blood pressure, lower rates of cardiovascular disease
and stroke, lower blood cholesterol levels, and low-
ered risks of colon andprostatecancer. There is also
evidence that vegetarian diets lower the risk of devel-
oping type 2 (adult-onset) diabetes, and assist in
weight reduction.
It is possible that ovovegetarianism is more bene-
ficial to maintaining fertility in women than vegetarian
diets allowing dairy foods. A group of researchers at
the Harvard School of Public Health reported in early
2007 that a high intake of low-fat dairy foods is asso-
ciated with infertility in women caused by failure to
ovulate.Precautions
The ADA strongly recommends that people con-
sult a registered dietitian as well as their primary
physician before starting any type of vegetarian diet.
The reason for this precaution is the variety of vegeta-
rian regimens as well as the variations in height,
weight, age, genetic inheritance, food preferences,
level of activity, geographic location, and preexisting
health problems among people. A dietitian can also
answer questions about the desirability of limiting egg
consumption within an ovovegetarian diet; for exam-
ple, the Seventh-day Adventist Dietetic Association
(SDADA) recommends that people following the
Adventist vegetarian diet limit their use of egg yolks
to three or less per week.Risks
The longstanding concern about all vegetarian
diets is the risk of nutritional deficiencies, particularly
for such important nutrients as protein, minerals
(iron,calcium,andzinc),vitamins(vitamin D,ribo-
flavin,vitamin B 12 , andvitamin A),iodine, and n-3
fatty acids. Although the ADA food guide does not
discuss ovovegetarians as a distinctive subgroup, their
recommendations for vegans would apply to ovovege-
tarians, since eggs do not supply as much vitamin D or
vitamin B 12 as milk. Moreover, ovovegetarians who
remove the yolks from the eggs they consume would
lose all the vitamin D content of the egg. The 2003
vegetarian food guide published by the ADA and DC
recommends that vegans in all age groups should take
supplements of vitamin B 12 and vitamin D, or use
foods fortified with these nutrients.
It is particularly important for pregnant women
to maintain an adequate intake of vitamin B 12 ,asa
lack of this vitamin can cause irreversible neurolog-
ical damage in the infant. A recent Canadian study
reported that a reduced intake of milk during preg-nancy, which would be characteristic of ovovegetar-
ians as well as nonvegetarian women suffering from
lactose intolerance, is associated with low birth
weight in the infant. In addition, some studies indi-
cate that vegans (and by implication ovovegetarians
as well) are at increased risk ofosteoporosisand bone
fractures compared to either meat-eaters or less strict
vegetarians because their average calcium intake is
lower.
There is some disagreement among researchers
regarding the cholesterol content of eggs as a health
risk. Some maintain that the cholesterol in eggs
actually raises high-density lipoprotein (‘‘good’’ cho-
lesterol) blood levels while lowering low-density lip-
oprotein (‘‘bad’’ cholesterol) levels. Other researchers
have noted wide variations among individuals in the
effect of egg consumption on blood lipids. One Indian
study of volunteers on a lacto-vegetarian diet found
that the subjects’ blood lipid levels rose for a few weeks
after adding one boiled egg per day to their diets, but
that the levels fell to baseline values by the end of 8
weeks for two-thirds of the subjects. The remaining
third were hyper-responsive to the addition of eggs to
their diet. This finding suggests that a vegetarian who
is concerned about blood cholesterol levels may wish
to find out whether he or she is hyper-responsive
before increasing their level of egg consumption. In
any case, the cholesterol in chicken eggs is concen-
trated in the yolk, and can be minimized or eliminated
by eating only part of the yolk or eating only the white
(albumen) of the egg—which is 87% water, 13% pro-
tein, and very little fat.Ovovegetarians should avoid eating raw or under-
cooked eggs, however, because of the danger of contam-
ination bySalmonella enteritidisand otherSalmonella
species associated withfood poisoning.Theshellofa
chicken egg ordinarily acts as a barrier against bacterial
contamination, but improper handling or an active
infection in the hen producing the egg may allowSal-
monellaand other disease organisms to enter. According
to a 2002 study produced by the U.S. Department of
Agriculture, only one in every 30,000 eggs produced in
the United States is contaminated, as most egg pro-
ducers wash the eggs with a sanitizing solution shortly
after they have been laid. It is best, however, to protect
oneself and others by cooking eggs thoroughly and by
not allowing containers or cutting boards that have held
raw eggs to come into contact with food that is ready to
eat. This precaution is particularly important for people
with weakened immune systems or who are taking drugs
that suppress the immune system.Ovovegetarianism