NUTR 2050 Flashcards
The study of nutrition
interdisciplinary science focused on the study of foods, nutrients and other food constituents and health
Principles of human nutrition
- Food is a basic need of humans
- food provides energy (calories), nutrients, and other substances needed for growth and health
- Health problems reltaed to nutrition originate within cells
- poor nutrition can result from both inadequate and excessive levels of nutrient intake
- Humans have adaptive mechanisms for managing fluctuations in food intake
- Malnutrition can results rom poor diets and from disease states, genetic factors, or combination of malnutrition & nutrigenomics
- Some groups of people are at higher risk of becoming inadequately nourished than others
- Poor nutrition can influence the development of certain chronic diseases
- Adequacy, variety and balance are key characteristics of a healthy diet
- There are no “good” or “bad” foods
Food security
something people experience when they have enough food to meet their needs at all times; they are able to acquire food in socially acceptable ways, without having to scavenge or steal food
Food insecurity
exists when the availability of safe, nutritious foods, or the ability to acquire them in socially acceptable ways is limited or uncertain
calorie
is a measure of the amount of the energy transferred from food to the body (not considered to be nutrients, because they are a unit of measure and not a substance actually present in food)
Nutrients
chemical substances in foods that are used by the body for growth and health
- every part of our body was once a nutrient consumed in food
Essential nutrients
nutrients the body cannot manufacture or produce sufficient amounts of
Nutrients required in the diet
→ carbohydrates, certain ”essential” amino acids such as histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
→ linoleic acid and alpha-linolenic acid (essential fatty acids)
→ vitamins, minerals, water
- all humans require the same set of essential nutrients but the amount of nutrients varies based on; age, body size, gender, genetics, growth, illness, lifestyle, medication use, pregnancy/lactation
Non-essential nutrients
nutrients that are present in food and used by the body but they do not have to be part of our diets → cholesterol, creatinine and glucose
Dietary Reference Intakes (DRI’s)
dietary intake standards account for major factors that influence nutrient needs, such as age, gender, growth, pregnancy and lactation
-this is a general term used for the nutrient intake standards for healthy people
Recommended Dietary Allowances (RDA’s)
these are levels of essential nutrient intake judged to be adequate to meet the known nutrient needs of practically all healthy people while decreasing the risk of certain chronic diseases
Adequate Intakes (AI’s)
these are “tentative” RDAs; AI’s are based on less conclusive scientific information than are the RDA’s
Estimated Average Requirements (EAR’s)
these are nutrient intake values that are estimated to meet the requirements of half the healthy individuals in a group; EARs are used to assess adequacy of intakes of population groups
Tolerable Upper Intake Levels (UL’s)
these are upper limits of nutrient intake compatible with health; the UL’s do not reflect desired levels of intake. They represent total, daily levels of nutrient intake from food, fortified foods and supplements that should not be exceeded
Daily Values (DVs)
he Nutrition facts panel on packaged foods ues standard levels of nutrient intakes based on an earlier edition of RDI levels
- are used to identify the amount of a nutrient provided in a serving of food compared to the standard level
- the % DV listed on nutrition labels represents the percentages of the standards obtained from one serving of the food product
Carbohydrates
used by the body mainly as a source of readily available energy
- consist of simple sugars (monosaccharides and disaccharides), complex carbohydrates (the polysaccharides), most dietary sources of fiber and alcohol sugars
Most common monosaccharides
Glucose & galactose
Most common disaccharides
sucrose (glucose + fructose), maltose (Glucose + glucose), lactose (glucose + galactose)
Complex carbohydrates
are called polysaccharides because they have more complex chemical structures than the simple sugars. Polysaccharides include; starches (plant form of stored carbohydrate), glycogen (the animal form of stored carbohydrate), most types of fiber
Carbohydrates provide __ calories per gram
4
Fiber
the total contribution of fiber to our energy intake is around 50 calories and supplying energy is not a major function of fiber; the main function of fiber is to provide ‘bulk’ to our stool for normal elimination
- high fiber can prevent CVD and obesity
Alcohol
alcohol (consumed by ethanol) is considered to be part of the carbohydrate family because its chemical structure is similar to glucose; it is a product of the fermentation of sugar with yeast
- with even 7 calories per gram, alcohol has more calories per gram than do other carbohydrates
Glycemic index
a measure of the extent to which blood glucose levels are raised by consumption of an amount of food that contains 50 g of carbohydrate compared to 50 g of glucose
- carbohydrates that are digested and absorbed quickly have a high glycemic index and raise blood glucose levels to a higher extent than do those with lower glycemic index values
- diets providing low glycemic index carbohydrates have generally been found to improve blood glucose control in people with diabetes
recommended % calories from carbs
45-65%
recommended grams of dietary fiber per day
females - 21-25 grams
males - 30-38 grams
Protein
protein in foods provide the body with amino acids used to build and maintain muscles, bone, enzymes and red blood cells
- the body can use protein as a source of energy
Amino acids
are the “building blocks” of protein, containing nitrogen
- 9 amino acids must be provided by the diet and are considered “essential amino acids”
- foods of high protein include a balanced assortment of all the essential amino acids
high quality protein
- protein from milk, cheese, meat, eggs and other animal products
- combinations of plant foods, such as gains or seeds with dried beans
proteins should contribute to ___% total energy intakte
10-35%
Kwashiorkor
a severe form of protein-energy malnutrition in young children; characterized by swelling, fatty liver, susceptibility to infection; cause is unclear
Good sources of protein
animal products and dried beans
Fats
- fats in food share the property of being soluble in fats but not in water
- fats and oils are made up of various types of triglycerides which consist of 3 fatty acids attached to glycerol
Glycerol
a component of fats that is soluble in water; it is converted to glucose in the body
Fats and oils are a _______ source of energy, and provide __ calories per gram
concentrated, 9
Essential fatty acids
linoleic acid and alpha linolenic acid; must be supplied in the diet
- these are found in phospholipids, which along with cholesterol, are primary lipids in the brain and other nervous system tissue
fats are needed for..
