Cooking and Human Brain Evolution

In this article, the argument presented is that cooking is at least partially responsible for human brain development. Interesing.

from New Scientist

Organ and Charles Nunn, also of Harvard, had predicted that if humans are uniquely adapted to eating cooked food, then we should spend far less time chewing than other primates, as cooked food tends to be softer than raw food. To test this, they gathered data from various primate species and looked at the correlation between chewing time and body size, taking into account how the different species were related to each other.

A primate species of our size should, in theory, spend 48 per cent of the waking day chewing, they found. Yet on average we chew for less than 10 per cent of the day, says Organ.

The pair then did a comparison of molar size and found that humans fall well outside the normal range for primates: we have small molars for our body size. When they included teeth from fossils of extinct hominins, the analysis revealed that Homo habilis and its contemporary H. rudolfensis fit well with the average for similarly sized primates. But Neanderthals and our direct ancestor, H. erectus, had small teeth for their body size.

High Heels Effect on Calves

ScienceDaily (July 16, 2010) — When it comes to shoes, some women will go through hell for a pair of Jimmy Choos. But what effect does wearing high heels have on our bodies? Clinicians have known for a long time that if you hold a limb in a shortened position over an extended period, the muscles shorten. High-heeled shoes push our heels up, which made Marco Narici from Manchester Metropolitan University wonder whether wearing heels on a regular basis could shorten our calf muscles.

According to Narici, there was some anecdotal evidence that something changed because secretaries in the 1950s complained about discomfort when they took their heels off and walked flat-footed. “I thought it was an experiment which was inadvertently being done by women. What we could do was test high heel wearers to see if we could find some changes in the calf muscle,” says Narici, who publishes his results on 16 July 2010 in the Journal of Experimental Biology…

more via Science Daily

Attention Span Benefits from Meditation

from Science Daily

…A new study looks at whether Buddhist meditation can improve a person’s ability to be attentive and finds that meditation training helps people do better at focusing for a long time on a task that requires them to distinguish small differences between things they see.

The research was inspired by work on Buddhist monks, who spend years training in meditation. “You wonder if the mental skills, the calmness, the peace that they express, if those things are a result of their very intensive training or if they were just very special people to begin with,” says Katherine MacLean, who worked on the study as a graduate student at the University of California, Davis. Her co-advisor, Clifford Saron, did some research with monks decades ago and wanted to study meditation by putting volunteers through intensive training and seeing how it changes their mental abilities…

…Participants got better at discriminating the short lines as the training went on. This improvement in perception made it easier to sustain attention, so they also improved their task performance over a long period of time. This improvement persisted five months after the retreat, particularly for people who continued to meditate every day…

more via Meditation helps increase attention span

Drinking, smoking and teenage migraines

from the blog KevinMD.com by Kristina Fiore

Drinking coffee and alcohol, smoking, and lack of physical activity all appear to be associated with migraine and tension-type headaches in teenagers, researchers found.

High consumption of cocktails appeared to put students at the greatest risk for these headaches, increasing the odds almost three-and-a-half-fold, Astrid Milde-Busch, PhD, of Ludwig Maximilians University Munich in Germany, and colleagues reported online in the journal Headache.

“Rather unexpectedly, recommendations to increase fluid intake as a means to prevent headache are not supported by this study,” they wrote.

Between 5% and 15% of adolescents suffer from migraines, and another 15% to 25% suffer from tension-type headaches. Yet the researchers said that association studies between these conditions and lifestyle and dietary factors have only been done in adult and other nonrepresentative populations…

…In multivariate analyses, all four factors were associated with combination headaches:

* Drinking cocktails: OR 3.4, 95% CI 1.9 to 6.0

(note: this OR{ odds ratio} of 3.4 means that headaches occurred 3.4 times more in subjects which reported drinking cocktails)

* Drinking coffee: OR 2.4, 95% CI 1.3 to 4.
* Smoking: OR 2.7, 95% CI 1.4 to 5.1
* Lack of physical activity: OR 2.2, 95% CI 1.3 to 3.7

Coffee and physical inactivity were particularly associated with migraine (OR 3.4, 95% CI 1.6 to 7.0 and OR 4.2, 95% CI 2.2 to 7.9, respectively).

Physical inactivity was associated with tension-type headache (OR 1.7, 95% CI 1.1 to 2.7).

much more via Drinking and Smoking Associated with Migraines

Childhood Diet and Future Brain Function

ScienceDaily (July 1, 2010) — Malnutrition early in life appears to diminish brain function in older adulthood, according to a study led by a Michigan State University researcher that has implications for many poor, developing nations.

The study of more than 15,000 elderly people in China suggests that fighting hunger throughout childhood not only saves lives and improves health but also may enhance cognitive well-being in late life. The study appears in the journal Social Science & Medicine.

Across the world, 178 million children under age 5 are stunted or short in stature due to hunger, infection or both, said Zhenmei Zhang, MSU assistant professor of sociology and lead researcher on the project.

“It’s important for policymakers to know that investing in children really has long-term benefits, not only for those individuals but for society as a whole,” Zhang said. “For example, fighting childhood hunger can reduce future medical expenditures. It’s very expensive for families and society to take care of people who suffer from dementia or cognitive impairment.”

