Avoid gaining weight and adding potentially dangerous fat around the abdomen. Watch your cholesterol. Get screened for cancer.
There is no end to the messages tailored to help adults maintain health, particularly for people who are overweight, inactive or have a family history that gives them higher odds of developing high blood pressure, diabetes, cardiovascular disease, arthritis or a number of other serious conditions.
But what if predisposition for a particular disease or health problem begins years before people pick up bad eating habits or skip exercise in favour of sitting on the couch?
In other words, what if the outlines of a person's future health map are drawn while still in the womb?
A burgeoning field in medicine is dedicated to studying how conditions in the womb – everything from nutrition to the environmental toxins a woman might be exposed to during pregnancy – can affect an unborn child for the rest of his or her life.
The field, known as developmental origins of health and disease, is based on the premise that, depending on the environment in utero, unborn children go through genetic or other physiological changes to prepare them for the specific conditions that await them in the outside world.
But those changes can have significant and lasting consequences that scientists are only just beginning to understand.
"It's a very active area – it's a very exciting science and there will be a lot learned in the next decade I think," said Kim Boekelheide, professor of pathology and laboratory medicine at Brown University in Providence, R.I.
Researchers studying this area also face many challenges. It's difficult to study what impact in utero conditions can have later in life because it would require following a group of people from the womb to late in life. Assessingthe effects of poor nutrition or exposure to pesticides on mice in the womb, for instance, may not accurately reflect the outcomes for a human fetus.
"It's very challenging," Dr. Boekelheide said.
But scientists are finding novel ways to explorethis area. Dr. Boekelheide and his colleagues place human tissue from spontaneously aborted fetuses into animals to study the effects of exposure to various elements.
Although the developmental origins field has been around for decades, it has been garnering an increasing amount of attention recently as more researchers recognize prenatal and early postnatal conditions may have connections to the trajectory of an individual's health for life.
Stephen Lye, professor of obstetrics and gynecology at the University of Toronto and associate director of the Samuel Lunenfeld Research Institute at Mount Sinai Hospital, has received this year's inaugural Connaught Global Health Challenge Award. The $1-million fund will enable him and his colleagues to create the Institute for Human Development to explore how early environments can affect health.
As well, Brown University recently announced it is creating a centre, led by Dr. Boekelheide, to study how certain conditions in utero can impact fetal lung, liver and prostate tissues.
One of the field's pioneers, British researcher David Barker, helped put the origins of disease on the map with his work in the 1980s and 1990s showing that babies born with low birth weight face heightened risks of developing coronary heart disease. Dr. Barker's theory says that fetuses with a limited nutrient supply may put increased attention on brain development and less priority on the pancreas, kidney and other organs, which could lead to vulnerability to disease decades later.
Other important research suggests women who experience high levels of stress in pregnancy are more likely to have children who become anxious, fearful or develop behaviour or cognitive problems. Researchers believe this is caused by fetal exposure to high levels of the stress hormone cortisol.
Certain conditions experienced in utero can also offer protections. Research presented in Orlando, Fla., this week at the Era of Hope, a top breast cancer research conference, found that baby mice whose mothers consumed high levels of fatty acids and nutrients such as folate and vitamin B12 when pregnant may have some protection against breast cancer.
It might seem depressing to contemplate that some individuals may be programmed for particular diseases before they are even born. But scientists believe if they can understand the complex interplay between genes and the environment and how conditions in utero lead to genetic or other changes, they can one day develop prevention measures to mitigate the negative consequences.
For instance, creating a better understanding of how poor nutrition in pregnancy can affect a fetus for life could lead to improved pre-natal education as well as programs to help low-income or disadvantaged women.
"There's no doubt that we could make significant improvements in health, learning and social functioning if we invest more in essentially the health of young women and young children," Dr. Lye said.