cholesterol and sex-hormone synthesis, components of cell membranes, vehicle for carrying certain vitamins that are soluble in fats only and suppliers of the essential fatty acids required for growth and health
Linoleic acid
is the parent of the omega-6 fatty acid family. One of the major derivatives of linoleic acid is arachidonic acid; which serves as a primary structural component of the central nervous system. Found in most veg. Oils and meats and human milk
Alpha-Linolenic acid
is the parent of the omega-3 fatty acid family. It is present in many types of dark green vegatables, vegetable oils and flaxseed
- derivatives of this essential fatty acid is Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
- EPA and DHA enter the body through intake of fatty, cold-water fish and shellfish and human milk
- the body only stores small amounts of alpha-linolenic acid, EPA and DHA
- recommended intake of EPA is 500mg daily even though most people in Canada and the US consume around 100mg
2 basic types of fats
saturated and unsaturated
monounsaturated fats
if one double bond is present in one or more of the fatty acids
Polyunsaturated fats
if two or more double bonds are present
Saturated fats
contain no double bonds between carbons and tend to be solid at room temperature
- animal products such as butter, cheese and meats and 2 plant oils (coconut and palm) are rich sources of saturated fats
Fats also come in forms of …
monoglycerides (glycerol+1 fatty acid) and diglycerides (glycerol+2 fatty acids)
fats in animal foods vs. plant foods
- animal foods contain more saturated and less unsaturated fat than plant foods
LDL cholesterol
- saturated fatty acids tend to increase blood levels of LDL cholesterol (the lipoprotein that increases heart-disease risk when present in high levels)
- trans fatty acids raise blood LDL- cholesterol levels to a greater extent than do saturated fatty acids
Type of fat vs. total intake
evidence indicate that the type of fat consumed is most important to health than is total intake
healthful fats vs. unhealthful
- fats that elevate levels of LDL cholesterol (Which increases the risk of heart diseases) are regarded as “unhealthful” while those that lower LDL cholesterol and raise blood levels of HDL cholesterol (the one that helps the body get rid of cholesterol in the blood) are considered healthful
% calories from fat
20-35 %
Cholesterol
the body generally produces only ⅓ of the cholesterol our bodies use because more than sufficient amount of cholesterol are provided in most people’s diets
- dietary cholesterol intake affects blood cholesterol level substantially less than do saturated and trans fat intake
- leading sources of dietary cholesterol are eggs yolks, meat, milk and milk products, and fats such as butter
- it is recommended that consumption of cholesterol intake should be minimal
Vitamins
chemical substances in foods that perform specific functions in the body
- 14 vitamins have been discovered and are either fat soluble or water soluble
- vitamins do not provide energy; but some play critical roles as coenzymes in chemical changes that take place in the body, known as metabolism
Fat soluble vitamins
vitamins A, D, E and K and are present in the fat portions of food (**DEKA = fat-soluble vitamins)
- fat-soluble vitamins are stored in the body’s fat tissues and the liver; these stores can be sizable and last from months to years when intake is low
- excessive consumption of the fat soluble vitamins from supplements, especially of vitamins A and D, produces various symptoms of toxicity
Vitamins B & C
- B-complex vitamins and vitamin C are soluble in water and found dissolved in water in foods
Water soluble vitamins
- except for vitamin B12, water-soluble vitamin stores in the body are limited and run out within a few weeks to a few months after intake becomes inadequate
- toxicity symptoms from water-soluble vitamins, however, tend to last a shorter time and are more quickly remedied
Coenzymes
chemical substances that activate enzymes
Metabolism
the chemical changes that take place in the body
- other vitamins (vitamins C and E, and beta-carotene, which is a precursor of Vitamin A) act as antioxidants and perform other functions; repairing damage to cells due to oxidation, these vitamins help maintain body issues and prevent disease
Phytochemicals
some plant pigments, hormones and other naturally occurring substances that protect plants from insects, oxidization and other damaging exposures also appear to benefit human health
- many of the phytochemicals that benefit health are pigments that act as antioxidants in the human body
Minerals
- humans require 15 minerals
- minerals consist of single atoms and carry a charge in solution
- the charge carried by minerals allows them to combine with other minerals to form stable complexes in bone, teeth, cartilage and other tissues
- the tendency of minerals to form complexes has implications for the absorption of minerals from food
- the proportion of total mineral intake that is absorbed is less than for vitamins
Water
- adults are about 60-70% water by weight
- water provides the medium in which most chemical reactions take place in the body
- water plays a role in energy transformation, the excretion of wastes and temperature regulation
- people need enough water to replace daily losses from sweating, urination and exhalation
- total water requirement of adult males is 15-16 cups from foods and fluids per day; females is 11 cups
Total water intake includes…
drinking water, water in beverages and water that is part of food
- people generally consume about 75% of their water intake from water and other fluids and 25% from foods
Alcohol and water
- alcohol tends to increase water loss through urination, so beverages such as beer and wine are not as “hydrating” as water is
caffeinated beverages
are hydrating in people who are accustomed to consuming them
Health problems related to nutrition originate within cells
- problems arise when a cell’s need for nutrients differs from the amounts that are available
- normal cell health and functions are maintained when a nutritional and environmental utopia exists within and around cells
- this state of optimal cellular nutrient conditions supports homeostasis in the body
- disruptions in the availability of nutrients, or the presence of harmful substances in the cell’s environment, initiate diseases and disorders that eventually affect tissues, organs and systems
Poor nutrition can result from both inadequate and excessive levels of nutrient intake
- inadequate intake of an essential nutrient esults in obvious deficiency diseases
- the length of time a deficiency of toxicity takes to develop depends on the type and amount of nutrient consumed and the extent of body nutrient reserves
- after a period of deficient intake of an essential nutrient, tissue reserves become depleted and subsequently, blood levels of the nutrient decline. When the blood level can no longer supply cells with optimal amounts of nutrients, cell processes change.
