Date of Award
2024
Document Type
Thesis - ECU Access Only
Publisher
Edith Cowan University
Degree Name
Doctor of Philosophy
School
School of Medical and Health Sciences
First Supervisor
Dr Lauren Blekkenhorst
Second Supervisor
Dr Lois Balmer
Third Supervisor
Dr Armaghan Shafaei Darestani
Fourth Supervisor
Professor Jonathan Hodgson
Fifth Supervisor
Associate Professor Joshua Lewis
Abstract
Observational studies suggest that higher consumption of cruciferous (e.g., broccoli, cabbage, cauliflower) and allium vegetables (e.g., garlic, onion, leek) are associated with reduced risk of cardiovascular disease. These vegetables are rich in sulfur-based compounds including glucosinolates and S-alk(en)yl cysteine sulfoxides, such as S-methyl cysteine sulfoxide (SMCSO). SMCSO is found in greater concentrations than glucosinolates in most of these vegetables yet considerably less research has been conducted to investigate the health effects of this compound. My thesis sought to explore whether some of the cardiovascular benefits of these vegetables could be from SMCSO, uncovering many novel findings.
Through a series of projects, my research was the first to examine the effects of SMCSO on the development of diet-induced cardiometabolic features in mice, observing beneficial changes to circulating high-density lipoprotein cholesterol levels. An SMCSO food database was developed, which compiled available SMCSO content from nineteen cruciferous and allium vegetables from around the globe. We reported Brussels sprouts and Chinese chives as having the highest levels of SMCSO, and leek and radish having the lowest. Recognising the lack of data on SMCSO[1]containing foods, particularly in Australia, my research was also the first to measure SMCSO within a selection of Australian-sourced vegetables. We also identified the most preferable domestic cooking methods (i.e., short-term microwaving and steaming) to retain SMCSO levels which may have important public health implications. Lastly, using our newly developed food database, we tested the validity of a commonly used food frequency questionnaire to reliably estimate SMCSO intakes in healthy, community-dwelling participants. We found that the food frequency questionnaire had moderate validity in estimating SMCSO intake. This finding will subsequently enable future research to explore the associations of SMCSO intake with health outcomes.
The results from my PhD can be used to assist in the design of future human trials, and for the first time, pave the way to explore the associations of SMCSO intake and health outcomes using large cohort data.
DOI
10.25958/svfa-vx56
Access Note
Access to this thesis is embargoed until 1 November 2027
Recommended Citation
Hill, C. R. (2024). Dietary S-methyl cysteine sulfoxide and human health: Mechanisms of action and cardiometabolic effects. Edith Cowan University. https://doi.org/10.25958/svfa-vx56