Researchers studied how a mother’s diet during pregnancy affects the types of healthy fats found in both the mother’s and baby’s bodies. They looked at rats that ate different diets—some with low amounts of a healthy omega-3 fat called ALA, and some eating high-fat diets. They discovered that different body parts store these healthy fats differently, and that what a mother eats is especially important for passing these fats to her babies. The liver was the best at making and storing these fats, while other organs weren’t as good at it. This research suggests that mothers need enough healthy omega-3 fats in their diet to give their babies the best start.

The Quick Take

  • What they studied: How a mother’s diet—especially the amount of healthy omega-3 fats and total fat—affects the types of fats stored in her body and her baby’s body during pregnancy and after birth.
  • Who participated: Laboratory rats (Sprague-Dawley breed) that were divided into four groups based on their diet: some got low omega-3 fats with regular food, some got low omega-3 fats with high-fat food, and two other groups got higher amounts of omega-3 fats with either regular or high-fat diets.
  • Key finding: Different parts of the body store healthy fats in different amounts. The liver is the best at making and storing these fats, but other organs like the heart, brain, and kidneys don’t store as much. What the mother eats matters a lot for giving babies these important fats.
  • What it means for you: If you’re pregnant or planning to become pregnant, eating enough foods with omega-3 fats (like fish, flaxseeds, and walnuts) may help ensure your baby gets these important nutrients. However, this study was done in rats, so more research in humans is needed before making major diet changes. Talk to your doctor about your diet during pregnancy.

The Research Details

Scientists conducted a controlled experiment with rats to see how different diets affected fat storage. They created four groups of rats with different diets: some ate normal food with very little omega-3 fat, some ate normal food with more omega-3 fat, some ate high-fat food with very little omega-3 fat, and some ate high-fat food with more omega-3 fat. The rats ate these diets before pregnancy, during pregnancy, and while nursing their babies.

After the rats were humanely euthanized, the researchers carefully collected samples from many different body parts—including the liver, heart, brain, kidneys, and fat tissue—from both mothers and their babies. They then used a special laboratory technique called gas chromatography to measure exactly what types and amounts of fats were in each tissue.

This approach allowed the researchers to see which body parts collected the most healthy omega-3 fats and whether the mother’s diet actually changed the fat content in her babies’ bodies.

This type of study is important because it lets scientists carefully control everything the animals eat and measure the exact results. You can’t do this kind of detailed study in humans because you can’t control pregnant women’s diets that strictly for research. By studying rats first, scientists can understand how nutrition works before testing ideas in people. The fact that researchers looked at many different body parts—not just one—gives a more complete picture of how fats are stored throughout the body.

This study was well-designed with clear groups and careful measurements. The researchers used a reliable laboratory method (gas chromatography) that accurately measures fat types. However, because this was done in rats, the results may not be exactly the same in humans. Rats and humans process food differently in some ways. The study also didn’t specify exactly how many rats were used, which would help readers understand how confident we should be in the results.

What the Results Show

The most important finding was that different body parts store healthy omega-3 fats in very different amounts. The liver was by far the best at making and storing these fats—it had much higher levels than other organs. This makes sense because the liver is like the body’s chemical factory, where many important conversions happen.

Other organs like the heart, brain, kidneys, and eyes stored some omega-3 fats, but much less than the liver. Interestingly, the amount of omega-3 fats in babies’ bodies didn’t always match what their mothers ate. This was surprising to the researchers because they expected a stronger connection between mother’s diet and baby’s fat levels.

When mothers ate high-fat diets, it seemed to interfere with how their bodies processed and stored the healthy omega-3 fats. This suggests that eating too much fat overall might make it harder for the body to use the healthy fats you do eat.

The research showed that mothers’ stored omega-3 fats became especially important for babies when the mother wasn’t eating enough omega-3 in her diet or was eating too much fat overall. In these stressful situations, the mother’s body seemed to share its stored omega-3 fats with the developing baby.

The study also found that the ratio of omega-6 to omega-3 fats (the balance between two types of healthy fats) varied across different tissues. Some body parts preferred to store more omega-6 fats, while others stored more omega-3 fats. The brain and eyes, which are especially important for development, showed particular patterns in how they stored these fats. The stomach contents of babies also showed different fat patterns depending on what the mother ate, suggesting that some fats pass directly from mother to baby through nursing.

Previous research has suggested that omega-3 fats are important for brain and eye development, and this study supports that idea by showing these organs do store some omega-3 fats. However, this study adds new information by showing that the liver is the main organ that processes these fats, and that other organs rely on the liver’s work. The finding that mother’s diet doesn’t always directly predict baby’s fat levels is somewhat different from what some earlier studies suggested, indicating that the body’s fat storage system is more complex than previously thought.

The biggest limitation is that this study was done in rats, not humans. Rats and humans have different body sizes, lifespans, and ways of processing food, so the results might not apply exactly to people. The study also didn’t specify how many rats were used in each group, which makes it harder to judge how reliable the results are. Additionally, the study only looked at one point in time (after the rats were euthanized), so it doesn’t show how fat levels change over time. Finally, the study didn’t measure whether these fat differences actually affected the rats’ health or development, only that the fats were present in different amounts.

The Bottom Line

Based on this research, pregnant women and women planning pregnancy should aim to eat adequate amounts of omega-3 rich foods (such as fatty fish, flaxseeds, chia seeds, and walnuts) and avoid excessive high-fat foods. However, this recommendation comes with moderate confidence because the study was done in rats. Before making significant dietary changes, especially during pregnancy, consult with your doctor or a registered dietitian who can give personalized advice based on your individual health situation.

This research is most relevant to pregnant women, women planning to become pregnant, and healthcare providers who advise them about nutrition. It’s also important for people interested in how nutrition affects fetal development. However, this study shouldn’t change the diet of people who aren’t pregnant, since the focus is specifically on pregnancy and early development. If you have concerns about your omega-3 fat intake, talk to your healthcare provider rather than making major changes on your own.

If a pregnant woman improves her omega-3 intake, the benefits would likely develop gradually throughout pregnancy and early childhood, since fetal brain and eye development happens over months. You wouldn’t see immediate changes. The most important time appears to be during pregnancy and nursing, when the baby is receiving fats from the mother. Long-term benefits for the child’s brain and eye health might not be fully apparent for years.

Want to Apply This Research?

  • Track daily servings of omega-3 rich foods (fatty fish, flaxseeds, walnuts, chia seeds) with a goal of 1-2 servings per day. Log the specific food and portion size to monitor consistency over weeks and months.
  • Add one omega-3 rich food to your daily routine: for example, sprinkle ground flaxseeds on breakfast cereal, add walnuts to salads, or eat a serving of salmon twice weekly. Start with one change rather than overhauling your entire diet.
  • Use the app to track omega-3 food intake weekly and create a simple chart showing your consistency over months. If pregnant, share this tracking data with your healthcare provider at prenatal visits to discuss whether your omega-3 intake is adequate. Set reminders for omega-3 rich meals and monitor how you feel and any changes in energy levels.

This research was conducted in rats and has not been tested in humans. The findings suggest potential relationships between maternal diet and fetal fat composition, but cannot be directly applied to human pregnancy without further research. If you are pregnant, planning pregnancy, or have concerns about your nutrition, consult with your healthcare provider or a registered dietitian before making significant dietary changes. This information is for educational purposes only and should not replace professional medical advice. Do not use this study as the sole basis for making health decisions during pregnancy.