Introduction
The drastic change in lifestyles all across the world and the increasing incidences of dietary diseases have led to an increasing wave of interest in preventive health care over the last few decades. This has led to a rise in research on dietary diseases hence contributing to the growth and the development of the profession. This paper thus seeks to prove that dietary habits during pregnancy have an effect on the child’s health by increasing the risk of developing serious diseases in the child’s future. I will also seek to show that fetal under-nutrition during different stages of pregnancy is related to the various congenital disorders in the child’s life. Thereafter I will propose various preventive measures for coronary heart diseases and other dietary diseases in adults. I will place particular emphasis on the studies carried out in the United Kingdom to support my points.
Nutrition in fetal life has elicited serious debate on the matter among both health practitioners and the scientists’ community who for a long time have suspected a co-relationship between fetal life and an individual’s future life. The debate of the issue has been raging with some health experts blaming it on premature birth. However, this has been disapproved by scientific research which found a strong correlation between impairment of the physiological, metabolic and structural processes of the fetus to the future life of an individual. Several collaborative studies carried on both humans and animals tend to point to this evidence.
Background
Nutrition in fetal life could have lifelong implications on the future health of an individual (1). Some of the possible ramifications include effects on the physiological properties of an individual and increased exposure to diseases in the future. Continuous research has availed evidence that some major diseases in later life originate from alterations in the intrauterine growth and development (2). Such dysfunctions include: coronary heart diseases, type 2 diabetes, and hypertension. These might occur as a result of impairment during a critical period of development which causes a permanent effect on the physiological, structural, and even metabolic processes of the fetus.
The ever changing lifestyles have become a big concern to many people raising fears over their potential contribution to the rise in lifestyle diseases among pregnant women. These lifestyle diseases do have an obvious effect on the health of the fetus which is manifested in the defects that are presented in the adult life. Many of the ready made foods today are gaining popularity especially with the urban populace in the society. The major concern in the society is that many contain a lot of cholesterol, fat, and sugar which are to blame for the increase in the incidences of obesity, cancers, hypertension, and heart diseases. Their long term ramification is that they often have an adverse effect on the developing fetus leading to congenital disorders.
Studies carried out on 25,000 people in UK established relationship between the size of the baby at birth to the occurrence of diabetes, hypertension, and coronary heart diseases in their middle ages. Those people with disproportionate weight and width at birth were found to be highly vulnerable to the above mentioned diseases which were manifested in high glucose insulin concentration, high levels pf cholesterol in their blood, and high blood pressure. Similar tests elsewhere have affirmed the fact that it is defects during the fetal growth rather than premature growth that was responsible for the health defects in future. The studies showed that low rates of fetal growth were to be blamed for many cardiovascular diseases in later life.
Issues
In this paper I seek to establish the link between under-nutrition in pregnant mothers and the increase in their offspring susceptibility to nutritional diseases in adulthood. Thereafter I will attempt to suggest mitigation measures to reduce this apparent exposure to these lifestyle diseases among pregnant women. It is apparently clear that there are serious health challenges facing pregnant women in UK and the rest of the world. These are related to nutritional needs during the pregnancy period which have been found to cause dietary related diseases in their offspring in later years. There has been a notable surge in many nutritional related diseases which include: cardiovascular diseases, type 2 diabetes, hypertension, high bloods pressure, and various mental disorders.
The rapid rise in the so called lifestyle diseases such as cardiovascular diseases and type 2 diabetes that are strongly associated with obesity and overweight has necessitated the need to address the nutritional habits in pregnant mothers. Early life nutrition has also been linked to other diseases such as osteoporosis, asthma, lung disease, and some strains of cancer in human beings (3). There is also growing compelling evidence that early life nutrition could play a role in cognitive and behavioral traits of children and adolescents. Some have even suspected a link to the cognitive decline and other problems that come with the ageing process.
