By Nurse Mark
Is It Possible To Conceive And Carry To Term And Produce A Healthy Child While Following A Vegetarian Diet?
Vegetarianism means different things to different people, and there are almost as many reasons given for the decision to follow a vegetarian diet as there are vegetarians to give them. Some of the more common reasons are:
- Health (32%)
- Because of chemicals and hormones in meat products (15%)
- Don’t like the taste of meat (13%)
- Love of animals (11%)
- Animal rights (10%)
- Religious reasons (6%)
- Concern for the planet (4%)
- To lose weight (3%)
- To reduce hunger and famine worldwide (1%)
(From a survey reported in “TIME Magazine: Veggie Tales”. Time. 2002-07-07)
Before going any further, please let me assure all of the proselytizing, evangelical vegetarians and vegans (who are going to bury my email inbox anyway in letters filled with testimonial tributes to their dietary choices and demands that I read their favorite pro-vegetarian / anti animal protein study or article) – I am not going to tell anyone to not be a vegetarian or a vegan. I am simply going to present some information regarding nutrition as it pertains to vegetarian and vegan diets.
How widespread and popular is the vegetarian diet?
A 2008 study, commissioned by Vegetarian Times, claims that 3.2 percent of U.S. adults, or 7.3 million people, follow a vegetarian-based diet and that 1 million of those are vegans, who consume no animal products at all.
The study further states that 10 percent of U.S., adults, or 22.8 million people, say they largely follow a vegetarian-inclined diet but fails to define what is meant by “largely follow” or “vegetarian-inclined.” Does this mean that they go meatless one day a week? Eat chicken but not beef? Usually have a salad with their steak dinner? Eat eggs but not ham for breakfast? The report doesn’t say.
Vegetarian for moral and other reasons?
In the Time Magazine study, a combined 32% of respondents reported following some degree of vegetarian diet for reasons of conscience: moral (animal rights), religious, or environmental beliefs. Such reasoning, like any firmly-held moral or religious conviction, cannot be argued with.
Another 13% say they don’t care for the taste of meat. Does this mean that they eat eggs or cheese or whey protein? Is it only beef that they dislike, or pork, or lamb? Is fish or shrimp acceptable? All have very different tastes and textures which can be further modified by cooking technique and healthful spices…
The concern expressed by some 15% regarding chemicals and hormones in meat products is certainly well-founded, but not impossible to address – certified all-organic, range fed, cage-free, free range, antibiotic and hormone free meats are increasingly available.
The adoption of a vegetarian diet for weight loss is sometimes given (3% of respondents) and would seem to be an acknowledgement that the vegetarian diet is somehow lacking in nutrient density in order that it could result in weight loss. Since the typical vegetarian diet tends to be a high carbohydrate, limited protein, low fat diet it would need to be carefully restricted in order for weight loss to occur.
That leaves vegetarian dieting for health reasons…
32% of those questioned in the Time Magazine study claimed that “health reasons’ were what motivated their decision to adopt a vegetarian or vegan diet.
There are a number of sources that promote vegetarian or vegan diets for health – perhaps some of the best known are “Eat More, Weigh Less” by Dr. Dean Ornish, the nutritionally similar but not necessarily strictly vegetarian “Pritiken Principle” popularized by Nathan Pritiken, and perhaps the ultimate “indictment” of an animal protein based diet, “The China Study” written by Dr. T. Colin Campbell.
On the plus side of the health equation, nutritionally well-planned vegetarian diets are usually rich in carbohydrates, omega-6 fatty acids, dietary fiber, carotenoids, folic acid, vitamin C, vitamin E, potassium and magnesium.
If not carefully planned however, a vegetarian diet can be deficient in vitamin B12, calcium, omega-3 fatty acids, vitamin D, iron, zinc, riboflavin (vitamin B2), and iodine. Poorly planned vegan diets can be especially deficient in vitamin B12 and calcium.
Of greater concern for vegetarians and especially vegans is getting adequate proteins (essential amino acids) in their diet. Though carefully chosen plant sources can supply adequate amounts of essential amino acids, the protein density of these foods is lower and thus more must be consumed.
