{"id":9249,"date":"2014-09-07T06:00:42","date_gmt":"2014-09-07T10:00:42","guid":{"rendered":"http:\/\/candostreet.com\/blog-parents\/?p=9249"},"modified":"2014-09-06T18:32:40","modified_gmt":"2014-09-06T22:32:40","slug":"a-long-childhood-feeds-the-hungry-human-brain","status":"publish","type":"post","link":"https:\/\/candostreetny.com\/blog-parents\/a-long-childhood-feeds-the-hungry-human-brain\/","title":{"rendered":"A Long Childhood Feeds the Hungry Human Brain"},"content":{"rendered":"

\u00a0\"brain\"<\/a><\/strong><\/p>\n

Findings in a recent study, reported by Erin White in a Northwestern University press release, give us insight into why human children take so long to grow and develop. The findings are an interesting read about brain development!<\/strong><\/span><\/em><\/h1>\n

EVANSTON, Ill, August 25, 2014<\/em><\/span>. — A five-year old\u2019s brain is an energy monster. A new study led by Northwestern University anthropologists has found that it <\/span>uses twice as much glucose (the energy that fuels the brain) as that of a full-grown adult.<\/span><\/p>\n

The study helps to solve the long-standing mystery of why human children grow so slowly compared with our closest animal relatives.<\/span><\/p>\n

The study shows that energy funneled to the brain dominates the human body\u2019s metabolism early in life and is likely the reason why humans grow at a pace more typical of a reptile than a mammal during childhood. Results of the study were published the week of Aug. 25 in the journal Proceedings of the National Academy of Sciences.<\/em><\/strong><\/span><\/h2>\n

\u201cOur findings suggest that our bodies can\u2019t afford to grow faster during the toddler and childhood years because a huge quantity of resources is required to fuel the developing human brain,\u201d said Christopher Kuzawa, first author of the study and a professor of anthropology at Northwestern\u2019s Weinberg College of Arts and Sciences. \u201cAs humans we have so much to learn, and that learning requires a complex and energy-hungry brain.\u201dKuzawa also is a faculty fellow at the Institute for Policy Research at Northwestern.<\/span><\/p>\n

The study is the first to pool existing PET and MRI brain scan data — which measure glucose uptake and brain volume, respectively to show that the ages when the brain gobbles the most resources are also the ages when body growth is slowest. At 4 years of age, when this \u201cbrain drain\u201d is at its peak and body growth slows to its minimum, the brain burns through resources at a rate equivalent to 66 percent of what the entire body uses at rest.<\/span><\/p>\n

The findings support a long-standing hypothesis in anthropology that children grow so slowly, and are dependent for so long, because the human body needs to shunt a huge fraction of its resources to the brain during childhood, leaving little to be devoted to body growth. It also helps explain some common observations that many parents may have.<\/span><\/p>\n

\u201c<\/strong><\/em>After a certain age it becomes difficult to guess a toddler or young child\u2019s age by their size,\u201d Kuzawa said. \u201cInstead you have to listen to their speech and watch their behavior. Our study suggests that this is no accident. Body growth grinds nearly to a halt at the ages when brain development is happening at a lightning pace, because the brain is sapping up the available resources.\u201d<\/strong><\/em><\/span><\/h3>\n

It was previously believed that the brain\u2019s resource burden on the body was largest at birth, when the size of the brain relative to the body is greatest. The researchers found instead that the brain maxes out its glucose use at age 5. At age 4 the brain consumes glucose at a rate comparable to 66 percent of the body\u2019s resting metabolic rate (or more than 40 percent of the body\u2019s total energy expenditure).<\/span><\/p>\n

\u201cThe mid-childhood peak in brain costs has to do with the fact that synapses, connections in the brain, max out at this age, when we learn so many of the things we need to know to be successful humans,\u201d Kuzawa said.<\/span><\/p>\n

\u201cAt its peak in childhood, the brain burns through two-thirds of the calories the entire body uses at rest, much more than other primate species,\u201d said William Leonard, co-author of the study. \u201cTo compensate for these heavy energy demands of our big brains, children grow more slowly and are less physically active during this age range. Our findings strongly suggest that humans evolved to grow slowly during this time in order to free up fuel for our expensive, busy childhood br<\/span>ains<\/strong><\/em>.\u201d <\/span>Leonard is professor and chair of the department of anthropology at Northwestern\u2019s Weinberg College of Arts and Sciences.<\/span><\/h3>\n

This study was a collaboration between researchers at Northwestern University, Wayne State University, Children\u2019s Hospital of Michigan, Icahn School of Medicine at Mount Sinai, University of Illinois, George Washington University and Harvard Medical School.<\/span><\/p>\n

The title of the paper, which is published in the Proceedings of the National Academy of Sciences, is \u201cEnergetic costs and evolutionary implications of human brain development.\u201d Authors include Kuzawa and Leonard as well as Harry T. Chugani, Lawrence I. Grossman, Leonard Lipovich, Otto Muzik, Patrick R. Hof, Derek E. Wildman, Chet C. Sherwood and Nicholas Lange.<\/span><\/p>\n

The study was funded by the U.S. National Science Foundation\u2019s Biological Anthropology Program.<\/span><\/p>\n

– See more at: http:\/\/www.northwestern.edu\/newscenter\/stories\/2014\/08\/a-long-childhood-feeds-the-hungry-human-brain.html#sthash.8fxf018q.dpuf<\/span><\/p>\n

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