Method
This paper will be based on the literature review of various books, academic journals and articles relating to the effects of nutrition to the fetus and the effects of variations nutritional needs in the adult life. I will also focus on the analysis on various research experiments carried out on animals and people in the United Kingdom. Websites analysis will also provide an important resource in my discussion. I will draw a comparison on the results emanating from experimental research on the animals to those findings from research on humans so as to arrive at reliable conclusions.
Results
A series of animal studies carried out found that even genetic traits such as the color of fur could be modified by an alteration of the nutrition of a pregnant woman during pregnancy. The permanent effect on the fetal life has come to be described by medical specialists as fetal programming (4). Some components of some diets will lead to the mutations of some genes along the DNA structure leading to a permanent change causing serious disorders in the fetal development. In Norway for example, there has been a marked change in the lifestyles among the women leading to the ever growing incidences of obesity which is a potential health challenge. The fears emanate from the fact that there exist a strong relationship between the maternal weight and the growth and development of a fetus (4). This is because the maternal weight affects the metabolic processes in the pregnant mother. Thus, it can be argued that these diets combined with the physical activity have an effect on the pregnant woman.
Studies have shown that underweight babies at birth are more susceptible to diabetes and cardiovascular diseases. These babies are often characterized by low birth weights, small size in relation to the placentas, thinness and shortness at birth while failing to gain weight in infancy (4). Variations in fetal and placental hormones cause the fetus to adapt to under-nutrition. Continuous variations in secretions of hormones and tissue sensitivity to them as a result of under-nutrition may cause abnormal structural growth, functionality of organs, and diseases in the adult life. There thus exist strong pointers to the effect that many of the cardiovascular diseases are as a result of the failure of the maternal placenta to match the demands of the fetus.
The above arguments are enforced by the fetal origin hypothesis which suggests that any alteration in the fetal nutrition and the endocrine processes causes adaptations in the fetus which causes permanent metabolic, physiological, and cardiovascular changes. This thereby predisposes the individual person to the respective disorders in later life (5). Programming on the other hand occurs when an abnormal stimulus at a critical period of fetal development causes long term effects to the fetus (6). Scientists suspect that coronary heart diseases are as a result of adaptations of the fetus to under-nutrition which is usually beneficial at that particular stage but highly detrimental in adult life (7).
Discussion
The placenta plays one of the most important roles in fetal nutrition. It creates an interface through which the fetus derives its nutrients while at the same time excreting the waste material. Through its own metabolism, it also modifies some food components in order to suit the fetus. As a result proper communication between the placenta and the fetus is very crucial especially in the intrauterine stage of the fetus (8). As discussed earlier, scientists for a long time have suspected a strong relationship between poor dietary habits in pregnancy to the development of serious diseases in the adult life. However, this was opposed by those who thought that premature birth was to blame for these disorders in the child’s development.
Various research projects carried out in different parts of the world among human beings and animals have however reaffirmed the long held belief that diets in pregnant women do affect the health of the developing fetus thereby affecting the life of the adults in the future. Various people have argued that those who had been exposed to adverse intrauterine environment will most likely continue to be adversely affected in their childhood all the way to their adulthood. They continue to reason that it is these later influences which produce the programming effect in an individual.
Fetal programming
This is evident from experimental studies in animals which have revealed strong indications that any defects in the nutrition of pregnant mothers have long term adverse effects on the offspring. These defects are presented in form of cardiovascular diseases. Studies on rats for example have shown that when pregnant rats are fed on low protein diets, the offspring develop a high blood pressure. Those that were fed on low ratio of protein to energy suffered permanent alteration of the hepatic glucose metabolism (6). On the other hand, those placed on a control experiment where they were administered the same diet during the postnatal period did not present any alteration (9). The alteration in maternal nutrition also led to changes in cholesterol metabolism, secretion of insulin, and abnormal renal development (10).
