Another positive piece of news for those getting on in years. From Jan. 20, 2014 Science News:
Forget About Forgetting: Elderly Know More, Use It Better
What happens to our cognitive abilities as we age? If your think our brains go into a steady decline, research reported this week in the Journal Topics in Cognitive Science may make you think again. The work, headed by Dr. Michael Ramscar of Tübingen University, takes a critical look at the measures usually thought to show that our cognitive abilities decline across adulthood. Instead of finding evidence of decline, the team discovered that most standard cognitive measures, which date back to the early twentieth century, are flawed. "The human brain works slower in old age," says Ramscar, "but only because we have stored more information over time."
Ramscar and his colleagues' work provides more than an explanation of why, in the light of all the extra information they have to process, we might expect older brains to seem slower and more forgetful than younger brains. Their work also shows how changes in test performance that have been taken as evidence for declining cognitive abilities in fact demonstrates older adults' greater mastery of the knowledge they have acquired.
The Tübingen research conclude that we need different tests for the cognitive abilities of older people -- taking into account the nature and amount of information our brains process. "The brains of older people do not get weak," says Michael Ramscar. "On the contrary, they simply know more."
Exposing skin to sunlight may help to reduce blood pressure and thus cut the risk of heart attack and stroke. From the January 17, 2014 Science Daily:
Here Comes the Sun to Lower Your Blood Pressure
Exposing skin to sunlight may help to reduce blood pressure and thus cut the risk of heart attack and stroke, a study published in the Journal of Investigative Dermatology suggests.
Research carried out at the Universities of Southampton and Edinburgh shows that sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood, reducing blood pressure... "NO along with its breakdown products, known to be abundant in skin, is involved in the regulation of blood pressure. When exposed to sunlight, small amounts of NO are transferred from the skin to the circulation, lowering blood vessel tone; as blood pressure drops, so does the risk of heart attack and stroke."
While limiting sunlight exposure is important to prevent skin cancer, the authors of the study, including Dr Richard Weller of the University of Edinburgh, suggest that minimising exposure may be disadvantageous by increasing the risk of prevalent conditions related to cardiovascular disease.
Cardiovascular disease, often associated with high blood pressure, accounts for 30 per cent of deaths globally each year. Blood pressure and cardiovascular disease are known to vary according to season and latitude, with higher levels observed in winter and in countries further from the equator, where ultraviolet radiation from the sun is lower.
From the January 15, 2014 Science Daily:
Don’t Just Sit There! Prolonged Sitting Linked to Early Mortality in Women
Led by Cornell University nutritional scientist Rebecca Seguin, a new study of 93,000 postmenopausal American women found those with the highest amounts of sedentary time -- defined as sitting and resting, excluding sleeping -- died earlier than their most active peers. The association remained even when controlling for physical mobility and function, chronic disease status, demographic factors and overall fitness -- meaning that even habitual exercisers are at risk if they have high amounts of idle time.
Seguin and co-authors found that women with more than 11 hours of daily sedentary time faced a 12 percent increase in all-cause premature mortality compared with the most energetic group -- those with four hours or less of inactivity. The former group also upped their odds for death due to cardiovascular disease, coronary heart disease and cancer by 13, 27 and 21 percent, respectively.
The assumption has been that if you're fit and physically active, that will protect you, even if you spend a huge amount of time sitting each day," said Seguin, assistant professor of nutritional sciences in Cornell's College of Human Ecology. "In fact, in doing so you are far less protected from negative health effects of being sedentary than you realize."
Researchers found that caffeine enhances memory.From Science Daily:
Michael Yassa, assistant professor of psychological and brain sciences in the Krieger School of Arts and Sciences at Johns Hopkins, and his team of scientists found that caffeine has a positive effect on long-term memory in humans. Their research, published by the journal Nature Neuroscience, shows that caffeine enhances certain memories at least up to 24 hours after it is consumed.
According to the U.S. Food and Drug Administration, 90 percent of people worldwide consume caffeine in one form or another. In the United States, 80 percent of adults consume caffeine every day. The average adult has an intake of about 200 milligrams -- the same amount used in the Yassa study -- or roughly one strong cup of coffee or two small cups of coffee per day.
