Professor Helen Macdonald is investigating how bone health and some chronic diseases may be affected by specific dietary factors, sunlight and dietary patterns.
Fruit and vegetables: There is increasing evidence that eating fruit and vegetables may be important for bone health. We have been investigating the mechanism behind this observation using epidemiological studies (APOSS, Macdonald et al AJCN 2005) and a 2-year randomized controlled trial (ADAFVT, Macdonald et al AJCN 2008). The results of the latter study suggest that for healthy women, making the diet more alkaline by eating more fruit and vegetables is not the reason for the beneficial effect. PhD work by Antonia Hardcastle and Claire Macdonald-Clarke has explored whether it is the bioactive compounds in fruit and vegetables that are important (the flavonoids, compounds found in tea, coffee and citrus fruits; and the anthocyanidins and carotenoids which are found in colourful fruits and vegetables).
Vitamin D: Being at high latitude (57°N), Aberdeen does not receive as much sunlight of the correct wavelength to make vitamin D, compared to places at lower latitude. Although it may be sunny, we cannot make vitamin D from October to the beginning of April. We have been investigating what influences how much vitamin D we have, and the role of Vitamin D on health, within four separate studies. The association study (APOSS, Macdonald et al Bone 2008) showed that bone turnover was higher at low vitamin D levels and that obese women had lower vitamin D status compared to other groups; the longitudinal (ANSAViD) study showed that the women in Aberdeen had low vitamin D status compared to those in the South of England; and our 1 year intervention trial (VICtORy, Wood et al JCEM 2008) has shown that seasonal effects in blood pressure are independent of vitamin D status. Intercalated BSc medical student Sarah Milliken observed effects on the immune system when people were given a course of narrow band UVB treatment which rapidly increased their synthesis of vitamin D (Milliken, JACI 2011). Cross-college collaboration as part of The North theme is considering the health aspects of light alongside the role of light in cultural contexts.
Figure 1: Simplified schematic diagram of Vitamin D sources.
Dietary Patterns: People do not eat separate nutrients. The foods we eat contain many different nutrients, and within each food type one nutrient may be a marker for another. There are interactions between the different nutrients and the food matrix, which means that studying dietary patterns may be a better way to help us to understand the relationship between what we eat and our health. We are currently studying how dietary patterns may influence low grade systemic inflammation, a condition which then predisposes people to chronic disease.
Professor Macdonald collaborates with Drs. Alex Mavroeidi on physical activity and Rebecca Barr on falls.
APOSS Aberdeen prospective osteoporosis screening study
- ADAFVT Aberdeen Dietary Acidity, Fruit and Vegetable Trial: ISRCTN86186352
- ANSAViD Aberdeen Nutrition, Sunlight and Vitamin D study: ISRCTN96210443
- VICtORy Vitamin D and Cardiovascular Risk study: ISRCTN20328039
Dr Rebecca Barr has research interests in falls and fracture prevention investigating the associated risk factors and genetics. She completed the first randomised controlled trial of osteoporosis screening, investigating whether screening women for osteoporosis by Dual energy X-ray Absorptiometry impacts on their medication use and their subsequent risk of fractures. In a 5-centre study, across England and Scotland, she has investigated whether peripheral Dual energy X-ray Absorptiometry measurement can be used to predict fractures in elderly women living in the community. Using quantitative ultrasound in a screening and calcium and vitamin D intervention study in elderly women she investigated participation rates and the impact of screening on the incidence of falls and fractures in women seen at their own GP practice. She is involved in investigating the relationship between falls and genetics with a particular interest in vitamin D receptor polymorphisms in the elderly. She has investigated the association between vitamin D receptor gene polymorphisms, falls, balance and muscle power in two independent studies. She is also involved in improving falls screening in the hospital setting.
Dr. Alex Mavroeidi's research focuses in optimising lifestyle factors (mainly physical activity) that might influence musculoskeletal diseases. Data from 1254 postmenopausal women that took part in the North of Scotland Osteoporosis Study (NOSOS) revealed that higher levels of habitual physical activity are associated with stronger bones (bone mineral density). This was an important finding, as although well-constructed exercise programmes have been shown to have an osteogenic effect we know that such interventions have poor adherence rates in the long term by older adults. As such, aiming to increase habitual activity levels might be a more sustainable option. Her interactive bone specific physical activity questionnaire (Mavroeidi, Macdonald et al. 2004) has been used in a number of Aberdeen based cohorts and is currently the main tool of physical activity assessment in a study by the University of Bristol.
