Skip to content

Once again a study finds that pesticide exposure is linked to an adverse health effect - that pesticide exposure in the home during pregnancy and early childhood is linked to an elevated risk of brain tumor in the child. Other studies have also found that pesticides used in the home are associated with a higher risk of childhood cancers.

This is because pesticides do cross the placental barrier, as the study researchers point out: "There is evidence that pesticides cross the fetal-placental barrier since residues of some insecticides have been found in umbilical cord blood, neonatal hair, and meconium following maternal exposure during pregnancy." Also, the International Agency for Research on Cancer (IARC) has classified "more than twenty pesticide chemical compounds as potential human carcinogens".

The following are examples (but there are more) of other studies finding pesticide and childhood cancer links: A meta-analysis published in 2015 in Pediatrics by researchers at Harvard University found that children exposed to indoor insecticides (also herbicides) have a higher risk of certain childhood cancers, specifically leukemia, lymphomas, and brain tumors. A 2013 study published in Cancer Causes and Control found that professional pest control applications in the home within a year of conception and during pregnancy was associated with a higher risk of childhood brain tumors. A review of studies published in 2010 found that pesticide exposure during pregnancy and childhood increased the risk of childhood leukemia.

The good news is that there are alternatives to exposing fetuses and children to toxic pesticides at home - by using alternative ways of dealing with pests, such as least toxic Integrated Pest Management (IPM) or organic methods. That means doing other things (such as sealing or caulking holes, putting out traps and baits, vacuuming), a focus on least toxic methods and on prevention (here and here), rather than routinely applying toxic pesticides. If needed, least toxic pesticides include boric acid and vinegar. Other sources of pesticide exposure for pregnant women and children are foods and exposure in settings outside the home - perhaps even a friend's yard. By the way, pesticide exposure for everyone is linked to a higher risk of health problems, not just pregnant women and children.

From Science Daily: Pesticide use during pregnancy linked to increased risk of childhood brain tumors

Previous epidemiological studies have suggested that exposure to pesticides during pregnancy may have a possible role in the development of childhood brain tumors. In a new International Journal of Cancer analysis, researchers found a link between maternal residential pesticide use -- particularly insecticides -- and the risk of childhood brain tumorsThe analysis included 437 malignant childhood brain tumor cases and 3102 controls from two French studies. Pesticide use was associated with a 1.4-times increased risk of childhood brain tumors.

The investigators noted that many pesticide compounds are classified as probable carcinogens, and there is evidence that some insecticides can pass through the feto-placental barrier. "Although such retrospective studies cannot identify specific chemicals used or quantify the exposure, our findings add another reason to advise mothers to limit their exposure to pesticides around the time of pregnancy," said Nicolas Vidart d'Egurbide Bagazgoïtia, lead author of the study. [Original study.]

OK, this study was done in mice, but it's the kind of study results that everyone hopes (and thinks) is also true for humans. So drink a nice cuppa black tea and think about how you're increasing bacteria in the gut associated with weight loss.

Black tea (as well as green tea) has polyphenols that stimulate the growth of gut bacterium and the formation of short-chain fatty acids. By the way, the mice were given decaffeinated tea extracts, so theoretically both decaf and caffeinated tea should have benefits. The big question though is - will drinking black tea daily actually result in weight loss? From Medical Xpress:

Black tea may help with weight loss, too

UCLA researchers have demonstrated for the first time that black tea may promote weight loss and other health benefits by changing bacteria in the gut. In a study of mice, the scientists showed that black tea alters energy metabolism in the liver by changing gut metabolites. The research is published in the European Journal of Nutrition. The study found that both black and green tea changed the ratio of intestinal bacteria in the animals: The percentage of bacteria associated with obesity decreased, while bacteria associated with lean body mass increased.

Previous studies indicated that chemicals in green tea called polyphenols are absorbed and alter the energy metabolism in the liver. The new findings show that black tea polyphenols, which are too large to be absorbed in the small intestine, stimulate the growth of gut bacterium and the formation of short-chain fatty acids, a type of bacterial metabolites that has been shown to alter the energy metabolism in the liver.

