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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. 

 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.

Most people know that heavy drinking of alcohol, smoking marijuana, cigarette smoking, and using methamphetamine during pregnancy should be avoided because they can have negative effects on the developing fetus. However, this study found that each of these also had a distinct negative effect on the placenta, suggesting that "different mechanisms mediate their effects on placental development". From Science Daily:

Effects of alcohol, methamphetamine, and marijuana exposure on the placenta

In the United States, prenatal alcohol exposure (PAE) is the most common preventable cause of developmental delay. Animal studies have shown some of the adverse effects of PAE on placental development, but few studies have examined these effects in humans. This is the first study to examine the effects of prenatal exposure to methamphetamine, marijuana, and cigarette smoking on human placental development.

Researchers collected placentas from 103 Cape Coloured (mixed ancestry) pregnant women recruited at their first antenatal clinic visit in Cape Town, South Africa. Of these, 66 heavy drinkers and 37 non-drinkers were interviewed about their alcohol, cigarette smoking, and drug use at three antenatal visits. A senior pathologist, blinded to exposure status, performed comprehensive pathology examinations on each placenta using a standardized protocol. In multivariable regression models, effects of prenatal exposure were examined on placental size, structure, and presence of infections and meconium.

Results show that alcohol, methamphetamine, and marijuana were associated with distinct patterns of pathology, suggesting that different mechanisms mediate their effects on placental development. Alcohol exposure was related to decreased placental weight and a smaller placenta-to-birth weight ratio. By contrast, methamphetamine was associated with larger placental weight and a larger placenta-to-birth weight ratio. Marijuana was also associated with larger placental weight. In addition, alcohol exposure was associated with an increased risk of placental hemorrhage. Finally, alcohol and cigarette smoking were associated with a decreased risk of intrauterine passing of meconium, a sign of acute fetal stress and/or hypoxia; methamphetamine, with an increased risk. These findings may be important in the long-term teratogenic effects of prenatal alcohol and drug exposure.

In the last few years some people have raised the issue of whether subconcussions in chidren, teenagers, and adults playing football also leads to brain changes similar to concussions. Subconcussions are head impacts that aren't as strong as concussions, but they routinely happen to players in football games and practice. Research says YES - worrying brain changes are occurring from subconcussions, but long-term effects from them are currently unknown. Earlier research found that the brains of high school football players (who had only received head impacts during the season) don't fully heal during the off-season when football is not played. (More related posts on subconcussions: high school players, football before age 12, teen football players, soccer players). The research discussed below is ongoing research. From Medical Xpress:

Subconcussions cause changes to brain, study of college football players shows

The average college football player receives about 1,000 head impacts each season. Some of these hits result in concussions – traumatic head injury that results in short-term, and possibly even long-term, damage to brain function. But what are the effects of the hundreds of routine head impacts, called subconcussions, that occur during a four-month season of practice sessions and games?

A University of Virginia neuroscience Ph.D. candidate is trying to find out. Using functional magnetic resonance imaging – fMRI – Bryson Reynolds studied the brain activity and connectivity of a group of healthy college football players, before and after a competitive season, and compared the data to brain-activity scans of healthy male college soccer and lacrosse players, and to a control group of college male non-athletes.

He found that the football players experienced a disruption in "local functional connectivity" – the way different areas of the brain communicate with each other – while soccer and lacrosse players' brain activity did not noticeably change after a competitive season. The result for the soccer and lacrosse players was comparable to the control group, which also displayed no brain activity changes during a four-month period. "This is an important discovery regarding the football players because a similar disruption of local functional connectivity has also been found in athletes diagnosed with a concussion," Reynolds said.

"We have no ideas how these subconcussions might be affecting players' brains, but we are seeing concussion-like changes to the brain, at least in the short term," Reynolds said. "This does not necessarily mean that something bad is happening to the brain, but clearly some changes are occurring over the course of a season."

Neurologists know that concussions cause headaches, dizziness and sometimes loss of consciousness, and may also increase the risk for developing serious long-term neurodegenerative disorders, such as Alzheimer's disease, amyotrophic lateral sclerosis and chronic traumatic encephalopathy.

