Developmental Origins of Health and Disease
Studies suggest that environmental 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, some cancers, and reproductive disorders are thought to result at least partly from environmental exposures that occur in the womb or during childhood.
Researchers supported by NIEHS are studying how certain diseases or conditions originate during critical time periods of development, also known as windows of susceptibility. They are identifying environmental stressors that increase disease risk and are investigating how heavy metals like arsenic, phthalates, flame retardants, pesticides, chemicals that interfere with hormones called endocrine disruptors, and other chemicals can change normal development in a way that leads to later disease or conditions. Researchers also are 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?
- How many windows of susceptibility are there?
- Which windows are most important?
- What mechanisms, such as epigenetic signals that help control when genes are turned on and off, are responsible for the increased sensitivity to disease in specific windows?
- How important are second hits, or challenges, later in life — such as a high-fat diet, other exposures, and stress — in interacting with a sensitive window to increase disease risk?
Recently, grantees have begun to examine the time before conception as another sensitive window of exposure and are studying the placenta as a site of endocrine disruptor action that may impact fetal health. They are also examining how vulnerability to disease is 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.