- if the deficiency continues, groups of cells malfunction, which leads to problems related to tissue and organ functions
- eventually, some problems produced by the deficiency can no longer be reversed by increased nutrient intake
- excessively high intakes of many essential nutrients produce toxicity diseases
- signs of toxicity stem from an increased level of the nutrient in the blood and the subsequent oversupply of the nutrient to cells
- for both deficiency and toxicity diseases, the best way to correct the problem is at the level of intake
- most foods contain many nutrients, so poor diets are generally inadequate in many nutrients
- dietary changes affect the level of intake of many nutrients; dietary changes introduced for the purpose of improving intake of a particular nutrient produce a “ripple effect” on the intake of other nutrients
Humans have adaptive mechanisms for managing fluctuations in food intake
- healthy humans have adaptive mechanisms that partially protect the body from poor health due to fluctuations in nutrient intake
- these mechanisms act to conserve nutrients when dietary supply is low and to eliminate them when excessively high amounts are present
- fluctuations in energy intake are primarily regulated by changes in appetite; if too few calories are consumed, the body will obtain energy from its glycogen and fat stores
- although they provide an important buffer, these built-in mechanisms do not protect humans from all the consequences of poor diets
Malnutrition
means “poor nutrition” and results from either inadequate or excessive availability of energy and nutrients
- malnutrition can result from poor diets as well as from diseases that interfere with the body’s ability to use the nutrients consumed
Primary malnutrition
results when a poor nutritional state is dietary in origin
Secondary malnutrition
is caused by a disease state, surgical procedure or medication (ex. Alcoholism, G.I Bleeding, AIDS)
Nutrigenomics
advances in knowledge about nutrient-gene interactions in health and disease are revolutionizing the science and practice of nutrition
- thousands of rare diseases related to a defect in a single-gene have been identified and many of these affect nutrient needs
- phenylketonuria (PKU), galactosemia, and hemochromatosis are 3 examples of single-gene defects that substantially affect nutrient needs or utilization
- most diseases related to genetic traits are not as well defined as are single-gene defects
- components of foods consumed affect gene function by turning specific genes “on” or “off”, thereby affecting what metabolic reactions occur within the body
- some examples of effects of nutrient-gene interactions on health status include:
→ consumption of high glycemic index carbohydrates appears to increase the risk of type 2 diabetes in individuals with a certain form of gene involved in insulin production and secretion
→ high alcohol intake during pregnancy in some women sharply increases the risk of fetal alcohol syndrome in her fetus, but the fetuses of other women with different genetic traits are not affected by high alcohol intake
→ regular consumption of green tea reduces the risk of prostate cancer in certain individuals with particular genetic trait
Some groups of people are at higher risk of becoming inadequately nourished than others
- women who are pregnant or breastfeeding, infants, children, people who are ill, and frail elderly people have a greater need for nutrients than healthy adults and elderly people do
- as a result, they are at higher risk of becoming inadequately nourished than others
chronic diseases
slow-developing, long-lasting diseases that are not contagious (eg. heart disease, cancer, diabetes); they can be treated but not always cured
- the leading causes of death among Americans are heart disease and cancer
- diets high in saturated and trans fats, and low in vegetables, fruits, and whole grain products, are linked to the development of heart disease
- diet is related to 3 leading causes of death: diabetes, stroke and Alzheimer’s disease
Adequacy, variety and balance are key characteristics of a healthy diet
- adequate diets are most easily obtained by consuming foods that are good sources of a number of nutrients but not packed with calories; such foods are considered nutrient-dense foods
- those that provide calories and low amounts of nutrients are considered empty-calorie foods
- variety is a core characteristics of healthy diets because the essential nutrient and phytochemical content of foods differ
- a healthy diet provides a balanced selection of food types and amounts
There are no “good” or “bad” foods
- people tend to classify foods as being “good” or “bad” but such opinions about individual foods oversimplify the potential contribution of these foods to a diet
- all foods can fit into a healthful diet as long as nutrients needs are met at calorie-intake levels that maintain a healthy body weight
Nutritional labeling
- nutrition labelling requires that almost all multiple-ingredient foods and dietary supplements be labeled with a Nutrition Facts panel
- the act also requires that nutrient content and health claims appearing on package labels, such as “trans-fat free” and “helps prevents cancer” qualify based on criteria established by the Food and Drug Administration (FDA)
Nutrition facts panel
- the nutrition facts panel must list the content of fat, saturated fat, trans fat, cholesterol, sodium, total carbohydrates, fiber, sugars, protein, vitamins A and C, calcium, and iron in a standard serving
- nutrition facts panels contain a column that lists the % Daily value (or %DV) for each relevant nutrient; this information helps consumers decide for example, whether the carbohydrate content of a serving of a specific food product is a lot or a little
- nutrient content claims made on food package labels must meet specific criteria. Product labeled “no trans fat” or “trans fat free” for example, must contain less than 0.5 grams of trans fat and of saturated fat
‘Low sodium’
- products labeled “low sodium” must contain less than 140mg of sodium per serving
Ingredient Label
- food products must list ingredients in an ingredient label
- the list must begin with the ingredient that contributes to the greatest amount of weight to the product and continue with the other ingredients on a weight basis
Dietary supplement labeling
labels on dietary supplements cannot claim to treat, cure or prevent disease
- dietary supplements can make other claims on product labels not approved by the FDA, such as “supports the immune system” or “helps maintain mental health” as long as the label doesn’t state or imply that the product will prevent, cure or treat disease
- some foods are labeled as “enriched” or “fortified”
- enrichment pertains only to refined grain products and covers some of the vitamins and one of the minerals lost when grains are refined
- any foods can be fortified with added vitamins and minerals and its manufacturers most often do so on a voluntary basis to enhance product sales
Herbal remedies
- FDA considers herbal remedies to be dietary supplements
- some herbal remedies act like drugs and have side effects, but they are not considered to be drugs and are loosely regulated
- the extent to which herbs pose a risk to health depends on the amount taken, the duration of use and the user’s age, lifecycle stage and health status
Functional foods
- include a variety of products that have been modified to enhance their contribution to a healthy diet
- foods are made “functional” by:
→ taking out potentially harmful components (eg. cholesterol from egg yolks and lactose from milk)
→ increasing the amount of nutrients and beneficial non-nutrients (eg. fiber-fortified liquid meals, calcium and vitamin c- fortified orange juice)
→ adding new beneficial compounds to foods (eg. “friendly” bacteria to yogurt and other milk products)
Prebiotics
- in a class of functional foods by themselves (with probiotics)
- are fiber like, indigestible carbohydrates that are broken down by bacteria in the colon; the breakdown products foster the growth of beneficial bacteria
Probiotics
is the term for live, beneficial “friendly” bacteria that enter food products during fermentation and aging processes
infant mortality
improvements in infant mortality in the past decades due to technological advances
Liveborn infant
outcome of delivery when a completely expelled or extracted fetus breathes, or shows any sign of life such as beating of the heart, pulsation of the umbilical cord, or definite movement of voluntary muscles, whether or not the cord has been cut or the placenta is still attached
