Human bones have lost density and become fragile since the dawn of agriculture, according to a new study that says increasingly sedentary lifestyles are to blame for the negative evolution.
Modern orangutans, whose bones are just as strong as those of hunter-gatherers from 7,000 years ago, help illustrate this point, according to the Cambridge University research team.
Foraging humans had a bone mass approximately 20 percent higher than those evolved since the farming age, and the researchers say it would take just three months of weightlessness to lose that amount of bone mass.
Researchers say they ruled out dietary changes and variations in body structure as possible causes for the change in bone mass over time and they believe there is no anatomical reason why a person born today could not achieve this bone mass.
Yet not even the most physically active people today manage to do so because their lifestyles don't measure up to those of hunter-gatherers in terms of the load and stress on bones, say the researchers.
"Contemporary humans live in a cultural and technological milieu incompatible with our evolutionary adaptations," says co-author Dr. Colin Shaw from the University of Cambridge's Phenotypic Adaptability, Variation and Evolution (PAVE) Research Group. "Sitting in a car or in front of a desk is not what we have evolved to do.
The findings support the theory that exercising could be more important than diet in preventing bone fractures and the onset of osteoporosis.
"You can absolutely morph even your bones so that they deal with stress and strain more effectively," says Dr. Shaw, who says there is much to be learned from the skeletons of prehistoric humans. "Hip fractures, for example, don't have to happen simply because you get older if you build your bone strength up earlier in life, so that as you age it never drops below that level where fractures can easily occur."
The type of bone tissue most affected by the evolutionary change is spongy bone, known as trabecular in the scientific community.
"Trabecular bone has much greater plasticity than other bone, changing shape and direction depending on the loads imposed on it," says Shaw. "It can change structure from being pin or rod-like to much thicker, almost plate-like. In the hunter-gatherer bones, everything was thickened."
The study was published in Proceedings of the National Academy of Sciences of the United States of America.
AFP RELAXNEWS
Wed Dec 24 2014
A study from Cambridge University in the UK says that human skeletons have lost density due to sedentary lifestyle. - AFP Photo
Kerajaan Persekutuan ambil alih Projek LRT Pulau Pinang
Projek pembangunan LRT Laluan Mutiara Pulau Pinang akan diambil alih oleh Kerajaan Persekutuan tetapi dengan meletakkan syarat kepada Kerajaan Negeri Pulau Pinang.
Pengarah syarikat dakwa pemilik RM500,000 beri keterangan esok - Ketua Polis Selangor
Pengarah syarikat yang mendakwa pemilik bagasi berisi wang RM500,000 yang ditemukan di tempat letak kereta dijangka hadir memberikan keterangan esok.
Bernas ceriakan Aidilfitri pesawah asnaf
Padiberas Nasional Berhad (BERNAS) menceriakan 45 asnaf dan komuniti pesawah sempena Aidilfitri tahun ini.
Inisiatif Gema Ramadan Menyantuni Penuh Ikhlas adalah sebagai inisiatif untuk menyumbang kepada masyarakat dengan menekankan fokus strategik ke atas impak yang lebih bermakna, melangkaui Tanggungjawab Sosial Korporat semata-mata.
Inisiatif Gema Ramadan Menyantuni Penuh Ikhlas adalah sebagai inisiatif untuk menyumbang kepada masyarakat dengan menekankan fokus strategik ke atas impak yang lebih bermakna, melangkaui Tanggungjawab Sosial Korporat semata-mata.
[TERKINI] Mahkamah Tinggi arah Isa dan Emir bayar RM3.31 juta
Mahkamah Tinggi Kuala Lumpur memerintahkan Tan Sri Isa Samad dan Datuk Mohd Emir Mavani Abdullah membayar lebih RM3.31 juta kepada FGV Holdings Berhad.
KJ akhirnya dapat isi PADU selepas identiti dicuri
Khairy Jamaluddin akhirnya berjaya mendaftar dalam sistem PADU selepas mendakwa akaunnya telah didaftarkan oleh individu yang tidak dikenali.
Aset rizab rasmi Malaysia AS$114.28 bilion akhir Februari 2024 - BNM
Aset rizab rasmi Malaysia berjumlah US$114.28 bilion pada akhir Februari 2024 manakala aset mata wang asing lain adalah US$202.69 juta (US$1=RM4.73), kata Bank Negara Malaysia (BNM).
Tiada kemunculan Amad, pertemuan Man United-Brentford
Kedua-dua pasukan Manchester United dan Brentford kehilangan seorang pemain kerana penggantungan untuk pertembungan Liga Perdana Inggeris Sabtu ini.
Singgah Sahur UMPSA santuni anak yatim, agensi keselamatan
Program Singgah Sahur UMPSA bukan sekadar bertujuan berkongsi rezeki, tetapi juga menjentik rasa keinsafan dan kesyukuran.
Sarawak Energy kini penaung Majlis Tenaga Dunia, pertama dari Asia Tenggara
Sarawak Energy secara rasmi menjadi penaung global Majlis Tenaga Dunia, sekali gus menjadikannya yang pertama dari rantau Asia Tenggara.
Dua lelaki tak mengaku rompak, menyamar polis
Dua lelaki dihadapkan ke Mahkamah Sesyen Seremban pada Jumaat atas pertuduhan melakukan rompak berkumpulan terhadap seorang lelaki, minggu lalu.
Pertanian adalah perniagaan
MAHA 2014 merupakan pameran pertanian tertua, terbesar dan unik di Malaysia. Ikuti infografik berikut bagi memahami pameran pertanian dwi-tahunan terbesar ini dengan lebih lanjut.