In other words, repeated head impacts over the course of a season, or perhaps a career, may be affecting the brain in ways not yet understood, but possibly similar to actual concussions. Reynolds' study did not include players who suffered concussions, and the subconcussions he observed were not causing perceptible problems or symptoms for the players. But the disruptions in brain activity recorded in the fMRI scans may indicate subtle changes that could be part of a larger picture. 

Some more bad news about BPA and other endocrine disruptors (hormone disruptors) such as the phthalate DEHP. Bottom line: Avoid plastics, BPA, BPS and other BPA substitutes (they're chemically similar and seem to have similar health effects) as much as possible. Most canned food has BPA or BPA substitutes in the can linings. Use glass and stainless steel to store food, microwave food in dishes (not in plastic containers or packages). Go to the Environmental Working Group site for more information on product information, what to avoid, and what to look for and get instead.

From Science daily: BPA substitute can trigger fat cell formation: Chemical used in BPA-free products exhibits similar endocrine-disrupting effects

Exposure to a substitute chemical often used to replace bisphenol A in plastics can encourage the formation of fat cells, according to a new study. The replacement chemical, bisphenol S, has a slightly different chemical structure than bisphenol A (BPA), a known endocrine disruptor. As of 2014, nearly 100 epidemiological studies have been published tying BPA to health problems, according to the Introductory Guide to Endocrine-disrupting Chemicals published by the Society and IPEN, a global network that supports sound chemicals management.

Concerns about BPA's health effects have encouraged some consumers to purchase food containers labeled "BPA-free." BPA-free products often contain bisphenol S (BPS)or other substitutes, but researchers have raised concerns that these replacements also interfere with the body's hormones and may pose similar threats to public health."Our research indicates BPS and BPA have comparable effects on fat cells and their metabolism," said the study's senior author, Ella Atlas, PhD, of Health Canada, the federal department responsible for helping Canadians maintain and improve their health. 

A report (a collaborative effort of 5 organizations) that looked for the presence of BPA and BPA substitutes in the linings of food cans from major food companies. And yes, they found BPA in most cans (67%). From the group Toxic Food Cans: Buyer Beware: Toxic BPA and regrettable substitutes found in the linings of canned food

This study set out to analyze the interior coatings and lids of nearly 200 canned foods collected in 19 states and one Canadian province to determine whether the use of bisphenol A (BPA) continues to be widespread among major national brands and retailers of canned foods. We also wanted to determine what replacement materials for BPA-based epoxy are being used by retailers and manufacturers and the extent to which those companies have studied the safety of those materials.

Our findings were alarming: This report validates our concerns that, despite consumer demand for BPA-free cans, 67 percent (129 of 192) of the cans we tested contained BPA-based epoxy in the body and/or the lid. Our investigation also found, for the first time, that some retailers and brands have replaced BPA with PVC, made from vinyl chloride, a carcinogen.

BPA is a hormonally active chemical. The scientific evidence linking BPA exposure to harm in humans is compelling and growing: More than 300 animal and human studies have linked exquisitely small amounts of BPA exposure, measured in parts per billion and even parts per trillion, to a staggering number of health problems, including breast and prostate cancer, asthma, obesity, behavioral changes (including attention deficit disorder), altered development of the brain and immune system, low birth weight and lowered sperm counts.

This study looked at plasticizers called phthalates (which are commonly found in medical tubes), and which also have endocrine disrupting effects. From Medical Xpress:  Attention deficit after kids' critical illness linked to plasticizers in medical tubes

Children who are often hospitalized in intensive care units are more likely to have attention deficit disorders later, and new research finds a possible culprit: a high level of plastic-softening chemicals called phthalates circulating in the blood. The researchers.....suggest these chemicals, which are added to indwelling medical devices such as plastic tubes and catheters, seep into the child's bloodstream.

"Phthalates have been banned from children's toys because of their potential toxic and hormone-disrupting effects, but they are still used to soften medical devices," said lead researcher Sören Verstraete, MD, a PhD student at KU (Katholieke Universiteit) Leuven in Leuven, Belgium. "We found a clear match between previously hospitalized children's long-term neurocognitive test results and their individual exposure to the phthalate DEHP during intensive care."