- 2/3 of deaths of liveborn infants occur within the first month after birth, or during the neonatal period
Low birth weight, preterm delivery & infant mortality
Infants born at low birthweight or preterm are at substantially higher risk of dying in the first year of life
Low-birthweight and preterm infant outcomes are intertwined in that the shorter the pregnancy, the less newborns tend to weigh
Rates of preterm delivery and low birthweight in the US have trended slowly upward since 1983 and remain higher in African American infants than in other infants
Infants weighing 3500 to 4500 grams at birth (7-10 pounds) are least likely to die within the first year of life
o They have better overall health status and mental development
o less likely to have heart disease, diabetes, lung disease, hypertension later in life
2020 health objective for the nation
focus on the reduction of low birthweight, preterm delivery, and infant mortality
- Also, improving prenatal weight gain, access to care, and behaviours that adversely affect the outcome of pregnancy
Physiology of pregnancy
Pregnancy begins at conception; that occurs approx. 14 days before a woman’s next menstrual period is scheduled to begin and ovulation occurs, avgs. 38 weeks or 266 days
Pregnancy is given at 40 weeks because it is measured from the first day of the last menstrual period (LMP)
The most common way of measuring pregnancy duration includes two non-pregnant weeks at the beginning
The anticipated date of delivery is called “the estimated date of confinement” or EDC
Assessment of duration of pregnancy as weeks from conception is correctly termed gestational age, whereas time in pregnancy estimated from LMP reflects menstrual age
Placenta
a dark-shaped organ of nutrient and gas interchange between mother and fetus. At term, the placenta weighs about 15 percent of the weight of the fetus
Normal physiological changes
Attempts to bring maternal physiological changes back to non-pregnant levels may cause more harm than good to the pregnancy
Physiological changes can be divided into 2 groups: those occurring in the first half of pregnancy and those occurring in the second half
- Approximately 10% of fetal growth is accomplished in the first half of pregnancy, and the remaining 90 percent occurs in the second half
First half physiological changes in pregnancy
considered maternal anabolic changes, they build the capacity of the mother’s body to deliver relatively large quantities of blood, oxygen and nutrients to the fetus in the second half of pregnancy
Second half physiological changes in pregnancy
called maternal catabolic changes, energy and nutrient stores and the heightened capacity to deliver stored energy and nutrients to the fetus, predominate
Body water changes during pregnancy
A woman’s body gains a lot of water during pregnancy due to increased volumes of plasma and extracellular fluid, as well as amniotic fluid
About two thirds of the expansion is intracellular (blood and body tissues) and one third is extracellular (fluid in spaces between cells)
Plasma volume begins to increase within a few weeks after conception and reaches a maximum at approx. 34 weeks
Early pregnancy surges in plasma volume appear to be the primary reason that pregnant women feel tired and exhausted easily
Fatigue associated with plasma-volume increases in the second and third months of pregnancy declines
Body water gain variance during normal pregnancy
High gains are associated with increasing degrees of edema (swelling due to an accumulation of extracellular fluid) and weight gain
o If not accompanied by hypertension, edema generally reflects a healthy expansion of plasma volume
Birth weight & plasma volume
Birth weight is strongly related to plasma volume: generally, the greater the expansion, the greater the new-born size
Hormonal changes
physiological changes during pregnancy are caused by hormones produced by placenta
The placenta serves many roles, but a key one is the production of steroid hormones such as progesterone and estrogen
Carbohydrate metabolism during pregnancy
Changes in carbohydrate metabolism promote the availability of glucose to the fetus
o Glucose is the fetus’s preferred fuel, even though fats can be utilized for energy
o Continued availability of a fetal supply of glucose is accomplished primarily through metabolic changes that promote maternal insulin resistance
o These changes are referred to as the diabetogenic effect of pregnancy and make normal pregnant women slightly carbohydrate intolerant in the third trimester of pregnancy
Carbohydrate metabolism in the first half of pregnancy
characterized by estrogen- and progesterone- stimulated increases in insulin production and conversion of glucose to glycogen and fat
Carbohydrate metabolism in the second half of pregnancy
rising levels of hCS and prolactin from the mother’s pituitary gland inhibit the conversion of glucose to glycogen and fat
insulin resistance builds in the mother, increasing reliance on fats for energy
Accelerated fasting metabolism during pregnancy
Maternal metabolism is rapidly converted toward glucogenic amino acid utilization, fat oxidation, and increased production of ketones with fasts that last longer than 12 hours
- Although these metabolic adaptions help ensure a constant fetal supply of glucose, fasting eventually increases the dependence of the fetus on ketone bodies for energy
Protein metabolism during pregnancy
Nitrogen and protein are needed in increased amounts during pregnancy for synthesis of new maternal and fetal tissues
- Estimated that 925 grams of protein are accumulated during pregnancy
Fat metabolism during pregnancy
Multiple changes occur in the body’s utilization of fats during pregnancy
Overall, changes in lipid metabolism promote the accumulation of maternal fat stores in the first half of pregnancy and enhance fat mobilization in the second half
Blood levels of many lipoproteins increase dramatically
High levels of triglycerides indicate the existence of insulin resistance prior to pregnancy
Insulin resistance before conception increases risk of diabetes and hypertension developing during pregnancy
Development of the placenta
placenta develops from embryonic tissue and is larger than the fetus
Development of the placenta precedes fetal development
Functions of the placenta
Hormone and enzyme production
o Nutrient and gas exchange between the mother and fetus
o Removal of waste products from the fetus
- harmful substances (alcohol, drugs, viruses) pass through placenta to the fetus
placenta is a barrier to the passage of maternal RBCs, bacteria, and many large proteins
The placenta also prevents the mixing of fetal and maternal blood until delivery
Structure of the placenta
Its structure, including a double lining of cells separating maternal and fetal blood, acts as a barrier to harmful compounds and controls rate of passage of nutrients and other substances into and out of fetal circulation
Nutrient transfer during pregnancy
Placenta uses 30-40 percent of the glucose delivered by the maternal circulation
If nutrient supply is low, the placenta fulfills its own needs before fetus
Nutrient transfer across the placenta depends on a number of factors such as:
o The size and the charge of molecules available for transport
o Lipid solubility of the particles being transported
o The concentration of nutrients in maternal and fetal blood
Small molecules with little or no charge (water) and lipids (cholesterol and ketones) pass through the placenta easily, but large molecules (insulin and enzymes) aren’t transferred
Nutrient exchange between the mother and fetus is unregulated for some nutrients, oxygen and carbon dioxide; It is highly regulated for other nutrients
Nutrients cross placenta membranes by simple diffusion from blood with high concentration of the nutrients to blood with lower concentration
Three primary mechanisms regulate nutrient transfer: facilitated diffusion, active transport, and endocytosis (or pinocytosis)
The fetus receives small amounts of water and nutrients from ingestion of amniotic fluid
By the second half of pregnancy, the fetus is able to swallow and absorb water, minerals, nitrogenous waste products, and other substances in amniotic fluid
Embryonic and fetal growth and development
The rate of human development is higher during gestation than any time thereafter
Critical periods: pre-programmed time periods during embryonic and fetal development when specific cells, organs, and tissues are formed and integrated, or function levels established. Also called sensitive periods.
