Diet is complex and requires time and effort to understand and balance nutritional needs. Negative health outcomes, including diabetes, cardiovascular disease, and obesity are associated with poor diet choices. As more women recognize a need to change their diet, some are turning to veganism, a vegetarian form of diet, as a potentially healthy alternative. Although many health benefits are associated with the vegan diet, it requires a strong knowledge base to plan and execute a complete intake of necessary nutrients. This is particularly important during pregnancy to assure all necessary nutrients are available for the developing fetus. The objective of this article is to provide information on the vegan diet and how it relates to the nutritional needs of pregnant women.
Keywords: Vegan, vegetarian, pregnancy, nutrition
Diet is one of the most contentious subjects on the planet. It is shaped by culture, politics, marketing, economics, desire, and necessity. Even among the scientific community, vast amounts of data can be marshaled that are diametrically opposed to one another. This is unfortunate, because our diet is one of the biggest factors in our overall health; the food we eat is important not just for bodily health but also health of the mind and spirit. A purposeful diet focuses on meeting the body's nutritional and energy needs, yet encompasses more than needed nutrition. Several emotions are often linked to food and include feeling loved and in general feeling nourished and secure. Many vegans associate spiritual well-being with their diet and believe that they honor their body by caring for it and seeking health.
An increased interest in diet is evident as more individuals seek ways to promote better health. This may be linked to the rising occurrence of chronic diseases that plague affluent society, such as obesity, diabetes, hypertension, cardiovascular disease, and cancer. Obesity, which represents excessive caloric intake, is a major concern in developed countries. Particularly the western culture's diet, with its emphasis on high fat, calorie dense foods, has been implicated as a connection to negative health outcomes and increased numbers of individuals are looking for alternatives.
One such alternative is the vegan diet. A vegan diet is absent of all animal products and by products: no meat, no milk, no eggs, and no other sundry animal bits. This means that with the exception of the odd mineral supplement or manufactured vitamin, 100% of a vegan's food is coming from plants. A vegan is an herbivore by choice, whereas humans in general are omnivores by definition, and traditionally need nutrients from both plant and animal sources to avoid deficiencies (Phillips, 2005). While a vegan diet may offer many health benefits, it may also offer nutritional challenges during pregnancy. The fetus is vulnerable to nutritional deficiencies and excesses and it is important to understand and devise proper nutritional support for women during pregnancy. The obvious questions to ask are whether a vegan diet is healthy, and why? The purpose of this article is to describe a vegan diet and implications for its use during pregnancy in order to arm childbirth educators with the necessary information to share with their pregnant clients.
Background: An Overview of the Historical Evolution of the Human Diet
Before discussing specifics of the vegan diet it is helpful to understand what has historically constituted the human diet and how our bodies have adapted to change in diet. While there are many ways to approach this, it makes sense to start from an evolutionary standpoint because it is so robust; biologically our genetic heritage is the fundamental basis for our body's adaptation to environmental changes. One might assume that generations ago our diet was similar to other species and an example may be seen in our nearest genetic relatives, the chimpanzees. Although chimpanzees are omnivores, they do not eat meat very often. Animal protein only comprises 1-5% of their diet, most often in the form of insects, eggs, or other monkeys. Mountain gorillas, again biologically similar to our bodies, ingest a great preponderance of leafy greens, and sport enormous abdomens in order to digest them. Humans, however, differ significantly from these similar mammals in that the lower digestive tract is smaller and not equipped to digest the large volume of leafy greens necessary to produce the metabolic energy our bodies require.
Evolution, which may also be thought of as adaptation, reflects changes in our genetic structure based on challenges the organism faces. According to Dr. Richard Wrangham, in Catching Fire, How Cooking Made Us Human (2009), our ancestors learned to make fire and flint tools, specifically cutting edges, which allowed us to butcher meat effectively. Early man (or woman) learned how to cook our food, which tenderizes it and denatures carbohydrates and proteins. In short, we outsourced part of our digestion, making it much easier to extract calories from our food, and allowing us to devote more of our basal metabolism to our brains and less to our guts; our anatomy changed accordingly.
Studies of the world's remaining hunter-gatherers indicate that their diets are governed by caloric return on expenditure of effort. Hunting provides an excellent metabolic return on investment. As a consequence, hunter-gatherers eat meat whenever they can, with an estimated 86% acquiring over half their calories from animal sources (Cordain, 2000). Based on this assumption, our diet changed toward a meat based one that may not be as healthy, but from a continuation of species standpoint, sustained nutritional needs long enough for procreation. From this perspective, then, it is reasonable to assume that humans have adapted to a cooked diet with a higher proportion of meat in place of one originally based on whole plants.
