Tuesday, July 22, 2014

Humans have become Taller, Fatter and Older in 100 Years – Study says.


Interesting research on how good food, clean environment can make man grow taller, longer and healthier. Two things that caught up with my eyes are that (1) any change in the body that happened in one generation (say, starvation due to lack of food), would continue to next few generations and it would take atleast 5 generations to wipe off that and (2) a set of food-cum- environment factors can increase the longevity. The first one reminds me of the karmic issues such as dosha or curse coming in a lineage that starts getting manifest in the off springs once after the causative karma has happened and continue atleast for  3 generations thereafter, unless correctives are done. The second reminds me of the long life, our ancestors in our country were supposed to have enjoyed. 'Jeevema sharadah shatam' was the prayer directed at the Sun! The Sun being the primary cause of all that happens on the earth, it is highly sophisticated knowledge that our ancestors have knocked the doors of this primary cause to get 100 years of life. Added to this is the disciplined life style and maintaining a balanced environment. It's no wonder they lived long and died peacefully. Similar research such as the present one must be done on ancient Indian living.

Having said this, I do have a doubt on the universality of this study. If good food alone matters, where does genetic component stand? It may be true that good food had increased life and body size, but that can not be the only criteria for height. For example the prominent sage who comes into my mind when I think of height is sage Agasthya! Definitely malnutrition was not the cause of his height.



There are reports of Denisovans of short stature who peopled earth some 30,000 years ago. The earth was more greener and cleaner and less peopled at that time. But they among others in other parts of the world had lived as short beings in comparison to others. So it must be something to do with their genetic map. The present day people may have been shorter for what they are originally due to malnutrition, wars and population explosion in the last few centuries. Perhaps they are getting into what they have to be originally with increase in better life style now.

**********************

From

Taller, Fatter, Older: How Humans Have Changed in 100 Years

By Agata Blaszczak-Boxe,
Live Science Contributor  
July 21, 2014 08:58am ET


Humans are getting taller; they're also fatter than ever and live longer than at any time in history. And all of these changes have occurred in the past 100 years, scientists say.

So is evolution via natural selection at play here? Not in the sense of actual genetic changes, as one century is not enough time for such changes to occur, according to researchers.

Most of the transformations that occur within such a short time period "are simply the developmental responses of organisms to changed conditions," such as differences in nutrition, food distribution, health care and hygiene practices, said Stephen Stearns, a professor of ecology and evolutionary biology at Yale University. [10 Things That Make Humans Special]

But the origin of these changes may be much deeper and more complex than that, said Stearns, pointing to a study finding that British soldiers have shot up in height in the past century.

"Evolution has shaped the developmental program that can respond flexibly to changes in the environment," Stearns said. "So when you look at that change the British army recruits went through over about a 100-year period, that was shaped by the evolutionary past."

And though it may seem that natural selection does not affect humans the way it did thousands of years ago, such evolutionary mechanisms still play a role in shaping humans as a species, Stearns said.

"A big take-home point of all current studies of human evolution is that culture, particularly in the form of medicine, but also in the form of urbanization and technological support, clean air and clean water, is changing selection pressures on humans," Stearns told Live Science.
"When you look at what happens when the Taliban denies the polio vaccination in Pakistan, that is actually exerting a selection pressure that is different in Pakistan than we have in New York City," he said.

Here's a look at some of the major changes to humans that have occurred in the past century or so.


(Some) people have grown taller

A recent British study, published by the Institute for the Study of Labor (IZA) in Bonn, Germany, showed that young men in the United Kingdom have grown by 4 inches (10 centimeters) since the turn of the 20th century.
In the study of British recruits, the average height of British men, who had an average age of 20, was about 5 feet 6 inches (168 centimeters) at the turn of the century, whereas now they stand on average at about 5 feet 10 inches (178 cm). The increase can be attributed, most likely, to improved nutrition, health services and hygiene, said the researchers from the University of Essex in Colchester.

