Abstract
Objectives: Modern humans may have gracile skeletons due to low physical activity levels and mechanical loading. Tests using pre-historic skeletons are limited by the inability to assess behavior directly, while modern industrialized societies possess few socio-ecological features typical of human evolutionary history. Among Tsimane forager-horticulturalists, we test whether greater activity levels and, thus, increased loading earlier in life are associated with greater later-life bone status and diminished age-related bone loss. Materials and Methods: We used quantitative ultrasonography to assess radial and tibial status among adults aged 20+ years (mean±SD age=49±15; 52% female). We conducted systematic behavioral observations to assess earlier-life activity patterns (mean time lag between behavioural observation and ultrasound=12 years). For a subset of participants, physical activity was again measured later in life, via accelerometry, to determine whether earlier-life time use is associated with later-life activity levels. Anthropometric and demographic data were collected during medical exams. Results: Structural decline with age is reduced for the tibia (female: -0.25 SDs/decade; male: 0.05 SDs/decade) versus radius (female: -0.56 SDs/decade; male: -0.20 SDs/decade), which is expected if greater loading mitigates bone loss. Time allocation to horticulture, but not hunting, positively predicts later-life radial status (βHorticulture=0.48, p=0.01), whereas tibial status is not significantly predicted by subsistence or sedentary leisure participation. Discussion: Patterns of activity- and age-related change in bone status indicate localized osteogenic responses to loading, and are generally consistent with the logic of bone functional adaptation. Nonmechanical factors related to subsistence lifestyle moderate the association between activity patterns and bone structure.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physical Anthropology |
| DOIs | |
| State | Accepted/In press - 2017 |
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Keywords
- Bone functional adaptation
- Mechanical loading
- Physical activity
- Tsimane
ASJC Scopus subject areas
- Anatomy
- Anthropology
Cite this
Horticultural activity predicts later localized limb status in a contemporary pre-industrial population. / Stieglitz, Jonathan; Trumble, Benjamin; Kaplan, Hillard; Gurven, Michael.
In: American Journal of Physical Anthropology, 2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Horticultural activity predicts later localized limb status in a contemporary pre-industrial population
AU - Stieglitz, Jonathan
AU - Trumble, Benjamin
AU - Kaplan, Hillard
AU - Gurven, Michael
PY - 2017
Y1 - 2017
N2 - Objectives: Modern humans may have gracile skeletons due to low physical activity levels and mechanical loading. Tests using pre-historic skeletons are limited by the inability to assess behavior directly, while modern industrialized societies possess few socio-ecological features typical of human evolutionary history. Among Tsimane forager-horticulturalists, we test whether greater activity levels and, thus, increased loading earlier in life are associated with greater later-life bone status and diminished age-related bone loss. Materials and Methods: We used quantitative ultrasonography to assess radial and tibial status among adults aged 20+ years (mean±SD age=49±15; 52% female). We conducted systematic behavioral observations to assess earlier-life activity patterns (mean time lag between behavioural observation and ultrasound=12 years). For a subset of participants, physical activity was again measured later in life, via accelerometry, to determine whether earlier-life time use is associated with later-life activity levels. Anthropometric and demographic data were collected during medical exams. Results: Structural decline with age is reduced for the tibia (female: -0.25 SDs/decade; male: 0.05 SDs/decade) versus radius (female: -0.56 SDs/decade; male: -0.20 SDs/decade), which is expected if greater loading mitigates bone loss. Time allocation to horticulture, but not hunting, positively predicts later-life radial status (βHorticulture=0.48, p=0.01), whereas tibial status is not significantly predicted by subsistence or sedentary leisure participation. Discussion: Patterns of activity- and age-related change in bone status indicate localized osteogenic responses to loading, and are generally consistent with the logic of bone functional adaptation. Nonmechanical factors related to subsistence lifestyle moderate the association between activity patterns and bone structure.
AB - Objectives: Modern humans may have gracile skeletons due to low physical activity levels and mechanical loading. Tests using pre-historic skeletons are limited by the inability to assess behavior directly, while modern industrialized societies possess few socio-ecological features typical of human evolutionary history. Among Tsimane forager-horticulturalists, we test whether greater activity levels and, thus, increased loading earlier in life are associated with greater later-life bone status and diminished age-related bone loss. Materials and Methods: We used quantitative ultrasonography to assess radial and tibial status among adults aged 20+ years (mean±SD age=49±15; 52% female). We conducted systematic behavioral observations to assess earlier-life activity patterns (mean time lag between behavioural observation and ultrasound=12 years). For a subset of participants, physical activity was again measured later in life, via accelerometry, to determine whether earlier-life time use is associated with later-life activity levels. Anthropometric and demographic data were collected during medical exams. Results: Structural decline with age is reduced for the tibia (female: -0.25 SDs/decade; male: 0.05 SDs/decade) versus radius (female: -0.56 SDs/decade; male: -0.20 SDs/decade), which is expected if greater loading mitigates bone loss. Time allocation to horticulture, but not hunting, positively predicts later-life radial status (βHorticulture=0.48, p=0.01), whereas tibial status is not significantly predicted by subsistence or sedentary leisure participation. Discussion: Patterns of activity- and age-related change in bone status indicate localized osteogenic responses to loading, and are generally consistent with the logic of bone functional adaptation. Nonmechanical factors related to subsistence lifestyle moderate the association between activity patterns and bone structure.
KW - Bone functional adaptation
KW - Mechanical loading
KW - Physical activity
KW - Tsimane
UR - http://www.scopus.com/inward/record.url?scp=85017202903&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85017202903&partnerID=8YFLogxK
U2 - 10.1002/ajpa.23214
DO - 10.1002/ajpa.23214
M3 - Article
C2 - 28345788
AN - SCOPUS:85017202903
JO - American Journal of Physical Anthropology
JF - American Journal of Physical Anthropology
SN - 0002-9483
ER -