o Critical periods are most intense during the first 2 months after conception
Hyperplasia
Critical periods of growth and development are characterised by hyperplasia, or an increase in cell multiplication
The brain is the first organ that develops in humans, and the CNS
The heart and adrenal glands come next after the CNS
Some degree of hyperplasia takes place in a number of organs and tissues in the first year or two after birth and during the adolescent growth spurt
Hyperplasia and Hypertrophy
Cell multiplication continues at a lower rate after critical periods of cell multiplication and is accompanied by increases in the size of cells
Cell size increases mainly due to an accumulation of protein and lipids inside of cells
increases in cell size can be determined by measuring the protein or lipid content of cells
Periods of hyperplasia-hypertrophy are followed by hypertrophy only
During this phase, cells continue to accumulate protein and lipids, and functional levels continue to grow in sophistication, but cells no longer multiply
Maturation during pregnancy
The last phase of growth and development is maturation – the stabilization of cell number and size; occurs after tissues and organs are fully developed later in life
Fetal body composition
The fetus undergoes marked changes in body composition during pregnancy
The general trend is toward progressive increases in fat, protein, and mineral content
Some of the most drastic changes take place in the last 5 weeks of pregnancy
Variations in fetal growth and development
Variations are not generally due to genetic causes but rather to environmental factors such as energy, nutrient, and oxygen availability, and to conditions that interfere with genetically programmed growth and development
Insulin-like growth factor-1 (IGF-1) is the primary growth stimulator of the fetus
o It promotes uptake of nutrients by the fetus and inhibits fetal tissue breakdown
o Levels of IGF-1 are sensitive to maternal nutrition; its levels are decreased by under nutrition
o Low levels of IGF-1 decrease muscle and skeleton mass and produce asymmetrical growth
Size of baby
Risk of illness and death varies with size at birth and is particularly high for newborns experiencing intrauterine growth retardation (IUGR)
For a portion of newborns, smallness at birth is normal and may reflect familial genetics
Because IUGR Is complicated to determine, it is usually approximated by assessment of size for gestational age using a reference standard
Infants are generally considered likely to have experienced IUGR if their weight for gestational age or length is low
o Newborns whose weight is less than the 10th percentile for gestational age are considered small for gestational age or SGA
o This is further categorized into disproportionately small for gestational age (dSGA) and proportionately small for gestational age (pSGA)
o Newborns who weight less than the 10th percentile of weight for gestational age but have normal length and head circumference for age are considered dSGA
o If weight, length, and head circumference are less than the 10th percentile for gestational age, then the newborn is considered pSGA
dSGA
Infants who are dSGA look skinny, wasted, and wrinkly
Have small abdominal circumferences, reflecting lack of glycogen stores in the liver, and little body fat
It appears that these infants have experienced in utero malnutrition in the 3rd trimester of pregnancy and that is compromised liver glycogen and fat storage
These infants are at risk of developing the “hypos” after birth (hypoglycemia, …)
perform worse academically, greater risk for heart disease, hypertension, and type 2 diabetes in the adult years
pSGA
Look small but well proportioned
Believed that these infants experienced long-term malnutrition in utero due to factors such as pre-pregnancy underweight, consistently low rates of maternal weight gain, and inadequate dietary intake or chronic exposure to alcohol
Generally, have a reduced number of cells in organs and tissues
Exhibit fewer health problems at birth than dSGA but catch-up growth is poorer even with nutritional rehabilitation
Remain short and lighter and have smaller head circumferences throughout life
LGA
Newborns with weights greater than the 90th percentile for gestational age are considered to be large for gestational age
Related to pre-pregnancy obesity, poorly controlled diabetes in pregnancy, excessive weight fain in pregnancy
Mascarriages
> 30% of implanted embryos are lost by reabsorption into uterus or expulsion before 20 weeks of pregnancy, roughly a third of these are recognized as miscarriages
early losses of embryos and fetuses are caused by non-inherited chromosomes abnormalities, thyroid disorders, hormonal imbalances, reproductive tract infections, drug or alcohol abuse, or other disorders
presence of nausea and vomiting early in pregnancy is related to low risk of miscarriage
nausea and vomiting occur as side effect of healthy changes in hormonal levels
women who enter pregnancy underweight are at higher risk of miscarriage
elevated blood cholesterol or triglyceride concentration and high levels of markers of inflammation in first half of pregnancy are linked to risk of miscarriage
use of multivitamin supplements are associated with reduced risk of one
Preterm delivery
infants born preterm are at greater risk of death, neurological problems reflected later in low IQ scores, attention deficit/hyperactivity disorder, and enrolment in special education
also chronic health problems such as cerebral palsy
underweight women who gain less than the recommended amount à high risk
women entering pregnancy obese are also at increased risk, but to a lesser extent
women who exercise during pregnancy à lower risk
reasons for preterm delivery: genital tract infections, insufficient uterine-placental blood flow, placental abruption, pre-pregnancy underweight, low weight gain during, short inter-pregnancy interval and high levels of stress
Development programming of later disease risk
process by which adverse nutritional and other exposures during critical periods of growth and development modify gene function
- such changes may predispose individuals to develop cardiovascular disease, type 2 diabetes, hypertension, obesity, and other disorders later in life
Development plasticity
concept that development can be modified by particular environmental conditions experienced by a fetus or infant
- environmental exposures modify development through epigenetic mechanisms that program gene function while not changing DNA structure
o the epigenetic mechanisms influence growth and development by silencing certain genes and activating others
Pregnancy weight gain
rates of low birth weight are higher in women gaining too little weight during pregnancy
· weight gain during pregnancy is an indicator of plasma volume expansion and positive calorie balance, and provides a rough index of dietary adequacy
· pre-pregnancy weight status affects the relationship between weight gain and birth weight
o higher the weight before pregnancy, the lower the weight gain needed to produce a healthy infant and vise versa
o duration of gestation, smoking, maternal health status, gravida (# of pregnancies experienced), and parity (# of previous deliveries) influence birth weight
· women who gain within recommendation are approx. half as likely to deliver low birth weight or SGA newborns
Rate of pregnancy weight gain
low rates of gain in the first trimester of pregnancy may down-regulate fetal growth and result in reduced birth weight and thinness