In our current era, there are indigenous groups with widely varying rates of animal consumption; some populations experience healthy outcomes irrelative to their meat consumption. For example, the traditional diets of the Inuit of the arctic and the Maasi herders of Kenya both have very high rates of animal consumption, while enjoying an absence of the chronic degenerative disease epidemics that plague developed nations (Eaton, 1988). In contrast, the rural population of the famous China Study subsists almost completely on a whole food, plant based diet, with meat providing less than 10% of it, and exhibit very low rates of cancer, cardiovascular disease, and diabetes (Campbell, 2006). Okinawans have the distinction of being the longest lived culture on the planet, and are remarkably free from chronic disease. Like the rural Chinese, the traditional Okinawan diet consists of fruits, vegetables, whole grains, legumes, and very little meat. What all three groups have in common are years of biological and cultural adaptation to their respective diets. All three also enjoy an absence of refined carbohydrates such as sugar, high fructose corn syrup, and white flour; these as well as corn based, industrial meat production, have been implicated in the chronic diseases of affluence, particularly in the modern western diet (Pollan, 2006). When these indigenous groups switch to a modern western diet, the diseases of affluence follow. Finally, all three populations lead physically demanding lives with high levels of activity, quite unlike large segments of modern society's population.
Humans can adapt to almost any diet, given enough time, and that physical activity plays an important role in how the body uses the fuel provided. While these groups represent homogeneous populations, many people come from a varied genetic background, thus making it difficult to predict what sort of dietary adaptations a given person possesses. This is one of the reasons that designing a diet suited to everyone is so contentious and complex. It behooves the individual seeking better health through nutrition to follow a holistic approach, and modify the diet on an individual needs assessment. Anyone considering a vegan diet needs to understand underlying principles of nutritional needs and ways to meet these needs.
Nutritional Considerations of a Vegan Diet
A well planned vegan diet can be nutritionally adequate, and is especially high in folic acid, fiber, antioxidants, phytochemicals, and carotenoids. In contrast, the animal products in conventional western diets are rich in protein, iron, zinc, vitamin B12, and vitamin D. For most people, adequate intake of protein is the biggest perceived concern with veganism. However, typical western protein intake is considerably higher than requirements, with subsequent concerns about possible health risks. Vegan protein intake, while lower, is still adequate, provided that both grains and legumes such as beans are eaten in order to garner the full complement of essential amino acids. The primary dietary concerns with veganism in general are low intakes of vitamin B12, vitamin D, calcium, and iodine (Phillips, 2005). Vegans run the risk of both deficiency or overexposure of iodine depending on their intake of seaweed supplements. Education and moderation are indicated and if supplementation is needed, iodized salt provides a readily acceptable source (Phillips, 2005).
Pregnancy and a Vegan Diet
Nutritional needs for the pregnant woman vary among individuals and should meet the woman's needs as well as the needs of the growing fetus. There is no set amount of nutrients and minerals that will guarantee a healthy baby, but there are general guidelines that correlate with optimal health for mother and child. A wide variety of food is needed and a balanced diet includes grains, fruits and vegetables, sources of protein, dairy products, and fats. During pregnancy, there are some required dietary increases including thiamin, riboflavin, folate, vitamin A, C, and D, and protein (Cox, 2008). The proper diet and caloric need is individualized and specific to each woman, and it should be noted that the following recommendations are generalized.
The number of calories consumed should be adequate to provide energy for the mother and child. If a woman is underweight prior to conception, she will need more calories and nutrients than a woman starting out at a normal body mass index (BMI). If a woman is obese, she will need fewer calories than a woman with a normal BMI (Williamson, 2006). It is important to assess what foods are being consumed because although a woman may be obese, she may not be consuming adequate vitamins and minerals. Use of a food diary, where all food consumed is written down for a finite period of time (e.g. one week) is helpful in identifying excess empty calories or missing nutrients. The physical activity level of the individual should be included when estimating caloric need (Williamson, 2006).
