Physical activity, diet and skeletal health

Abstract

Diet and physical exercise concur in the determination of skeletal mass at the end of adolescence and in the conservation of it during adult life. The functional demand imposed on bone is a major determinant of its structural characteristics. Stress applied to a skeletal segment affects the geometry of the bone, the microarchitecture and the composition of the matrix. The stimulatory effect occurs when the skeleton is subjected to strains exceeding habitual skeletal loads, and the intensity of load is more important than the duration of the stimulus.Physical activity leads to greater bone density in children and adolescents and, to a minor extent, in adults. Weight bearing activities, such as walking, have a greater effect than non weight bearing activities, such as cycling and swimming. Reduction of loads as in bed resting or in space flights leads to bone loss. Intense training may cause damage, promptly repaired, as in stress fractures observed in army recruits. Female athletes may experience oligo-amenorrhea, though they still have a positive bone balance.There is an important interaction between the mechanical demands and the availability of nutrients to manufacture bone tissue. The increase in bone density in post-menopausal women is positively related to calcium intake when calcium supplementation is accompanied by exercise. When mechanical demands are low, such as during immobilisation, the intestinal calcium absorption is reduced. Calcium intake should also be analysed in the light of other dietary factors affecting the balance between absorption and excretion, and in combination with a number of other minerals, trace elements and bioactive substances with an impact on bone metabolism.

The sports and exercise life-course: A survival analysis of recall data from Ireland

“…Higher levels of activity are associated with reduced risks of coronary heart disease (Batty, 2002), stroke (Wendel-Vos, Schuit, Feskens, Boshuizen, Verschuren, Saris et al, 2004), diabetes (Jeon, Lokken, Hu & van Dam, 2007), various cancers (e.g. Tardon, Lee, DelgadoRodriguez, Dosemeci, Albanes, Hoover et al, 2005;Monninkhof, Elias, Vlems, van der Tweel, Schuit, Voskuil et al, 2007) and improved skeletal health (Branca, 1999).…”

“…Higher levels of activity are associated with reduced risks of coronary heart disease (Batty, 2002), stroke (Wendel-Vos, Schuit, Feskens, Boshuizen, Verschuren, Saris et al, 2004), diabetes (Jeon, Lokken, Hu & van Dam, 2007), various cancers (e.g. Tardon, Lee, DelgadoRodriguez, Dosemeci, Albanes, Hoover et al, 2005;Monninkhof, Elias, Vlems, van der Tweel, Schuit, Voskuil et al, 2007) and improved skeletal health (Branca, 1999).Evidence for these and other health benefits has been extensively reviewed in the United States by the Physical Activity Guidelines Advisory Committee (2008), which concluded that there was very strong evidence linking physical activity to better health-related fitness, lower risk of developing disabling medical conditions and lower rates of various chronic diseases.Increasing physical activity is a medical recommendation and a public health policy objective (e.g. World Health Organization, 2002).…”

Phytoestrogens regulate transcription and translation of vitamin D receptor in colon cancer cells

“…However, E2 has also been associated with enhanced breast and uterus carcinogenesis. Interest in soy and soybean constituents is driven primarily by reported potential health benefits in a variety of areas, including the prevention of cancer (Cross et al 2004) and osteoporosis, improvement of bone health (Branca 1999, 2003, Branca & Lorenzetti 2005, and a lowered risk of cardiovascular diseases (Cos et al 2003, Dixon 2004, Valachovicova et al 2004, Beck et al 2005. Their estrogenic activities may play an important role in their health-enhancing properties.…”

Validity and reproducibility of self-reported total physical activity—differences by relative weight

“…Regular physical activity among adults has been associated with decreased risk of obesity, 1 coronary heart disease, 2,3 non-insulin-dependent diabetes mellitus, 4 osteoporosis, 5 and certain types of cancer, especially colon cancer. 6,7 Studies also show an inverse association between physical activity and all-cause mortality.…”