Relationship between fetal growth and coronary heart diseases
Coronary heart diseases have risen drastically since the beginning of the twentieth century to become one of the greatest killers in the western countries. The incidences are now seen to expand to other areas of the world that are experiencing western influence (11). These include china, India and Western Europe. Researchers attribute this to the rapidly changing lifestyles. They concluded that adverse exposure to the Western lifestyle in the early life was to blame for the rising incidences. This hypothesis was supported by further research which found the siblings born of parents with coronary heart diseases had twice the probability of giving birth to still births and high infant mortality rate when compared to those in the control experiment. Researchers in Norway found those areas which had recorded high postnatal and neonatal mortality rates earlier in the century presented an increased death rate due to coronary heart diseases (12). This was reasonable given the strong correlation between low birth weights and elevated coronary heart diseases. This led to the hypothesis that low birth babies who survived death during their infancy and early childhood were at higher risk of developing coronary heart diseases during their adult life.
Similar studies in UK have confirmed that low rates of fetal growth are associated with coronary heart diseases in adult life (6). Tests carried out on people aged 45 years and above showed that 15% of those who were 2.5 kg and below at birth had coronary heart disease as compared to 4% of those who weighed 3.2 kg in the similar group at birth (13). Programming of a variety of organs and systemic tissues by the intrauterine environment was largely accountable for the findings.
High blood pressure and hypertension
Various studies carried out around the world established a strong relationship between low birth weight and high blood pressure among children in pre-puberty age and adults (14). Just like in coronary heart diseases, high blood pressure is much more prevalent to children born with low birth weights unlike those born prematurely. Similarly those who were too thin or too short at birth tended to be at higher risk of suffering high blood pressure and hypertension as adults (10).
Type 2 diabetes and insulin resistance
A test carried out in several countries established a close association between low birth weight and alteration in glucose metabolism (15). In the study, the prevalence of type 2 diabetes was seen to fall as we moved from low birth weights to those who were born relatively larger in most of the populations sampled. For example, in a sample of 370 men of 65 years, prevalence of type2 diabetes and that of altered glucose tolerance tended to fall as you moved from low births weights at 40% for 2.54 kg to 14 % for those at 4.31kg (16). Obesity in adults when combined with intrauterine effects worsened the conditions leading to higher prevalence.
Scientific evidence point out to the fact that poor growth of the fetus results to a reduction in the number of pancreatic β cells whose end effect is a reduced capacity to secrete sufficient insulin. As a result, these individuals have less ability to withstand the stress of becoming obese in adulthood (9). Those born thin are mostly insulin resistant and usually have impaired metabolism which tends to conserve fuel (17). Deeper studies revealed that adults who were born thin had lesser glycolysis and another component referred to as glycolytic ATP. It was also noted that their lipid content in such tissues as the muscles was lower (18). The rate of glucose oxidation in this group was very low according to the findings.
Fetal nutrition
Fetal genome was previously thought to be the dominant determinant of the fetal growth. However, fresh evidence has overridden this earlier held opinion by suggesting that it only plays a subordinate role in growth of the fetus (6). The dominant determinants have been found to be the nutritional and hormonal factors surrounding the fetus. This is particularly served by the supply of oxygen and nutrients (11). Further evidence is to be found in embryo transfer studies which points out that the growth of fetus is largely influenced by the recipient rather than the donor mother. It has been found that when a fetus is transferred to a larger uterus, the probability is that it achieves a larger birth size (19).
Studies in animals have also revealed that under-nutrition in early stages of gestation leads to small but proportionate offspring as opposed to the under-nutrition in the latter stages which tends to produce disproportional offspring but with normal birth weight. The variations is caused by different critical development stages of various organs and systems which presents varying but specific short term and long term effects on the fetus (20). Gonads for instance have a critical development period which occurs early on the gestation period as opposed to the renal development which takes place later in the gestation (21). Those babies symmetrically short, thin or small at birth were found to have varying disorders in their adult life (22).
