In obese pregnant rats, chia seed enrichment altered omega-3 metabolism and increased DHA availability in maternal tissues, placenta, and fetal brain lipid profiles during critical developmental periods.
Study: Enhancement of chia seeds in high-fat, high-sugar diet-induced obesity: a strategy to increase DHA levels in maternal tissues, fetal placenta, and brain during pregnancy. Image credit: The Very Hungry Owl / Shutterstock
In a recent study published in the journal Prostaglandins, leukotrienes, essential fatty acidsResearchers investigated whether adding chia seeds to a high-fat, high-sugar diet during pregnancy increases the availability of docosahexaenoic acid (DHA) in maternal tissues, placenta, and fetal brain in a rat model of diet-induced obesity.
Chia seeds and pregnancy DHA background
Obesity during pregnancy is a growing concern, with millions of women consuming Western-style diets high in sugar and saturated fat but low in healthy omega-3 fatty acids. This imbalance impedes the development of the fetal brain and increases the likelihood of future metabolic and neurological problems in the child.
DHA, an omega-3 long-chain polyunsaturated fatty acid, is important for maintaining normal placental function and supporting brain development during pregnancy. Demand for plant-based omega-3 fatty acids is increasing as concerns about contaminants, sustainability, and dietary preferences may limit reliance on marine DHA sources.
Chia seeds are a plant-based source of alpha-linolenic acid (ALA), which is converted to EPA and DHA in the body. Further research is needed to understand how maternally derived ALA supports fetal DHA during maternal obesity.
High-fat diet pregnancy study design
First, female Wistar rats were fed a high-fat, high-sugar diet for six weeks to induce obesity before pregnancy. After mating, the rats were divided into two groups according to their diet during pregnancy. One group did not change their diet throughout pregnancy, while the other group maintained the same diet and ate whole chia seeds to add ALA, a precursor to long-chain omega-3 fatty acids. The chia-enriched diet had significantly more ALA than the other groups’ diets. Animals were studied on days 15 and 20 of pregnancy, representing the second and third stages of pregnancy related to fetal brain development.
Maternal blood, adipose tissue, liver, placenta, and fetal brain were collected after euthanasia. The researchers measured the mothers’ triglyceride, cholesterol, and leptin levels. Fatty acid composition in tissues was analyzed using gas and liquid chromatography combined with mass spectrometry. Additionally, gene expression analysis was performed to determine the expression levels of enzymes involved in long-chain polyunsaturated fatty acid metabolism and lipid transport across the placenta to the fetus. Western blotting was also used to assess the abundance of FADS1 and FADS2 proteins in maternal liver tissues.
To determine the metabolic effects of chia seed supplementation during pregnancy related to obesity, statistical comparisons were performed between dietary groups at each pregnancy stage.
Findings on maternal omega-3 metabolism
Rats consuming chia-supplemented diets ingested higher levels of ALA throughout pregnancy. Maternal body weight and organ weights remained unchanged, but significant metabolic improvements were observed. By late pregnancy, maternal blood triglyceride and cholesterol levels were significantly lower in the chia-fed group, suggesting improved lipid regulation despite continued exposure to a high-fat, high-sugar diet. Fetal weight decreased slightly on day 20 of gestation, but placental weight remained unchanged.
The most striking discovery concerned the metabolism of omega-3 fatty acids. Chia supplement intake significantly increased the levels of ALA, eicosapentaenoic acid, and DHA in maternal liver tissue taken during both second and third trimesters. In the second trimester, liver DHA content was approximately 20% higher and in the third trimester it was 40% higher. At the same time, some omega-6 fatty acids were reduced, but the effects varied by tissue, pregnancy stage, and lipid species. These modifications suggest that the maternal liver actively processes and synthesizes long-chain omega-3 fatty acids derived from plant ALA during pregnancy and fetal development.
Chia supplements increased the omega-3 fatty acid content of maternal adipose tissue. Increased concentrations of DHA and eicosapentaenoic acid indicate that maternal tissues were storing beneficial fatty acids during pregnancy. Additionally, the researchers observed increased incorporation of DHA into triglycerides and phosphatidylcholine molecules in plasma, two major carriers of fatty acid transport.
DHA findings in placenta and fetal brain
Significant metabolic adaptations were evident in the placenta. Chia supplement intake increased placental concentrations of ALA, eicosapentaenoic acid, and DHA during both pregnancy stages. Phospholipids were enriched with DHA-containing phosphatidylcholine and phosphatidylethanolamine species, which are important for membrane structure and lipid processing. Moreover, fatty acid transport genes were more prominently expressed, especially at the end of gestation, centered on major facilitator superfamily domain-containing protein 2A (MFSD2A). Overall, these placental changes suggest an increased ability to process and transport long-chain omega-3 fatty acids, although transport efficiency was not directly measured.
Importantly, fetal brain tissue also reflected these nutritional improvements. During the second trimester, the brains of fetuses in the chia-fed group contained more phospholipids rich in ALA and DHA. However, these fetal brain lipid differences were not observed at gestational day 20. Because DHA is an important component of neural membrane and brain development, these findings suggested that dietary chia seeds may enhance early brain lipid composition during critical developmental periods in this rat model.
How plant-based DHA affects pregnancy
The results of this study demonstrated that adding chia seeds to a high-fat, high-carbohydrate diet during pregnancy improved maternal omega-3 fatty acid metabolism and increased DHA availability to the placenta and fetal brain during the second trimester. Maternal tissues also showed evidence of increased ALA synthesis and incorporation into beneficial long-chain omega-3 fatty acids despite the dietary stress associated with obesity.
Enhancement of placental lipid transport markers may improve fetal brain nutrition during mid-gestation, a critical developmental period in rat models. Therefore, these findings suggest that affordable plant-based foods, such as chia seeds, warrant further investigation as a potential strategy to improve maternal and fetal lipid profiles during obesity-related pregnancy, although their relevance to functional offspring outcomes and humans remains to be established.
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Reference magazines:
- Dalix, G., Cloteau, C., Ouguerram, K., Castellano, B., Panheleux, A.-L., Grit, I., Winer, N., Boquien, C.-Y., and Ferchaud-Roucher, V. (2026). Enrichment of chia seeds in high-fat, high-sugar diet-induced obesity: a strategy to increase DHA levels in maternal tissues, fetal placenta, and brain during pregnancy. prostaglandins, leukotrienes, and essential fatty acids. 209. DOI: 10.1016/j.plefa.2026.102746 https://www.plefa.com/article/S0952-3278(26)00024-4/fulltext