Cereals tend to be low in the essential amino acid lysine meaning that this must be made up with increased bean and soy products.
Another important substance, Carnitine is biosynthesized from the amino acids lysine and methionine and may be lacking. In general, while anywhere from 20 to 200 mg are ingested per day by those on an omnivorous diet, people on a strict vegetarian or vegan diet may ingest as little as 1 mg per day.
A similar-sounding but different amino acid, Carnosine is important to muscle and brain tissues. Vegetarian diets are thought to be lacking in carnosine though opinions differ as to the effect this deficiency has on vegetarians.
Yet another organic acid, Taurine is found only in animal foods, and plays an vital role in brain development, blood pressure control, blood glucose regulation, as an antioxidant, and more. Taurine essential for cardiovascular function, and development and function of skeletal muscle, the retina and the central nervous system. Although the body can synthesize taurine from amino acids, many people — including pregnant or breast-feeding women — are unable to produce enough without a source from diet.
Vegetarians who follow an ovo-lacto (eating eggs and dairy) eating plan are at much lower risk for many of these dietary deficiencies.
While soy is an important protein source for vegetarians and vegans, increases in the amounts of soy consumed brings risks and problems since soy is a potent allergen for many people and can cause significant food intolerance, gut problems and inflammatory reactions. Soy is also a rich source of isoflavones called genistein and daidzein, which are a source of phytoestrogens that can potentially cause hormone disruptions and imbalances in both men and women.
Soy is also a rich source of phytic acid.
Phytic acid is also found within the hulls of nuts, seeds, and grains and has a strong binding affinity to important minerals, such as calcium, magnesium, iron, and zinc causing them to become non-absorbable in the intestines and actually chelating them. For this reason vegetarians and vegans who rely heavily on these food sources must be especially careful to supplement these minerals.
Beans and legumes form an important part of most vegetarian / vegan diets. They can also cause significant digestive and immune distress in many people as they contain a substance called lectin.
Foods containing lectin, such as beans, cereal grains, seeds, nuts, and potatoes, can be harmful when eaten in uncooked or improperly cooked form. Adverse effects may include nutritional deficiencies, and immune (allergic) reactions and associated inflammatory response. Lectins are thought to cause gastrointestinal distress through their interaction with (and damage to) the gut epithelial cells.
Lectin may also cause leptin resistance which could be responsible for obesity in people who have high levels of leptin.
Vegetarian / vegan diets are usually rich in Omega-6 fatty acids but can be deficient in Omega-3 fatty acids. This imbalance, if not carefully addressed, can lead to subtle inflammation. Omega-6 fatty acids are considered to be inflammatory, while Omega-3 fatty acids, as are found in fish oil, are considered to be anti-inflammatory.
One possible source of anti-inflammatory Omega-3 essential fatty acids for vegetarians and vegans is walnuts. Another is flax seed and flax oil though the a-linoleic acid in flax requires additional conversion by the body to provide EPA (Eicosapentaenoic Acid) and DHA (Docosahexanoic Acid) – a conversion that many people find difficult to achieve. Fish oil is a far more reliable source of pre-formed EPA and DHA essential fatty acids.
Since most vegetarian and vegan diets tend to be low fat diets as well deficiencies of fat soluble vitamins are a significant concern.
Vitamin D, acting as a hormone, increases the absorption of dietary calcium and phosphorus and works with a number of other vitamins, minerals, and hormones to promote bone mineralization.
Research further suggests that vitamin D helps to maintain immune system health and helps regulate cell growth and differentiation.
Obviously, vitamin D deficiencies can cause serious health problems, and those choosing vegetarian or vegan diets would do well to perform a Vitamin D test and to supplement with this important vitamin.
Vitamin B12 deficiency is potentially very serious and can lead to megaloblastic anemia, nerve degeneration and irreversible neurological damage. Since vegetarians and especially vegans can be at high risk for B12 deficiency, most authorities recommend supplementation with this vitamin.