· rate of weight gain is generally highest around mid pregnancy – prior to time fetus gains most of its weight
· some weight (3-5 pounds) should be gained in the 1st trimester, followed by gradual and consistent gains thereafter. Weight should not be lost until after delivery
· the fetus only comprises about a third of the total weight gained during pregnancy
o the rest is the increased weight of maternal tissues
· body fat stores increase the most between 10-20 weeks of pregnancy
Postpartum weight retention
women are gaining more weight during pregnancy and losing less after delivery
· women of all pre-pregnancy weight statuses tend to lose about 14 pounds within the first 6 weeks after delivery, after that amount varies
· weight losses of 1-2 pounds per month postpartum with diet and exercise are appropriate
The need for energy during pregnancy
energy requirements during pregnancy increase due to protein and fat tissue synthesis
· protein synthesis occurs in fetal, placental, uterine, and breast tissues
· most of the fat synthesized during pregnancy is used to buildup maternal fat stores
· the increased need for energy in pregnancy averages 300 kcals a day or a total for pregnancy of 80,000 kcal
· DRIs for energy intake are +340 kcal per day for the second trimester and +452 kcal per day for third trimester
Carbohydrates during pregnancy
45-65 percent of total caloric intake should come from carbs
· good sources: vegetables and fruit, whole-grain products containing fiber
Alcohol and pregnancy
alcohol passes through placenta to fetus, interrupts normal growth and development
· large amounts can cause risk of abnormal mental development and growth in offspring
· avoidance of alcohol is most necessary during second half of first trimester
Protein during pregnancy
71 grams daily for pregnant individuals
· protein requirements increase during pregnancy because of protein tissue accretion
Need for fat during pregnancy
estimated pregnant women should consume 33 % of total calories on average from fat
· fat consumed is used as energy source for fetal growth and development
· recommendation: 13 grams of linoleic acid daily, and 1.4 grams of the other essential fatty acid, alpha-linoleic acid
· Recommendation for Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
o 300 mg per day
Folate during pregnancy
inadequate folate is associated with anemia and reduced fetal growth
o Folate is involved in replication of DNA, gene expression, and amino acid metabolism à deficiency impairs these processes
o Folate abnormalties: neural-tube defects (NTDs) are malformations of the spinal cord and brain, three major types:
§ Spina bifida (spinal cord failing to close), anencephaly (absence of the brain or spinal cord), encephalocele (protrusion of brain through skull)
o Sources of folate: vegetables and fruit
Choline during pregnancy
increases during pregnancy due to its role as a component of phospholipids in cell membranes and a precursor of intracellular messengers
o RDA for choline: 450 mg daily
o Major sources: eggs and meat
Vitamin A during pregnancy
plays important roles in reactions involved in cell differentiation
o Deficiency: can produce malformations of the fetal lungs, urinary tract, and heart
o High doses of retinoic acid: retinoic acid syndrome: small ears or no ears, abnormal or missing ear canals, brain malformation, and heart defects
o Take no more than 5000 IU during pregnancy
Vitamin D during pregnancy
supports fetal growth, addition of calcium to bone, and tooth and enamel
o Lack of it: compromises feta as well as childhood bone development
o Intake of 15 mcg (600 IU) daily
Calcium during pregnancy
needed for fetal skeletal mineralization and bone health
o Approx. 30 grams of calcium is moved from mother to fetus during pregnancy
o In last quarter of pregnancy, 300 mg per day of calcium needed
o Calcium and release of lead from bones
- Lead in maternal blood can cross placenta and be taken up by fetus
- Cause of concern because its related to miscarriage, preterm birth, low-birthweight infants, impaired central nervous system development
- Women who do not consume enough calcium show greater increases in blood lead levels
Flouride during pregnancy
limited amount of fluoride transferred from mother’s blood to developing enamel of fetus, however, major gains occur in the years after birth
Iron during pregnancy
women require about 1000 mg (1g) of additional iron for pregnancy
o Iron deficiency and iron deficiency anemia is most common worldwide
o Rates of iron deficiency are lower in 1st trimester, increase in second, and peak in third
o Increases risk of preterm delivery and low-birthweight by 2-3 times
o Pregnant women should take a 30 mg iron supplement daily after 12th week of pregnancy
Iodine during pregnancy
needed for thyroid function and energy production, and fetal brain development
o Deficiency can lead to hypothyroidism
Bioactive components of food
Constituents in foods or dietary supplements other than those needed to meet basic human nutritional needs that are responsible for changes in health status
· Examples: antioxidant pigments in plant foods and caffeine
Coffee & pregnancy
Caffeine increases hear rate and stimulate central nervous system
- Reducing caffeine intake doesn’t appear to improve pregnancy outcomes
Water during pregnancy
Large increase in water during pregnancy is generally met by increased levels of thirst
Factors affecting dietary intake during pregnancy
Changes in the way certain foods taste, and the odor of foods, and other substances affect two out of three women during pregnancy
Pica
classified as an eating disorder, affects over half of pregnant women, compulsion to eat substances that are not food
o Types: pagophagia (compulsive consumption of ice or freezer frost), amylophagia (compulsive consumption of laundry starch or cornstarch), geophagia (compulsive consumption of clay or dirt)
Vegetarian Diets and Pregnancy
Diets of pregnant vegetarians are sometimes low in Vitamins B12 and D, calcium, iron, zinc, and the omega-3 fatty acids eicosapentaenoic, and socosahexaenoic acids
· Protein intake is adequate in vegetarian diet but may be low in vegans
· Protein sources: legumes and grains
Dietary supplements and pregnancy
Dietary supplements used by pregnant women come in pill, powder, chewable, liquid, and snack bar form
· About 95% of pregnant women take a vitamin and mineral supplement regularly
· Herbs are regarded by the public and health professionals as helpful, safe, and gentle
o Many aren’t approved for use in pregnancy, about 1/3 are deemed unsafe
Listeria monocytogenes
food-borne illness, placenta does not protect the fetus from listeria infection in the mother
o Associated with spontaneous abortion and stillbirth in one-third of fetuses and mild infection in mothers
o To prevent: pregnant women should not eat raw or smoked fish, oysters, unpasteurized cheese, raw or undercooked meat, or unpasteurized milk
Toxoplasma gondii
can be transferred from mother to fetus and cause mental retardation, blindness, seizures, and death
Mercury Contamination
mercury can pass from mother’s blood to the fetus, it is a fetal neurotoxin that can produce mild to severe effects on fetal brain development
o Fetuses exposed to high amounts of mercury can develop intellectual disabilities, hearing loss, numbness, and seizures
o High levels of mercury are likely to be in muscles of large fish such as sharks, swordfish, tilefish, albacore tuna, walleye, pickerel, and bass
Exercise and Pregnancy
