Award Date

May 2016

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Kinesiology and Nutrition Sciences

First Committee Member

John C. Young

Second Committee Member

Laura J. Kruskall

Third Committee Member

James Navalta

Fourth Committee Member

Robbin Hickman

Number of Pages

55

Abstract

Introduction: While individuals with gluten sensitivities are instructed to follow a strict gluten-free diet, misinformed concerns over the consumption of gluten products has led to a rise in gluten avoidance diets, without a diagnosis of celiac disease. Gluten-free products, and therefore the diet as a whole, have been found to have twice as much fat, reduced carbohydrates and fiber, and approximately one-third less protein (Miranda 2014). Research on the effects of gluten-free diets on adolescent development is lacking. With recorded nutrient deficiencies in those that abstain from gluten, detrimental effects could be seen in adolescents who are put on non-prescribed gluten- free diets. Body mass is one factor in puberty onset, and may occur earlier in individuals consuming a gluten-free diet, from lower quality ingredients used in gluten-free products.

Purpose: To evaluate the effects of gluten on weight gain, body composition, glycemic response, and puberty onset in newly weaned female rats, hypothesizing that gluten restriction causes a faster increase in body fat, triggering an earlier onset of puberty. Also, that gluten-restriction causes a higher increase in blood glucose than gluten- containing food.

Methods: Sprague-Dawley female weaned rats (n=20), age 23 days, were randomly separated into two groups, and fed either a gluten-free chow or a normal chow diet. Animals were housed separately at the UNLV LACF in a 12-hour light/dark cycle room; water was provided ad libitum. Food intake, body weight and blood glucose were recorded daily for two weeks. Blood was collected from a tail clip, and glucose was measured using a Bayer Contour glucose meter and test strips. Rats were checked daily for vaginal opening starting on the 25th day of life. After vaginal opening was confirmed, rats were euthanized and body composition was measured by a DXA scan. Results: Vaginal opening in the gluten-free group occurred earlier than in the control group (30 ± 2 vs 31 ± 2 days for gluten-free vs control respectively, p=0.01). Percent body fat was increased in the gluten-free group compared with controls (13.8 ± 0.39 vs 10.4 ± 0.72, p=0.015), however, weight gain (86 ± 2 vs 84 ± 3 g), food intake (236 ± 30 vs 215 ± 24 g), and daily blood glucose (83 - 86 mg/dL vs 80 mg/dL - 85 mg/dL for gluten-free and control respectively) were not significantly different between the two groups.

Conclusion: Vaginal opening, and hence onset of puberty, occurred sooner in rats fed the gluten-free diet. Percent body fat was higher in the gluten-free group, consistent with the suggestion that increased body fat plays a role in the decreasing age of menarche in adolescent females. These results reinforce the importance of diet and how it can affect growth and maturation.

Keywords

body fat; glucose; gluten; gluten-free; puberty; rat

Disciplines

Nutrition

Language

English


Included in

Nutrition Commons

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