Consistent with these studies, those babies that are born proportionally small are more vulnerable to high blood pressure but have lower risk of developing coronary heart disease. Under-nutrition in early development tends to force the fetus to slow down its growth by cutting its demand for nutrients in response to the expected relative under-nutrition in later gestation (10). Those that were disproportionately short during birth tend to suffer from disorders of liver controlled systems (23). They also tend to be highly vulnerable to coronary heart disorders in adulthood. This can be explained by abnormal development of the liver which is associated with cranial distribution of blood that occurs later in the gestation period (24). A follow up study carried out among adults whose mothers had been exposed to famine during their third trimester of their pregnancy found out that many suffered from glucose intolerance later in their adult lives (6).
Influences of mothers on fetal nutrition
Studies indicate that a mother’s own fetal growth, her diet and her body composition can affect the balance between fetal demand for nutrients and the placental capacity to meet the demands. The lack of capacity of the placenta to fully meet the needs of the fetus leads to adaptations of the fetus and changes in development which might help it to survive in the short term but which might be detrimental in the long term. This results due to permanent impairment of the structure, metabolism, and physiology which may expose the child to cardiovascular and metabolic disorders later in life (25).
The trajectory of fetal growth
If the trajectory of growth in fetus is too rapid, the demand for nutrients increases. Larger fetuses as a result of faster growth trajectories have higher maintenance requirements as compared to smaller fetuses. The nutritional requirement for the fetus is normally lower till late in pregnancy. According to the experiment carried on ewes, rapid growth trajectories and the subsequent large fetal size had better survival chances but at the same time risked reduction in maternal placental supply in the late stages of gestation. Maternal under-nutrition in the last stages of gestation was found to have adverse effect in the development a rapidly growing fetus as opposed to those that experienced slower growth (24). These fetuses made adaptations to survive which included wasting of the fetal lean mass in order to provide amino acids necessary for its development.
The fetal growth trajectories are set in the early stages of development during pregnancy. Experimental studies in sheep have shown that alteration in the intake of maternal nutrients and plasma progesterone can impair the gene expression leading to the change of the growth trajectory of the fetus. Changes in the environment have been seen to cause changes in the rate of growth of the embryo. For example, maternal progesterone treatment can lead to the permanent alteration of the growth trajectory resulting to changes in the allocation of cells between the various organs (15). The growth trajectory is known to be faster in male fetuses as opposed to the female fetuses. The faster growth trajectory could explain the increase in coronary heart diseases with westernization and the elevated death rates in men than women.
Intergenerational effects
Under-nutrition when it recurs over many generations can have adverse effects on the reproductive performance over the subsequent generations. Experiment in rats revealed that when rats were administered protein deficient diets over a period of 12 generations they presented fetal retardation over the succeeding generations. When re-administered normal diets, they regained their normal growth and development after 3 generations (25).
Further evidence in human beings provides strong evidence that a woman’s weight at birth influences the birth weight of her child (14). Low birth weight mothers have high likelihood of giving birth to thin offspring. This finding is consistent with the earlier finding that low maternal birth weight may lead to reduced materno-placental supply line which might not be able to satisfy the demand of the fetus. This could be as a result of the alteration of the vascular system, altered metabolism, and impaired placenta.
Size of the Placenta and transfer capabilities
The size of placenta is strongly related to the fetal size at birth according to research findings. Studies carried out on sheep indicated that maternal nutrition influenced the growth of the placenta which in turn affected the fetal development (15). It was found that when poorly fed ewes during the time of conception were fed on high nutrient diets during early pregnancy the size of the placenta increased. On the other hand, well fed ewes during the time of conception when given a high nutrient intake during the early pregnancy had a smaller placenta size.
Follow up studies in humans found that babies with disproportionately small placentas were predisposed to the reduction in placental supply capacity. On the other hand those with disproportionately large placentas tended to experience fetal catabolism and wasting of the cell mass to provide amino acids for consumption of the placenta (22). These fetal adaptations might be responsible for high death rates in people with high or low placenta ratios as a result of coronary heart diseases.