The researchers also collected samples from the mice's large intestines (to measure bacteria content) and liver tissues (to measure fat deposits). In the mice that consumed either type of tea extract, there was less of the type of bacteria associated with obesity and more of the bacteria associated with lean body mass. However, only the mice that consumed black tea extract had an increase in a type of bacteria called Pseudobutyrivibrio, which could help explain the difference between how black tea and green tea change energy metabolism.

The new study also concluded that both green tea and black tea have different effects on liver metabolism. According to Henning, the molecules in green tea are smaller and can more readily be absorbed into the body and reach the liver directly, while black tea molecules are larger and stay in the intestine rather than being absorbed. When black tea molecules stay in the intestinal tract, they enhance the growth of beneficial bacteria and the formation of microbial metabolites involved in the regulation of energy metabolism. [Original study.]

A newly published study suggests that exercising an hour or more per week could lower the incidence of depression. The study followed 33,000 adults in Norway  for 11 years, and found that an hour or more of weekly exercise was associated with 12% fewer cases of developing depression. But note that it didn't prevent anxiety. Interestingly, the researchers found that "regular leisure-time exercise of any intensity" had these positive effects - it doesn't have to be aerobic or incredibly strenuous exercise. Exercise is associated with a number of biological changes that could have an impact on mental health. From Science Daily:

One hour of exercise a week can prevent depression

A landmark study led by the Black Dog Institute has revealed that regular exercise of any intensity can prevent future depression -- and just one hour can help. Published in the American Journal of Psychiatry, the results show even small amounts of exercise can protect against depression, with mental health benefits seen regardless of age or gender.

In the largest and most extensive study of its kind, the analysis involved 33,908 Norwegian adults who had their levels of exercise and symptoms of depression and anxiety monitored over 11 years. The international research team found that 12 percent of cases of depression could have been prevented if participants undertook just one hour of physical activity each week.

A healthy cohort of participants was asked at baseline to report the frequency of exercise they participated in and at what intensity: without becoming breathless or sweating, becoming breathless and sweating, or exhausting themselves. At follow-up stage, they completed a self-report questionnaire (the Hospital Anxiety and Depression Scale) to indicate any emerging anxiety or depression.

Results showed that people who reported doing no exercise at all at baseline had a 44% increased chance of developing depression compared to those who were exercising one to two hours a week. However, these benefits did not carry through to protecting against anxiety, with no association identified between level and intensity of exercise and the chances of developing the disorder. [Original article.]

Is frequent sauna bathing beneficial? That's what one study suggests. When the study started all 1621 men (aged 42 to 60) had normal blood pressure and none had been diagnosed with hypertension, and the follow-up was about 22 years later. The study took place in Finland, where sauna bathing is an important part of the culture - for all men, from all walks of life. The study found that frequent sauna bathing lowered the risk of developing hypertension - 46% when comparing men who sauna bathed once a week vs those who sauna bathed 4 to 7 times a week.

How could sauna bathing have these effects? There are several possibilities, but one is that sauna bathing produces "acute vasodilation" of the blood vessels, which leads to a significant drop in blood pressure. The temperature in the sauna is usually from 80 °C to 100 °C (176 to 212 degrees Fahrenheit), and the average sauna session (in this study) lasted an average of 14.4 minutes. From Science Daily:

Frequent sauna bathing keeps blood pressure in check

Frequent sauna bathing reduces the risk of elevated blood pressure, according to an extensive follow-up population-based study carried out at the University of Eastern Finland. The risk of developing elevated blood pressure was nearly 50% lower among men who had a sauna 4-7 times a week compared to men who had a sauna only once a weekThe same researchers have previously shown that frequent sauna bathing reduces the risk of sudden cardiac death, and cardiovascular and all-cause mortality. Elevated blood pressure is documented to be one of the most important risk factors of cardiovascular diseases.

The Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) involved 1,621 middle-aged men living in the eastern part of Finland. Study participants without elevated blood pressure of over 140/90 mmHg or with diagnosed hypertension at the study baseline were included in this long-term follow-up study. Based on their sauna bathing habits, men were divided into three sauna frequency groups: those taking a sauna once a week, 2-3 times a week, or 4-7 times a week. During an average follow-up of 22 years, 15.5% of the men developed clinically defined hypertension. The risk of hypertension was 24% decreased among men with a sauna frequency of 2-3 times a week, and 46% lowered among men who had a sauna 4-7 times a week.

Sauna bathing may decrease systemic blood pressure through different biological mechanisms. During sauna bathing, the body temperature may rise up to 2 °C degrees, causing vessels vasodilation. Regular sauna bathing improves endothelial function, i.e. the function of the inside layer of blood vessels, which has beneficial effects on systemic blood pressure. Sweating, in turn, removes fluid from the body, which is a contributing factor to decreased blood pressure levels. Additionally, sauna bathing may also lower systemic blood pressure due to overall relaxation of the body and mind.

[NOTE: Above photo is of interior of a modern Finnish sauna. Credit: Wikipedia]

Two studies looked at manganese and found that high levels are associated with problems. Manganese is an essential trace mineral necessary for development, metabolism, the antioxidant system, and for normal brain and nerve function. Getting manganese through foods (e.g. nuts, seeds, whole grains) is beneficial, but ingesting large amounts through supplements or being exposed to high levels in some other way (such as polluted air) is associated with various health problems. 

The first study found that high manganese in the diet (in mice) was associated with an increased risk of staph (Staphylococcus aureus) heart infection. The second study (done in East Liverpool, Ohio) found that exposure to consistently high levels of manganese in the air is associated with lower IQ scores in children. And why did the air the children were breathing have high levels of manganese? Because there was a nearby hazardous waste incinerator and a facility that handles manganese.

From Medical Xpress: Excess dietary manganese promotes staph heart infection

Too much dietary manganese—an essential trace mineral found in leafy green vegetables, fruits and nuts—promotes infection of the heart by the bacterium Staphylococcus aureus ("staph"). The findings, reported this week in the journal Cell Host & Microbe, add to the evidence that diet modifies risk for infection. The discovery also suggests that people who have excess levels of tissue manganese, including those who consume dietary supplements with high concentrations of the metal, may be at increased risk for staph infection of the heart.

Skaar and his colleagues studied the impact of dietary manganese on staph infection in a mouse model. Most of the mice that consumed a high manganese diet—about three times more manganese than normal—died after infection with staph. The investigators discovered that the animals on the high manganese diet were particularly susceptible to staph infection of the heart, which was a surprise, said Skaar, who is also professor of Pathology, Microbiology and Immunology.... The researchers found that excess manganese inactivates a key line of defense against pathogens: the innate immune system's reactive oxygen burst. 

Staph is the leading cause of bacterial endocarditis (infection of the inner lining of the heart chamber and heart valves) and the second most frequent cause of bloodstream infections. Interestingly, some populations of people have both increased risk for staph infections, particularly endocarditis, and higher than normal levels of tissue manganese, Skaar noted. These populations include intravenous drug users, patients with chronic liver disease and patients on long-term intravenous diets.

From Medical Xpress: Higher manganese levels in children correlate with lower IQ scores, study finds

A study led by environmental health researchers at the University of Cincinnati (UC) College of Medicine finds that children in East Liverpool, Ohio with higher levels of Manganese (Mn) had lower IQ scoresThe study analyzed blood and hair samples of 106 children 7 to 9 years of age from East Liverpool and surrounding communities, who enrolled in the study from March 2013 to June 2014.... The study found that increased Mn in hair samples was significantly associated with declines in full-scale IQ, processing speed and working memory.

Manganese is an element generally found in combination with iron and many minerals. It plays a vital role in brain growth and development, but excessive exposure can result in neurotoxicity. Manganese is used widely in the production of steel, alloys, batteries and fertilizers and is added to unleaded gasolineLocated in northeast Ohio along the Ohio River, East Liverpool has a demonstrated history of environmental exposures, with EPA records showing elevated levels of manganese concentrations since 2000.... all  [air] monitors in East Liverpool had "consistently exceeded" health-based guidelines set by the agency.

