World Vegetarian Congress 1996 - research in Japan

Comparing Nutrition and Health of Japanese High School Students: SDA Vegetarians and Non-vegetarians
from EVU News, Issue 4 / 1996

About the authors: (Department of Home Economics, Osaka Shin-Ai College)

ABSTRACT
A food intake survey for three consecutive days was conducted and the Cornell Medical Index-Health Questionnaire papers (C. M. I.) were given to Japanese high school students who were 14 to 16 years old: 120 SDA vegetarians and 120 nonvegetarians. The following results were obtained:

1. Each mean value of the nutrients consumed, except for niacin, met the requirements of dietary allowance for SDA vegetarians.
   The energy, calcium and iron intakes for non-vegetarians showed lower mean values compared with the values of the dietary allowance.
2. Height, weight, obesity and emaciation were not significantly different between the two groups.
3. As a results of C. M. L, the subjective symptoms of alimentary system of SDA vegetarians were significantly less than those of non-vegetarians.

Considering the results, we would like to recommend the vegetarian diet and spread it all over Japan.

1. Introduction

A lot of research reports concerning nutrition and health of vegetarians exist in the United States. They say death rate for vegetarians from various cancers is lower than that of people who eat a non-vegetarian diet and that incidence rate for vegetarians of geriatric diseases such as ischaemia, heart disease, diabetes, osteoporosis and hypercholesterolemia is low.

In 1988, the American Dietetic Association issued the commentary which technically supported a vegetarian diet. The commentary reported that vegetarians rarely contract diabetes.

The nutrient problems such as shortages of vitamin B12 in a complete vegetarian diet, where only food of plant origin is eaten, were pointed out. There is not so much research into the vegetarians during the period of growth, and moreover, the amount of the research into the vegetarian diet on which the Japanese are targeted is extremely small.

Then, the authors studied Japanese students who lived in a dormitory and lived on the Lacto-ovo-vegetarian diet of the SDA method, and students of the same age, junior high school and high school students, in Osaka Prefecture, who ate a non-vegetarian diet. The nutrition and health of the students were investigated in this study. We used the Cornell Medical Index-Health Questionnaire (abbreviated C.M.I.) to examine the health condition of the students.

2. Method

Subjects
The vegetarians investigated were students from 14 to 16 years old, who studied at Hiroshima San-iku Gakuin, a school in Hirosima Prefecuture. The non-vegetarian group consisted of junior high school and high school students, who lived on a non-vegetarian diet. The two groups each consisted of 120 students: 60 males and 60 females. Both the C.M.I. and the food intake survey of the two groups were conducted.

Table 1: Number of Subjects shows the number of students with valid answers.

Investigation
The C.M.I. was used to investigate the physical condition of the subjects. This questionnaire was developed for the purpose of detecting the mental and physical subjective symptoms for a short period of time. The question items were translated into Japanese in this survey.

The mental and physical subjective symptoms are shown in Table 2: The Section on the Cornell Medical Index. In this particular survey, we used 160 question items relating to physical subjective symptoms for males and corresponding 162 question items for females.

The food intake investigation was conducted for three consecutive weekdays to investigate the nutrient intake. The percentage of the dietary allowance of each nutrient was calculated according to stature, weight, and the intensity of daily activity (middle degree) of the subjects.

3. Results

We would like to talk about the nutrient intake survey.

The vegetarian students ate meals at a dormitory cafeteria. The meals included dishes made from soybean protein and wheat protein. Main dishes were such as rice and bread. The students were free to have fruit and beverage of their own choice. For three consecutive days, they wrote on the forms what they ate at each meal. The non-vegetarian students wrote down the kind and amount of the food they ate.

In the vegetarian students of both sexes, the dietary intake average value of each nutrient except niacin fulfilled the recommended dietary allowance. On the other hand, in the non-vegetarian students of both sexes, the dietary intake average value of energy, calcium and iron did not meet the recommended dietary allowance. In both sexes, the vegetarian diet group’s intakes of energy, lipid, calcium, iron, vitamin A, and vitamin B2 were significantly higher than those of the non-vegetarian group.

