11/03/2023
By Oladimeji Akinlawon
Candidate Name: Oladimeji Jimmy Akinlawon
Defense Date: Friday, November 10, 2023
Time: noon to 2 p.m.
Location: Join Zoom Meeting https://uml.zoom.us/j/7579469837
Thesis/Dissertation Title: Bioavailable Phosphorus and Associated Health Outcomes among Adults from the Jackson Heart Study and the Boston Puerto Rican Health Study
Committee:
Prof. Dhimiter Bello, Department of Biomedical and Nutritional Sciences, University of Massachusetts, Lowell
Prof. Sabrina Noel, Department of Biomedical and Nutritional Sciences, University of Massachusetts, Lowell
Prof. Wenjun Li, Department of Public Health, University of Massachusetts, Lowell
Advisor: Prof. Katherine Tucker, Department of Biomedical and Nutritional Sciences, University of Massachusetts, Lowell
Brief Abstract:
Americans are high consumers of processed foods. Phosphates are widely utilized in food processing and have been found in more than 20,000 food products. In older adults, this poses a significant burden on the kidney and may impact cognitive function. Excessive added phosphorus (P) intake within short periods can cause hyperphosphatemia, thus, the high bioavailability of added P intake is likely to lead to greater bodily exposure to P, with a deleterious effect on eGFR. A major impact of hyperphosphatemia involves an imbalance in endocrine regulation and calcification of non-skeletal tissues, particularly in the kidney. These particles can initiate tubule-interstitial inflammation, activate toll-like receptor 4 to cause tubule damage, induce and aggravate renal injury, and may lead to decreasing renal function.
In the kidney, the P regulatory system is activated to induce phosphaturia. As mechanisms become insufficient, high P exposure may cause the formation and deposition of calcium-phosphate complexes in vascular tissues. which may restrict oxygen flow to deep regions of the brain and impact cognition.
There is currently no distinction between P intake from additives and natural P in food composition databases, and total P intake is reported with unknown bioavailability. The implication of the widespread use of added P remains unknown. Thus, in this thesis, we distinguished natural from additive P, and calculated bioavailable P consumed by participants in the Jackson Heart (JHS) and Boston Puerto Rican Health (BPRHS) studies, using a novel algorithm. Associations between total P, P from additives and natural P with kidney and cognitive outcomes were examined. Further, we measured the P content of key foods frequently consumed by Puerto Ricans that may be a potential source of added P, to validate or update the P measures used in our algorithm.