Honglei Chen, MD, PhD

Professor of Epidemiology and Biostatistics

Department of Epidemiology and Biostatistics
909 Wilson Road Room B601
East Lansing, MI  48824

Curriculum Vitae

Dr. Chen is a Professor at the Department of Epidemiology and Biostatistics of Michigan State University. His research focuses on neurodegenerative diseases, especially Parkinson's disease. He works on several large prospective cohorts to ascertain the environmental and genetic causes of Parkinson's disease and to characterize high risk populations through research on prodromal symptoms and biomarkers. The ultimate goal is disease prevention and more effective clinical management.


Primary Research Interests

Environment and genetic risk factors for Parkinson's disease: Genes and environmental factors, alone or in combination, contribute to the pathogenesis of Parkinson's disease. Over the past decade, Dr. Chen’s research has contributed to a better understanding of the role of environmental factors in Parkinson's etiology. For example, he reported that long duration of smoking, rather than smoking intensity, might underlie the lower risk of Parkinson's disease among smokers. He and collaborators also found that moderate to vigorous exercise, ibuprofen use, and higher plasma urate were each associated with a lower risk of Parkinson's disease, whereas pesticides, air pollution, and diary intake may potentially contribute to Parkinson’s risk.

Prodromal neurodegeneration: Parkinson’s disease takes decades to develop, and by the time of diagnosis, is generally too far gone to intervene. Over the past decades, it has become clear that a variety of nonspecific symptoms (e.g., olfactory impairment and REM sleep behavior disorder) may develop years, if not decades, prior to Parkinson’s clinical diagnosis. Dr. Chen analyzes these prodromal symptoms with two important goals: first to characterize populations at-risk and second to identify factors that either initiate or perpetuate disease prodromal pathogenesis. As these symptoms also develop in the prodromal stage of dementia and some other neurodegenerative diseases, Dr. Chen’s research will have broad implications in understanding neurodegeneration beyond Parkinson’s disease.


Major Research Projects

Airborne pollutants as triggers of Parkinson's Disease via the olfactory system- This is a multi-PI project supported by the US Department of Defense (9/2017-8/2022). In this project, Dr. Chen and his team have objectively assessed the sense of smell of ~3,400 women, ages 50-79, from the NIEHS Sister Study. The primary goal of this project is to assess roles of air pollutants in olfactory impairment and their relevance to Parkinson’s disease.

Pesticides, olfaction, and neurodegeneration among US farmers- This is a newly funded R01 project (2/2019 – 1/2024) to investigate roles of pesticides in olfaction impairment and their relevance to prodromal neurodegeneration. In this study, we will first objectively test the sense of smell of ~2,400 farmers from the Agricultural Health Study and then conduct in-home clinical assessments for ~450 farmers to assess cognitive and motor symptoms.

In addition to olfactory impairments, both cohorts have collected extensive exposure data and assessed other prodromal symptoms of neurodegenerative diseases. Finally, Dr. Chen also conducts similar research in two other population-based cohorts – the Atherosclerosis Risk In Communities Study and the Health ABC study. With these valuable and complementary resources, Dr. Chen aims to decipher the codes of poorly understood prodromal neurodegeneration.



Dr. Chen earned his M.D. from TianJin Medical University in TianJin, China, and Master's degree from the Chinese Academy of Preventive Medicine in Beijing, China. In 2001, he earned his Ph.D. in Nutritional Epidemiology from Tufts University in Boston, MA and then worked as a Research Fellow and Instructor at the Harvard School of Public Health. From 2005-2016, Dr. Chen worked at the Epidemiology Branch of the National Institute of Environmental Health Sciences and received his Tenured Senior Investigator appointment from NIH in 2013. He serves on the editorial board of the American Journal of Epidemiology and has more than 160 original publications.

