Jufen Liu

Title: Assistant professor (Tenure Track)

Major: Epidemiology and Biostatistics

E-mail: liujufen@bjmu.edu.cn

Address: 38 Xueyuan Rd ,Haidian District,Beijing,China

Personal profile

02/2020-present	Peking University, School of Public Health, Institute of Reproductive and Child Health，Assistant professor (Tenure Track)
11/2023-11/2024	University College London (UCL), UK, Honorary Research Fellow
08/2015-08/2016	University of Southern California (USC), USA, Visiting Scholar
03/2013-09/2013	University of Toyama , Japan, Visiting researcher
08/2009-01/2020	Peking University, School of Public Health, Institute of Reproductive and Child Health，Assistant professor
09/2007-10/2008	University of Southern California (USC), USA, Joint Doctoral Program
06/2007-08/2007	Young Scientist Summer Program, International Institute for Applied Systems Analysis (IIASA), Austria
09/2003-07/2009	Peking University, Institute of Population Research, Ph.D.
09/1998-07/2003	Shanxi Medical University, School of Public Health, Bachelor

Brief introduction of Teaching and Research

Dr. Jufen Liu lead her research team aims to develop scientific knowledge that uses life course and social epidemiology, multiple longitudinal cohorts, interdisciplinary, integrated and systems approaches to address future health challenges and the impact of environmental factors, including social environment, nutrition on health and development across the life course. Dr. Liu has a broad interest in birth defects and disability, focusing on neurodevelopmental disorders, degenerative diseases, chronic diseases and multi-morbidities at all ages. She led the research to investigate the early life determinants and trajectories of chronic diseases, study clusters of conditions and the interactions between their trajectories throughout the life course, through which to develop population level interventions to prevent chronic diseases and multimorbidity, as well as to support translation of discovery into policy and practice both within in China and in the global community. Dr. Liu has led on original research articles and her publications are featured in journals such as International Journal of Epidemiology, eClinicalMedicine, Social Science and Medicine, Globalization and Health, General Psychiatry, Chinese Journal of Epidemiology, Chinese Journal of Preventive Medicine, and so forth. Their findings have provided policy consultation reports to national ministries such as the health and environmental protection departments. Her research has been recognized with awards from Huaxia Medical Science and Technology Assiociation, Chinese Preventive Medicine Association, Beijing Preventive Medicine Association and Ministry of Education.

Dr. Liu developed and lead the course for graduate and undergraduate students (Frontiers of Population Health Science, Epidemiology of Disabilities, Social Epidemiology and Its Applications). Dr. Liu is an associate editor of textbooks "Epidemiology of Disabilities" and key editorial board member of "Prevention and Control of Disabilities: Basic Knowledge and Methods".

Additionally, Dr Liu served as various contribution to scientific communities, she is a standing committee member of the China Maternal and Child Health Association's Professional Committee on Perinatology and Metabolism; a member of the Chinese Preventive Medicine Association's Professional Committee on Birth Defects Prevention and Control, and the Committee on Family-School-Community Education of the Chinese Family Education Society. She is also served in the editorial boards of several academic journals, including Reproductive Health (Deputy Editor), BMC Pregnancy and Childbirth (Editorial Board Member), China CDC Weekly (Guest Editor), Frontiers in Nutrition (Guest Editor), Nutrients (Guest Editor), and China Journal of Reproductive Health (Editor).

Main research directions

Neurosciences: Development, Disorders and Degeneration of Nervous System

Lifelong Health: Reproductive, Maternal Health and Early Origins of Health, Ageing

Representative scientific research projects

1. Key Project of Regional Innovative Development Joint Fund of National Natural Science Foundation of China, U23A20420, Research on Important Susceptibility Factors, Pathogenic Mechanisms, and Early Intervention Strategies of Folate Non-Responsive Neural Tube Defects, 01/2024-12/2028, 416,000 RMB, Subproject Leader/Core member, Ongoing

2. Major Project of National Social Science Foundation, 21&ZD187, Study on Disability Prevention Strategies and Applications under the Background of Population Aging, 01/2022-12/2025, 600,000 RMB, Core member, Ongoing

3. National Key Research and Development Program of Ministry of Science and Technology, 2022YFC2705205, Establishment of Early Diagnosis, Intervention, and Early Warning System for Common Developmental Behavioral Disorders in Children, 01/2022-12/2025, 600,000 RMB, Core member, Ongoing

