Studies suggest that harmful exposures that occur early in life, while tissues and organs are developing, may increase the risk of disease later in life. Sometimes these risks carry over into future generations. This concept is called the developmental origins of health and disease, or DOHaD.
A variety of diseases and conditions are thought to result at least partly from exposures that occur in the womb or during childhood. Some of these include obesity, type 2 diabetes, insulin resistance, asthma, cardiovascular diseases, behavioral disorders, neurodegenerative diseases, reproductive disorders, and some cancers.
What Is NIEHS Doing?
Researchers supported by the NIEHS DOHaD program study how certain diseases or health conditions originate during critical time periods of development, known as windows of susceptibility. They are also pinpointing times during development when people are most susceptible to the combined effects of environmental exposures and genetic factors.
For example, researchers are examining the time before conception as a window of susceptibility, and the placenta as a site of endocrine disruptor action that may affect fetal health. To do this, they investigate how heavy metals, phthalates, flame retardants, pesticides, and other chemicals that interfere with hormones can potentially alter normal development in a way that leads to later disease.
NIEHS-funded researchers are also using model systems and human population studies to determine windows of susceptibility for perinatal exposures and the mechanisms that may lead to disease later in life. Many are exploring epigenetic factors and whether vulnerability to disease can be passed to future generations.
Studies suggest that disadvantaged populations may experience greater risk of exposure to environmental hazards and exhibit higher rates of disease incidence, morbidity, and mortality. Understanding these risks during windows of susceptibility offers the promise of disease prevention and reduction of health disparities.
NIEHS-funded 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 exposures later in life such as a high-fat diet, certain chemicals, and stress, in combination with exposures during windows of susceptibility?