27 May 2011

Fitness, hunter-gatherer style

Aché man hunting. Credit: Wiki
“So the bottom line is that foragers are often in good shape and they look it. They sprint, jog, climb, carry, jump, etc all day long but are not specialists.”
The quote above is excerpted from a description given by anthropologist Kim Hill (whose work I've previously written about here) of his experience observing the behaviors of the Aché of Paraguay and the Hiwi of Venezuela. The ASU professor, who has been living and studying the tribes for more than 30 years, recently had his work highlighted in a commentary published in Progress in Cardiovascular Diseases.

The article, whose lead author was James O'Keefe, MD, examines the daily physical activity patterns among hunter gatherers and fossil hominins. According to the authors, ancestral hunter-gatherers expended as much as five times more amounts of energy on physical activity than the average modern sedentary adult.

Based on data from Cordain's earlier work and that of colleagues, the article proposes a cross-training exercise regimen, as opposed to specialized trainings of Olympic athletes, intended to mimic the way of life that is required of a typical hunter gatherer. The "prescription for organic fitness" includes 14 essential features, which the authors suggest "appear to be ideal for developing and maintaining fitness and general health while reducing risk of injury."

16 May 2011

How Neandertals Lived, Hunted, and Ate

This Discovery Channel series "Neanderthal" presents a wonderful re-enactment of how Neandertals lived in small groups, how they hunted together, and how they ate.

I was especially taken by how much we know about the way they used tools to butcher meat, scraped animal hides (by holding the hides in their teeth and face as a tool to spread the stress around the skull) for use in making clothing (shown in Part 1).

It's amazing that we know so much about these ancient peoples -- how strong they were, how intelligent, how adaptive, as said in the documentary.

The scientific techniques mentioned that lend to our understanding of Neandertals are studies on fossilized feces, worn-out teeth from scraping animal hides, and bone fractures that reveal injuries that led to illness or death.

08 May 2011

Those daily extra cups of joe not linked to hypertension

An extra shot of espresso can surely help wake you up in the morning, but what does it mean for your blood pressure? It is well known that coffee's caffeine content can raise blood pressure temporarily, especially in people who have hypertension. Could habitually drinking high amounts have long-term effects on blood pressure too?

Java lovers will rejoice in a large study's findings that more cups daily isn't associated with increased risk of hypertension. The study, published in American Journal of Clinical Nutrition on March 30, was a systematic review and meta-analysis that examined six prospective cohort studies.

Diagnosing Darwin's multiple gastrointestinal diseases

Charles Darwin (Credit: Wikimedia)
Throughout most of Charles Darwin's adult life, the famed author of On the Origin of Species struggled with repeated episodes of severe abdominal pain, nausea and vomiting that could last for hours at a time, often occurring about three hours after breakfast, and thought to have been brought on by times of emotional stress.

England's physicians of the time could not properly diagnose the syndrome of cyclic vomiting, although they tried by suggesting its etiology was anything to do with allergies, gout, and mental overwork. But what of an assessment of Darwin's symptoms by modern physicians of today?

On Friday, May 6, modern physicians gathered to discuss Darwin's lifelong illness at the 18th Historical Clinicopathological Conference sponsored by University of Maryland Health Care System. The conference previously has examined and provided modern medical diagnoses of other prominent historical figures such as Abraham Lincoln and Edgar Allan Poe. The scientists chose Darwin for this year's conference to commemorate the naturalist's 200th birthday.

At the conference, the medical researchers determined that the nature of Darwin's sickness may be explained by multiple gastrointestinal illnesses he might of contracted while traveling to remote areas of South America, the Pacific, Far East, and Africa. A transmission of parasites, for example, may have led to what would become chronic "Chagas disease" and "peptic ulcer disease," further explaining the onset of Darwin's cardiac symptoms and eventual heart disease.

06 May 2011

Getting off the death chair

My stand-up desk
As bipedal apes, our bodies are meant for walking and running, which may have even been a catalyst for eventually bringing about the means of evolving larger brains.

Physical activity is strongly linked to brain performance. The exercise boosts blood flow in the brain and improves our memory and cognitive function. Exercise acts like a trigger for the brain saying, "It's time to be alert, find food, survive." Exercise may even fuel brain power by increasing neurogenesis and also guard against the harmful effects of stress.

Yet now we sit, and sit, and sit. Until the sitting kills us.

This article in the New York Times magazine gives a pretty good description of just what really happens when you sit in that death chair with quotes from Marc Hamilton, an inactivity researcher at the Pennington Biomedical Research Center:
This is your body on chairs: Electrical activity in the muscles drops — “the muscles go as silent as those of a dead horse,” Hamilton says — leading to a cascade of harmful metabolic effects. Your calorie-burning rate immediately plunges to about one per minute, a third of what it would be if you got up and walked. Insulin effectiveness drops within a single day, and the risk of developing Type 2 diabetes rises. So does the risk of being obese. The enzymes responsible for breaking down lipids and triglycerides — for “vacuuming up fat out of the bloodstream,” as Hamilton puts it — plunge, which in turn causes the levels of good (HDL) cholesterol to fall.
Isn't that enough to scare the "sit" out of you? If not, this infographic will do the trick.