Press Release

  1. Olfaction predicts risk of death
  2. MSU lands 5 million NIH grant to connect dots between pesticides and Parkinson’s
  3. High pesticide exposure event linked to poor olfaction
  4. DoD funding to study air pollution and Parkinson’s prodromal risk
  5. Olfaction predicts Parkinson’s risk


Selected Publications

Liu B, Luo Z, Pinto JM, Shiroma EJ, Tranah GJ, Wirdefeldt K, Fang F, Harris TB, Chen H. Relationship Between Poor Olfaction and Mortality Among Community-Dwelling Older Adults: A Cohort Study. Ann Intern Med. 2019 May 21;170(10):673-681. doi: 10.7326/M18-0775. Epub 2019 Apr 30. PubMed PMID: 31035288.

Shrestha S, Kamel F, Umbach DM, Freeman LEB, Koutros S, Alavanja M, Blair A, Sandler DP, Chen H. High Pesticide Exposure Events and Olfactory Impairment among U.S. Farmers. Environ Health Perspect. 2019 Jan;127(1):17005. doi:10.1289/EHP3713. MID: 30648881.

Palta P, Chen H, Deal JA, Sharrett AR, Gross AL, Knopman D, Griswold M, Heiss G, Mosley TH. Olfactory Function and Neurocognitive Outcomes in Old Age: the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS). Alzheimers Dement 2018 pii: S1552-5260(18)30073-6. doi: 10.1016/j.jalz.2018.02.019. PMID: 29605223

Chen H, Shrestha S, Huang X, Jain S, Guo X, Tranah GJ, Garcia ME, Satterfield S, Phillips C, Harris TB; Health ABC Study. Olfaction and incident Parkinson disease in US white and black older adults. Neurology. 2017 Sep 6. pii: 10.1212/WNL.0000000000004382. PMID: 28878051.

Dong J, Pinto JM, Guo X, Alonso A, Tranah G, Cauley JA, Garcia M, Satterfield S, Huang X, Harris T, Mosley TH Jr, Chen H. The Prevalence of Anosmia and Associated Factors Among U.S. Black and White Older Adults. J Gerontol A Biol Sci Med Sci. 2017 Aug 1;72(8):1080-1086. doi: 10.1093/gerona/glx081. PMID: 28498937.

Liu R, Young MT, Chen JC, Kaufman JD, Chen H. Ambient Air Pollution Exposures and Risk of Parkinson Disease. Environ Health Perspect. 2016 Nov;124(11):1759-1765. Epub 2016 Jun 10. PMID: 27285422; PMC5089873.

Alonso A, Huang X, Mosley TH, Heiss G, Chen H. Heart rate variability and the incidence of Parkinson’s disease: the ARIC study: Ann Neurol. doi: ;77(5):877-83. doi: 10.1002/ana.24393, 2015. PMID: 25707861

Liu R, Umbach D, Peddada S, Tröster AI, Huang X, Chen H. Potential sex differences in non-motor symptoms in early drug-naive Parkinson disease: Neurology, 2015, PMID: 25925983

Fang F, Wirdefeldt K, Jacks A, Kamel F, Ye W, Chen H. CNS Infections, sepsis, and the risk for Parkinson’s disease. Int J Epidemiol. 41(4):1042-9. 2012; PMID: 22523201; PMC3429872

Chen H, Huang X, Guo X, Mailman RB, Park Y, Kamel F, Umbach DM, Xu Q, Hollenbeck A, Schatzkin A, Blair A. Smoking duration, intensity, and risk of Parkinson disease. Neurology. 2010;74(11):878-84. PMID: 20220126; PMC2836869.

Xu Q, Park Y, Huang X, Hollenbeck A, Blair A, Schatzkin A, Chen H. Physical activities and future risk of Parkinson disease. Neurology. 2010;75(4):341-8. PMID: 20660864; PMC2918886.

Chen H, Jacobs E, Schwarzschild MA, McCullough ML, Calle EE, Thun MJ, Ascherio A. Nonsteroidal antiinflammatory drug use and the risk for Parkinson's disease. Ann Neurol. 2005;58(6):963-7. PMID: 16240369

Chen H, Zhang SM, Hernán MA, Schwarzschild MA, Willett WC, Colditz GA, Speizer FE, Ascherio A. Nonsteroidal anti-inflammatory drugs and the risk of Parkinson disease. Arch Neurol. 2003 Aug;60(8):1059-64. PubMed PMID: 12925360.