A New Food Frequency Questionnaire to Assess Cocoa Consumption and its relationship with Health in University Students

Abstract

Cocoa is a well recognized source of polyphenols, but studies on their consumption refer that it contributes with a low proportion to the daily polyphenol consumption. Cocoa polyphenol content is plenty recognized and the benefits from its consumption in human health are established. However, the contribution of cocoa to daily polyphenol intake is not totally clear due to the lack of studies estimating cocoa consumption.

Taking these facts into account, the hypothesis of this thesis was that cocoa consumption is underestimated in overall food intake studies and perhaps it can be associated with healthy status. Therefore, the present thesis was carried out on the following aims: 1) to develop and validate a food frequency questionnaire (FFQ) including the main cocoa food products common in Catalan and Portuguese dietary habits in a young population; 2) to establish the consumption of cocoa in university students of Catalonia and Portugal; and 3) to establish the relationship between cocoa intake and healthy status, including the presence of allergies, and healthy lifestyle practices.

The FFQ developed as well as the other questionnaires to validate them have been applied to a sample of 50 students from the University of Barcelona and to a sample of 70 students from Egas Moniz Health Sciences Institute. Afterwards, validated FFQ together questionnaires inquiring about physical activity and also health status were applied to a sample of 270 students from both institutions.

The main results of this thesis consist in the development and validation of a FFQ devoted to know the real cocoa intake in University students in Spanish and Portuguese languages. This FFQ allows the assessment of more cocoa/chocolate product intake than others FFQ because it considered a wide range of products which were not included in others FFQ (dairy, pastry, desserts, cereals and spreads). According the developed FFQ, students from the University of Barcelona use to eat 2.5 portions of products containing cocoa or chocolate per day that represents 12 g of cocoa per day, whereas the students of the Egas Moniz Health Science Institute consume more than 3 products per day which represent 14 g of cocoa per day. Moreover, differential cocoa consumption patterns between both cohorts have been found.

In a cohort of 270 students from both Universities it has been established correlations between cocoa consumption and physical activity, body mass index, blood pressure, recent illness and also allergic processes. In addition, the values of these variables were assessed in students grouped according their cocoa consumption (low, moderate and high consumers). There was not a significant correlation of cocoa intake with physical activity and blood pressure, but there was a significantly lower proportion of overweight individuals in the high cocoa consumers group. The proportion of allergic people in the moderate and high cocoa consumers resulted statistically lower than that in the students in the low cocoa consumer group. Moreover, the cocoa intake, especially moderate consumption, was also associated with lower presence of allergic derived symptoms.

In summary, the present study evidences the underestimation of cocoa consumption due to approach limitations and has generated a valid tool for estimating real cocoa consumption. Cocoa intake in University students has been assessed, and different patterns of consumption have been found between Portuguese and Spanish university students regarding the type of cocoa source more frequently consumed. Finally, some clear associations between cocoa consumption and health status have been found. Therefore, this study can be the first part of a new study using the same methodology in a higher number of participants or different type of population. Alternatively, these health improvements by cocoa consumption showed here can be confirmed by an interventional clinical study.

El cacao posee efectos beneficiosos para el organismo, si bien estudios sobre ingesta de alimentos revelan su bajo consumo. Los objetivos de esta tesis han sido: 1) desarrollar y validar una encuesta de frecuencia de consumo alimentario que incluya los alimentos con cacao frecuentes en la dieta de Cataluña y Portugal; 2) estimar la ingesta de cacao en estudiantes universitarios de los dos países; y 3) evaluar la asociación entre ingesta de cacao e indicadores de actividad física y de salud, incluyendo las alergias.

El FFQ desarrollado se ha validado con 50 estudiantes de la Universidad de Barcelona y 70 estudiantes de Egas Moniz Health Sciences Institute. Posteriormente, se ha aplicado a 270 estudiantes de ambas instituciones junto con cuestionarios acerca de su actividad física y su estado de salud.

Los resultados muestran el desarrollo y validación de un FFQ dedicado a conocer la ingesta real de cacao en los estudiantes universitarios. Su aplicación ha permitido evaluar la ingesta de más productos de cacao/chocolate que otros FFQ, puesto que considera una amplia gama de productos. Según el FFQ desarrollado, los estudiantes de la Universidad de Barcelona ingieren 2,5 porciones de productos con cacao/chocolate por día, lo que representa unos 12 g/día, mientras que los estudiantes del Egas Moniz Health Sciences Institute consumen más de 3 productos por día, que representan unos 14 g/día.

Se han estudiado la relación entre el consumo de cacao y la actividad física, el índice de masa corporal, la presión arterial, una enfermedad reciente y también procesos alérgicos. No se ha hallado una correlación significativa entre la ingesta de cacao y la actividad física y la presión arterial, pero existe una proporción menor de personas con sobrepeso en el grupo de estudiantes con elevado consumo de cacao. El porcentaje de personas alérgicas en el grupo con moderado y elevado consumo de cacao ha resultado ser inferior a la de los estudiantes en el grupo de baja ingesta de cacao. Por otra parte, el consumo de cacao, especialmente el consumo moderado, también se ha podido asociar a una menor presencia de manifestaciones alérgicas.