Omega-3 Fatty Acids and Pregnancy - Functions and Requirements

Introduction

Nutrition is the key factor for a successful pregnancy. Nutritious food and a balanced diet fulfill the various nutritional requirements of the pregnancy. One of the important nutritional substances required for pregnancy is omega 3. This fatty acid acts as a bundle block of cellular activity. Not only that, it is essential for the child's neural development.

What Is Omega-3?

Omega-3 is a polyunsaturated fatty acid. These are a type of dietary fat and are considered as healthy fat. In the human body, these polyunsaturated fatty acids help to reduce cholesterol and triglyceride level. They also reduce the chance of plaque formation and are considered heart-friendly fatty acids. Omega-3 polyunsaturated fatty acids (PUFAs) are available in nature in three types. These are: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

Alpha-linolenic acid (ALA) can be obtained from various plant sources like flaxseeds, canola (rapeseed), soybeans, soybean oil, pumpkin seeds, walnuts, and walnut oil. Whereas the source of the eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are fish. Fishes like sardines, tuna, salmon, and oil derived from these fishes are the source of such essential fatty acids. Sadly most of the world's population doesn't have access to fish products. But, this problem has been solved by nature. Alpha-linolenic acid (ALA), which is abundant in nature and easily available in plant substances, can convert to form eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). But, this conversion rate could be higher. Only 4 percent of ALA is converted to DHA, and eight to ten percent is converted to eicosapentaenoic acid (EPA).

What Is the Role of Omega-3 in Pregnancy?

DHA and ALA play a pivotal role in maintaining a healthy pregnancy.

1. Adequate blood supply is necessary for fetal growth. Limited blood supply may arise in situations like preterm delivery, stillbirth, fetal growth restriction, and preeclampsia. DHA is one of the key factors which regulate new blood vessel formation. Increased vascular endothelial growth factor (VEGF) expression is also associated with DHA levels. Angiopoietin-like protein 4 (ANGPTL4), platelet-activating factor (PAF), and matrix metalloproteinases (MMP) are crucial for blood vessel development. EPA influences the expression of these factors.

2. A diet rich in ALA produces abundant arachidonic acid (AA; a type of omega- 6 fatty acid). This serves as a precursor of prostaglandins (PGs) E2 and PGF2 - alpha, and the vasoconstrictor thromboxane (TX) A2. These factors are essential in initiating labor and preterm labor.

3. Eicosapentaenoic acid (EPA) is essential in producing various prostaglandins like prostaglandin E3 and prostaglandin I3. These are essential for the relaxation of the myometrium.

4. The concentration of fatty acid in the fetal blood is important. This concentration depends upon the dietary entail of the omega-3 fatty acids. But in the circulation, fatty acid binding proteins (FABPs) play an important role in the transport of the DHA from maternal blood to fetal circulation. EPA is important for the production of fatty acid transport proteins (FATPs) via the expression of mRNA. These transport proteins aid in the formation of fatty acid-binding proteins (FABPs). As a result; to a higher concentration of EPA is important for a higher concentration of DHA in fetal circulation. Activation of G protein-coupled receptor GPR120 by fatty acids responsible for insulin sensitization and anti-diabetic effects.

5. Prevention of gestational diabetes is an important function of omega-3 fatty acids. Increased progesterone synthesis in pregnancy suppresses insulin's action to suppress glucose in the liver. Also, increased production of cortisol (a type of stress hormone) is associated with impaired insulin signaling. High dietary intake of DHA in the early days of pregnancy has shown preventive effects on developing gestational diabetes.

What Is the Role of Omega 3 In Fetal Development?

The two important fatty acids that help develop brain and cognitive functions are EPA and DHA. Also, these fatty acids aid other neural structures and retinal development.

One of the main functions of these fatty acids is reducing the production of inflammatory substances. These help to reduce oxidative stress. Oxidative stress generated during inflammation is responsible for the production of free radicals. These radicals have intracellular antioxidant capacity. These cause damage to protein synthesis and DNA formations. The high level of inflammatory mediators like tumor necrosis factor (TNF) reduces neural stem cell proliferation by decreasing the activity of cAMP-responsive element binding protein (CREB). The anti-inflammatory action of omega-3 is associated with the following mechanism:

1. It inhibits the cyclooxygenase (COX) activity and decreases subsequent eicosanoid production (a type of signaling molecule).

2. Production of proinflammatory cytokines is reduced.

3. The functionality of pro-inflammatory transcription nuclear factor kappa B (regulates pro-inflammatory signaling pathways) is inhibited.

4. Adhesion of leukocytes and their chemotaxis activity is inhibited.

5. Production of inflammation-resolving resolvins, maresins, lipoxins, and proteins is increased.

Other than this, several other mechanisms also play a crucial role in developing brain and neural tissues.

1. Omega-3 fatty acids stabilize cellular integrity and protect the cellular membranes.

2. One of the interesting mechanisms by which brain and neural tissues are protected is the prevention of hypoxia. Preeclampsia (a hypertensive condition in pregnancy) is crucial in developing hypoxia during pregnancy. Angiogenesis functioning of DHA and anti-inflammatory action of omegas- 3 help to reduce these hypoxic conditions.

3. The fetal brain and eye development occurs in the third trimester. The growing fetus depends mostly on the maternal DHA’s placental supply. The placental trophoblast takes up maternal free fatty acids and DHA via several membranes spanning proteins.

4. EPA and DHA are important for the formation of the neural tube (early brain and spinal cord).

Increased intake of ALA plays a crucial role in preventing obesity and insulin resistance in the offspring.

What Is the Recommended m Dietary Intake?

According to research, 0.05 ounces (oz) of omega-3 fatty acids as alpha-linolenic acid should be consumed. Vegetable oil like soybean oil and canola oil are important for this purpose. Daily intake of 0.023 ounces (oz) of omega-3 fatty acids such as EPA and DHA is essential. The daily dietary requirement of DHA 0.010 ounces (oz). Fish oil supplements and fish oil tablets are essential sources of DHA for pregnant mothers.

Conclusion

Brain development is the key factor for the proper growth and development of the child. This also aids in the cognitive development of the child. Omega-3 fatty acids are essential in developing brain and neural tissues. Also, pregnancy complications like preterm delivery and preeclampsia can be prevented.