Rosemary Walzem to retire after 27 years bridging poultry science and heart health
Texas A&M nutritional biochemist’s work reshaped understanding of cardiovascular disease
For Rosemary Walzem, Ph.D., a registered dietitian, the secret to a healthy heart was hiding in an egg yolk.
After more than 27 years, Walzem, professor and associate head for graduate programs in the Department of Poultry Science and also professor in the Department of Nutrition, both in the Texas A&M College of Agriculture and Life Sciences, will retire on Aug. 31.
Recruited to Texas A&M University by Joanne Lupton, Ph.D., a fellow University of California-Davis graduate, Walzem came to study how lipoproteins transport lipids through the bloodstream in birds and mammals and influence metabolism.
While her work began in poultry science, its impact reached far beyond the barnyard. By using birds to answer fundamental questions about how the body processes fats, she helped researchers better understand why some lipoproteins contribute to cardiovascular disease in humans while others do not.
Her research also challenged long-held assumptions about cholesterol by demonstrating that metabolic health depends not simply on individual nutrients, but on how the body regulates energy, clears lipoproteins and responds to excess.
Walzem’s work will continue to shape nutrition science as she helps develop international guidance for evaluating how dietary patterns influence chronic diseases such as Type 2 diabetes, cardiovascular disease, obesity and cancer.
A bird’s-eye view of heart health
Walzem discovered that a lipoprotein produced by hens to form egg yolk could help explain how similar particles behave in the human body. Its resemblance to the LDL cholesterol particle associated with heart disease made it a valuable research model.
She and her colleagues showed that when these particles remain in the bloodstream too long instead of being cleared naturally, they become more vulnerable to oxidation, a harmful chemical change linked to disease.
“Lipoprotein clearance rates are crucial to heart health,” Walzem said.
Birds dramatically retool their liver chemistry to produce eggs, and their vascular systems interact with lipoproteins similarly enough to humans to provide valuable insight, even when the differences prove most instructive, she said.
That comparative approach came naturally to Walzem as a nutritionist who viewed metabolism as a connected system. This perspective was part of the reason she was invited to serve on the National Academy of Science, Engineering and Medicine’s committee to develop the Nutrient Requirements of Poultry 10th Revised Edition.
Teaching skepticism through science
Walzem challenged the notion that individual foods or nutrients alone determine heart health. She found that the body’s overall energy balance and ability to properly process nutrients and metabolize lipoproteins play a much larger role in metabolic disease.
Her research showed that hens fed excess energy develop fatty liver disease, arrhythmias and reproductive failure resembling polyendocrine metabolic ovarian syndrome in women. This opened new avenues for studying the shared mechanisms behind metabolic disease in birds and humans.
In the classroom, where she taught graduate students about vitamin and mineral metabolism, Walzem said she hoped students left with the habit of questioning scientific claims, evaluating whether the biological rationale held up and determining whether the underlying measurements and dosing supported the conclusions.
That mindset lives on through the students she mentored into careers across academia, industry and public health, including a distinguished professor in Taiwan and researchers shaping food policy, animal health and human nutrition across the country.
What’s next
Retirement will not mean stepping away entirely. Walzem plans to finish papers with her final cohort of students and continue serving with the Institute of Food Technologists at the Codex Committee on Nutrition and Foods for Special Dietary Uses, where she helps develop guidance for evaluating diet-related chronic disease risk.