Dietary effects on specific fetal tissues
Alterations of the diets in the early stage have been shown by studies to have tissue specific effects on the animal’s proportions. For example, experiment on pigs revealed that when pigs are administered protein deficient food, their offspring had disproportionately larger heads, ears, and genitals as opposed to those fed on energy deficient food (16). Experiments on guinea pigs showed that maternal under-nutrition caused altered body proportions on the offspring at birth and unusually high level of cholesterol when high cholesterol diets were administered. Follow up experiment on women found out that women who had low dairy protein intake gave birth to thinner children on an average at birth (12).
Relationship between Maternal dietary balance and body composition
Experiments have indicated that the balance of macro nutrients in a maternal diet can have profound long term and short term effects on the offspring. Low ratios of protein to carbohydrates and fats in a maternal diet have adverse effect on the development of the placenta and also caused a permanently elevated high blood pressure in the offspring (16). The relationship between the maternal composition and adverse health effects on the offspring were established during a study among the Jamaican women. It was found that those mothers who had thin skin fold thickness and low weight gain during their pregnancy had children with elevated blood pressure from age eleven (16). Low maternal weight during pregnancy according to experiments in India was found to increase the risk of coronary heart disease to the offspring in adulthood (24).
Further studies in Finland revealed that high body mass index during pregnancy increased the chances of coronary heart diseases in the offspring. However, research revealed that increase in body mass during pregnancy had little effect on tall women as apposed to shorter women (25). The interpretation of this phenomenon was that increased body mass index increase the fetal size thereby increasing the fetal demand for nutrients across the placenta. In shorter women, their marteno-placental capacity to meet this demand for nutrients is highly reduced thereby posing an adverse effect on the fetal development.
Under-nutrition and slow childhood growth
Slow childhood growth as a result of under-nutrition during the gestation period leads to low intellectual ability in later life. Research carried out on military conscripts in Finland found out that small head circumference at birth resulted to poor verbal skills and arithmetic skills in adults. The experimental study revealed that those who had slowed growth and weight gain between half (a year) to 2 years of birth failed in all the intellectual tests administered (21).
Migration effect on maternal nutrition
UK for a long time has been faced with heavy migration of people from other countries. This has brought about new cultural patterns in the society especially on the side of food culture. As a result, the immigrants are usual spoilt for choice due to the variety of the food at their disposal. However, they easily succumb to the westernization and the lifestyles that come with it. The biggest challenge to nutritionists is how to ensure that the immigrants’ women have good diet and their health is also good during their stay. The major source of concern is their exposure in the aspect of westernization and the subsequent changes in lifestyles increase the immigrant’s vulnerability to lifestyle diseases. There is a rise in incidences of obesity and overweight among the immigrants which exposes them to these diseases.
Mitigation measures
To prevent nutritional disorders related to under-nutrition during the pregnancy period in mothers, scientists have come up with various radical measures. Some have however come under sharp criticism owing to their ineffectiveness and their adverse effect. For example, nutritional supplements during the nearly periods of pregnancy has been proved to be ineffective and sometimes has produced very undesirable effects. It has been found to cause a disproportionate growth in the size of the fetus relative to the placental size which affects the nutrient uptake. This causes an imbalance in nutrient uptake across the placenta due to its impairment. The end result is usually an exposure to coronary heart diseases, cardiovascular diseases, and other dietary diseases.
The best strategy is to avoid starchy and fatty foods which tend to expose the mother to obesity thereby increasing the chances of dietary diseases. Higher quantity of fruits and vegetables should be incorporated in all the diets while ensuring all the diets are balanced. The changing lifestyles which are exposing people to readily prepared food which are mostly sold in fast food shops are particularly risky to pregnant mothers by altering the growth of fetus due to their heavy fat and sugar content which leads to obesity and other nutritional disorders.
