Hi Science Readers,

This is a very interesting piece of research that explains just how stress can kill you, admittedly it has been done with monkeys but then again we are only hairless monkeys ourselves ( under a microscope we can be seen to have as much, if not more hair than Chimps, but ours is white and short and doesn't stand out like their black hair)


Fat-Bellied Monkeys Suggest Why Stress Sucks
By Alice Park Saturday, Aug. 08, 2009


It's no secret that stress isn't good for you. But what's less clear is how social stressors like a high-pressure job or a failing marriage affect your physical well-being.

Researchers at Wake Forest University who study stress in monkeys think they may have discovered a clue: fat. More specifically, the particular form of fat called visceral fat that tends to build up in the abdomen (those dreaded beer bellies and love handles). Researchers believe this abdominal fat lodges deep within visceral organs, such as the heart, liver and blood vessels, and may be an indicator of increased heart attack risk. In a study of 42 female monkeys, the scientists found that those with the most social stress — in the monkeys' case, that meant being at the bottom of the social hierarchy — packed away the most fat around the middle.

"For years now there has been a recognition that the pattern in which people lay down fat is associated more with health than the absolute amount of fat," says study co-author Carol Shively, a pathologist at Wake Forest. "Fat cells that live in the visceral depot behave differently than cells that live in other areas of the body."

Recent evidence suggests that visceral fat cells are active, unlike the fat cells found elsewhere in the body just under the skin, known as subcutaneous fat. Those fat cells are essentially just storage sinks for calories. But visceral fat cells actively secrete hormones and other agents that affect the metabolism of sugar and the way the body burns calories. In people, visceral fat has been linked to metabolic changes, such as higher blood pressure and blood sugar levels, that increase risk for diabetes and heart disease.

Shively and her colleagues also knew that people who produce excessive amounts of the stress hormone cortisol tend to have bulky waistlines; they have apple-shaped bodies, rather than pear-shaped. So the researchers wanted to examine all these factors — stress, abdominal fat and health risk — in one study. The problem, of course, is that measuring the relationship between stress and visceral fat in people in a controlled fashion isn't easy. So, the team turned to monkeys. For nearly two and a half years, she and her team fed the animals a typical Western diet, with 40% of calories coming from fat, measured their cortisol levels and used CT scans to calculate the amount of visceral fat each monkey carried.

The monkeys were housed in groups of four, automatically prompting them to establish a linear hierarchy of dominance. The dominant monkey in each group experienced the least stress, according to researchers. "They were groomed more than the subordinates, and they would get relaxed. Their eyes would roll up, sort of like they were getting a massage," says Shively. Monkeys further down the power chain, however, appeared more stressed-out. They were more vigilant, constantly scanning their environment for potentially aggressive threats from the leader. They also spent more time alone, out of contact with the other monkeys.

CT scans showed that group leaders and the second most dominant monkeys showed lower amounts of visceral fat than their subordinates, who carried the bulk of their body fat in their guts. In human populations, something similar happens: Studies have linked lower social status to a higher incidence of metabolic syndrome — the condition whose symptoms include being overweight and having high blood pressure and high glucose levels — which promotes heart disease.

Together with Shively's findings, says Dr. David Katz, director and co-founder of the Yale Prevention Research Center, the human data suggests a possible cause-and-effect link: Stress may promote accumulation of visceral fat, which in turn causes metabolic changes in the body that contribute to heart disease and other health problems.

"This study shows that psychological stress, which we know can affect stress hormone levels, can have a fairly rapid influence on where extra calories go," he says. "I'm generally quite cautious about animal research but here I think we're seeing something that has direct relevance to human health as well."