 Manganese (Mn). Credit: Wikipedia

Image result for chlamydia wikipediaThe annual Sexually Transmitted Disease Surveillance Report was released today by the US Centers for Disease Control and Prevention (CDC) and the news wasn't good. More than two million cases of chlamydia, gonorrhea and syphilis were reported in the United States in 2016 - the highest number ever. But the CDC acknowledges that the actual numbers are far higher - that most cases of STDs are not reported to the CDC. The CDC estimates that there are actually 20 million new STDs in the U.S. each year, including other sexually transmitted diseases such as genital herpes and human papillomavirus, and half of these are among young people ages 15 to 24 years.

The report discusses the four STDs (sexually transmitted diseases) that are reported to the CDC. The 4th one is chancroid, but there were only 7 cases reported last year. Most of the new cases of STDs involved chlamydia, a bacterial infection that affects both men and women - about 1.6 million cases were reported to the CDC. Gonorrhea also increased among men and women last year, but the steepest rise was among men, especially among men who have sex with men (MSM). The CDC is especially concerned about the threat of gonorrhea becoming resistant to all treatments. Untreated STDs have serious health consequences (e.g. infertility, still-birth in infants)

This report stresses the need for STD screening and treatment, especially among pregnant women (make it part of prenatal care). There is also a need for STD education, and greater use of condoms to reduce risk of STDs. The CDC has a page on STD prevention (practice abstinence, use condoms, have fewer sexual partners and exclusive relationships, get the HPV vaccine, and talk with your partner about safe sex).  Excerpts from CDC:

STDs at record high, indicating urgent need for prevention

More than two million cases of chlamydia, gonorrhea and syphilis were reported in the United States in 2016, the highest number ever, according to the annual Sexually Transmitted Disease Surveillance Report released today by the Centers for Disease Control and Prevention (CDC).

The majority of these new diagnoses (1.6 million) were cases of chlamydia. There were also 470,000 gonorrhea cases and almost 28,000 cases of primary and secondary syphilis – the most infectious stages of the disease. While all three of these STDs can be cured with antibiotics, if left undiagnosed and untreated, they can have serious health consequences, including infertility, life-threatening ectopic pregnancy, stillbirth in infants, and increased risk for HIV transmission.

While young women continue to bear the greatest burden of chlamydia (nearly half of all diagnosed infections), surges in syphilis and gonorrhea are increasingly affecting new populations.

Syphilis rates increased by nearly 18 percent overall from 2015 to 2016. The majority of these cases occur among men – especially gay, bisexual and other men who have sex with men (MSM) – however, there was a 36 percent increase in rates of syphilis among women, and a 28 percent increase in syphilis among newborns (congenital syphilis) during this period. More than 600 cases of congenital syphilis were reported in 2016, which has resulted in more than 40 deaths and severe health complications among newborns. The disease is preventable through routine screening and timely treatment for syphilis among pregnant women.

While gonorrhea increased among men and women in 2016, the steepest increases were seen among men (22 percent). Research suggests that a large share of new gonorrhea cases are occurring among MSM. These trends are particularly alarming in light of the growing threat of drug resistance to the last remaining recommended gonorrhea treatment.

Image result for chlamydia wikipedia Chlamydia trachomatis (chlamydia) - in brown. Credit: Wikipedia

Another problem for overweight or obese men: an increased risk of poor sperm quality. Researchers in India found that compared to normal weight men, obesity was associated with lower sperm count, lower volume of semen, lower sperm concentration, poor sperm motility (the movement of sperm), as well as sperm defects. There is some evidence (from other studies and the researchers own work) that there is improvement in sperm quality with weight loss.

The researchers pointed out that other studies have shown that "paternal obesity at conception had deleterious effects on embryo health, implantation, pregnancy, and live birth rates." And that poor sperm quality is a cause of infertility. So.... what do the researchers recommend? Weight loss and exercise, and perhaps bariatric surgery, for obese men having fertility problems due to poor sperm quality. From Medical Xpress: 

As men's weight rises, sperm health may fall

A widening waistline may make for shrinking numbers of sperm, new research suggests. Indian scientists studied more than 1,200 men and found that too much extra weight was linked to a lower volume of semen, a lower sperm count and lower sperm concentration. In addition, sperm motility (the ability to move quickly through the female reproductive tract) was poor. The sperm had other defects as well, the researchers added. Poor sperm quality can lower fertility and the chances of conception.

