Studies suggest that exposures that occur while tissues and organs are developing increase risk of disease later in life, and sometimes in future generations. This concept is called the developmental origins of health and disease, or DOHaD.
Diseases and conditions such as obesity, type 2 diabetes, insulin resistance, asthma, cardiovascular diseases, dyslipidemia, cognitive and behavioral disorders, neurodegenerative diseases, reproductive disorders, and some cancers, are thought to result at least partly from exposures that occur in the womb or during childhood.
Researchers supported by NIEHS are studying how certain diseases or health conditions originate during critical time periods of development, also known as windows of susceptibility. They are investigating how heavy metals, phthalates, flame retardants, pesticides, and chemicals called endocrine disruptors that interfere with hormones, can potentially alter normal development in a way that leads to later disease or health conditions. Researchers are also pinpointing times during development when people are most susceptible to the combined effects of environmental exposures and genetic factors.
Researchers are asking questions such as:
- What determines a window of susceptibility?
- Which windows of susceptibility are most important?
- What mechanisms, such as signals that help control when genes are turned on and off, are responsible for the increased sensitivity to disease in specific windows of susceptibility?
- How important are challenges later in life — such as a high-fat diet, other exposures, and stress — in interacting with windows of susceptibility to increase disease risk?
Recently, grantees have begun to examine the time before conception as another window of susceptibility and are studying the placenta as a site of endocrine disruptor action that may impact fetal health. They are also examining whether vulnerability to disease can be passed to future generations.
NIEHS grantees are also studying how early life exposures may affect cancer risk. They are examining the association between perinatal exposure to bisphenol A and later development of breast tumors, as well as the genetics of breast cancer risk during windows of susceptibility. Other researchers are investigating prostate cancer that occurs after early exposures to estrogens.
Thaddeus T. Schug, Ph.D.
Health Scientist Administrator
P.O. Box 12233Mail Drop K3-15Durham, N.C. 27709