JacobHeitmann
2014-11-02, 12:10
Abstract
Evidence is growing that diet, lifestyle factors and chronic inflammation influence sarcopenia. Sarcopenia is the progressive decline of muscle mass, strength and function that occurs with healthy ageing. The ageing process is also associated with a gradual increasing production of pro-inflammatory cytokines, which may potentially enhance the development of sarcopenia. Dietary longitudinal studies have shown associations between protein intake and muscle mass in older people but results of supplementation studies in enhancing muscle mass and strength are equivocal. Additionally, short-term dietary interventions with essential amino acid supplementation have shown promising effects on muscle protein synthesis. Emerging evidence suggests that a number of nutrients may be associated with muscle mass and strength either due to their anti-inflammatory properties or their involvement in muscle biology. However, there are currently few population studies examining the relative importance of specific nutrients in association with muscle mass, muscle strength and muscle quality. Therefore, this thesis aimed to examine associations between the habitual dietary intake of a range of micronutrients, and diet quality (assessed by five predefined diet quality scores) and indexes of muscle mass, strength and muscle quality in female participants aged 18-79 years from the TwinsUK cohort. An additional aim was to examine associations between diet and biomarkers of inflammation and to investigate whether diet could also influence the relationship between muscle mass and inflammation. The results suggested a significant positive association between intakes of vitamins C and E, magnesium, potassium and a range of carotenoids and indexes of muscle mass with scale of associations ranging between 1.5-4.6%. However, no associations were observed for protein and essential amino acid intakes. Higher adherence to the Mediterranean Diet score (MDS), Healthy Diet Indicator (HDI), Diet Quality Index (DQI), Alternate Healthy Eating Index (AHEI), and DASH-style score was significantly associated with measurements of muscle mass, with associations ranging between 1-3% between quintiles. Furthermore, a number of nutrients and the HDI and AHEI scores were inversely associated with plasma levels of the inflammatory marker C-reactive protein (CRP). Interestingly, intakes of magnesium, potassium, vitamin C, carotene, β-carotene, glutamine, and the MDS, HDI and AHEI scores attenuated the association between indexes of muscle mass and CRP by 1-8%, inferring that these components mediate the relationship between muscle mass and inflammation. In conclusion, the findings of this thesis emphasise the importance of consumption of a variety of plant-based nutrients and of overall diet quality for the conservation of muscle mass, and shed new light on the influence of these dietary components on sarcopenia related inflammation.
https://ueaeprints.uea.ac.uk/48746/
Evidence is growing that diet, lifestyle factors and chronic inflammation influence sarcopenia. Sarcopenia is the progressive decline of muscle mass, strength and function that occurs with healthy ageing. The ageing process is also associated with a gradual increasing production of pro-inflammatory cytokines, which may potentially enhance the development of sarcopenia. Dietary longitudinal studies have shown associations between protein intake and muscle mass in older people but results of supplementation studies in enhancing muscle mass and strength are equivocal. Additionally, short-term dietary interventions with essential amino acid supplementation have shown promising effects on muscle protein synthesis. Emerging evidence suggests that a number of nutrients may be associated with muscle mass and strength either due to their anti-inflammatory properties or their involvement in muscle biology. However, there are currently few population studies examining the relative importance of specific nutrients in association with muscle mass, muscle strength and muscle quality. Therefore, this thesis aimed to examine associations between the habitual dietary intake of a range of micronutrients, and diet quality (assessed by five predefined diet quality scores) and indexes of muscle mass, strength and muscle quality in female participants aged 18-79 years from the TwinsUK cohort. An additional aim was to examine associations between diet and biomarkers of inflammation and to investigate whether diet could also influence the relationship between muscle mass and inflammation. The results suggested a significant positive association between intakes of vitamins C and E, magnesium, potassium and a range of carotenoids and indexes of muscle mass with scale of associations ranging between 1.5-4.6%. However, no associations were observed for protein and essential amino acid intakes. Higher adherence to the Mediterranean Diet score (MDS), Healthy Diet Indicator (HDI), Diet Quality Index (DQI), Alternate Healthy Eating Index (AHEI), and DASH-style score was significantly associated with measurements of muscle mass, with associations ranging between 1-3% between quintiles. Furthermore, a number of nutrients and the HDI and AHEI scores were inversely associated with plasma levels of the inflammatory marker C-reactive protein (CRP). Interestingly, intakes of magnesium, potassium, vitamin C, carotene, β-carotene, glutamine, and the MDS, HDI and AHEI scores attenuated the association between indexes of muscle mass and CRP by 1-8%, inferring that these components mediate the relationship between muscle mass and inflammation. In conclusion, the findings of this thesis emphasise the importance of consumption of a variety of plant-based nutrients and of overall diet quality for the conservation of muscle mass, and shed new light on the influence of these dietary components on sarcopenia related inflammation.
https://ueaeprints.uea.ac.uk/48746/