Here is the Abstract (Proof)


Behavior and Psychology

Obesity (2009) doi:10.1038/oby.2009.74
Social Stress, Visceral Obesity, and Coronary Artery Atherosclerosis in Female Primates

Carol A. Shively1, Thomas C. Register1 and Thomas B. Clarkson1

1Department of Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA

Correspondence: Carol A. Shively (cshively@wfubmc.edu)

Received 22 August 2008; Accepted 24 February 2009; Published online 26 March 2009.
Top of page
Abstract

Our previous work in cynomolgus monkeys demonstrated significant relationships between (i) social reorganization stress and visceral fat deposition, and (ii) central fat deposition and coronary artery atherosclerosis (CAA). Nevertheless, direct relationships between CAA and visceral fat have not been demonstrated in people or animals, nor have relationships among stress, visceral obesity, and CAA been observed within a single study. Here, we examine the hypothesis that visceral obesity provides a link between social stress and CAA. Subjects were 41 socially housed females that consumed an atherogenic diet for 32 months. Social behavior and ovarian function were continuously recorded; dexamethasone suppression tests, telemetered overnight heart rate, BMI, visceral (VAT) and subcutaneous abdominal (SAT) adipose tissue were measured before necropsy. Females with high VAT:SAT were relatively subordinate, socially isolated, received more aggression and less grooming, desensitized to circulating glucocorticoids, had impaired ovarian function, higher heart rates late in the day, and more CAA than low VAT:SAT females. High-BMI females had higher heart rates than low-BMI females. Poor ovarian function in high VAT:SAT females is a novel observation suggesting the need for studies of fat distribution and ovarian function in women. The results of this study are the first to demonstrate a relationship between CAA and visceral obesity, and suggest that social stress may exacerbate CAA in part by increasing the ratio of visceral:subcutaneous fat mass in selected individuals susceptible to diet-induced CAA. Further studies are needed to understand the complex and multifactorial temporal relationship among relative visceral obesity, physiological stress responses, and CAA.

Cheers

Interesting, I thought it would be the other way round, typically when I am stressed I eat considerably less.. .I wouldn't read too much into this though, since it's not always easy to say that the results of the tests performed on monkeys can be applied or transfered to humans.

Hi Jerry,
Because we also are monkeys with only 0.4% of difference in our important DNA, maximum 1.0%, doesn't leave a huge amount of difference, although that small variance can leave us worlds apart as one can easily see upon closer inspection,from speech/no speech to susceptibility to some diseases, as well as appearance of course. Humans only vary by 0.1% and we can see huge differences here.

http://www.pubmedcentral.nih.gov/articlere...gi?artid=423159

http://esciencenews.com/articles/2009/02/1...and.chimpanzees

The main point for investigators of health is that the differences are so small in the important areas for comparison of disease effects, they usually can say that what happens to a monkey ( Chimp) will also happen to another monkey ( humans).

Cheers I have to swing back up into the trees and search for breakfast now.

Stress I thought can make the "chubby"-> slim and for the already slim: slimmer. Why? because stress triggers the mind not to stop thinking and mere using our head is enough to tone down those fats. But reading this post makes me think otherwise. But I can't imagine myself being fat because until now I'm still slim in spite the stress I have.

Hi Hampers,
This is a good study and we should be able to rely on it to produce the same results in people as it did in monkeys. While I agree with what you say about the mind being over active, we still find the most stressed people with visceral fat build up, and this group have linked it via measurements to cortisol which has a large influence on sugar metabolism.

Cheers

Stress can make you fat as people tend to eat more. This happens not every person. It is not that you are hungry or have any urge for food. You just feel like munching something when you are stressed and if its high in calories, surely you will put on weight.

Hi livehealthy,

This is not so much about food or calorie intake as it is about deposition of fat. The stress hormones deposit the fat around visceral organs creating a very dangerous health situation. Remember a few years ago a research paper recognised TOFI, which stood for thin outside fat inside, this also was about fat deposition around organs.

Investigations around the world right now are focussing on inflammation, inflammation is linked to heart disease via blocked coronary arteries, and various cancers, and fat is a known cause of inflammation.

Cheers

Long term stress not only causes weight gain but it does a number on your immune system. You become susceptible to colds and flus and feel just plain tired. Wounds take longer to heal because cortisol prevents the normal buildup of killer white cells in the body. Even just taking a test can stress you out and make you sick. Dental students were given wounds to the roof of their mouths three days before their final exam and again during summer vacation (does this give you an idea of what professors think of their students?). Not surprisingly, the wounds took 40% longer to heal during the test time because of a 70% decline in the production of a particular type of white blood cell messenger RNA.201 This same response was found in caretakers of Alzheimer patients, proving that psychological stress can make you a target for illness.

social stress could lead to heart disease by causing the body to deposit more fat in the abdominal cavity and could also speed up harmful plaque build-up in blood vessels, according to new research, and that's why except of losing weight your fat increased.