Foods whose cholesterol content is very high should also be avoided by pregnant women at all cost. These could potentially be harmful to the mother and the fetus resulting to an increased probability of health complications in the adult life of the offspring. Cholesterol is known to cause many health complications in adults which include among others Coronary heart diseases, diabetes, cardiovascular diseases, and high blood pressure. Daily body exercise also helps to reduce excess fats and also burn cholesterol thus helping to live a healthy life during pregnancy.
Authorities should put in place measures to ensure that pregnant women do not suffer from the adverse effect of the famines which have been shown to cause fetal nutrient deficiencies. These ultimately cause adaptations and programming in the fetus which are harmful to the health of the adults in the adulthood. As discussed earlier these effects cause harm by permanently altering the metabolic, physiological, and structural form of the organs and tissues in the fetus. These adaptations are usually beneficial to the fetus during the gestation period but later pose adverse effects on the adult.
Conclusion
Various research findings from both experiments on animals and human beings point out to the fact that poor maternal nutrition had an adverse effect in the size of the fetus which in turn reduced the capacity of the maternal placenta to meet nutritional requirements of the developing fetus. This caused a permanent alteration of the structural, physiological, and metabolic processes of the organs and systems leading to elevated risk to cardiovascular diseases, coronary heart diseases, metabolic disorders, type 2 diabetes, and hypertension. The increasing change of lifestyles and the consequent change in the dietary habits have been found to be an important risk factor which leads to what is commonly referred to as lifestyle diseases. This calls for careful scrutiny of the diets in order to curb the spread and exposure to the lifestyle diseases.
A strong association has been found to exist between low birth weight and hypertension and high blood pressure in adults. Similarly insulin resistance and type 2 diabetes has been found to be prevalent to people born with low birth weights. Fetuses with rapid growth trajectories have also been found to have a high vulnerability to coronary heart diseases and cardiovascular diseases. Small, size of placentas inhibit the transfer capability of the nutrients across the placenta while the balance of micronutrients in the placenta has profound effects on the blood pressure of the offspring.
Nutritional supplements during pregnancy have been found to be ineffective in preventing nutritional related diseases caused by under-nutrition during pregnancy. They have also been found to have adverse effect on the fetus sometimes even worsening the situation. The best preventive measure is to observe good dietary habits especially by taking well balanced diets during pregnancy. Foods with heavy quantities of sugar and fat content should be avoided as they may lead to obesity which is detrimental both to the health of the fetus and the mother. Those with high cholesterol content should also be avoided they could cause health complication. Daily exercise of pregnant mother is highly advised for good health. Slow childhood growth as a result of under-nutrition during pregnancy leads to low intellectual ability in later life. Research carried out on military conscripts in Finland found out that small head circumference at birth resulted to poor verbal skills and arithmetic skills in adults. According to the study those who had slowed growth and weight gain between half (a year) to 2 years of birth failed in all the intellectual tests administered (21).
Foods whose cholesterol content is very high should also be avoided by pregnant women at all cost as they could be harmful to the mother and the fetus resulting to an increased probability of health complications in the adult life of the offspring. Cholesterol is known to cause many health complications in adults which include among others Coronary heart diseases, diabetes, cardiovascular diseases, and high blood pressure. Daily body exercise also helps to reduce excess fats and also burn cholesterol thus helping to live a healthy life during pregnancy. Physical activity should be highly advised for pregnant mothers to help keep fit and avoid accumulation of excess fats.
Authorities should put in place measures to ensure that pregnant women do not suffer from the adverse effect of the famines which have been shown to cause fetal nutrient deficiencies. These ultimately cause adaptations and programming in the fetus which are harmful to the health of the adults in the adulthood. As discussed earlier these effects cause harm by permanently altering the metabolic, physiological, and structural form of the organs and tissues in the fetus. These adaptations are usually beneficial to the fetus during the gestation period but later pose adverse effects on the adult.
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