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Star Bulletin Alan Titchenal & Joannie Dobbs Health Options
Alan Titchenal
 & Joannie Dobbs
                   Wednesday, November 8, 2000

 

Vegan diet insufficient in some cases

WE have been asked often why we do not promote vegetarian diets in our column as being superior to other diets. Although we consumed a vegetarian diet for about 25 years each, we are not convinced that this is the healthiest way to eat.

Many studies have reported a reduced incidence of various chronic diseases in groups of people like the Seventh-Day Adventists who generally consume a vegetarian diet. However, it must be remembered that the results of these studies reflect only the trend for the study group. A diet that benefits a group of people may actually be detrimental to an individual if his or her needs are not the same. Health Options is about offering options based on science and not on ethics and personal philosophy.

Those who espouse the virtues of a vegetarian diet often promote the vegan diet (excludes eggs, milk and meats) as superior to other vegetarian diets. The major assumption of this premise is that if an all plant-based diet is good for young healthy adults, then it is also good for aging adults, immune challenged adults and all individuals with or without various medical conditions.

SADLY, individuals who know very little about the complexity of health and nutrition see the world in modes of "good and bad" foods. This leads to the promotion of "one-size-fits-all" diets. However, we are not all genetically the same or at the same stage of life, nor are we all leading the same lifestyles.

Vegan diets are typically low in iron, zinc, calcium, vitamin B-12, and protein. These diets contain no EPA and DHA (the longer omega-3 fatty acids found in fish and some algae oils). Due to these limitations, vegan diets for children and pregnant women must be carefully planned. Children raised on a vegan diet are often smaller than other children.

Active children and young adults eat more food and are less likely to have problems with the limitations of a vegan diet. However, individuals with reduced calorie needs can find it very challenging to meet nutrient needs with a vegan diet. This challenge becomes more difficult for those whose activity is restricted by injury, illness, or aging.

The appropriate use of supplements and foods fortified with iron, calcium, and B-12 can often improve the nutrient composition of a vegan diet. Algae oil supplements high in DHA are available, although it's an expensive way to obtain amounts found in fatty fish.

PROTEIN needs do not go down with decreased calorie needs. For healthy individuals able to consume a lot of calories without gaining weight, meeting protein needs is relatively simple. However, for individuals with low calorie needs, meeting one's protein requirement on a vegan diet can be a challenge.

Inadequate dietary protein is a common reason for muscle and weight loss in senior citizens. Also, inadequate dietary protein can compromise normal function of the immune system, reducing the ability to fight infection. Blood proteins can affect one's ability to regulate body water and the end result can adversely affect blood pressure and heart function.

Certainly, eating a plant-based diet is a great way to obtain many natural antioxidants and phytochemicals. However, it's all a matter of proportions. As health professionals, we find that nutrition science supports inclusion of reasonable amounts of animal foods into a plant-based diet.


Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S.
are nutritionists in the Department of Human Nutrition, Food and Animal Sciences,
College of Tropical Agriculture and Human Resources, UH-Manoa.
Dr. Dobbs also works with the University Health Service

© 2000 Honolulu Star-Bulletin -- http://starbulletin.com
http://www.nutritionatc.hawaii.edu/HO/2000/87.htm

NutritionATC
Human Nutrition, Food & Animal Sciences · University of Hawai`i at Mānoa
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