4. National Key Research and Development Program of Ministry of Science and Technology, 2021YFC2701101, Systematic Identification of Pathogenic Mutations in Major Birth Defects, 01/2021-12/2024, 1,000,000 RMB, Core member, Ongoing

5. Family Education Research Project of China Family Education Association (2021-2025), Study on the Relationship between Preschool Children's Screen Exposure, Family Rearing Environment, and Child Behavioral Development, 04/2023-12/2025, 50,000 RMB, Principal Investigator, Ongoing

6. Epidemiology and Health Statistics Core Competency Training Effectiveness Evaluation Project of China CDC (Multiple Stages, Continuing), 11/2022-12/2025, 120,000 RMB, Principal Investigator, Ongoing

7. Research Project on High-quality Population Development in 2024 by National Health Commission, Study on Promoting Reproductive Health across the Life Course and Policy Response, 04/2024-12/2024, Core member, Ongoing

8. China Nutrition Society Nutrition Research Fund, CNS-ZD2020-115, Study the Influence of Multiple Vitamin Supplementation on Gestational Diabetes and Its Immunological Mechanisms, 01/2021-12/2022, 190,000 RMB, Principal Investigator, Completed

9. National Natural Science Foundation of China, 81202265, Study on the Correlation between COMT and MTHFR Gene Polymorphisms and Plasma Protein Expression and Neural Tube Defects, 01/2013-12/2015, 230,000 RMB, Principal Investigator, Completed

10. Research Project on Beijing Disabled Persons' Federation, Study on the Policy of Early Retirement for Disabled People in Beijing, 12/2016-06/2017, 120,000 RMB, Principal Investigator, Completed

10 representative papers (Corresponding author)

1. Liu J, Li Z, Ye R, Ren A, Liu J. Folic acid supplementation and risk for congenital limb reduction defects in China. Int J Epidemiol. 2019, Dec 1;48(6):2010-2017. doi: 10.1093/ije/dyz130.

2. Liu J, Li Z, Ye R, Liu J, Ren A. Periconceptional folic acid supplementation and risk for parent-reported asthma in children at 4–6 years of age. ERJ Open Res. 2020 Apr 6;6(1):00250-2019. doi: /10.1183/23120541.00250-2019.

3. Liu J, Li Z, Ye R, Ren A, Liu J. Folic acid supplementation and risk for congenital hydrocephalus in China. Public Health Nutr. 2021 Sep;24(13):4238-4244. doi: 10.1017/S136898002100029X. Epub 2021 Jan 26.

4. Chen X, Du Y, Xia S, Li Z, Liu J*. Vitamin B12 and gestational diabetes mellitus: a systematic review and meta-analysis. Br J Nutr. 2023, 28 April;129(8): 1324-1331. doi: 10.1017/S000711452200246X.

5. Wang D, Song Z, Zhang Y, Zhang L, Jin L, Ren A, Li Z, Liu J*. Prevalence and Trends of Birth Defects - Five Counties, Shanxi Province, China, 2003-2022. China CDC Wkly. 2023 Sep 8;5(36):797-802. doi: 10.46234/ccdcw2023.153.

6. Ren Z, Xu Y, Sun J, Han Y, An L, Liu J*. Chronic diseases and multimorbidity patterns, their recent onset, and risk of new-onset Parkinson’s disease and related functional degeneration in older adults: a prospective cohort study. eClinicalMedicine 2023 Oct 6;65:102265.doi:10.1016/j.eclinm.2023.10226

7. Du Y, Luo Y, Zheng X, Liu J*. Number of children and cognitive function among Chinese menopausal women: The mediating role of depressive symptoms and social participation. J Affect Disord. 2023 Nov 1;340:758-765. doi: 10.1016/j.jad.2023.08.084.

8. Ren Z, Xia S, Sun J, Wang D, Du Y, Li N, Liu J*. Internet use, cardiometabolic multimorbidity, and death in older adults: a multi-cohort study spanning developing and developed countries. Global Health. 2023 Nov 6;19(1):81. doi: 10.1186/s12992-023-00984-z.