In a number of other developed countries, people have been growing taller, too, reaching the world's current greatest average height of 6 foot 1 inch (1.85 meters) in the Netherlands. Interestingly, Americans were the tallest people in the world by World War II, measuring 5.8 feet (1.77 meters), but by the end of the 20th century, they fell behind, and the average U.S. height has stagnated, according to a study by John M. Komlos, currently a visiting professor of economics at Duke University. [Why Did Humans Grow 4 Inches in 100 Years?]



And even in some of those countries where the average height has been rising, the increase has not been uniform. For instance, people from former East Germany are still catching up height-wise with former West Germans after years of communist rule, said Barry Bogin, a professor of biological anthropology at Loughborough University in the United Kingdom. And in some non-Western countries that have been plagued by war, disease and other serious problems, average height has decreased at one point in time or another. For instance, there was a decline in the mean height among blacks in South Africa between the end of the 19th century and 1970, Bogin wrote in one of his studies, published in the Nestle Nutrition Institute workshop series in 2013. He explained that the decline was likely related to the worsening of socio-economic conditions before and during apartheid.
"It shows you the power and the generation-after-generation effects of something bad that happened to your mother gets carried on to you and your children, and it takes about five generations to overcome just one generation of starvation, or epidemic illness, or something like that," Bogin told Live Science.

Unfortunately for those individuals, height seems to improve humans' quality of life and chances of survival. For instance, in the United States, taller people make more money on average, as they are perceived as "more intelligent and powerful," according to one such study published in 2009 in the Economic Record.


Everyone is getting fat

Since the 1970s, Bogin has been studying growth patterns of Maya children and their families living in Guatemala, Mexico, and the United States. When Maya people move to the United States, their kids born here are 4.5 inches (11.4 centimeters) taller than siblings born in Mexico or Guatemala. This likely results from the accessibility of more-nutritious food in the United States, for instance, through lunch programs at schools, as well as better health care, Bogin noted. The Maya kids are also less exposed to infectious diseases, which are less common in the United States than in the countries of the parents' origin. [7 Devastating Infectious Diseases Explained]
But this increase in height comes with a high price tag.



"Not only do these Maya kids begin to look more like Americans in height, but they become even super-Americanized in their weight, by becoming overweight," Bogin told Live Science.

"People are getting fatter everywhere in the world," he said. (In 2013, 29 percent of the world's population was considered overweight or obese, according to a study published May 29 in the journal The Lancet.)
Exactly why humans are getting fatter is currently a question of heated scientific debate. Some researchers point to the traditional argument of eating too much and exercising too little as the culprit, whereas others offer alternative explanations, including the role of genetics and viruses that have been linked to obesity. The issue of excessive weight and obesity gets even more complicated, as many studies have linked being fat with poverty, which goes against a popular association of obesity and wealth.

Interestingly, the Maya kids in Indiantown, Florida, on whom Bogin focused his studies, had the highest rates of being overweight and obese of all ethnic and racial groups in the area, including Mexican-Americans, African-Americans, Haitians and European-Americans. This may have something to do with epigenetics, or heritable changes that turn genes on and off but that are not caused by changes in the DNA sequence. For instance, the environment may have caused epigenetic changes to some ethnic groups that affect how the body stores excessive energy from food, Bogin said.
"There may be an expectation that since your mother suffered and your grandmother suffered, somehow this suffering gets passed on to the current generation of children, and they kind of expect that there is going to be bad times and there is not going to be enough food," he said. "So when there are good times, eat as much as you can, and the body should preferentially store the extra energy as fat."

This mechanism of fat storage driven by a history of malnutrition or starvation may be occurring in other poor populations in the world who are becoming overweight and obese, he said.


