti-inflammatory activity," he said.

Finley also noted that combining the fiber in cocoa with prebiotics is likely to improve a person's overall health and help convert polyphenolics in the stomach into anti-inflammatory compounds. "When you ingest prebiotics, the beneficial gut microbial population increases and outcompetes any undesirable microbes in the gut, like those that cause stomach problems," he added. Prebiotics are carbohydrates found in foods like raw garlic and cooked whole wheat flour that humans can't digest but that good bacteria like to eat. This food for your gut's helpful inhabitants also comes in dietary supplements.

Over and over research shows that moving your body is a key to good health. And to build muscles one has to move a lot. From Science Daily:

Older adults: Build muscle and you'll live longer

New UCLA research suggests that the more muscle mass older Americans have, the less likely they are to die prematurely. The findings add to the growing evidence that overall body composition - and not the widely used body mass index, or BMI -- is a better predictor of all-cause mortality.

The researchers analyzed data collected by the National Health and Nutrition Examination Survey (NHANES) III, conducted between 1988 and 1994. They focused on a group of 3,659 individuals that included men who were 55 or older and women who were 65 or older at the time of the survey. The authors then determined how many of those individuals had died from natural causes based on a follow-up survey done in 2004.

The body composition of the study subjects was measured using bioelectrical impedance, which involves running an electrical current through the body. Muscle allows the current to pass more easily than fat does, due to muscle's water content. In this way, the researchers could determine a muscle mass index -- the amount of muscle relative to height -- similar to a body mass index. They looked at how this muscle mass index was related to the risk of death. They found that all-cause mortality was significantly lower in the fourth quartile of muscle mass index compared with the first quartile.

"In other words, the greater your muscle mass, the lower your risk of death," said Dr. Arun Karlamangla, an associate professor in the geriatrics division at the Geffen School and the study's co-author. "Thus, rather than worrying about weight or body mass index, we should be trying to maximize and maintain muscle mass."

BPA is in many consumer products, but research is finding more and more problems with it. The findings of these two studies may motivate people to try to lower their exposure to plastics and BPA. From Newsweek:

BPA Levels Higher in Men With Prostate Cancer: Study

Bisphenol-A is everywhere. If you are reading this in the United States, there is a greater-than-90 percent chance you have BPA in your system, according to the Centers for Disease Control. The chemical is nearly ubiquitous: it is all over your receipts and soup cans, and it gives plastic bottles useful properties like flexibility and durability. It also mimics human estrogen in the body, and studies have linked it to breast cancer, diabetes, obesity, and hormone abnormalities in children, though what doses are dangerous is a matter of debate.

Now, for the first time, scientists are adding prostate cancer to the list of possible health problems from exposure.

Prostate cancer is the second most prevalent form of cancer among men, afflicting one in six, mostly later in life. A new study published Monday in the journal Plos One found that men with prostate cancer have BPA in their urine at levels 2- to 4-fold higher than cancer-free men. Aging is the best-known risk for prostate cancer, which makes the study’s findings particularly salient: BPA concentrations were especially high in prostate cancer patients under the age of 40, when aging is less of a contributing factor to the development of prostate cancer.

From Science Daily:

BPA linked to breast cancer tumor growth

UT Arlington biochemists say their newly published study brings researchers a step closer to understanding how the commonly used synthetic compound bisphenol-A, or BPA, may promote breast cancer growth.

Subhrangsu Mandal, associate professor of chemistry/biochemistry, and Arunoday Bhan, a PhD student in Mandal's lab, looked at a molecule called RNA HOTAIR. HOTAIR is an abbreviation for long, non-coding RNA, a part of DNA in humans and other vertebrates. HOTAIR does not produce a protein on its own but, when it is being expressed or functioning, it can suppress genes that would normally slow tumor growth or cause cancer cell death.

High levels of HOTAIR expression have been linked to breast tumors, pancreatic and colorectal cancers, sarcoma and others.

UT Arlington researchers found that when breast cancer and mammary gland cells were exposed to BPA in lab tests, the BPA worked together with naturally present molecules, including estrogen, to create abnormal amounts of HOTAIR expression. 

"We were surprised to find that BPA not only increased HOTAIR in tumor cells but also in normal breast tissue," said Bhan. He said further research is needed, but the results beg the question -- are BPA and HOTAIR involved in tumor genesis in addition to tumor growth?

BPA has been widely used in plastics, such as food storage containers, the lining of canned goods and, until recently, baby bottles. It belongs to a class of endocrine disrupting chemicals, or EDCs, which have been shown to mimic natural hormones. These endocrine disruptors interfere with hormone regulation and proper function of human cells, glands and tissue. 