9. Ren Z, Du Y, Lian X, Luo Y, Zheng X, Liu J*. Bidirectional longitudinal associations between depressive symptoms and somatic conditions after adverse childhood experiences in middle-aged and older Chinese: a causal mediation analysis. Soc Sci Med. 2023 Dec 1;338: 116346. doi:10.1016/j.socscimed.2023.116346

10. Ren Z, Nie L, Du Y, Liu J*. Intertwined depressive and cognitive trajectories and the risk of dementia and death in older adults: a competing risk analysis. Gen Psychiatr. 2024; Apr 9;37(2):e101156. doi:10.1136/gpsych-2023-101156

Main research progress

Birth defects seriously affect the quality of the population and are a significant reproductive health issue both in China and worldwide. Meanwhile, the prevalence of chronic diseases is increasing, particularly multimorbidity, including cardiovascular and metabolic diseases, neurodegenerative disorders, and mental disorders, poses important challenges to aging societies globally. Our research team employes comprehensive research methods, including multiple cohort studies, integrated and systems approaches, to conduct studies on the epidemiology of birth defects, systematic evaluations on the effects of folic acid supplementation, and research on the behavioral and social determinants of health. The representative works include the following:

1. Epidemiology of Birth Defects

Birth defects refer to abnormalities in physical structure, metabolism, or function that occur during fetal development. Severe birth defects can be fatal or lead to disabilities, posing serious health risks to the population and imposing significant medical, economic, and social burdens. Investigating the susceptibility factors and mechanisms of birth defects is crucial for their prevention and control. The research team has conducted a series of studies on the prevalence, risk factors, and effectiveness of folic acid interventions for major birth defects in China. Their findings have provided policy consultation reports to national ministries such as the health and environmental protection departments. The "Periconceptional Folic Acid Supplementation for the Prevention of Neural Tube Defects" study was selected as a teaching case by the China Professional Degree Case Center, and her research had been recognized with awards for scientific and technology from different associations. The main research content includes the following aspects:

1.1 Tracking the Prevalence of Major Birth Defects in High-Incidence Areas in China

The research team has long focused on the prevalence of major birth defects, primarily neural tube defects (NTDs), in high-incidence areas in northern China. They have conducted a series of studies on the etiology and pathogenic mechanisms of NTDs, providing first-hand data for related research in this field. Through population-based birth defect monitoring systems and case-control studies, they have successively revealed the prevalence of NTDs and their subtypes (Liu J, et al. Birth Defects Res A Clin Mol Teratol. 2016), multiple malformations associated with NTDs (Che X, Biology-Basel, 2022), cleft lip and palate (Liu J, China CDC Weekly, 2021), and congenital heart disease (Wang D, et al. China CDC Weekly, 2023).

1.2 Conducting Multidimensional Research on Risk Factors for Birth Defect

The research team delved into findings from case-control studies linking tea drinking with neural tube defects and innovatively proposed the role of catecholamine O-methyltransferase (COMT) metabolism in the disease process. Experimental studies confirmed that the gene polymorphism of this enzyme is associated with the risk of NTDs, revealing that the COMT gene polymorphism in women of childbearing age in high-incidence areas is linked to NTDs in their offspring. They discovered interactions between environmental factors (tea drinking) and genes (COMT), and between different genes (COMT and MTHFR) in the occurrence of NTDs (Liu J, et al. Birth Defects Res A Clin Mol Teratol. 2014; Liu J, et al. Metab Brain Dis. 2015). The team was the first to reveal that high manganese content in the placenta increases the risk of NTDs, showing a significant dose-response relationship (Liu J, et al. J Trace Elem Med Bio. 2013). Additionally, they were the first to reveal gender differences in the effectiveness of folic acid supplementation for preventing NTDs in the Chinese population. Analysis of large cohort studies and birth defect monitoring data before and after folic acid supplementation showed that supplementation successfully reduced the prevalence of NTDs across the population, with significant reductions in anencephaly and overall NTDs in females (Liu J, et al. Nutr J. 2018; Liu J, et al. BMJ Open. 2018). This research provides important theoretical basis for further elucidating the mechanisms of NTDs, identifying molecular markers for screening high-risk populations, and developing and implementing population-based preventive measures.