Di(2-ethylhexyl)phthalate, or DEHP, is the most commonly used plastic softener in medical devices made of polyvinyl chloride (PVC). Verstraete called the use of medical devices containing this phthalate "potentially harmful" for the brain development and function of critically ill children.

A recent study in the Journal of Internal Medicine had interesting results regarding sun exposure - more was beneficial for health.

In the study, women were followed for 20 years, and any  deaths were put into one of 3 groups: as being from: heart disease, cancer, or other (non-heart disease and non-cancer). Swedish women followed for 20 years found that the more sunlight exposure they had, the longer the life expectancy, the less death from heart disease (cardiovascular disease) and causes other than heart disease or cancer (non-heart disease and non-cancer group), but the more skin cancer (basal cell carcinoma, squamous cell carcinoma and melanoma) they developed. 

Thus the main finding is of a dose-dependent relationship between sun exposure and life expectancy.

One surprising result was that nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group. Those who avoided sun exposure had an increased risk of death mainly due to heart disease and "other causes" (non-cancer/non-heart disease).

I wondered about other cancers in this study, and this is all they had to say in the journal article:  "Thus, women with NMSC (nonmalignant skin cancer) had a 37% higher prevalence of other internal cancers than those without NMSC and a fourfold increased prevalence of MM (malignant melanoma). The incidence of other internal cancer was not increased subsequently on NMSC diagnosis."  I now have another question:  How do the women with cancer in the high and low sun exposure group do after another 10 or 20 years?  I would have liked for this study to continue longer.

The researchers felt that sunshine and vitamin D had a role in these results, and suggested that we need to rethink the "avoid sunshine" advice now given to people. In other words, some sunshine is good for health. From Science Daily:

Why do sunbathers live longer than those who avoid the sun?

New research looks into the paradox that women who sunbathe are likely to live longer than those who avoid the sun, even though sunbathers are at an increased risk of developing skin cancer. An analysis of information on 29,518 Swedish women who were followed for 20 years revealed that longer life expectancy among women with active sun exposure habits was related to a decrease in heart disease and noncancer/non-heart disease deaths, causing the relative contribution of death due to cancer to increase.

Whether the positive effect of sun exposure demonstrated in this observational study is mediated by vitamin D, another mechanism related to UV radiation, or by unmeasured bias cannot be determined. Therefore, additional research is warranted. 

"We found smokers in the highest sun exposure group were at a similar risk as non-smokers avoiding sun exposure, indicating avoidance of sun exposure to be a risk factor of the same magnitude as smoking," said Dr. Pelle Lindqvist, lead author of the Journal of Internal Medicine study. "Guidelines being too restrictive regarding sun exposure may do more harm than good for health."

A cataract is a clouding of the lens in the eye leading to a decrease in vision. It can affect one or both eyes, it is more common with age, and can even lead to blindness. About 20 million people globally are blind due to cataracts. Vitamin supplements have failed to find an effect in numerous studies.

But in this study, eating foods rich in vitamin C and to a smaller degree manganese had the beneficial effect of slowing cataract progression over the course of 9 1/2 years. Manganese is a micronutrient that is necessary in small amounts, but it is rare to be deficient in manganese. However manganese has numerous negative effects if too much is ingested or if there is too much exposure. Bottom line: increased intake of fruit and vegetables (for vitamin C) could help prevent the development or progression of cataracts.  From Medical Xpress:

Increased vitamin C in the diet could help protect against cataracts

Higher dietary intake of vitamin C has been found to have a potentially preventative effect on cataract progression in the first twin study of cataracts to examine to what degree genetic and environmental factors influence their progression with age. Cataract is a common condition in which the lens of the eye becomes cloudy as a result of oxidation over time. Whilst this is a natural part of ageing for many, for others it is more severe and causes blurred vision, glare and dazzle that cannot be corrected by glasses or contact lenses.