Earlier puberty

In many countries, children mature earlier these days. The age of menarche in the United States fell about 0.3 years per decade from the mid-1800s (when girls had their first menstrual period, on average, at age 17) until the 1960s, according to a 2003 study in the journal Endocrine Reviews, which also suggested better nutrition, health and economic conditions often play roles in lowering the age of menarche. Today the average age of menarche in U.S. girls is about 12.8 to 12.9 years, according to Bogin. The onset of puberty, however, is defined as the time when a girl's breasts start to develop. In the United States, it is 9.7 years for white girls, 8.8 years for black girls, 9.3 years for Hispanic girls and 9.7 years for Asian girls.
Studies have also pointed to a link between obesity and early puberty, as girls with higher body mass indexes (BMIs) are generally more likely to reach puberty at younger ages.

"The influence of BMI on the age of puberty is now greater than the impact of race and ethnicity," Dr. Frank Biro, a professor of pediatrics at Cincinnati Children's Hospital in Ohio, told Live Science in a 2013 interview.
And earlier puberty may have long-term health consequences, Biro said. For instance, studies have suggested that girls who mature earlier are more likely than those who mature later to develop high blood pressure and type 2 diabetes later in life.

There are also social consequences of earlier puberty; in some cultures, when a girl is biologically mature, she is also considered mature enough for marriage, Bogin noted. This may mean that she will not be able to continue her education or have a career once she does get married.

Therefore, the later a girl gets her first period, the better for her overall educational and life prospects. In fact, a Harvard study published in 2008 in the Journal of Political Economy showed that, in rural Bangladesh, where 70 percent of marriages occur within two years of menarche, each year that marriage is delayed corresponds to 0.22 additional year in school and 5.6 percent higher literacy.


Longevity and its bittersweet consequences

Humans are now living longer than ever, with average life expectancy across the globe shooting up from about 30 years old or so during the 20th century to about 70 years in 2012, according to the World Health Organization. The WHO predicts global life expectancy for women born in 2030 in places like the United States to soar to 85 years. The boost in life expectancy could be linked to significant advances in medicine, better sanitation and access to clean water, according to Bogin.

Although all of these factors have also greatly reduced mortality rates from infectious diseases, the deaths from degenerative diseases such as Alzheimer's, heart disease and cancer have been on the rise, Stearns said. In other words, people are living longer and are dying from different diseases than they did in the past.

"An American baby born in the year 2000 can expect to live 77 years and will most likely die from cardiovascular disease or cancer," Bogin said. [The Top 10 Leading Causes of Death]
As is often the case with biological advantages that humans sometimes gain, old age also comes with trade-offs.

"As more of us live longer, then more and more of us are encountering a death which is protracted and undignified," Stearns said. "So there are costs to all of this wonderful advance."

Autoimmune diseases such as multiples sclerosis and type I diabetes have also become more common, according to Stearns. Some scientists think the surge in such diseases is related to improved hygiene — the same factor that has allowed people to get rid of many infectious diseases, said Joel Weinstock, chief of gastroenterology at Tufts University Medical Center in Massachusetts. When the body is not exposed to any, or very few, germs, the immune system can overreact to even benign bugs, the thinking goes.
"Our theory is that when we moved to this super-hygiene environment, which only occurred in the last 50 to 100 years, this led to immune disregulation," Weinstock told Live Science in a 2009 interview. "We're not saying that sanitation is not a good thing — we don't want people to jog up to riverbanks and get indiscriminately contaminated. But we might want to better understand what factors in hygiene are healthy and what are probably detrimental, to establish a new balance and hopefully have the best of both worlds."


What is next for the human species?

It is hard so say what is in store for humans, as technology is changing the world so quickly.

"There is some fear out there that an esoteric cabal of scientists in white coats is going to take over the future of evolution with genetic engineering," Stearns said. "Whether we want to or not, we have already changed our future course of evolution, and it is not being done by some small group of people who are thinking carefully and planning, it is being done as a byproduct of thousands of daily decisions that are implemented with technology and culture."

"And we don't really know where that is going," he said, adding that, "once you accept that culture [including medicine, technology, media and transportation] has become a really strong driving force in human evolution, that is — we don't know how to predict culture."