Safe weight loss for seniors through diet and exercise

In the United States, the number of obese older adults has reached disturbing heights—now affecting approximately 20 percent of those ages 65 and older—and is only expected to rise as more Baby Boomers become senior citizens.

Weight loss through calories reduction or exercise are generally good for most people as an intervention in obesity, although the appropriateness of these methods has historically been a matter of controversy in older, obese adults.

A major concern with weight loss is the accompanying loss of lean tissue, which can accelerate existing sarcopenia (age-related loss of muscle and strength), and result in reduction of bone mineral density that could worsen frailty. This could lead to greater risk of bone fractures and broken hips. Studies have yet to provide sufficient evidence, one way or another, as to whether or not weight loss provides a true enhancement to quality of life.

03 May 2011

Printing organs for transplants

Advances in medicine are allowing us to live longer than ever, but with our older age comes a greater risk that our organs will fail us. In fact, the shortage of organs available for transplant increases by the day, according to Anthony Atala who spoke at TEDMED.

In his talk, posted in March, Atala presents developments in regenerative medicine including new devices that use the same technology of scanners, fax, copy machines and printers. Instead of using ink in their cartridges, they simply use cells.

On stage, Atala shows us how one of these devices works, actually printing a kidney in as little as seven hours. It's mind bending.

I feel as though I'd like to show this video to every person I know. This is our future medicine. This technology will no doubt keep us living longer than ever. One day, like salamanders, we will be growing our own organs whenever needed -- kidneys, livers, lungs, etc.

Can you even imagine? Eat and drink whatever you like, ruin your liver and kidneys, then have new ones printed in all but a few hours, and you're as good as new?

It's almost sickening.

News that "Nutcracker Man didn't eat nuts" isn't exactly news

Photosimulation montages of "Nutcracker Man's" dental microwear. Reference: Ungar et al. PLoS One 2008. 
Because of a huge jaw and large, flat molars, Paranthrapus boisei was nicknamed Nutcracker Man and thought to have eaten a diet comprised largely of hard nuts and seeds.

But, it turns out, the hominin species who in evolutionary terms has been likened to our great uncle was more likely to have eaten soft fruits, leaves and grass, according to carbon stable isotope data just published in PNAS by Thure Cerling and his team from University of Utah.

See more about Cerling's paper on John Hawks's blog.

A big deal has been made of this new paper and rightly so, but reporters should also note that the findings are a confirmation of what was already supposed based on dental microwear (shown above) almost exactly three years ago.

On 30 April 2008, Peter Ungar and colleagues at University of Arkansas also told us Nutcracker Man didn't eat nuts in a study in PLoS One (and featured by @9brandon in Wired Science here) citing wear and tear on the hominin's teeth that looked nothing like that of what would've been produced by hard foods.

02 May 2011

Michael Ruse on "Origins of Human Evolution"

Michael Ruse

Why were the great Greek philosophers (including Plato and Aristotle) firmly set against the idea of natural origins? Why were they so adamant that natural origins were impossible? According to Michael Ruse, a philosopher of biology at Florida State University, the reason is the problem of "final causes."

Aristotle, for example, "could not see how something like this could come about through blind law," said Ruse in a lecture given at Arizona State University’s Origins Project Science and Culture Festival on April 7, 2011.

This is why, for good scientific reason, said Ruse, they turned their back and rejected the idea of natural origins.

What was the big move? Robert Boyle particularly put his finger on it, said Ruse, we’ve changed the thinking of the world as an organism, to the world as a clock. This was a new metaphor for the world—the world is at some level a machine.

Resveratrol Improves Insulin Sensitivity in Humans

Low-dose supplementation of resveratrol daily may reduce oxidative stress and improve the body's sensitivity to insulin, a study from University of Pecs in Hungary suggests.

In a double-blind, placebo-controlled study published in the British Journal of Nutrition, Hungarian researchers report observations that people with type 2 diabetes who take 5 milligrams of resveratrol twice daily improved their sensitivity to insulin after only our weeks.

"The present study shows for the first time that resveratrol improves insulin sensitivity, which might be due to a resveratrol-induced decrease in oxidative stress that leads to more efficient insulin signaling via the Akt pathway," the authors concluded.

The Akt pathway is a pathway involved in cellular uptake of glucose in response to insulin—it induces glucose transport, particularly into muscle cells. When working properly, insulin stimulates cells to take in glucose from the blood stream, thereby lowering circulating glucose levels and providing carbohydrate for the cells for energy production.

In this study, the researchers randomized 19 Caucasian male participants with type II diabetes into two groups. The intervention group received 5 milligrams of resveratrol, twice daily for four weeks. The control group received a placebo twice daily.

By the fourth week, the intervention group showed significantly reduced oxidative stress and increased levels of phosphroylated Akt, indicating improved insulin sensitivity. Similar studies also documented a glucose-lowering effect of resveratrol in diabetic rodents.

Resveratrol, a naturally occurring compound found in grapes and other foods, is also famed because of evidence as an anti-aging bioactive and an aid in weight management.


Brasnyo P, Molnar GA, Mohas M et al. Resveratrol improves insulin sensitivity, reduces oxidative stress and activates the Akt pathway in type 2 diabetic patients. Br J Nutr 2011;1-7.