According to Williamson (2006) a growing fetus needs a constant supply of glucose and amino acids. Amino acids are the constituents of proteins (Cox, 2008). Proteins are found in a variety of foods other than meat and animal based products, such as nuts, grains, legumes, and tofu. Individual plant sources, however, do not provide all the necessary essential amino acids by themselves. It is therefore important to eat a wide range of plant based protein products, for example grains and legumes, to make a complete protein. During the first trimester no additional protein is required; during the second and third trimester the need for protein increases from approximately 46 grams per day to 71 grams per day (Cox, 2008; National Research Council, 2005). If additional protein is indicated for the vegan diet, 25 gms of protein may easily be added by including 1.5 cups of lentils or 2.5 cups of soy milk per day.
Polyunsaturated Fatty Acids (PUFAs)
Oil rich fish is important provides polyunsaturated fatty acids (PUFAs) and if acceptable should be a considered addition for vegans during pregnancy. Fetal brain and nervous system development depends on these fatty acids and the addition of two portions of oil rich fish per week meets requirements. It should be noted that while fish is a good addition, certain fish should not be eaten or only be limited to two portions per month; others may be consumed twice weekly. Although reports vary, marlin, swordfish, shark, and fresh tuna should be avoided due to their high mercury content. High mercury levels may have a detrimental effect on fetal nervous system development (Williamson, 2006). Light canned tuna is considered safe and may be consumed in moderation.
It is important to know the type of fish being consumed and present recommendations for safe choices. Contaminates may vary locally and each practitioner should familiarize themselves with knowledge of their local area fish supply. Data on local fish may be available from the area health department. In addition to mercury, other contaminates or pollutants may be of concern; generally fish such as tilapia, that are farm raised, are a good choice.
Other sources of essential fatty acids are made from another fat called linolenic acid that is found in flaxseed, flaxseed oil, canola oil, walnuts, and soybeans. Fish oil supplements should be avoided, or carefully monitored during pregnancy due to their high levels of vitamin A. Excessive consumption of vitamin A has been linked to fetal mental retardation, facial deformities, cardiovascular problems, nervous system malformation, and thymus malformation. It can also cause nephrotoxicity in the mother (Williamson, 2006).
Approximately 40% of women between 19 and 34 years of age do not have a sufficient store of iron (Williamson, 2006). During pregnancy, iron deficient anemia may develop due to inadequate iron intake and from an increased oxygen demand created by the growing fetus and enlarged reproductive organs (Williamson, 2006). Iron is needed for hemoglobin formation and adequate supplies are important to meet the pregnant woman's needs. A caution for the vegan diet is that all iron sources are not alike; heme iron derived from meat is more bioavailable than the iron found in plants such as leafy greens. Therefore, higher iron intakes may be indicated on a vegan diet (Phillips, 2005).
On a positive note, the body's homeostatic response system increases iron absorption when stores are low (Williamson, 2006). Dietary intake is recommended during pregnant for 27mg of iron per day and may be enhanced by including soy, bean, lentils, spinach, molasses, dried apricots, prunes, and raisins. Combing foods high in Vitamin C, such as oranges increases the rate of iron absorption (Penney & Miller, 2008; Physicians Committee for Responsible Medicine, 2008). Unfortunately, it is difficult for any woman to meet the recommended amount of iron through diet alone, and this becomes even more complicated with a vegetarian/vegan diet. A simple iron supplement, however, can easily avoid this problem and should be recommended during pregnancy (Physicians Committee for Responsible Medicine, 2008).
Along with iron, it is important for the pregnant woman to maintain enough calcium. Calcium levels are tightly controlled by the parathyroid and are thus a poor indicator of adequate calcium intake, which is reduced in the vegan diet due to lack of milk consumption. Calcium is important for many systems, including cellular homeostasis and neuromuscular conduction. Extremely low serum calcium (hypocalcemia) may result in tetany, or muscle spasms. Cardiac conduction may be affected if calcium levels fall too far, either high or low. Acid-base balance is also affected by serum calcium. A high protein diet can lower pH, which the body buffers with calcium, at the cost of bone density. A vegan diet, which is unlikely to be extremely high in protein, can therefore protect calcium stocks (Campbell, 2006).
The body seeks balance and will adjust to the demand for calcium by increasing absorption, therefore supplementation is rarely needed (Williamson, 2006). Daily recommendations for calcium are 1000mg, and this number is the same whether pregnant or not (Penney & Miller, 2008). This value can be easily met in the vegan diet by including foods like tofu, bok choy, dark leafy greens, broccoli, and calcium fortified nondairy milk (Mangels, 2012).