Two related studies showing the importance of the intestinal bacterial community for health and preventing diseases. Both also discuss how antibiotics disrupt the gut microbial community. From Science Daily:

Microbes help to battle infection: Gut microbes help develop immune cells, study finds

The human relationship with microbial life is complicated. Although there are types of bacteria that can make us sick, Caltech professor of biology and biological engineering Sarkis Mazmanian and his team are most interested in the thousands of other bacteria -- many already living inside our bodies -- that actually keep us healthy. Now, he and his team have found that these good bugs might also prepare the immune cells in our blood to fight infections from harmful bacteria.

In the recent study, published on March 12 in the journal Cell Host & Microbe, the researchers found that beneficial gut bacteria were necessary for the development of innate immune cells -- specialized types of white blood cells that serve as the body's first line of defense against invading pathogens.

In addition to circulating in the blood, reserve stores of immune cells are also kept in the spleen and in the bone marrow. When the researchers looked at the immune cell populations in these areas in so-called germ-free mice, born without gut bacteria, and in healthy mice with a normal population of microbes in the gut, they found that germ-free mice had fewer immune cells -- specifically macrophages, monocytes, and neutrophils -- than healthy mice. Germ-free mice also had fewer granulocyte and monocyte progenitor cells, stemlike cells that can eventually differentiate into a few types of mature immune cells

Khosravi and his colleagues next wanted to see if the reduction in immune cells in the blood would make the germ-free mice less able to fight off an infection by the harmful bacterium Listeria monocytogenes -- a well-studied human pathogen often used to study immune responses in mice. While the healthy mice were able to bounce back after being injected with Listeria, the infection was fatal to germ-free mice. When gut microbes that would normally be present were introduced into germ-free mice, the immune cell population increased and the mice were able to survive the Listeria infection.

The researchers also gave injections of Listeria to healthy mice after those mice were dosed with broad-spectrum antibiotics that killed off both harmful and beneficial bacteria. Interestingly, these mice also had trouble fighting the Listeria infection. "We didn't look at clinical data in this study, but we hypothesize that this might also happen in the clinic," says Mazmanian. "For example, when patients are put on antibiotics for something like hip surgery, are you damaging their gut microbe population and making them more susceptible to an infection that had nothing to do with their hip surgery?"

More importantly, the research also suggests that a healthy population of gut microbes can actually provide a preventative alternative to antibiotics, Khosravi says. 

From Science Daily:

Large study identifies exact gut bacteria involved in Crohn's disease

While the causes of Crohn's disease are not well understood, recent research indicates an important role for an abnormal immune response to the microbes that live in the gut. In the largest study of its kind, researchers have now identified specific bacteria that are abnormally increased or decreased when Crohn's disease develops. The findings, which appear in the March 12 issue of the Cell Press journal Cell Host & Microbe, suggest which microbial metabolites could be targeted to treat patients with this chronic and currently incurable inflammatory bowel disease.

Twenty-eight gastroenterology centers across North America have been working together to uncover how microbes contribute to the inflammatory cascade of Crohn's disease. Researchers took biopsies from 447 individuals with new-onset Crohn's disease and 221 nonaffected individuals at multiple locations along the gastrointestinal tract and then looked for differences between the two groups. They also validated their methods in additional individuals, resulting in a total of 1,742 samples from pediatric and adult patients with either new-onset or established disease.

The team found that microbial balance was disrupted in patients with Crohn's disease, with beneficial microbes missing and pathological ones flourishing. Having more of the disease-associated organisms correlated with increasing clinical disease activity. 

When the researchers analyzed the effects of antibiotics, which are sometimes used to treat Crohn's disease symptoms prior to diagnosis, they found that antibiotic usage in children with Crohn's disease could be counterproductive because it causes a loss of good microbes and an increase in pathological ones.

Head lice is a big, big concern for parents of young school age children. From Science Daily:

Ordinary conditioner removes head lice eggs as effectively as special products

Eggs from head lice, also called nits, are incredibly difficult to remove. Female lice lay eggs directly onto strands of hair, and they cement them in place with a glue-like substance, making them hard to get rid of. In fact, the eggs are glued down so strongly that they will stay in place even after hair has been treated with pediculicides -- substances used to kill lice.

Some shampoos and conditioners that contain chemicals or special oils are marketed as nit-removal products. However, new research just published in the Journal of Medical Entomology shows that ordinary hair conditioner is just as effective.

In an article called "Efficacy of Products to Remove Eggs of Pediculus humanus capitis (Phthiraptera: Pediculidae) From the Human Hair," scientists from Belgium gathered 605 hairs from six different children. Each hair had a single nit attached to it. Approximately 14% of the eggshells contained a dead egg, whereas the rest were empty.