2. Systematic Evaluation on the Effect of Folic Acid Supplementation

The research team has long paid attention to the status of folic acid among women of reproductive age in China. In the context of the major public health project of "Folic Acid Supplementation to Prevent Neural Tube Defects", they have conducted multiple surveys on folic acid supplementation and examined folate concentration, which started relatively early to systematically evaluated various health effects of folic acid supplementation. There studies provide evidence from China in folic acid related fields. The main research contents include the following aspects:

2.1 Objective Evaluation on the Effectiveness of Periconceptional Folic Acid Supplementation and Recommendations for Standardized Supplementation

Despite significant increases in folic acid awareness, supplementation rates, and folic acid levels among women of childbearing age following the implementation of the free folic acid supplementation program, folic acid deficiency remains prevalent, and the proportion of women taking folic acid before pregnancy is still very low. Future efforts should focus on promoting and implementing folic acid supplementation starting before pregnancy, especially in rural areas (Liu J, et al. Birth Defects Res A Clin Mol Teratol. 2016; Liu J, et al. Public Health Nutr, 2015; Zhang X*, Liu J*, et al. Matern Child Nutr. 2019).

2.2 Providing Evidence that Folic Acid Supplementation Reduces Other Birth Defects

Based on the earliest large-scale folic acid intervention populations in China, the research team found that periconceptional folic acid supplementation reduced the risk of congenital limb reduction defects in women with very low folic acid levels. This research was published in the International Journal of Epidemiology (Liu J, et al. Int J Epidemiol, 2019), providing large-sample evidence from China for this field and having significant public health implications for the prevention and control of birth defects in China and globally. The research team also analyzed the preventive effects of folic acid supplementation on multiple malformations (Che X, Biology-Basel, 2022), abdominal wall defects, and congenital hydrocephalus (Liu J, et al. Public Health Nutr, 2021; Liu J, et al. Br J Nutr, 2021).

2.3 Exploring the Long-Term Health Effects of Folic Acid Supplementation

Folic acid supplementation is crucial not only for newborn health but also for the long-term health of women of childbearing age. The research team systematically evaluated folic acid levels among women of childbearing age in multiple countries and regions worldwide (Che Xiaoyu, et al. Chinese Journal of Preventive Medicine, 2022), exploring factors influencing folic acid levels, the relationship between folic acid supplementation and metabolic diseases such as gestational diabetes, hypertension, and central obesity, providing evidence from the Chinese population for evaluating the long-term health effects of folic acid.

2.3.1 Factors Affecting Folic Acid Concentration: Through field questionnaires and laboratory folic acid testing, the team found that cooking with non-clean fuels like coal or wood was associated with an increased risk of red blood cell folic acid deficiency in women (Xia S, et al. Int J Environ Health Res, 2023); physical activity was related to plasma folic acid levels in women of childbearing age (Chen J, et al. Chinese Journal of Reproductive Health, 2021).

2.3.2 Effects of Folic Acid Supplementation on Metabolic Diseases: Prospective cohort studies of pregnant women found potential benefits of periconceptional folic acid supplementation in preventing gestational diabetes (Xia S, et al. China CDC Weekly, 2023). Additionally, the team explored the effects of vitamin B12 and vitamin C supplementation, which are closely related to folic acid metabolism, in reducing the risk of gestational diabetes (Ge Shuangbo, et al. Chinese Journal of Evidence-Based Medicine, 2022; Chen X, et al. Br J Nutr, 2022; Ge Shuangbo, et al. Modern Preventive Medicine, 2022). A cross-sectional survey of the nutritional status of women of childbearing age in nine provinces in China revealed that folic acid deficiency is a risk factor for hypertension and central obesity (Du Y, et al. Nutr Res, 2022; Zhang J, et al. Front Public Health, 2022).

2.3.3 Effects of Periconceptional Folic Acid Supplementation on Offspring Allergic Diseases: Long-term evaluation of folic acid supplementation did not find an impact on asthma and allergic diseases in offspring, providing evidence from China for the long-term health effects of folic acid (Liu J, et al. ERJ Open Res, 2020).

3. Research on Healthy Behaviors and Social Determinants of Health

Life course epidemiology aims to explore the factors affecting health at different stages from birth to death. Using sensitive period models and cumulative models, it reveals the roles of various risk factors in the development and progression of diseases. The sensitive period model emphasizes that early life exposures can affect the development of various body systems, thereby having long-term health impacts. The cumulative model focuses on the cumulative effects of various risk factors over an individual's life, highlighting the harm of continuous exposure to multiple adverse factors on long-term health.