The study, led by King's College London and published in the journal Ophthalmology, looked at the progression of cataracts in the eyes of 324 pairs of female twins .... They found that those participants who had a higher intake of vitamin C were associated with a 33 per cent risk reduction of cataract progression and had 'clearer' lenses after the 10 years than those who had consumed less vitamin C as part of their diet.

The study, funded by the Wellcome Trust and Guide Dogs for the Blind, also found that environmental factors (including diet) influenced cataract more than genetic factors, which only explained a third of the change in lens opacity. The fluid in the eye that bathes the lens is high in vitamin C, which helps to stop the lens from oxidising and protects it from becoming cloudy. It is thought that increased intake of vitamin C has a protective effect on cataract progression by increasing the vitamin C available in the eye fluid.

Kate Yonova-Doing, the study's first author said: 'The human body cannot manufacture vitamin C, so we depend on vitamins in the food we eat. We did not find a significantly reduced risk in people who took vitamin tablets, so it seems that a healthy diet is better than supplements.'

Makes sense that not driving to work in a car, but using mass transit (public transport), cycling, or walking to work results in lower body mass index (BMI) and body fat. They're moving more! From Science Daily:

Public transport, walking and cycling to work are all associated with reductions in body fat for adults in mid-life

Adults who commute to work via cycling or walking have lower body fat percentage and body mass index (BMI) measures in mid-life compared to adults who commute via car, according to a new study incThe Lancet Diabetes & Endocrinology journal. Even people who commute via public transport also showed reductions in BMI and percentage body fat compared with those who commuted only by car. This suggests that even the incidental physical activity involved in public transport journeys may be important.

The study looked at data from over 150000 individuals from the UK Biobank data set, a large, observational study of 500000 individuals aged between 40 and 69 in the UK. The study is the largest to date to analyse the health benefits of active transport.

The strongest associations were seen for adults who commuted via bicycle, compared to those who commute via car. For the average man in the sample (age 53 years; height 176.7cm; weight 85.9kg), cycling to work rather than driving was associated with a weight difference of 5kg or 11lbs (BMI difference 1.71 kg/m2). For the average woman in the sample (age 52 years; height 163.6cm; weight 70.6kg), the weight difference was 4.4kg or 9.7lbs (BMI difference 1.65 kg/m2). After cycling, walking to work was associated with the greatest reduction in BMI and percentage body fat, compared to car-users (BMI difference 0.98 kg/m2 for men; 0.80 kg/m2 for women). For both cycling and walking, greater travelling distances were associated with greater reductions in BMI and percentage body fat.

Commuters who only used public transport also had lower BMI compared to car-users (BMI difference of 0.70kg/m2 for men), as did commuters who combined public transport with other active methods (BMI difference 1.00 kg/m2 for men; 0.67 kg/m2 for women). The effect of public transport on BMI was slightly greater than for commuters who combined car use with other active methods (BMI difference 0.56 kg/m2 for men). The link between active commuting and BMI was independent of other factors such as income, area deprivation, urban or rural residence, education, alcohol intake, smoking, general physical activity and overall health and disability.

Brain aging can be viewed as having 2 parts: chronological age (normally  the brain grey matter volume slowly shrinks with advancing age) and a lifetime of exposures - which can be negative from unhealthy lifestyle and injuries, and positive from a healthy lifestyle and enriched environments. That's why after a lifetime there can be wide variation in the physiological age of our brains. These differences in the  brain (in the grey matter) can be measured with magnetic resonance imaging (MRIs).

The researchers in this study used the concept of physiological age - the difference between the chronological age and predicted age, as a marker of brain health. They looked at adults of varying ages,and found that the more flights of stairs a person climbs daily, and the more years of school a person had completed, the "younger" their brain physically appears.  This study was a cross-sectional study and so shows an association rather than a definite cause, but interestingly other forms of exercise did not show this link (walking/hiking, jogging, running, bicycling, aerobic exercise, lap swimming, tennis.squash/racquetball, low intensity exercise). From Science Daily:

Want a younger brain? Stay in school -- and take the stairs

Taking the stairs is normally associated with keeping your body strong and healthy. But new research shows that it improves your brain's health too -- and that education also has a positive effect. In a study recently published in the journal Neurobiology of Aging, researchers led by Jason Steffener, a scientist at Concordia University's Montreal-based PERFORM Centre, show that the more flights of stairs a person climbs, and the more years of school a person completes, the "younger" their brain physically appears.