Zhang said researchers previously have focused on how childhood malnutrition affects physical health and mortality, with little attention devoted to the long-term, negative effects on brain development and function.

Zhang and colleagues from Portland State University and the University of Texas examined the data of 15,444 elderly people who participated in the Chinese Longitudinal Healthy Longevity Survey, which is funded by the U.S. National Institutes of Health. The survey included a screening test for cognitive impairment, measurements of arms and lower legs (which indicate childhood malnutrition or infection) and a question on childhood hunger.

According to the study, women who suffered from childhood hunger were 35 percent more likely to have cognitive impairment at age 65 or older, while men who suffered from childhood hunger had a 29 percent higher chance.

Beet juice and blood pressure

The nitrate content of beetroot juice helps lower blood pressure, research has shown.

A study in the US journal Hypertension found that blood pressure was reduced within 24 hours in people who drank beetroot juice or took nitrate tablets.

The higher the blood pressure, the greater the impact of the nitrates.

This research suggests there is hope of using a more “natural” approach to bring down blood pressure. Nitrates are found in a number of vegetables.

A previous study found that drinking a pint of beetroot juice lowered blood pressure significantly in people with normal blood pressure.

more via BBC

Diabetes and Hot Weather

…Researchers from Mayo Clinic in Arizona, in collaboration with the National Ocean and Atmospheric Administration and the National Weather Service, surveyed patients at a Phoenix diabetes clinic and analyzed 152 surveys. Responses showed that people living with diabetes in hot climates need increased awareness of how heat affects their disease, said lead researcher Adrienne Nassar, MD, third-year medical resident at Mayo Clinic.

“People with diabetes have an impaired ability to sweat, which predisposes them to heat-related illness, as do uncontrolled, high blood sugars,” Nassar said. “Many patients surveyed had suboptimal glycemic control during the summer, possibly increasing their risk of dehydration.”

Past research shows that during hot weather people with diabetes have an increased number of emergency room visits, hospitalizations and deaths due to heat illness.

Yet one in five survey respondents said they would not take precautions until temperatures exceeded 100 degrees Fahrenheit. “Heat illness can take place at 80 to 90 degrees when you factor in the heat index,” Nassar said. …

more via Science Daily

Pollutants in the bones

ScienceDaily (June 18, 2010) — Exposure to chemical pollutants is of growing concern to regulators, health workers, and environmentalist groups alike. Now, researchers in the US and Russia have demonstrated that samples of human bone can act as a biological marker for dozens of metals and toxic elements across the periodic table.

They describe details in a study published in the International Journal of Environment and Health.

Sofia Zaichick of the Department of Immunology and Microbiology, at Northwestern University, in Chicago, and her father Vladimir Zaichick of the Department of Radionuclide Diagnostics, in the Medical Radiological Research Centre of Russian Academy of Medical Sciences, in Obninsk, describe analyses of rib bones. The team used Instrumental Neutron Activation Analysis (INAA) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) to analyze the intact rib-bone post mortem of 84 previously healthy 15 to 58 year-old citizens of a non-industrial region in the Central European part of Russia. They applied statistical methods to observe any effect of age and gender on major, minor and trace element content of the bone.

Of the 92 natural chemical elements in the periodic table, not counting those from which human tissues are mainly composed, including carbon, hydrogen, oxygen, and nitrogen, the team demonstrated the presence of 44 additional elements. Among them are toxic elements, such as aluminium, arsenic, samarium and thallium, as well as the trace elements necessary for life, including calcium, iron, magnesium, and phosphorus.

“Bone is a tissue in which the turnover of these elements, particularly those that have an affinity for bone, is extremely slow and their biological half-lives are estimated to be from few years to decades,” the team explains. “This gives bone several important features as a subject of environmental monitoring.”….

more via Science Daily

Popular diets and micronutrient deficencies

It is estimated that at any given time, as many as a third of people with overweight and obesity are on a restrictive diet (in addition to an unknown number of normal weight people, who follow diets in the hope that they are healthier and may prevent weight gain).

As most of the popular diets consist of restricting overall caloric intake (despite often misleading claims to the contrary) and amounts of certain foods, the question arises whether or not there may be any potential drawbacks to being on such diets.

This question is of particular importance as many people with overweight and obesity often have nutrient deficiencies to start with – a situation that can potentially become worse as total food consumption decreases….

more at DrSharma.ca

Berries as Cancer-Fighters

Garden-variety berries provide about the same cancer-fighting punch as more exotic ones, a study of rats with esophageal cancer shows. A separate study finds a potentially protective effect against breast cancer as well.

Cancer biologist Gary Stoner of Ohio State University in Columbus and his colleagues tested seven berry types against cancer of the esophagus in rats —black raspberries, red raspberries, blueberries, strawberries, noni berries, açai berries and wolfberries (also called goji berries).

The scientists injected the animals with a carcinogenic chemical and gave some of the rats normal food, while others got similar chow containing 5 percent of one of the berries in dehydrated form.

While nearly all of the rats fed normal chow developed tumors rapidly, only about two-thirds of the berry-supplemented rats did. Overall, these rats had about half as many tumors as the others, the researchers report in the June Pharmaceutical Research. The berry-fed rats also had lower concentrations of interleukin-5 and a rat version of interleukin-8, inflammatory proteins implicated in esophageal cancer….

more at Science news