3.1 Revealing the Lifelong Impact of Adverse Early-Life Exposures

Childhood adversity is a typical adverse early-life exposure that can activate the body's stress response system and lead to chronic stress, affecting early development of the immune, endocrine, and cardiovascular systems, thus increasing the risk of various health problems later in life. Using sensitive period and cumulative models, the research team has long focused on different sources of childhood adversity, including domestic violence, economic hardship, parental divorce, serious illness or death, and neglect or abuse. They have explored the associations between these adversities and risks of dementia in middle and old age (Ren Z, et al. Gen Psychiatr, 2023), neuropsychiatric symptoms (Ren Z, et al. Gen Psychiatr, 2023), various functional limitations (Ren Z, et al. Soc Sci Med, 2023), and healthy life expectancy (Du Y, et al. Child Abuse Negl, 2023). Additionally, the team has focused on interventions for adverse early-life exposures, including promoting healthy lifestyles to mitigate mental and chronic pain and metabolic comorbidities (Ren Z, et al. J Affect Disord, 2023; Ren Z, et al. China CDC Weekly, 2023), improving education levels (Ren Z, et al. Gen Psychiatr, 2023), and exploring the associations between new comorbidities and the risk of Parkinson's disease and related functional decline (Ren Z, et al. eClinicalMedicine, 2023), providing population-based evidence for healthy aging.

3.2 Conducting Research on Screen Exposure Omics

Differences in health levels among individuals begin to form early in life, resulting from the accumulation of health differences at various stages of the life cycle: infancy, adolescence, adulthood, and old age. Promoting whole-population health from a life course perspective involves investigating the social, environmental, and behavioral risk factors affecting health throughout life, which is essential for developing health policies that cover the entire life span. In recent years, the research team has focused on lifestyle-related exposures such as screen exposure and internet use behavior, exploring their health impacts on developmental behavioral disorders in children and neurodegenerative diseases in middle-aged and elderly people.

3.1 Current Status of Children's Screen Exposure: The widespread and younger-age use of electronic products has become a global trend. Lack of parental supervision and companionship may lead to excessive screen exposure in children, and digital life habits formed during childhood can have lasting impacts. The research team has conducted studies on screen exposure among young children, including the current status of screen exposure (Zhao Chunxia, et al. Chinese Family Education, 2022), factors influencing screen exposure such as family nurturing environment and sibling relationships (Lian Xinyao, et al. Chinese Family Education, 2022; Lin Yuxin, et al. Chinese Family Education, 2022), and the effects of screen exposure on children's mental health (Xu Qingsong, et al. Health Education and Health Promotion, 2022; Cao Hui, et al. Chinese School Health, 2023). They have systematically analyzed the status of screen exposure in preschool children, the relationship between screen exposure and early development and emotional-behavioral problems in preschool children, and screen exposure interventions, providing important scientific support for policy formulation in related fields.

3.2 Research on Multimorbidity in Middle-Aged and Elderly People: Utilizing large cohort data with national representation from both domestic and international sources, the research team has deeply explored the factors affecting health in an aging society. The research found that internet use rates and healthy lifestyles among the elderly are associated with reduced risks of cardiovascular and metabolic multimorbidities (Ren Z, et al. Global Health, 2023). These findings offer new insights for chronic disease screening and prevention strategies and for developing intervention programs that promote healthy aging.

Future work

Our future work will primarily focus on exploring continuously the impact of nutrition, environment, and other factors on birth defects and other adverse birth outcomes, as well as their pathogenic mechanisms in selecting representative regions. Simultaneously, we will conduct use interdisciplinary integrated systems research and use data-driven approaches, make great use of cross-national cohorts and cohort-derived data resources, develop partnership with scholars in China and abroad to carry out research on multimorbidity across life course. Furthermore, based on machine learning and deep learning methods, harness and development of multi-source big data and methodological research, we will continue to delve into the early determinants and trajectories of chronic diseases and multi-morbidities, developing early warning models for chronic diseases, especially multi-morbidities. These models aim to explore and establish personalized treatment methods, formulate population-level intervention measures, and facilitate the transformation of policies and practices by providing foundational evidence and tools.

The key areas addressed are as follows:

(1) To investigate the risk factors and pathogenic mechanisms of early adverse health events in early life such as birth defects and rare diseases.

(2) To Analyze health effect of folic acid across the life course and explore the mechanisms.

(3) To identify the early life determinants, clusters, models, and trajectories of multimorbidity and construct predictive tools for disease onset.