"It's known that obese women take longer to conceive," said lead researcher Dr. Gottumukkala Achyuta Rama Raju, from the Center for Assisted Reproduction at the Krishna IVF Clinic, in Visakhapatnam. "This study proves that obese men are also a cause for delay in conception," he added.

But in continuing research, the study team is looking to see if losing weight will improve the quality of sperm. Although that study is still in progress, early signs look good that sperm quality improves as men lose weight, Rama Raju said. Recent reports have found that extreme weight loss after bariatric surgery reversed some of the sperm decline, he said.

For the study, Rama Raju and his colleagues used computer-aided sperm analysis to assess the sperm of 1,285 men. Obese men, they found, had fewer sperm, a lower concentration of sperm and inability of the sperm to move at a normal speed, compared with the sperm of men of normal weight. Moreover, the sperm of obese men had more defects than other sperm. These defects included defects in the head of the sperm, such as thin heads and pear-shaped heads.  [Original study.]

 Human sperm. Credit: Wikipedia

OK everyone - even if you sit all day at a desk job, the research is clear: try to get up and stretch or move a little every 30 minutes. Researchers followed middle-aged and older adults over a 5 1/2 year period and found that total sitting time (sedentary behavior) and prolonged, uninterrupted sedentary behavior were associated with in increased risk for death from any cause (all-cause mortality). But..adults who kept most of their sitting bouts to less than 30 minutes had the lowest risk of death. The researchers felt that getting up and moving every half hour seems to protect against the health risks (cardiometabolic effects) from just sitting and sitting and sitting. Are you moving yet?

From Science Daily: Long sitting periods may be just as harmful as daily total

A new study finds that it isn't just the amount of time spent sitting, but also the way in which sitting time is accumulated during the day, that can affect risk of early deathThe study, published online today in Annals of Internal Medicine, found that adults who sit for one to two hours at a time without moving have a higher mortality rate than adults who accrue the same amount of sedentary time in shorter bouts.

The researchers used hip-mounted activity monitors to objectively measure inactivity during waking time over a period of seven days in 7,985 black and white adults over age 45. (The participants were taking part in the REGARDS study, a national investigation of racial and regional disparities in stroke.)

On average, sedentary behavior accounted for 77 percent of the participants' waking hours, equivalent to more than 12 hours per day. Over a median follow-up period of four years, 340 of the participants died. Mortality risk was calculated for those with various amounts of total sedentary time and various sedentary patterns. Those with the greatest amount of sedentary time -- more than 13 hours per day -- and who frequently had sedentary bouts of at least 60 to 90 consecutive minutes had a nearly two-fold increase in death risk compared with those who had the least total sedentary time and the shortest sedentary bouts.

The researchers also found that participants who kept most of their sitting bouts to less than 30 minutes had the lowest risk of death. "So if you have a job or lifestyle where you have to sit for prolonged periods of time, we suggest taking a movement break every half hour. This one behavior change could reduce your risk of death, although we don't yet know precisely how much activity is optimal," Dr. Diaz said. [Original study.]

A major new report about colorectal cancer found that a number of lifestyle factors (diet, physical activity) increase or lower the risk of colorectal cancer. The report was an analysis of global research studies and was published by the American Institute for Cancer Research and World Cancer Research Fund.

They found that there is strong evidence that: being physically active, consuming whole grains, consuming foods containing dietary fiber, consuming dairy products, and taking calcium supplements all decrease the risk of colorectal cancer. On the other hand, there is strong evidence that: consuming red meat, consuming processed meat, consuming 2 or more alcoholic drinks per day, being overweight or obese, and being tall all increase the risk of colorectal cancer.