Follow Agata Blaszczak-Boxe on Twitter. Follow Live Science @livescienceFacebook Google+. Original article on Live Science.

Editor's Recommendations

19 comments:

Unknown said...

You are touching on the topic of epigenetics.Its a hot topic right now considering the research on cancer.Its fascinating looking at the genes being switched off and on depending upon the food you consume.People have higher chances of cancer upon eating certain foods. ITs as if those foods dictate the working of certain genes.

I feel both genetic factors and environment play comparable roles. A person who is short genotypically, that disadvantage could be offset to a certain extent with proper nutrition.At the same time, you cant expect that person to be a behemoth with just nutrition.There is some leeway but not much.

There are many instances when a regular child with improper nutrition can also exhibit growth stunting.

Either Way, the nature and nurture play a delicate dance to decide on the final outcome.With the exposure to multitude of hormones from food,pesticides in western countries, You would see few outliers which would skew the normal physical constitution.

Unknown said...

Nice information sharing. People are not care astro predictions. We are offering all your astrological problem solutions by world famous astrologer Love Psychic Spiritial Healer in London&UK|Psychic Spiritial Healer Voodoo Service in London

இராமகிர்ஷ்ணாராவ் said...

Dear Jayasreeeji,

Hope you are doing good. Wondering why there has not been any article from you for the past few weeks.
I am praying for your good health and long service to provide useful knowledge to many seekers like me.
Regards,
Ramakrishna

Unknown said...

We provide with the best astrology solutions in love problem, family problem, business problem, or any concern.
http://greatindianastrologer.in/

aravamudhan swamy - a.g.swamy said...

madam, you have been quite for some time. Hope you are fine and doing well and continue to write.
with the court verdict on 27th sep to Jaya on DA case, i want you to analysis the horoscope of Jaya and give your opinion. i wish like every one that she should come out successfully. However we have to take in to consideration of her horoscope planetary positions.

Amma runs jupiter dasa and coming bukthi in early oct 14 is saturn.
jupiter being the lord of 7th and 10th kendrathipathi dosha is placed in 7th sign itself in ketu star at dhanusu. saturn the bukthi lord is the ownership of 8th and 9th lord from mituna lagna being the netural but placed in 2nd sign cancer. so dasa lord jupiter is in 7th own sign and saturn in 2nd sign. Both 2nd and 7th signs are maraka sthanas. they are in exis of sastanga 6/8 to each other. Also saturn is in mercury star which planet mercury is placed in 8th sign from saturn ( i e kumbham)

In kochara, saturn will be transiting to her 4th sign from moon sign. this is not good and will give her mental/physical problems. Also jupiter is in present transit to 12th sign from her star magham, the house of losses.

so i feel that she will be like sonia - MMS pattern of ruling TN state by installing a CM like lalu did before. Hwr if karmas can be changed by god grace, she should come out successfully to rule TN state as CM which everyone wishes.

Raghu said...

Hope you are well. It is unusual of you to remain silent so long.

Skandan said...

Respected Madam,

I do have the same question like Ramakrishnarao. What happened to madam?

Prayers for good health and long life.

Pranams
Skandan

Vebadan said...

I am no expert but I like to learn and evolution as a subject is one of them.

In concurrence with R.Bijjula's comments, our scientists are realizing more and more everyday how important a role epigenetics play in our evolution.

Having identical genetic make-up, two individuals can grown into two physiologically different beings depending on nutrition, genetics and epigenetic mutations and epigenetic inheritance and so on.

But let me (attempt to) paint a very broad and vague picture on why humans have become taller and fatter.

Considering the fact that food / nutrition was far more scarce then than it is today, our bodies had learned to adapt. Having a smaller body-mass-footprint facilitates lower need for nutrition, lower levels of heat transfer through skin etc.