Exercise during pregnancy benefits both the mother and her fetus and is encouraged
· Women who exercise during pregnancy feel healthier, have an enhanced sense of well-being, and somewhat short labours
· Reduces risk of developing gestational diabetes, hypertension, low back pain, excessive weight gain, and blood clots
· Should exercise 3-5 times a week for 20-30 minutes
Nausea and vomiting during pregnancy
Nausea occurs in 8/10 pregnancies, vomiting in 5/10
· Symptoms of nausea begin around week 5 of gestation and disappear by week 12
· Actually occurs at all times, not just in the morning
· Iron supplements may aggravate nausea and vomiting when taken in first trimester
· Between 1-2 percent of pregnant women with nausea and vomiting develop hyperemesis gravidarum (characterized by severe nausea and vomiting lasting throughout pregnancy)
General recommendations for experiencing nausea and vomiting during pregnancy
Continue to gain weight, Separate liquid and solid food intake, Avoid odors and foods that trigger nausea, Select foods that are well tolerated
3 dietary supplements that decrease symptoms of nausea and vomiting in pregnancy
Vitamin B6, Diclectin, multivitamin supplements, and ginger
Heartburn and pregnancy
Pregnancy is accompanied by relaxation of gastrointestinal tract muscles
o This effect is attributed primarily to progesterone
· Relaxation of muscular value known as cardiac or lower esophageal sphincter is thought to lead to the heart burn
o Prevention and management: Ingest small meals frequently, Do not go to bed with full stomach, Avoid foods that seem to make heartburn worse
Constipation and pregnancy
Relaxed gastrointestinal muscle tone is responsible for this
· Prevention: consume approx. 30 grams of dietary fiber daily
Programs improving pregnancy outcomes
- The Montreal Diet Dispensary
- The WIC Program
The Montreal Diet Dispensary
Assesses usual dietary intake of pregnant women
· Determines individual nutritional rehabilitation needs
·Teaches clients the importance of optimal nutrition
· Provides regular follow-up and supervision
The WIC Program
Serves nutritional needs of low-income women and families
· Provides nutritional assessment, education and counseling, food supplements, and access to health services
Risk Factors for the Development of Preeclampsia during pregnancy
The roots of preeclampsia lie very early in pregnancy but there is no reliable means of identifying the exact reason for developing the condition.
However, women with insulin resistance, obesity, very high triglyceride levels and other such characteristics do contribute in developing the disease.
The risk of developing preeclampsia is higher in women who were born smaller for gestational age.
Functional units of the mammary gland
The functional units of the mammary gland are the alveoli
Each alveolus is composed of a cluster of cells (secretory cells) with a duct in the center, whose job it is to secrete milk
Myoepithelial cells surround the secretory cells
Mammary gland development
As the ductal system matures, cells that can secrete milk develop, the nipple grows and its pigmentation changes
The luteal and placental hormones (placental lactogenic and chorionic gonadotropin) allow further preparation for breastfeeding
Estrogen stimulates development of the glands that will make milk
Progesterone allows the tubules to elongate and the cells that line the tubules to duplicate
Lacto genesis
The first stage begins during the last trimester of pregnancy
Can be impacted by premature delivery, method of delivery, and other factors
These may explain why mothers who deliver prematurely are often unable to develop full milk supply
Second and third stages occur after birth
Lacto genesis I
During the first stage of milk production, milk begins to form, and the lactose and protein content of milk increase. This stage extends through the first few days postpartum
Lacto genesis II
This stage begins 2-5 days postpartum and is marked by increased blood flow to the mammary gland. Clinically it is considered the onset of copious milk secretion or ‘when milk comes in’. Siginifcant changes in both milk composition and the quantity of milk that can be produced occur over the first 10 tens of the baby’s life
Lacto genesis III
This stage of breast milk production begins about 10 days after birth and is the stage in which the milk composition becomes stable
Hormonal control of lactation
Prolactin us a hormone that stimulates milk production
Stress, sleep and sexual intercourse also stimulate prolactin levels
Oxytocin release is also stimulated by suckling or nipple stimulation. It also acts on the uterus, causing it to contract, seal blood vessels and shrink its size
secretion of milk
Water, sodium, potassium and chloride are able to pass through alveolar cell membranes in either direction
Immunoglobulin A and other plasma proteins are captured from the mothers blood and taken into the alveolar cells
The letdown reflex
The stimuli from the infant suckling are passed through nerves to the hypothalamus, which responds by promoting oxytocin release from the posterior pituitary gland
The oxytocin causes concentration of the myoepithelial cells surrounding the secretary cells
Milk is released through the ducts, making it available to the infant
Other stimuli, such as hearing a baby cry, sexual arousal and thinking about nursing can also cause letdown and milk will leak from the breasts
Human milk consumption
Human milk consumption is changeable over a single feeding over a day, according to the age of the infant or gestation at delivery with the presence of infection in the breast, with menses and with maternal nutritional status
Colostrum
The first milk, colostrum is a thick often yellow fluid produced during lactogenic II
It provides about 580-700 kcal/L and is higher in protein and lower in carbs and fat than mature milk
Secretory immunoglobin A and lactoferrin are the primary proteins present in colostrum but other proteins present in mature milk are not present
Has higher concentrations of sodium, potassium and chloride than more mature milk
Water & milk
This biological design of milk means that babies do not need water or other fluids to maintain hydration, even in hot weather
Energy & milk
Human milk provides approx. 0.65 kcal/mL although the energy content varies with its fat composition
Infants who are breastfed are thinner for their weight at 8-11 months than infants fed HMS, b but these differences disappear by 12-23 months of age and few differences are notable by 5 years of age
Lipids and milk
Lipids provide half of the energy of human milk
Human milk fat is low at the beginning of a feeding in foremilk and higher at the end in the hind milk that follows
Effect of maternal diet on fat composition
When diets rich in polyunsaturated fats are consumed more polyunsaturated fatty acids are present in the milk
When very low diets with adequate calories from carbs and protein are fed, more medium chain fatty acids are synthesized in the breast
DHA
Milk DHA levels are increased by maternal supplementation
DHA is essential for retinal development
Trans fatty acids
Stemming from the mothers diet are present in human ilk
Removal of trans fatty acids from many food products in Canada led to lower levels of trans fat in human milk
Cholesterol
Essential component of all cell membranes is needed for growth and replication of cells
Early consumption of cholesterol through breast milk appears to be related to lower blood cholesterol levels later in life
Protein and milk
