Your long-term health and rate of aging may already be determined when you're in the womb, a new study has found.
Published in the International Journal of Epidemiology, the study showed that 22 metabolites in the blood – chemical "fingerprints" from before birth or in infancy – are linked to aging and could predict how susceptible a person is to having an age-related disease later in life.
The researchers found that a higher concentration of these metabolites in the blood was directly related to higher blood pressure, lower bone mass and lower lung capacity.
One of the 22 metabolites – C-glyTry – is linked to aging traits such as lung function and bone mineral density, and is strongly associated with birth weight.
Exploring the link between C-glyTy and birth weight, researchers were able to show that the gene influencing the metabolite levels could be modified epigenetically (genes are switched on and off, triggered by a person's environment or lifestyle). Those epigenetic changes might influence metabolism during that person's lifetime, which would then influence their risk of age-related disease.
"This unique metabolite, which is related to age and age-related diseases, was different in genetically identical twins that had very different weight at birth," said Ana Valdes, lead researcher at King's College London.
"This shows us that birth weight affects a molecular mechanism that alters this metabolite. This may help us understand how lower nutrition in the womb alters molecular pathways that result in faster aging and a higher risk of age-related diseases 50 years later."
The team of researchers looked at people between the ages of 18 to 85. They found the older participants tended to have higher concentrations of metabolites in their blood.
Someone aged 55 with a higher concentration of these metabolites would be older – not chronologically, but in terms of aging – than someone the same age who didn't have the same metabolite presence.
"The key question was, 'What makes people age?' not chronologically, but what makes people age or stay young, and what is the molecular basis of aging? That's really the underlying basis of it," Valdes said.
She said the study showed it might be possible to look at these markers of aging with simple blood tests in the future.
If someone had a high concentration of these metabolites and showed they may be at higher risk for high blood pressure, it would be possible for doctors to target treatment for that specific issue.
"What is going on with a person in their 20s and 30s that we might be able to influence?" Valdes said.
"Maybe it might be just losing weight, or it might be a drug, or it might be gene therapy. Whatever it [the thinking] is, is there something we can do when people are in their 20s, 30s, 40s that means when they are 50, 60, 80, they are not going to have as high risk of fracture?"
Another study found that what happens in the womb can have lasting effects on a person's stress levels. When a female is exposed to distress while pregnant, this can cause changes in the expression of a gene linked to the stress mechanism in her baby's body.
This study was from the University of Haifa and found that female mice that were exposed to "minor" stress, including changes in temperature and daily routine for a week, passed that stress on to their offspring; immediately after birth, the newborns had an enhanced expression of the CRF-1 gene (which is linked to the body's stress-control system).
The study provides insight into what mothers who go through stressful situations may pass on to their children.
"We are learning more and more about intergenerational genetic transfer," the researchers said, "and in light of the findings, and in light of the fact that in today's reality many women are exposed to stress even before they get pregnant, it's important to research the degree to which such phenomenon take place in humans."