Ahm, excuse me but HUMANS ARE NOT MONKEYS!!!!!!!! I don't care about the pointless evolution theory or whatever your research is. All I know is that God created MAN to be higher than any other creatures on earth. MAN is special and God showed it by really using His hands to mold man and breathed unto his nostrils to give man life. Please don't die believing in that stupid lie. Jesus gave His life to give man salvation, not the monkeys.

Hi green screen,
whether we like it or not the answers we have to give, in order to be marked correct, on this subject are clearly spelled out in the following. Evidence and peer pressure, as well as indoctrination, help shape our views and beliefs, but we can all refute the evidence, as often happens on here with health issues, and follow our own bias.

Humans



photo of a young man and woman at the beach

Typical human
sexual dimorphism


In addition to the great apes, the family Hominidae includes our species, Homo sapiens click this icon to hear the preceding term pronounced. In the past, there also were other species of humans as well as hominids more similar to us than the chimpanzees and bonobos. They will be described in the last three tutorials of this series.

It has been historically difficult for people to accept that we are in fact just another primate species with African origins and that we differ physically only in degree from some of the others. The similarities can be seen throughout our bodies. For instance, humans and the African apes all lack external tails and have hands with a thumb that is sufficiently separate from the other fingers to allow them to be opposable for precision grips. Humans are also sexually dimorphic--males are 5-10% larger on average and have greater upper body muscular development. Like chimpanzees and bonobos, we are omnivorous. We kill other animals for food in addition to eating a wide variety of plants. Internally, our bodies are even more similar to the great apes. We have essentially the same arrangement of internal organs and bones. We share several important blood types. We also get many of the same diseases.
photo of a chimpanzee with an outstretched hand photo of a human with an outstretched hand
Similar chimpanzee and human hands

photo of 2 humans running bipedally
Bipedal locomotion

The comparatively minor anatomical differences between humans and apes are largely a result of our habitual bipedalism click this icon to hear the preceding term pronounced. A number of changes in our bodies were related to the evolution of this form of locomotion. Unlike apes, our arms are relatively short and weak compared to our legs. Our feet no longer have the ability to effectively grasp and manipulate objects because the toes became shorter and the big toe moved up into line with the others. Human feet also have lengthened and acquired an arch, making them better body supports. The human pelvis and spinal column also have been modified for an erect posture and efficient bipedal locomotion. The pelvis became shorter, broader, and more bowl shaped. This provided greater stability for walking and running. We are now essentially fully terrestrial animals. Nature very likely selected for longer legs in humans because it is more efficient for walking and especially running bipedally. Research done by Herman Pontzer of Washington University in St. Louis, Missouri indicates that longer legs require less up-and-down movement while running and, therefore, reduce the amount of energy needed to move rapidly. This relatively lower rate of energy consumption would also allow humans to travel farther with the same calorie expenditure. In addition, the largely hairless human body with its abundance of sweat glands allows us to remain cooler while running than if we only relied on panting like most other mammals. This no doubt was a major advantage for our early human ancestors in the competition with other hunters and scavengers for meat in warm climates.

With the exception of these few outward differences, we are quite similar to the African apes anatomically and genetically, especially to the chimpanzees and bonobos. Humans have 46 chromosomes in their cells while all of the great apes have 48. In reality, this difference is not as great as it would initially seem because the human chromosome 2 is a fusion of ape chromosomes 12 and 13 with most of the same genes.

click this icon in order to see the following video Human chromosome 2--video clip from Teachers' Domain
This link takes you to a new webpage. To return here, you must click the
"back" button on your browser program. (length = 3 mins 27 secs)

Work on discovering the entire genome of common chimpanzees was completed in 2005. A comparison between this and the human genome (completed in 2001) shows that 98.77% of DNA base pairs of humans and chimpanzees are the same. However, there are an additional 2.7% differences between the two species in duplicated non-protein coding segments of DNA. Where we differ appears to be largely in the genes that control speech, smelling, hearing, digesting proteins, and susceptibility to certain diseases. These minor differences are to be expected given that we have been on essentially separate evolutionary tracks for 6-7 million years. During that time, we have been subject to somewhat different natural selection pressures. These differences led to bipedalism for our ancestors along with a much larger brain and, ultimately, speech.