They then tried to remove the eggs and tested the amount of force needed to do so. They found that nits on the hairs that were left completely untreated were the most difficult to remove. Eggs on hairs that had been soaked in deionized water were much easier to remove, as were the eggs on hairs that had been treated with ordinary hair conditioner and with products specifically marketed for the purpose of nit removal.

However, they found no significant differences between the ordinary conditioners and the special nit-removal products. In all cases, less force was required to remove the nits after the hair had been treated, but the effectiveness of the products was essentially the same.

The authors hypothesize that the deionized water was effective because it acts as a lubricant, so less friction is needed to remove the nits from the hairs. The same goes for the conditioners.

From Science Daily:

Dropped your toast? Five-second food rule exists, new research suggests

Food picked up just a few seconds after being dropped is less likely to contain bacteria than if it is left for longer periods of time, according to the findings of research carried out at Aston University's School of Life and Health Sciences.

The findings suggest there may be some scientific basis to the '5 second rule' -- the urban myth about it being fine to eat food that has only had contact with the floor for five seconds or less. Although people have long followed the 5 second rule, until now it was unclear whether it actually helped.

The study, undertaken by final year Biology students and led by Anthony Hilton, Professor of Microbiology at Aston University, monitored the transfer of the common bacteria Escherichia coli (E. coli) and Staphylococcus aureus from a variety of indoor floor types (carpet, laminate and tiled surfaces) to toast, pasta, biscuit and a sticky sweet when contact was made from 3 to 30 seconds.

The results showed that:  - Time is a significant factor in the transfer of bacteria from a floor surface to a piece of food; and  - The type of flooring the food has been dropped on has an effect, with bacteria least likely to transfer from carpeted surfaces and most likely to transfer from laminate or tiled surfaces to moist foods making contact for more than 5 seconds.

Professor Hilton said: "Consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at the time; however the findings of this study will bring some light relief to those who have been employing the five-second rule for years, despite a general consensus that it is purely a myth. We have found evidence that transfer from indoor flooring surfaces is incredibly poor with carpet actually posing the lowest risk of bacterial transfer onto dropped food.

From Science Daily:

Meat and cheese may be as bad for you as smoking

That chicken wing you're eating could be as deadly as a cigarette. In a new study that tracked a large sample of adults for nearly two decades, researchers have found that eating a diet rich in animal proteins during middle age makes you four times more likely to die of cancer than someone with a low-protein diet -- a mortality risk factor comparable to smoking.

"There's a misconception that because we all eat, understanding nutrition is simple. But the question is not whether a certain diet allows you to do well for three days, but can it help you survive to be 100?" said corresponding author Valter Longo, the Edna M. Jones Professor of Biogerontology at the USC Davis School of Gerontology and director of the USC Longevity Institute.

Not only is excessive protein consumption linked to a dramatic rise in cancer mortality, but middle-aged people who eat lots of proteins from animal sources -- including meat, milk and cheese -- are also more susceptible to early death in general, reveals the study to be published March 4 in Cell Metabolism. Protein-lovers were 74 percent more likely to die of any cause within the study period than their more low-protein counterparts. They were also several times more likely to die of diabetes.

But how much protein we should eat has long been a controversial topic -- muddled by the popularity of protein-heavy diets such as Paleo and Atkins. Before this study, researchers had never shown a definitive correlation between high protein consumption and mortality risk.

Rather than look at adulthood as one monolithic phase of life, as other researchers have done, the latest study considers how biology changes as we age, and how decisions in middle life may play out across the human lifespan.

In other words, what's good for you at one age may be damaging at another. Protein controls the growth hormone IGF-I, which helps our bodies grow but has been linked to cancer susceptibility. Levels of IGF-I drop off dramatically after age 65, leading to potential frailty and muscle loss. The study shows that while high protein intake during middle age is very harmful, it is protective for older adults: those over 65 who ate a moderate- or high-protein diet were less susceptible to disease.

"The research shows that a low-protein diet in middle age is useful for preventing cancer and overall mortality, through a process that involves regulating IGF-I and possibly insulin levels," said co-author Eileen Crimmins, the AARP Chair in Gerontology at USC. "However, we also propose that at older ages, it may be important to avoid a low-protein diet to allow the maintenance of healthy weight and protection from frailty."

Crucially, the researchers found that plant-based proteins, such as those from beans, did not seem to have the same mortality effects as animal proteins. Rates of cancer and death also did not seem to be affected by controlling for carbohydrate or fat consumption, suggesting that animal protein is the main culprit.

People who ate a moderate amount of protein were still three times more likely to die of cancer than those who ate a low-protein diet in middle age, the study shows. Overall, even the small change of decreasing protein intake from moderate levels to low levels reduced likelihood of early death by 21 percent.