Calcium requires vitamin D for absorption in the gastrointestinal tract. Therefore, vitamin D is needed to maintain calcium levels and protect the bone health of the mother, while providing the nutrients needed for the developing skeleton of the fetus (Williamson, 2006). While one study by C.S. Williamson recommends 10 ug of Vitamin D per day for pregnant women, the Institute of Medicine recommends 600 IU per day to be most beneficial, which calculates out to 15 ug per day (2000).
Vitamin D is a hormone that is naturally made in our bodies with the help of sunlight exposure on our skin. It is also found in fortified foods, particularly milk. Vegans run the risk of vitamin D deficiency, particularly in northern latitudes, both from diet and due to lack of exposure to the sun, especially in winter. Vitamin D supplements are the usual remedy for this. Vegans are thus encouraged to pursue plant sources such as beans, broccoli, and leafy greens, which can be further fortified with calcium supplements. Serum levels of vitamin D are easily measured if there is concern regarding intake of this essential nutrient.
Folic Acid and Vitamin B-12
One of the most important nutrients for a pregnant woman to consume is folic acid. Inadequate supplies of folic acid may increase the risk for neural tube defects. The two most prevalent neural tube defects, spina bifida and anencephaly, affect the brain and spine. Spina bifida occurs when the spine column does not close completely, and usually results in spinal nerve damage that causes some paralysis. Anencephaly is the absence of the brain or skull, and the fetus is frequently miscarried (Williamson, 2006). There is no cure for either of these neural tube defects, but there are preventative measures that will lower the incidence
of these problems. It is recommended that a woman of child bearing age consumes 600 ug/day of folic acid until the 12th week of pregnancy (Williams, 2006).
Vitamin B-12 works in concert with folic acid to synthesize DNA and red blood cells (Penney & Miller, 2008). It also contributes to the maintenance of myelin sheaths, the insulation of peripheral nerves (Penny & Miller, 2008). Deficiencies in B-12 are thought to cause neural tube defects, growth failure, developmental abnormalities, and anemia, as well as several maternal complications (Penney & Miller, 2008).
Vitamin B12 is not found in plant sources, and therefore must be obtained through animal consumption or via supplements. The amounts required are tiny, and healthy adults may have up to a three year supply stored in their body's tissues. Because vitamin B-12 is found solely through animal sources, it is important for those following a vegan diet to take B-12 supplementation, or to consume B-12 fortified foods (Williamson, 2006). Guidelines for the pregnant woman include a minimum of 2.6 ug per day of Vitamin B-12 (Institute of Medicine, 2000).
At Risk Populations
Special consideration should be given to populations at risk for nutritional complications. Individuals with metabolic diseases, such as diabetes, severe food allergies, or absorption problems require additional planning and counseling and are beyond the scope of this paper. It is suggested that they be referred to a specialist to develop an individual eating plan.
Teen pregnancies are potentially high risk because the typical teenage diet may lack appropriate intake of nutrients even before conception. An inadequate store of nutrients may lead to competition between the growing teenager and the growing fetus ultimately causing harm to both mother and child (Williamson, 2006). Teen pregnancies are often unplanned and there may be a general knowledge deficit among teenage girls regarding the appropriate nutrients needed for optimal health. Many lack nutrients like folic acid amongst others (Williamson, 2006). Due to the high nutrient requirements for growth and development in teens, it is particularly important that pregnant teenagers are provided education on their dietary needs (Williamson, 2006). An additional calcium supplement should be considered for this population to support mother and fetal bone growth (Williamson, 2006).
Discussion of the Vegan Choice
A pregnant woman following the vegan diet should follow the same guidelines for nutrients and minerals as a non-vegan pregnant woman. The vegan diet, when administered properly, provides adequate amounts of riboflavin, Vitamin B, calcium, iron, and zinc (Penney & Miller, 2008). These nutrients and minerals can be easily met as long as dietary planning takes place prior to, during, and after the pregnancy. Many consider the vegan diet to be very healthy for both the pregnant woman and the developing fetus. Studies have shown a lower risk of heart disease, obesity, diabetes, high blood pressure, and some cancers in persons who consume a vegan diet (Cox, 2008). Women with high blood pressure prior to pregnancy are considered to have a higher risk pregnancy and may have serious complications associated with hypertension. Cardiovascular disease and hypertension are major concerns in today's society and the vegan diet may lower the risk factors. Vegans are among the lowest population to have cardiovascular disease or the risk factors associated with it (Phillips, 2005).