The modern human brain is 3 times larger in volume than those of the great apes. More importantly, the human brain to body size ratio is significantly larger, and it has a much bigger cerebral cortex with a higher concentration of neurons. Evolving a larger brain comes at a steep energy cost. The human brain uses about 25% of the energy derived from the nutrients that we consume and 20% of the oxygen. Recent research has suggested that our intelligence advantage may be due to evolutionary changes in the HAR1F regulator gene beginning about 6 million years ago in our pre-human ancestors but not in those of chimpanzees or other apes. This gene is involved in the production of brain tissue between the 7th and 19th week after conception. It is not surprising that there are some striking differences between the great apes and humans in mental abilities. People have much more complex forms of verbal communication than any other primate species. We are the only animal to create and use symbols as a means of communication. We also have more varied and complex social organizations. The most distinctive feature of humans is our mental ability to create new ideas and complex technologies. This has proven invaluable in the competition for survival. However, the great apes are remarkably intelligent, having mental levels equivalent to a 3-4 year old human child. This is sufficient to allow them to learn and use the sign language of deaf humans in at least a rudimentary way, but they do not have the capability of producing human speech and language. This is likely due to the fact that they have a different form of another key regulator gene known as FOXP2.

There are two additional curious differences between humans and all other primates that are worth noting. We are the only primate species that now lacks a thick insulating fur over our entire bodies. This has allowed humans to cool efficiently by the evaporation of sweat when it is hot and we are exerting considerable energy in running and other strenuous physical activities. We are also the only species of primate in which all older females go through menopause and become sterile, often decades before dying of old age. Female chimpanzees, gorillas, and other non-human primates usually remain capable of conception and giving birth even when they are very old. In the wild, they usually live a relatively short amount of time following menopause if they go through it at all. One explanation for this difference in humans is that years of life following menopause has proven to have natural selection value for our species. Having raised their own children, post-menopausal women around the world often take care of their grandchildren while their daughters are working. It is argued that this increases the chances that the grandchildren will survive to adulthood because they receive this additional experienced and caring attention.

click this icon in order to see the following video What Makes Us Human--video clip from the Leakey Foundation
This link takes you to a new webpage. To return here, you must click
the "back" button on your browser program. (closed caption version)
(length = 7 mins 27 secs)

Let us review the classification of apes and humans. Both are members of the suborder Anthropoidea, the Infraorder Catarrhini, and the superfamily Hominoidea.

ANTHROPOIDS
suborder: Anthropoidea
infraorder: Platyrrhini Catarrhini
superfamily:

Ceboidea
Cercopithecoidea Hominoidea
species: New World monkeys Old World monkeys apes
humans

Within the superfamily Hominoidea, there are two families. People are closest to the African apes genetically, especially the chimpanzees and bonobos.

HOMINOIDS
superfamily: Hominoidea
family:

Hylobatidae
Hominidae
subfamily: Ponginae Gorillinae Homininae
tribe: Panini Hominini
species: gibbons orangutans

gorillas chimpanzees
bonobos
humans



News: The genome of rhesus macaque monkeys has been completed by a consortium of 23 laboratories (Science April 13, 2007). Comparing this genome with those already established for chimpanzees and modern humans will provide an even better tool for understanding the similarities and differences between the major groups of primates. Preliminary analysis indicates that macaques are similar to humans in 93% of their DNA sequences, while chimpanzees share about 98% of their DNA with us. This is to be expected since the last common ancestor of macaques and humans was about 19 million years ago, while the chimpanzees and human evolutionary lines diverged only around 6-7 million years ago. The U.S. National Human Genome Research Institute (NHGRI) has plans to sequence the genomes of marmosets, northern white-cheeked gibbons, orangutans, and gorillas.

click this icon in order to see the following video The Macaque Genome--video clips from the Science Multimedia Center
This link takes you to 3 short videos at an external website.
(closed caption version)



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This page was last updated on Sunday, December 06, 2009.
Copyright © 1998-2009 by Dennis O'Neil. All rights reserved.
illustration credits


http://anthro.palomar.edu/primate/prim_8.htm

Research indicates that humans and monkeys/apes evolved from a common ancestor.

This forum, as far as I know, is about learning rather than arguing.

Cheers and have a good day.