The researchers found that brain age decreases by 0.95 years for each year of education, and by 0.58 years for every daily flight of stairs climbed -- i.e., the stairs between two consecutive floors in a building.

For the study, Steffener and his co-authors used magnetic resonance imaging (MRI) to non-invasively examine the brains of 331 healthy adults who ranged in age from 19 to 79. They measured the volume of grey matter found in participants' brains because its decline, caused by neural shrinkage and neuronal loss, is a very visible part of the chronological aging process. Then, they compared brain volume to the participants' reported number of flights of stairs climbed, and years of schooling completed. 

Results were clear: the more flights of stairs climbed, and the more years of schooling completed, the younger the brain. "This study shows that education and physical activity affect the difference between a physiological prediction of age and chronological age, and that people can actively do something to help their brains stay young," he says.

Yes, the chemicals in personal care products and cosmetics you use absolutely get into your body, have effects, and can be measured in the urine. Of especially big concern are the endocrine (hormone) disrupting chemicals such as phthalates, parabens, triclosan, and oxybenzone (BP-3). This study shows that even taking a 3 day break from these chemicals lowers their levels in your body. The researchers found that : "The adolescent girls in this study experienced an average within girl decline of 27-45% in urinary concentrations of certain phthalates, certain parabens, triclosan, and oxybenzone after three days of abstaining from conventional personal care products and using replacement products with labels indicating they did not contain these chemicals."

Bottom line: Read the ingredient lists of all personal care products and try to avoid those with phthalates, parabens, triclosan, and oxybenzone (BP-3). Try to buy "unscented" or "fragrance-free" products.The site ewg.org also has lists of personal care products to avoid, and rates many products. From Science Daily:

Teen girls see big drop in chemical exposure with switch in cosmetics

A new study led by researchers at the University of California, Berkeley, and Clinica de Salud del Valle de Salinas demonstrates how even a short break from certain kinds of makeup, shampoos and lotions can lead to a significant drop in levels of hormone-disrupting chemicals in the body. The results, published Monday, March 7, 2016 in the journal Environmental Health Perspectives, came from a study of 100 Latina teenagers participating in the Health and Environmental Research on Makeup of Salinas Adolescents (HERMOSA) study.

Researchers provided teen study participants with personal care products labeled free of chemicals such as phthalates, parabens, triclosan and oxybenzone. Such chemicals are widely used in personal care products, including cosmetics, fragrance, hair products, soaps and sunscreens, and have been shown in animal studies to interfere with the body's endocrine system.

"Because women are the primary consumers of many personal care products, they may be disproportionately exposed to these chemicals," said study lead author Kim Harley, associate director of the UC Berkeley Center for Environmental Research and Children's Health. "Teen girls may be at particular risk since it's a time of rapid reproductive development, and research has suggested that they use more personal care products per day than the average adult woman."

Analysis of urine samples before and after a three-day trial in which the participants used the lower- chemical products found significant drops in levels of these chemicals in the body. Metabolites of diethyl phthalate, commonly used in fragrances, decreased 27 percent by the end of the trial period. Methyl and propyl parabens, used as preservatives in cosmetics, dropped 44 and 45 percent respectively. Both triclosan, found in antibacterial soaps and some brands of toothpaste, and benzophenone-3 (BP-3), found in some sunscreens under the name oxybenzone, fell 36 percent. Surprisingly, there was a small increase in concentrations in two less common parabens. Those levels were small and could have been caused by accidental contamination or a substitution not listed on the labels, the study authors said.

The researchers noted that cosmetics and personal care products are not well-regulated in this country, and that getting data about health effects from exposure, particularly long-term ones, is difficult. But they say there is growing evidence linking endocrine-disrupting chemicals to neurobehavioral problems, obesity and cancer cell growth. (Original study.)