Alex is currently interested in developing novel exercise approaches (like the use of active video games e.g. ‘WiiFit’ based exercises) to promote good bone health in the elderly (e.g. reduce fall rates) in collaboration with colleagues from NHS Grampian (Dr Roy Soiza) and the epidemiology group (Dr Gareth Jones). In addition, she has just completed a systematic review and meta-analysis on the role of active video games in adult weight loss in collaboration with Dr Lorna Aucott (Medical Statistics) and Ms Fiona Stewart (Health Services Research Unit) (publication in progress).
In collaboration with other members of the group (e.g. Dr Lynne Hocking and Dr Henning Wackerhage) she has also investigated potential gene-physical activity interactions affecting bone health (in terms of BMD and falls) (Judson, Wackerhage et al. 2011) and interactions between diet-physical activities and BMD (Mavroeidi, Stewart et al. 2009).
Alex is also interested in the interplay between vitamin D (from diet and sunlight sources) and physical activity in relation to health. In collaboration with Professor Helen Macdonald she has been involved in a number of vitamin D studies (Mavroeidi, O'Neill et al. 2010; Macdonald, Mavroeidi et al. 2011; Macdonald, Mavroeidi et al. 2011), cardiovascular disease (ViCTORY) (Wood, Secombes et al. 2012) and chronic low-grade systemic inflammation (currently on-going work).
- Barr RJ, Gregory JS, Reid DM, Aspden RM, Yoshida K, Hosie G, Silman AJ, Alesci S, Macfarlane GF (2011). Predicting osteoarthritis progression to total hip replacement: can we do better that risk factors alone using active shape modelling? Rheumatologydoi: 10.1093/rheumatology/ker382
- Barr RJ, Macdonald HM, Stewart A, McGuigan F, Rogers A, Eastell R, Felsenberg D, Glueer CC, Roux C, Reid, DM (2010) . Association between vitamin D receptor gene polymorphisms, falls, balance and muscle power: results from two independent studies (APOSS and OPUS). Ost Int. 21457-466
- Barr RJ, Stewart A, Torgerson DJ, Reid D.M (2010). Population screening for osteoporosis risk: A randomised control trial of medication use and fracture risk. Ost Int. 21561-568
- Judson R, Wackerhage H, Hughes A Mavroeidi A, Barr RJ, Macdonald H, Ratkevicius A, Reid DM, Hocking L (2011). The functional ACTN3 577X variant increases the risk of falling in older females: results from two large independent cohort studies. J Gerontol A Biol Sci Med Sci. 66 (1):130-5
- Macdonald HM, Mavroeidi A, Barr RJ, Black AJ, Fraser WD, Reid DM (2008). Vitamin D status in postmenopausal women living at higher latitudes in the UK in relation to bone health, overweight, sunlight exposure and dietary vitamin D. Bone 42 996-1003
- Macdonald, H. M., A. Mavroeidi, et al. (2011). Skin color change in Caucasian postmenopausal women predicts summer-winter change in 25-hydroxyvitamin D: findings from the ANSAViD cohort study. J Clin Endocrinol Metab 96(6): 1677-1686
- Macdonald, H. M., A. Mavroeidi, et al. (2011). Sunlight and dietary contributions to the seasonal vitamin D status of cohorts of healthy postmenopausal women living at northerly latitudes: a major cause for concern? Osteoporos Int 22(9): 2461-2472
- Mavroeidi, A., H. M. Macdonald, et al. (2004). Validity and repeatability of the Aberdeen bone specific physical activity questionnaire. Osteoporos Int 15 (suppl 2): S30
- Mavroeidi, A., F. O'Neill, et al. (2010). Seasonal 25-hydroxyvitamin D changes in British postmenopausal women at 57 degrees N and 51 degrees N: a longitudinal study. J Steroid Biochem Mol Biol 121(1-2): 459-461
- Mavroeidi, A., A. D. Stewart, et al. (2009). Physical activity and dietary calcium interactions in bone mass in Scottish postmenopausal women. Osteoporos Int 20(3): 409-416
- Wood, A. D., K. R. Secombes, et al. (2012). Vitamin D3 Supplementation Has No Effect on Conventional Cardiovascular Risk Factors: A Parallel-Group, Double-Blind, Placebo-Controlled RCT. J Clin Endocrinol Metab 97(10): 3557-3568