Many cruciferous vegetables like broccoli, cauliflower, Brussel sprouts, kale, kohlrabi, mustard, turnips, rutabaga, cassava and cabbage, as well as soy products, pine nuts and peanuts, and millet are goitrogenic – meaning that when eaten in large quantities they can interfere with the normal functioning of the thyroid gland. Thyroid function testing may be well-advised for those who have been eating a lot of these foods or who suspect they may be experiencing decreased thyroid function.
This is not intended to be an exhaustive list of the potential problems that can be encountered by those electing to follow a vegetarian / vegan diet – but rather a summary of the problems that we see most often here at the Wellness Club and amongst vegans and vegetarians who come to Dr. Myatt seeking dietary advice.
Since dietary needs are increased in women who are pregnant, these problems and potential dietary deficiencies become that much more important – since a dietary deficiency in the mother will obviously be a dietary deficiency in the child growing in the womb.
For those who are struggling to conceive, the subtle inflammations, dietary deficiencies and hormonal disruptions that can be caused by vegetarian and vegan diets can effectively sabotage all efforts to implant and maintain an embryo. Should a couple be successful in conceiving and carrying to term, they may find that maternal nutritional deficiencies have resulted in developmental problems or congenital flaws in the newborn.
For this reason, Dr. Myatt is adamant that strict vegan diets are not appropriate for pre-conception or pregnant women, and that strict vegetarian diets are ill-advised unless very carefully monitored and supplemented.
For women who wish to maintain some degree of vegetarian diet while improving health during pre-conception and maintaining maternal and fetal health during pregnancy, Dr. Myatt is available for consultation.
Junk Food Vegetarians
Another problem that we often see is with people who have adopted what they think is a vegetarian diet but who have actually only succeeded in removing essential nutrition from their diet. These are the people who have decided to eliminate animal-source protein and fats from their diet without replacing them with appropriate plant-based sources of these nutrients.
We call these people “junk food vegetarians” because they substitute nutritionally empty junk foods for the previously healthy meats, eggs, and dairy that they have given up.
There are many foods, especially convenience foods that qualify as “vegetarian” and potato chips, donuts, Kellogg’s “Pop Tarts”, any number of other nutritionally empty “foods” creep into the diet. Even those who manage to avoid the processed junk food trap often find themselves eating a diet of almost pure carbohydrates: a breakfast of oatmeal and bananas or cereal and fruit, a lunch of bread and peanut butter or a muffin, and then beans or corn or rice for supper’ Ensuring a varied and nutritionally complete vegetarian or vegan diet can be difficult with the hectic and harried schedules of most people.
Yes, high fructose corn syrup is vegan – NO, it is not healthy! Peanut butter is not a complete protein, provides no Omega-3 fatty acids, and can harbor aflatoxin – a potent carcinogen. While there are plenty of chocolate and granola and fruit bars all marketed to vegetarians and vegans and claiming to be “healthy” they are often no better than a standard candy bar, containing the same high fructose corn syrups, cane sugar, hydrogenated vegetable oils and other ingredients.
References and resources:
http://en.wikipedia.org/wiki/Vegetarianism_by_country
http://en.wikipedia.org/wiki/Vegetarian_nutrition
Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets http://www.journals.elsevierhealth.com/periodicals/yjada/article/S0002-8223(03)00294-3/fulltext#section45
The China Study: http://www.ncbi.nlm.nih.gov/pubmed/9860369
Dr. Mercola critiques The China Study; http://articles.mercola.com/sites/articles/archive/2010/09/08/china-study.aspx
Another well researched critique of The China Study: http://rawfoodsos.com/the-china-study/
A look at some of the pitfalls of vegetarian dieting by a former vegan: http://rawfoodsos.com/for-vegans/
A maternal vegetarian diet in pregnancy is associated with hypospadias: http://onlinelibrary.wiley.com/doi/10.1046/j.1464-410x.2000.00436.x/full
A comprehensive list of goitrogens: http://en.wikipedia.org/wiki/Goitrogen