Proteins in pregnancy diet
Under-nutrition was a problem that public health experts were dealing with in most lower and middle income countries. Food availability to the poor was a major concern. With improvement in agriculture, transport and storage facilities, food is not a major issue anymore in most parts of the world. But back in the previous decade malnutrition was majorly under-nutrition. To increase their size and ability to make infants thrive and prevent growth faltering in them at a later date, it was stressed that the pregnant mother feeds on large amounts of proteins in diet. Such a diet contributed to reduction in under-nutrition.
In the current scenario, diseases of the affluent or the non communicable diseases like hypertension have peaked. This has instigated research work in the field of health and nutrition to combat the risk factors leading to non-communicable diseases. Moreover, in the past decade, with the help of experiments on animals, observations in humans, scientists have encroached upon the status of fetus also due to diet taken during pregnancy as crucial to the development of healthy adulthood among the babies that are born. For letting the babies in the womb to grow normally, recent guidelines suggest balancing the diet during pregnancy instead of stressing upon high amounts of protein. Estimated average requirement of proteins in adults is 0.66 g/kg body weight. This applies to the pregnancy needs in the first trimester also. During the second and third trimester, the protein requirement increases. Around 0.88 g/kg body weight is recommended for healthy fetal development and not more than that.
Excessive protein intake has been found to program the fetus towards non communicable diseases like elevated blood pressure. According to the Motherwell study from Scotland, DaFO88 study from Denmark, high protein diet during pregnancy can program the fetus to develop elevated blood pressure. A high protein and low carbohydrate diets were tested in the Motherwell study whereas the Denmark study provided evidence against high protein diet only and not carbohydrates associated with higher blood pressure in the offspring at 27 to 30 years of age. These studies were old, conducted several years ago but now raise novel concerns and so are being re-tested. American Heart Association suggests that high protein diets elevated diastolic blood pressure and not systolic.
Conversely, in experiments on animals like rats, it was found that low nephron (kidneys) numbers play a key role in the developmental programming of cardiovascular disease, HTN and kidney disease. A low protein diet was found to increase blood pressure, low nephron number and HTN related to renal hyperfiltration and activation of rennin angiotensin and aldosterone system. Many factors contribute to non communicable disease priming of the fetus like high fructose diet in the mother or high fat diet and so on. In animal studies increasing amino acids glycine and citrulline among only 9% maternal low protein diet, prevented hypertension among rodent offspring, measured after four weeks of life of offspring rats.
Efforts to reprogram the nutrition levels in newborns or in utero can prevent NCDs by correcting the mother’s protein intake. Protein diet is a double edged sword. Adequate amounts are required for healthy fetal growth. The association between maternal protein diet and developmental HTN follows a U-shaped curve.
Further research is required to assess the effects of protein diet and involving mechanisms around which the development of NCDs like HTN takes place in adulthood that is rooted in pregnancy nutrition of the mother. A multi-ethnic research base is required for decision making for adequate proteins in diet pattern that must be followed by the pregnant or lactating mothers.
