About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Manís Superior Ability To Digest Starch Puts Him Above Other Animals

by Medindia Content Team on September 10, 2007 at 3:32 PM
Font : A-A+

Manís Superior Ability To Digest Starch Puts Him Above Other Animals

New genetic research points to man's ability to digest starch as a clue to his success on planet Earth.

The report in Nature Genetics by University of California Santa Cruz authors says that as against primates, humans have many more copies of a specific gene crucial to the breakdown of calorie-rich starches. They speculate that these extra calories may have been essential for fuelling the larger brains of humans.

Advertisement

Experts have always pondered if meat in the diet was the answer to man's intelligence.Contradicts lead researcher Dr Nathaniel Dominy: "Even when you look at modern human hunter-gatherers, meat is a relatively small fraction of their diet.

"To think that, two to four million years ago, a small-brained, awkwardly bipedal animal could efficiently acquire meat, even by scavenging, just doesn't make a whole lot of sense."
Advertisement

The scientists found that humans carry extra copies of a gene, called AMY1, which is essential for making the salivary enzyme amylase that digests starch. When they studied groups of humans with differing diets, they discovered that those with high-starch diets tended to have more copies of AMY1 than individuals from populations with low-starch diets.

For example, the Yakut of the Arctic, whose traditional diet revolves around fish, had fewer copies than the related Japanese, whose diet includes starchy foods like rice.

These researchers believe that early human ancestors began searching for new food sources other than the ripe fruits primates eat.These were starches, stored by plants in the form of underground tubers and bulbs - wild versions of modern-day foods like carrots, potatoes, and onions.

Coincidentally, in earlier work this year, the team found that animals eating tubers and bulbs produced body tissues with a chemical structure akin to what has been measured in early fossilized humans.

Dominy opines that when early humans mastered fire, cooking starchy vegetables would have made them even easier to eat. It would also have made extra amylase gene copies an even more valuable trait, he says. "When you cook, you can afford to eat less overall, because the food is easier to digest. Marginal food resources can become part of the staple diet.

"Now you can have population growth and expand into new territories", Dominy postulates.

Yet, Professor John Duprť, a professor of philosophy of science at Exeter University in the UK, urges caution when interpreting the findings.

According to Duprť, it is impossible to conclude that the introduction of starchy foods into the diet lies behind the emergence of larger brains in humans.

"Lots of things differ between ourselves and our closest relatives and apart from the difficulty of establishing the relative places in the evolutionary sequence of any of these, the assumption that there is any one fundamental to such change is dubious.

"The results on amylase genes are quite interesting, and a good indication of something we are beginning to appreciate more widely - the functional plasticity of the genome", he concedes.

Source: Medindia
ANN/J
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
News Category
What's New on Medindia
January is the Thyroid Awareness Month in 2022
Menstrual Disorders
Coffee May Help You Fight Endometrial Cancer
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Indigestion 

Recommended Reading
Doubt ĖThe Driving Force Behind Evolution In Some Birds
Members of some bird species will stick around longer to help a relative raise their young, instead ...
Evolution Open To Hitherto Uncommon Happenings
Scientists at the University of Rochester and the J. Craig Venter Institute have discovered a copy ....
Indigestion
Indigestion or dyspepsia is referred to nonspecific symptoms or discomfort that causes persistent p...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2022

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use
open close
CONSULT A DOCTOR
I have read and I do accept terms of use - Telemedicine

Advantage Medindia: FREE subscription for 'Personalised Health & Wellness website with consultation' (Value Rs.300/-)