If you missed these recent articles about weight and gut bacteria, please go read them now. Amazing stuff. From the December 9, 2013 Washington Post:
The microbes in your gut may be making you fat or keeping you thin
...a growing body of evidence suggesting that naturally occurring bacteria and other microbes in the body, and possibly even viruses, can influence weight in ways that scientists are only just beginning to understand. Numerous studies are underway looking at the role of intestinal organisms in obesity, with a focus on how they extract energy from food and how this affects weight gain or loss.
From September 5, 2013 Science News: Gut infections keep mice lean
Skinniness could be contagious. Gut bacteria from thin people can invade the intestines of mice carrying microbes from obese people. And these invaders can keep mice from getting tubby, researchers report in the Sept. 6 Science.
But the benefits come with a catch. The invading microbes drop in and get to work only when mice eat healthy food. Even fat-blocking bacteria can’t fight a bad diet, suggests study leader Jeffrey Gordon, a microbiologist at Washington University in St. Louis.
Fat and thin people have different microbes teeming in their intestines, for example. And normal-weight mice given microbes from obese mice pack on extra fat, says coauthor Vanessa Ridaura, also of Washington University.
Starting this month, it will finally be possible to buy upholstered furniture without added toxic flame retardants. From the December 31, 2013 Scientific American:
Cancer-Linked Flame Retardants Eased Out of Furniture in 2014
From the January 4, 2014 Huffington Post:
Flame-Retardant Furniture May Leave A Toxic Legacy
California's new Technical Bulletin 117 removes a decades-old requirement that flame retardants be included in the filling of upholstered furniture. The state rule, which became the de facto standard for the rest of the nation, meant use of the chemicals flourished for years nationwide, despite mounting evidence implicating them in neurological and reproductive disorders, and cancers. For all their ills, the chemicals may not actually slow fires.
"Right now, most people have harmful flame retardants in their homes and in their bodies," said Blum, a University of California, Berkeley, chemist. "And the chemicals don't serve a benefit.
As for finding new flame retardant-free furniture, Blum recommended looking for the new "TB 117-2013" tag and asking retailers whether a specific item contains flame retardants. It may be best to wait a few more months to allow new products to arrive in stores and old stock to be sold out, she noted.
A tomato rich diet may help protect women from breast cancer.From Science Daily:
Diet Rich in Tomatoes May Lower Breast Cancer Risk
A tomato-rich diet may help protect at-risk postmenopausal women from breast cancer, according to new research accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism.Breast cancer risk rises in postmenopausal women as their body mass index climbs. The study found eating a diet high in tomatoes had a positive effect on the level of hormones that play a role in regulating fat and sugar metabolism.
"The advantages of eating plenty of tomatoes and tomato-based products, even for a short period, were clearly evident in our findings," said the study's first author, Adana Llanos, PhD, MPH, who is an Assistant Professor of Epidemiology at Rutgers University. "Eating fruits and vegetables, which are rich in essential nutrients, vitamins, minerals and phytochemicals such as lycopene, conveys significant benefits. Based on this data, we believe regular consumption of at least the daily recommended servings of fruits and vegetables would promote breast cancer prevention in an at-risk population."
The longitudinal cross-over study examined the effects of both tomato-rich and soy-rich diets in a group of 70 postmenopausal women. For 10 weeks, the women ate tomato products containing at least 25 milligrams of lycopene daily. For a separate 10-week period, the participants consumed at least 40 grams of soy protein daily. Before each test period began, the women were instructed to abstain from eating both tomato and soy products for two weeks.
When they followed the tomato-rich diet, participants' levels of adiponectin -- a hormone involved in regulating blood sugar and fat levels -- climbed 9 percent. The effect was slightly stronger in women who had a lower body mass index.
Breast milk contains hundreds of species of bacteria.From the December 8, 2013 Scientific American:
The bacteria in breast milk
Several recent studies have found that breast milk contains a healthy dose of commensal bacteria; all the staphylococci, streptococci, and lactic acid bacteria that are found in the infant gut. This isn’t just bacteria from the skin which have contaminated the samples, but bacteria that have come from inside the breast as an integral component of the milk.