The metabolic rate increases with body bass (some understanding of that relationship already exists in the scientific community) -> hence the requirement for higher energy inputs (diet) but not having access to nutrition rich diet and the frequency of the meals being far too less as compared to now, our bodies had adapted with having a smaller over-all gait.

Ofcourse there are many other considerations and there are always exceptions (possibly).

Narayanan said...

Sri:
Hope you are doing fine. Wondering why there are no articles from you recently. I regularly used to browse your page for good articles... Wondering what is going on.
Narayanan Kazhiyur

harish27 said...

Hello Jeyashree Mam,

Hope you are doing good. I am wondering why there has been no post from you for a long time. We are all eager enough to read your thoughts and wisdom on subjects from astrology to politics. Please continue your service. Thanks

Kalaivani said...

HI Jeya mam,

Please write more articles. I am daily checking on why there is no update on your blog.

I have benefited a lot from your articles.
- Vani, Singapore/

Unknown said...

Hi Jayasreeeji,
Hope you are well and doing great. It's been a very long time since you posted on your blog (almost 6 moths i guess).
Actually i have couple of questions hope you go through my comment and have time to reply back.
1.) What is the best way to explain why sleveless shirts or see through dresses, skirts, minis are not ours and we should think twice before getting used to that dress culture.
2.) If your kids born abroad or working for a mnc in inidia or company abroad and wear dresses like mentioned above
and if they say be a roman in rome, how to best answer that.
3.) The best way to tell a woman by not hurting her that i dont like the type of dresses mentioned above.(It's just that they might say it's my body, my freedom, my liking and i like to
dress the way i want to). If possible, can you please explain the best way to answer each point.
The reason for asking you this is that you can explain from our Indian culture, tradition and woman point of view as well.
I might sound stupid and ridiculous it's just that i was born and bought up in a village and am not used to/like that way of dressing much. It's not that our saree
expose but its just that we are used to our tradition. Also if possible can you please let me know your email ID. Thought of sharing some horoscopes to check the
marriage compatability. Hope understand.Thanks!!!. Also ifpossible can you please not post this comment on your blog.

Unknown said...

Namaskara,madam jayasree. Such a wonderful blog with tremendous amount of information. Hats off !

Anyway,regarding this page,I find it difficult to digest that the average life of humans is increasing.We generally are accustomed to see our ancestors living a long life of 90 years or more,then year by year people die at 80, then 70 and it is getting reduced gradually. Effects of kali yuga ? It is also said that humans will live barely for 20 years and would be too short that they'll be forced to use ladders to climb grass plants. Also that in the dwapara yuga,bhishma studied sastras for 525 years, still did'nt get moksha,indicating the long lifespan then, or is it that bhishma was previliged because he was ganga's son.,or is it simply exageration? Your take on this.

pllblks said...

Dear ma'am,

It has been a long time since your last blog. Wondering why you stopped writing? Or have to shifted to some other blog.

Thanks,
Krishna

Unknown said...

Pandit Bhushan is the most experienced and world reputed astrologer in Punjab, India. He always serves the high superiority services to in order to keep all his guests more happy and secure. He wants that all the people can easily come out back from his daily life problems through astrology services. contact no: +919872026893

Best Astrologer

Famous Astrologer

appalam vadaam said...

Dear Mami,

Ya, echoing the same thoughts.
No posts for a long time.

Hope all is well with you.

Regards
Vasundhara

Unknown said...

Pandit Bhushan is the most experienced and world reputed astrologer in Punjab, India. He always serves the high superiority services to in order to keep all his guests more hacppy and secure. He wants that all the people can easily come out back from his daily life problems through astrology services.

Famous Astrologer

Unknown said...

Our astrologer Pandit Bhushan Sharma doesn’t solely give the assorted services like kala jadu, love drawback solutions, wedding life solutions, tarot card reading and so on, however additionally offers the data however you'll simply use these services at your home.
Universal Healer

Som said...

wake up Mamdam, its been long time.