Harmful Effects Of Plastic Containers And Heat-Inducing Foods During Pregnancy

Pregnancy can be quite a life-transforming experience for a woman, especially if it is her first pregnancy. From being handed down unsolicited advice to being told to be extra cautious of diet, there is a lot that a woman has to keep track of during pregnancy.

While there are many guidelines on the foods to consume and avoid, pregnant women are also warned about the harmful effects of plastic containers as well as heat-inducing foods during pregnancy.

Let us take a look at the threat to pregnant women posed by plastic containers and heat-inducing foods.

Plastic containers

Pregnant women have frequently been warned of an increased risk of miscarriage from food that had been heated in plastic containers.

As per a study conducted by Stanford University, findings of which were presented at the American Society for Reproductive Medicine's annual conference in Boston, high levels of contact with the chemical found in various plastics can greatly increase the likelihood of miscarriage.

The threat has been linked with the presence of the chemical Bisphenol A [BPA] that leaks from certain kinds of plastics that are exposed to high temperatures.

BPA, one of the most widely used chemicals today, can be found in a wide range of consumer products such as water bottles, flooring, food and drink containers etc. BPA monomers can be released from such consumer products that are exposed to either high temperatures or acidic and/or alkaline conditions [1]

Due to the widespread usage and potential leaching, the main route for exposure to BPA in humans is believed to be via dietary ingestion. [2]

Various studies have reported a wide range of effects of BPA on infants and foetuses. These effects include disruption of the brain and behaviour. One of the most infamous known effects of BPA exposure on offsprings is that of developing an "anxiety-like behaviour". [3]

The effects of BPA are witnessed even when the period of exposure is limited to pregnancy and lactation alone. While behavioural abnormalities in infants can be taken to reflect a change in the brain, the extent and nature of the brain development varies during the different gestational periods. [4]

According to the National Center for Biotechnology Information [NCBI], "the BPA sensitivity of the foetus is elevated in late pregnancy, as assessed by behavioural effects observed in pups exposed at different prenatal periods." [5]

Heat-inducing food

Epidemiological studies have reported an association between high temperatures and adverse pregnancy outcomes such as stillbirth, preterm birth, congenital heart defects, as well as low birth weight [LBW]. [6]

Ambient temperature can also affect the neural tube in the foetus developing in the womb of the pregnant woman.

Clinical research and studies have found heat-related vulnerabilities across pregnancy. Heat exposure in the first trimester of pregnancy - wherein the formation of the major organs occurs - has been linked with certain birth defects. [7]

Heat exposure in the subsequent trimesters, when there is a rapid growth and development of the foetus, can cause stillbirth or preterm birth. [8]

While heat exposure in the first trimester might cause birth defects and lead to stillbirth or preterm delivery in the second and third trimester, the risk of a low birth weight is there throughout the pregnancy with exposure to heat. [9]

Generally, being pregnant can cause the core body temperature of a woman to rise. Weight gain during pregnancy lowers the ratio of body mass to the body surface area, thereby making heat dissipation harder in pregnant women. [10]

Moreover, the metabolic demands of the developing foetus also generate heat in the body of a pregnant woman. Dehydration is also quite commonly seen in pregnant women. If present towards the later stages of pregnancy, dehydration might also trigger contractions of the uterus, leading to the onset of early labor. [11]

It is for these reasons that pregnant women are advised to minimise or completely eliminate heat-inducing foods from her maternal diet. Generally, heat-inducing foods are believed to be - oily or fried foods, spicy foods, unripe or semi-ripe papaya, pineapple, and eggplant or baigan.

Through controlled in vivo and in vitro pharmacological methods, it has been discovered that "the contractile effect of crude papaya latex was characterized by tetanic spasms". [12] Studies have revealed that while the normal consumption of ripe papaya by a pregnant woman does not pose any danger as such, the semi-ripe or unripe papaya is best avoided by pregnant women.

Unripe or semi-ripe papaya contains a high concentration of latex that can lead to uterine contractions, causing preterm birth.

Similarly, the consumption of pineapple - ripe or unripe - is generally not recommended for pregnant women. In folklore medicine, pineapple was used as an abortifacient or a drug causing an abortion. Ripe pineapple fruit has been used orally in some cultures as a traditional medicine for inducing abortion. Other cultures have been known to use the juice of the unripe pineapple for the same effect. [13]

In a study by Placek& Hagen, it was found that 'hot' and 'black' foods can be dangerous to consume during pregnancy. For the current study, hot foods included chicken, fish, eggplant, Palmyra sprouts, mango - ripe and unripe, sour items, papaya, and pineapple. [14] Black items in the study, on the other hand, included jamun and black grapes.

The importance of the right diet during pregnancy can hardly be overstated. For a pregnant woman, the diet has to be balanced and should be based on the general recommendations for all healthy adults. [15]

In a balanced diet, while plant-based foods and calorie-free beverages should be consumed in abundance, animal-based foods are ideal to be eaten in moderation.

Snacks and sweets, on the other hand, should only be consumed sparingly.

Dietary habits and lifestyle during pregnancy and breastfeeding affect the health of both the mother as well as child. The consumption of a balanced and varied diet right from the preconception period is essential for ensuring maternal well-being and pregnancy outcomes. [16]

The first 1000 days after conception are seen as a sensitive window of time defining both the health of the child as well as the risk of later non-transmissible diseases. Especially in this phase of life, the importance of a healthy lifestyle along with exercise and a balanced diet can be regarded as a building block for the prevention of such diseases. [17]