In a study of 16 women it was found that while each milk sample contained hundreds of different bacterial species, around half of the microbiotic community was made up of nine species present in all samples. The other half varied from person to person. This pattern is also found in human gut microbes; a core set present in all individuals along with a large diversity of separate species to make up a unique individual microbiome.
So how do bacteria get into breast milk? Some of them may come from the mouth of the baby. During feeding the skin of both the mother and baby will be in contact with the baby’s open mouth and a certain amount of flow-back can occur between the mouth and nipple. More excitingly it’s been suggested that immune cells in the mothers gut may be able to pick up bacteria and carry them around the body using the lymphatic system. The lymphatic system is a network of vessels used to transport blood plasma. It’s a main highway for immune cells inside the body and is also involved in the absorption and transports of fats.
Like all humans, infants have a range of bacteria within their gut. It looks like these bacteria are initially supplied from the mother’s vaginal and skin bacteria, before being replaced by bacteria from the breast milk. Researchers also found that when babies started eating solid food a whole new range of bacteria was introduced, forming the gut microbiome that persisted into adulthood.
The importance of 5 healthy behaviors in having the best chance of leading a disease free life. The 5 behaviors are: taking regular exercise, non-smoking, a low body weight, a healthy diet and a low alcohol intake. And as the researchers point out: "healthy behaviors have a far more beneficial effect than any medical treatment or preventative procedure".From Science Daily:
35 Year Study Finds Exercise Reduces Risk of Dementia
The study identifies five healthy behaviors as being integral to having the best chance of leading a disease-free lifestyle: taking regular exercise, non-smoking, a low body weight, a healthy diet and a low alcohol intake.
The people who consistently followed four or five of these behaviors experienced a 60 per cent decline in dementia and cognitive decline -- with exercise being the strongest mitigating factor -- as well as 70 per cent fewer instances of diabetes, heart disease and stroke, compared with people who followed none.
"The size of reduction in the instance of disease owing to these simple healthy steps has really amazed us and is of enormous importance in an aging population," said Principle Investigator Professor Peter Elwood from Cardiff University's School of Medicine. "What the research shows is that following a healthy lifestyle confers surprisingly large benefits to health -- healthy behaviors have a far more beneficial effect than any medical treatment or preventative procedure.
The Caerphilly Cohort Study recorded the healthy behaviors of 2,235 men aged 45-59 in Caerphilly, South Wales.
From the December 11, 2013 National Geographic:
You Are What You Eat, All 100 Trillion Of You
By setting ten volunteers on either a vegetarian menu or a carnivorous one,Lawrence David from Duke University and Harvard University’s Peter Turnbaugh have shown that when our diet changes, our gut bacteria react very quickly. Within days, some species step into the limelight, while others fade into the background. They activate different genes, pull off different metabolic tricks, and secrete different substances. Our microbiome, it seems, can rapidly switch between plant-eating and meat-eating modes.
David’s team wanted to see what happens over days. If you flood your gut with different food, how long does it take for your microbiome to react?
They did this by recruiting ten volunteers who were willing to collect daily faecal samples. They each ate two different diets for five straight days —a plant-based one that was rich in grains, legumes, fruit and vegetables, and an animal-based one composed of meat, eggs and cheese.
In general, the animal diet led to more dramatic changes than the plant one.
David and Turnbaugh’s team also found that the altered gut communities did different things. During the plant diet, they became better at breaking down carbohydrates; during the animal diet, protein digestion was their forte. On the meat-heavy days, they activated more genes for breaking down harmful chemicals found in charred meat, and for making vitamins.
And these changes happened very quickly. Some were obvious by day one. By day four, you could pick up a stool sample, list the active genes within it, and predict with total accuracy which diet the owners had been on.
Just two days after the volunteers stopped their diets, things were back to normal. The gut microbiome, it seems, is a fickle beast—easily changed, but not permanently so. The team also found that our food doesn’t just change the microbes that already exist in the gut—they also add some new ones.
The point is that our gut microbiomes are more flexible than we previously thought. A recent study showed that most of the strains in our guts stay there for decades or more. But while the roster is clearly stable, their relative numbers fluctuate a lot, and food-borne newcomers can gain a foothold.