Also, that there is some evidence that: consuming foods containing vitamin C, consuming fish, vitamin D, consuming multivitamin supplements lower the risk of colorectal cancer. And there is some evidence that: low consumption on non-starch vegetables, low consumption of fruit, and consumption of foods containing haem iron might increase the risk of colorectal cancer. [NOTE: There are 2 types of iron in food: haem and non-haem iron. Haem iron is only found in meat, chicken, and fish, and is easily absorbed. Non-haem iron is found in plant foods, such as vegetables, cereals, beans, and lentils, but is not absorbed as well by the body.]

Finally, their cancer prevention recommendations for preventing cancer in general include: maintaining a healthy weight, being physically active and eating a healthy diet. (other posts on this - here, here, here). They also advise eating a healthy diet (think Mediterranean style diet) rather than relying on supplements to protect against cancer. The report also noted that inflammatory bowel disease and smoking increase the risk of colorectal cancer. From Science Daily:

Whole grains decrease colorectal cancer risk, processed meats increase the risk

Eating whole grains daily, such as brown rice or whole-wheat bread, reduces colorectal cancer risk, with the more you eat the lower the risk, finds a new report by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF). This is the first time AICR/WCRF research links whole grains independently to lower cancer riskDiet, Nutrition, Physical Activity and Colorectal Cancer also found that hot dogs, bacon and other processed meats consumed regularly increase the risk of this cancer. There was strong evidence that physical activity protects against colon cancer.

The new report evaluated the scientific research worldwide on how diet, weight and physical activity affect colorectal cancer risk. The report analyzed 99 studies, including data on 29 million people, of whom over a quarter of a million were diagnosed with colorectal cancer.

Other factors found to increase colorectal cancer include:  - Eating high amounts of red meat (above 500 grams cooked weight a week), such as beef or pork, - Being overweight or obese, - Consuming two or more daily alcoholic drinks (30 grams of alcohol), such as wine or beer. The report concluded that eating approximately three servings (90 grams) of whole grains daily reduces the risk of colorectal cancer by 17 percent. It adds to previous evidence showing that foods containing fiber decreases the risk of this cancer.

In the US, colorectal cancer is the third most common cancer among both men and women, with an estimated 371 cases diagnosed each day. AICR estimates that 47 percent of US colorectal cancer cases could be prevented each year through healthy lifestyle changes[The report.]

It seems like I can't stop writing about coffee (here and here). Coffee drinkers rejoice: another study (presented at the European Society of Cardiology) finds health benefits from drinking several cups of coffee daily. This study, like other previous studies, found an inverse relationship between drinking coffee and early death ("all-cause mortality") - meaning the more one drinks coffee, the less likely one is to have a premature death. The biggest effect was in drinking 4 cups daily in people aged 45 and older! It was an observational study, so can't prove it definitely - can only say there's an association. But still... it's looking good. From Medical Xpress:

Higher coffee consumption associated with lower risk of death

Higher coffee consumption is associated with a lower risk of death, according to research presented today at ESC Congress. The observational study in nearly 20,000 participants suggests that coffee can be part of a healthy diet in healthy people. 

The purpose of this study was to examine the association between coffee consumption and the risk of mortality in a middle-aged Mediterranean cohort. The study was conducted within the framework of the Seguimiento Universidad de Navarra (SUN) Project, a long-term prospective cohort study in more than 22,500 Spanish university graduates which started in 1999. This analysis included 19,896 participants of the SUN Project, whose average age at enrollment was 37.7 years old. .... Patients were followed-up for an average of ten years. 

During the ten year period, 337 participants died. The researchers found that participants who consumed at least four cups of coffee per day had a 64% lower risk of all-cause mortality than those who never or almost never consumed coffee. There was a 22% lower risk of all-cause mortality for each two additional cups of coffee per day.

The researchers examined whether sex, age or adherence to the Mediterranean diet had any influence on the association between baseline coffee consumption and mortality. They observed a significant interaction between coffee consumption and age. In those who were at least 45 years old, drinking two additional cups of coffee per day was associated with a 30% lower risk of mortality during follow-up. The association was not significant among younger participants.