Niacin is the only nutrient whose intake is higher in non-vegetarian than in vegetarians and the difference in the female students was significant. Thus, the lack of inorganic substances such as calcium and iron was as conspicuous as for non-vegetarians. On the other hand, although a lack of niacin was observed, the percentage of the recommended dietary allowance of male and female vegetarians was about 90 percent or more. Thus, we came to a conclusion that the diet on which the vegetarian students live was well-balanced overall in terms of nutrient. Let us go on to the physical features of the students.

The average values of the vegetarian students’ stature were smaller than those of the non-vegetarian students’ stature in each age group. However, there was no significant difference between the two groups. Likewise, there was no significant difference in weight between the two groups.

Table 3 shows the average value and the standard deviation of points in the C.M.I. The question items here are about physical features. In terms of points totalled, the value of male vegetarians was smaller than that of male non-vegetarians and the value of female non-vegetarians was smaller than that of female vegetarians. There was a significant difference in values in the question items about digestive tract and habit. In questions about habit, the value of female non-vegetarians was significantly smaller than that of female vegetarians. However, further examination revealed that the difference came from the dormitory life they lead, because there was a significant difference of points in questions such as "Do you find it impossible to take a regular rest period each day?” and "Do you find it impossible to take regular daily exercise?” In questions of digestive tract, the values registered for male vegetarians are significantly smaller than those for male non-vegetarians.

See Table 4: Questions Relating to Digestive Tract. There were 28 questions in this section. After close examination, it was revealed that the values for male vegetarians were significantly smaller than those of their non-vegetarian counterparts in 6 question items such as "Are you often sick in your stomach?” and that the values for female vegetarians were significantly smaller than those for their non-vegetarian counterparts in 2 questions. It is noticeable that the values for female non-vegetarians were smaller than those for their vegetarian counterparts only in one question "Do you usually feel bloated after eating?”

4. Consideration

A lot of research reports concerning nutrition and health of vegetarians exist in the United States. However, most of them are about adults, and there is comparatively not so many research into vegetarians during the growthperiod. Generally, the scarce amount of protein, vitamin B 12 and iron cause worry about the vegetarian diet.

However, according to the research of Herdinge and Register, both pure-vegetarian diet and lacto-ovo-vegetarian diet quantitatively and qualitatively meet the recommended dietary allowance of protein. In research concerning infants, Dwyer investigated vegetarians from 1 to 8 years old. For the child, the values of stature were smaller than a standard value. They considered that this was due to the inheritance factor of parents’ stature rather than eating habits factor. They noted that no other particular tendency was observed in respect of physical features. They conclude that there is no problem with a vegetarian diet in respect of health. Sanders reported that pure-vegetarian children from 1 to 6 years old who ate only food of plant origin did not have the feared intake shortage in nutrient of the vitamin B12 and iron.

There are reports that a lacto-ovo-vegetarian diet is a meal enough to meet the recommended dietary allowances of each nutrient such as energy, protein, carbohydrate, vitamins, and minerals.

Likewise, our survey revealed that lacto-ovo-vegetarian students’ nutricional state is better than that of students of a non-vegetarian diet. No particular tendency was observed in the physical features between the two groups.

Therefore, it can be concluded that the lacto-ovo vegetarian diet has no problem at all as a meal during growth. Moreover, it has been reported that the incidence rate and death rate among adult vegetarians from large intestinal tumours and cancers of the digestive organs are lower than those of people eating a non-vegetarian diet. And this survey shows the subjective symptoms of the stomach and intestines are very few in vegetarians in their early teens.

This is an interesting result from a viewpoint of preventive medicine.

For information contact:
Dr. Mitsuru Kakimoto
c/o Department of Environmental Sciences
Osaka Shin-ai College 2-7-10 Furuichi, Joto-ku, Osaka, 536, Japan
Tel.:+ 816-939-4391, Fax: +816 931 0373
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