With careful planning, then, a vegan diet can be at least as nutritionally healthy as a conventional diet. However, nutrition may not be the only motivation for a vegan diet; for many veganism represents more than food, it is a lifestyle. In today's modern society, nutrition is often an afterthought rather than a fore thought. Life is hectic; meals are selected for convenience rather than health and individuals are often more preoccupied with past grievances, future plans, or the distractions of media and conversation than what they are eating.
Spirituality and Veganism
For those who find a spiritual connection through veganism, it is important to recognize their belief system and work with them to achieve the optimal state of health they seek. Understanding their view may be helpful to the healthcare educator and although certainly goes beyond this writing, is described in brief.
Similar to meditation, mindful eating focusing on the here and now, rather than the past or future (Kabat-Zinn, 2006). Healthful veganism, with its focus on plant based whole foods, provides a rich palette of colors, shapes, and textures on which to center one's attention. It is food that the individual recognizes, and may automatically connect to their perceptions of the ground, sunshine, and rain which nurtured it. This connection, this expansion of perception rather than reduction, is a fundamental characteristic of veganism.
Mindful eating allows one to spend more time in the present and to achieve a rebalancing of any past, present, or future perceptions (Kabat-Zinn, 2006). It connects the information about nutrition eventfully and persistently, not just as a sea of facts, but as an analysis, a synthesis of new insights, and wisdom. . Mindful eating, coupled with a devotion to good nutrition, may be interpreted as a tremendous expression of love from the expectant mother to the child within her. The resulting positive emotion and psychological well being have been shown to lower stress and improve both maternal health and fetal development (Cheng & Pickler, 2010). This is also evidenced physiologically through a negative correlation with maternal cortisol, both during pregnancy and post partum (Cheng & Pickler, 2010).
In the November 2011 volume of this journal, Dr. Debra Wilson defined spirituality as "the essence of who we are and involves a connectedness to that which is outside of us" (Wilson, 2012, p .4). Thus spirituality is a perception and awareness personal identity, place in the world, and the ties that bind and connect the subtle, ephemeral sense of self. Spirituality is fabricated from one's innermost beliefs, thoughts and feelings. It is the habits, the rituals of each individual and when a devout vegan plans, prepares, and consumes food, each may be considered an opportunity to connect those innermost beliefs with other facets of life (Kabat-Zinn, 2006). This sense of spirituality may enhance the pregnant woman's desire to integrate her efforts toward a healthy pregnancy and result in reduced stress through peace of mind.
Veganism can be an avenue to a better life and healthier living, provided that it is done well. This requires diet planning and practice that capitalizes on whole plant, nutrient dense foods, with special attention toward intake of folic acid, iron, calcium, vitamin B-12, and vitamin D.
Nutrition is part of childbirth education and Childbirth Educators are in the ideal position to provide guidance, resources, and referral so that all pregnant women can be armed with knowledge regarding the vegan diet for those who chose it. Recommendations include designing an individual plan and should begin with the client keeping a food diary and reviewing it with the childbirth educator. Caloric needs are determined based on BMI with the pre-pregnancy weight guiding optimal weight gain during pregnancy. Points to remember include: Protein needs increase to almost double during the last trimester; Fatty acids are needed and fish is a good source; flaxseed, walnuts, and soybeans may be added for the strict vegan diet; and a prenatal multivitamin with iron should be recommended to support needed vitamins and minerals. Finally, in order to provide holistic care, the childbirth educator should be aware of the spiritual component that veganism may represent. The spiritual vegan may approach their diet and their lifestyle emotionally with engagement of positive feelings that promote healthful nutrition, well-being, and stress reduction. This holistic process provides a tremendously supportive environment for the pregnant mother and her developing child.
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by Steven Tyree, BS; Bethany R. Baker, BS; and Deborah Weatherspoon, MSN RN CRNA
Steven Tyree has a BS degree in English. He is a senior BSN student at Middle Tennessee State University.
Bethany Baker holds a BS in Biology, with a minor in Psychology. She is a senior BSN student at Middle Tennessee State University.
Deborah Weatherspoon is a RN and a CRNA with 35 years of nursing experience in a variety of clinical settings and specialties. She is an assistant professor and teaches nursing courses at Middle TN State University.