Concentration of proteins synthesized in the breast are more affected by the age of the infant than maternal intake and maternal serum proteins
Proteins and their digestive products, such as peptides, exhibit a variety of antiviral and antimicrobial effects
Enzymes present in human milk might also provide protection by facilitating actions that present inflammation
Casein
Major class of protein in mature milk from women who deliver either at arm or preterm Casein, calcium phosphate and other ions such as magnesium and citrate appear as an aggregate and are the source of milks white appearance
Whey proteins
Proteins that remain soluble in water after casein in precipitated from milk by acid or enzymes
The enzymes present in whey proteins aid in digestion and protection against bacteria
Nonprotein nitrogen
Some of this nonprotein nitrogen is used to produce other proteins with biological roles such as hormones, growth factors, free amino acids, nucleic acids, nucleotides and carnitine
Nucleotides appear to play important roles in growth and disease resistance
Milk carbohydrates
Lactose enhances calcium absorption
Oligosaccharides
Can be free or bound to proteins as glycoproteins or bound lipids as glycolipids or they can bind to other rides are classified as glycan’s
Prevent the binding of pathogenic microorganisms to the gut thereby preventing infection and diarrhea
Vitamin A & milk
Colostrum has approx. twice the concentration of vitamin A as mature milk does
Beta-carotene
Vitamin D and milk
Vary with maternal diet and exposure to sunshine
Maternal exposure to sunlight has been reported to increase vitamin D3 level milk tenfold
Unknown how much maternal and infant vitamin D status when sunlight exposure is insufficient, through researchers are actively pursuing the answer
Vitamin E and milk
Levels of alpha-tocopherol decrease from colostrum to transitional milk and to mature milk, whereas beta and gamma tocopherols remain stable throughout each stage of lactation
Levels of vitamin E in preterm milk have been reported to be the same and higher than in term milk
Vitamin K and milk
Approx. 5% of breastfed infants at risk for vitamin L deficiency based on vitamin K dependent clotting factors
Water soluble vitamins and milk
Clinical problems relating to water-soluble vitamins are rare in infants and nursed by mothers with inadequate diets
Vitamin B is considered most likely to be deficient in human milk: levels of B6 in human milk directly reflect maternal intake
Vitamin B12 and folic acid and milk
Are bound to whey protein in human milk; therefore their content in milk is less influenced by maternal intake of these vitamins than are the other water soluble vitamins
Folate levels increase with the duration of lactation despite a decrease in maternal serum and red blood cell folate
B12 deficiency or low levels of B12 in milk, has been reported for women who have had gastric bypass surgery have hypothyroidism, consume vegan diets have latent pernicious anemia, or are generally malnourished
Minerals in human milk
Monovalent ion secretion is managed closely by the alveolar cells, in balance with lactose to maintain the isosmotic composition of human milk
Mineral content is low in breast milk than in cow’s milk
Bioavailability
Breastfed infants have little risk of anemia despite the seemingly low concentration or iron in human milk
Zinc and milk
Importance of zinc to human growth is well established
Bound to protein and is highly available in comparison to cow’s milk and cow’s milk-based HMS
Rare cases of zinc deficiency which appears as intractable diaper rash, have been noted in exclusively breastfed infants
A defect in the mammary gland uptake of zinc has been described as the cause of low milk concentration when maternal serum zinc concentrations are normal
Trace minerals and milk
Copper, selenium, chromium, manganese, nickel, and flouring
Levels of trace minerals in human milk are not altered by the mother’s diet or supplement use expecting fluoride
Taste of human milk
The flavour of human milk is an important taste experience for newborn infants but flavour is often ignored when benefits of human milk or its composition are considered
Exposing infants to a variety of flavours in human milk may contribute to their interest in and consumption of human milk as well as their acceptance of new flavours in solid foods
Breastfeeding benefits for mothers
Increases oxytocin levels, a hormone that stimulates uterine contractions minimizes maternal postpartum blood loss and helps the uterus to return to non-pregnant size
Psychological benefits including increased self-confidence and facilitated bonding with their infants
Women who nurse at a younger age and for longer duration have lower risk of breast and ovarian cancer and rheumatoid arthritis
Nutritional breastfeeding benefits for infants
The balance of nutrients in human milk matches human infants requirements for growth and development closely; no other animal milk or HMS meets infant needs as well
Human milk is isosmotic and therefore meets the requirements for infants without other forms of food or water
Human milk provides generous amounts of lipids in the form of essential fatty acids, saturated fatty acids, medium-chain triglycerides and cholesterol
Long chain polyunsaturated fatty acids, especially docosahexaenoic acids (DHA) which promotes optimal development of the of the central nervous system are present in human milk
Minerals in breast milk are largely protein bound and balanced to enhance their availability and meet infant needs with minimal demand on maternal reserves
Immunological benefits
Cellular components in human milk are especially high in colostrum but are also present for months in mature human milk in lower concentrations
The function of macrophages in human milk includes phagocytosis of fungi and bacteria, killing of bacteria and production of the complement proteins, lysozyme and lactoferrin and immunologlobin A and G
Binding proteins in human milk bind iron and vitamin B12, making the nutrients unavailable for pathogens to grow in infants gastrointestinal tract
Growth factors and hormones in human milk, such as insulin, enhance th maturation of the infants gastrointestinal tract
These substances also help to protect the infant, espcially neonates, against viral and bacterial pathogens
Fewer acute illness with use of breastfeeding
Reduced infant illness is evidence in countries with high infant illness and death rates, poor sanitation and questionable water
Reductions in chronic illness when breastfeeding
Lower rate of acute illnesses in breastfed children, breastfeeding also seems to protect against chronic childhood diseases including celiac disease, inflammatory bowel disease, and leukemia
Breastfeeding and childhood weight
Breastfed infants typically are leaner than HMS-fed infants at one year of age without any difference in activity level or development
Cognitive benefits to breastfeeding
The differences in cognitive function are also greater in premature infants fed human milk than those HMS
Fatty acid composition of milk plays an important role in neuropsychological development bolsters the credibility of psychological or cognitive benefits from breastfeeding
Analgesic effects of breastfeeding
Breastfeeding may be used to reduce infant discomfort during minor invasive procedures
Can women make enough milk?
Milk production can range from 450-1200mL over day in women who are nursing one infant
Milk increases to meet the demand of twins, triplets, infants and toddlers suckling simultaneously; it can also be increased by pumping the milk
