The food consumed by a pregnant mother just got a little bit more important.
According to a new study on pregnant mice, a diet rich in fiber improves the long-term heart health of developing offspring, significantly lowering their risk of cardiovascular disease later in life.
It's a finding that is nicely consistent with current dietary advice for pregnant mothers, bolstering the importance of nutritional balance, especially when growing a whole new person.
"Dietary fiber, which is found in foods such as fruits, vegetables, and whole grains, is well-known for its health benefits," says biomedical scientist Francine Marques of Monash University in Australia.
"Our research shows that its impact extends beyond the mother, and can shape the development of her child's heart."
Navigating diet choices during pregnancy can be a bit of a minefield. Don't eat soft cheese. Eat more spinach. Avoid lunch meat. Eat yogurt. Generally, however, the basic principles remain the same as advice for healthy eating for everyone, and that includes a high proportion of dietary fiber, the benefits of which include a healthier bowel, and lower cholesterol.
To determine what effect, if any, dietary fiber intake has on the development of a fetus, Marques and her colleagues conducted experiments on mice, feeding pregnant and lactating groups of mice high- and low-fiber diets, respectively. Baby mice were fed diets with standard fiber levels after they had been weaned.
Once one group of eight baby mice reached six weeks of age, the researchers performed RNA sequencing on their cardiac tissue. They found that a high-fiber diet resulted in hearts that were less sensitive to inflammatory and immune stimuli, making the heart more robust to relatively minor irritations.
The next step was a focus on cardiovascular disease. This involved administering the hormone angiotensin to six-week-old mice to induce organ damage due to hypertension. Hypertension, or high blood pressure, is a leading cause of cardiovascular disease, so it's a good way to measure susceptibility.
The mice born of mothers fed a low-fiber diet had hearts in significantly worse condition than those of their high-fiber counterparts. These mice had much larger hearts, with thicker walls and higher collagen deposition, suggesting that they were more susceptible to conditions such as hypertrophic cardiomyopathy, in which the walls of the left ventricle thicken, reducing its ability to pump blood, and cardiac fibrosis, the formation of scar tissue in the heart.
Both mothers and babies with a high-fiber diet also had healthier guts and gut bacteria, the researchers found, and mothers had 50 percent higher blood plasma levels of short-chain fatty acids.
Fiber promotes the growth of short-chain fatty acids in the gut, which travel through the bloodstream to the placenta and then the fetus, where they help shape gene activity in the developing heart.
The findings suggest that we may have underestimated the impact of a mother's prenatal diet, though further research is needed to determine if the results translate to humans. We do know that a high-fiber diet helps maintain a healthy gut and microbiome in humans, so it makes sense to think that pregnant people could also glean the benefits.
"Cardiovascular disease is a leading cause of death worldwide, and this research suggests that a simple dietary change during pregnancy could have lifelong benefits for children," Marques says.
"Our work adds to the growing body of evidence highlighting the importance of a healthy diet during pregnancy."
She recommends that mothers continue to work with their medical providers to make sure they are, truly, eating for two, with the best interests of both in mind.
The findings have been published in Circulation Research.