Efeito de uma mistura de cereais, sementes e grãos (“Ração Humana”) no estado nutricional de ferro e zinco, na composição corporal e na saúde óssea
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2012-02-15
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Universidade Federal de Viçosa
Resumo
A epidemia de obesidade tem atingido todo o mundo e as prevalências têm crescido principalmente em áreas urbanas de países com renda média ou baixa. No Brasil, a prevalência é maior para o sexo feminino, atingindo cerca de 16,5% das mulheres. Ainda existem muitas dúvidas quanto aos efeitos do excesso de peso na saúde óssea. Entretanto, acredita-se que durante a redução ponderal, possíveis perdas ósseas sejam ocasionadas. Dentre os tratamentos para o excesso de peso, o uso de alimentos ricos em fibras tem sido muito orientado e utilizado. Dentro desse contexto, a indústria de alimentos tem lançado no mercado diversos produtos que visam colaborar com a perda de peso, dentre os quais está a “Ração Humana”. Trata-se de uma mistura de cereais, sementes e grãos (MC), ingredientes esses de origem vegetal, e que, isoladamente apresentam benefícios à saúde. Tais ingredientes veiculam fibra alimentar à alimentação, entretanto, a presença de fatores antinutricionais/fitoquímicos como fitatos e taninos, podem prejudicar a biodisponibilidade de minerais, como ferro e zinco. Devido à escassez de estudos na literatura sobre os reais efeitos da “Ração Humana” na saúde, este trabalho objetivou avaliar a biodisponibilidade de ferro de três versões de uma mistura de cereais, sementes e grãos (“Ração Humana”) em ratos Wistar, além de seu efeito no peso, na composição corporal, na saúde óssea, no controle da saciedade e no estado nutricional referente aos minerais ferro e zinco em mulheres com excesso de peso. O primeiro experimento teve como objetivo avaliar a biodisponibilidade de ferro em três versões de uma mistura de cereais sementes e grãos (“Ração Humana”), light (MCL), regular (MCR) e caseira (MCC) por meio do método de depleção/repleção, utilizando um nível de ferro 12mg·kg -1 . Os grupos MCL e grupo controle (GC) não diferiram quanto ao ganho de hemoglobina, eficiência de regeneração de hemoglobina e valor biológico relativo. Consequentemente apresentaram biodisponibilidade de ferro similar, 80,02 ± 36,63 e 99,99 ± 27,62, respectivamente. Os demais grupos apresentaram valores inferiores. O grupo MCR apresentou maior teor de ferro (23,2 mg·100 -1 ), contudo, o elevado teor de tanino (12,45 ± 1,2 mg·100 -1 ) pode explicar sua menor biodisponibilidade. O grupo MCL apresentou maior consumo de fibra solúvel (21,15 ±0.92 g), além de maior teor de propionato no conteúdo fecal (65,49 ± 11,08 μmol/g), e ambas as variáveis se correlacionaram positivamente (r= 0,5712; P= 0,0018). O grupo MCL apresentou menor consumo de tanino e maior consumo de fibra solúvel, o que possivelmente favoreceu a maior solubilidade e biodisponibilidade de ferro sendo fonte comparável ao sulfato ferroso. O segundo estudo teve como objetivo avaliar o efeito de consumo de MC no peso, na composição corporal, na pressão arterial, na saúde óssea, no controle da saciedade e no estado nutricional de ferro e zinco em mulheres com excesso de peso. Foi realizado um ensaio clínico em delineamento crossover, onde foram realizados dois tratamento, restrição energética de 15% associada ao consumo de MC (teste) ou consumo de um placebo (controle). Cada um deles apresentou duração de cinco semanas e houve uma semana de washout entre os tratamentos. Não houve diferença significativa em relação ao peso, composição corporal, pressão arterial e na saúde óssea. Da mesma forma, não foi possível observar diferenças entre os tratamentos quanto ao controle da saciedade. A redução ponderal foi maior no primeiro período para o tratamento controle (P= 0,0434) e para o tratamento teste no segundo período do estudo (P= 0,0086). Houve associação positiva entre densidade mineral óssea e índice de massa corporal (r=0,3956, P=0,0127). Quanto ao estado nutricional dos minerais, houve aumento significativo da hemoglobina durante o consumo de MC (P= 0,0001) e não houve prejuízos quanto à absorção de zinco. Esse trabalho permitiu a confirmação dos dados de biodisponibilidade de ferro em animais e em humanos, o que nos permite concluir que, apesar da origem vegetal dos componentes da MC, ela pode ser considerada uma boa fonte de ferro, e seu consumo diário não foi capaz de prejudicar o estado nutricional de zinco. O consumo diário de MC, entretanto, não alterou o peso, a composição corporal, a pressão arterial e o controle de saciedade de mulheres com excesso de peso.
The obesity epidemic has been a worldwide issue and the prevalence has increased mainly in urban areas of countries with medium or low income. In Brazil, the prevalence is higher for females, reaching about 16.5% of women. There are still many doubts about the effects of overweight on bone health. However, it is believed that during the weight reduction, potential bone loss may be caused. Among the treatments for overweight, the use of food rich in dietary fiber has been widely suggested and used. In this context, the food industry has launched several products on the market designed to help in weight loss, such as “Human Ration”. This is a mixture of cereals, seeds and grains (MC), composed by vegetable ingredients which present health benefits. These ingredients convey dietary fiber to the diet, however, the presence of antinutritional factors/phytochemicals such as phytate and tannins may impair the mineral bioavailability such as iron and zinc. Given the scarcity of studies addressing the actual effect of “Human Ration”, this study aimed to evaluate the iron bioavailability of a mixture of grain, seeds and grains (“Human Ration”) in Wistar rats, as well as its effect on body weight, body composition, bone health, the control of satiety and nutritional status related to iron and zinc minerals in overweight women. The first experiment aimed to evaluate the iron bioavailability in three types of a mixture of cereals, seeds and grains (“Human Ration”), light (LMC), regular (RMC) and homemade (HMC) through the depletion/repletion method, using a 12 mg·kg -1 iron level. The LMC and control group (CG) did not differ from hemoglobin gain, hemoglobin regeneration efficiency and relative biological value. Consequently it showed similar iron bioavailability, and 80.02 ± 36.63 99.99 ± 27.62, respectively. The other groups showed lower values. The RMC group showed a higher content of iron (23.2 mg·100 -1 ), however, the high tannin content (12.45 ± 1.2 mg·100 - ) may explain its lower bioavailability. The LMC group had a higher intake of soluble fiber (21.15 ± 0.92 g), and higher levels of propionate in fecal content (65.49 ± 11.08 μmol/g), and both variables were positively correlated (r= 0.5712, P = 0.0018). The LMC group had lower tannin intake and higher intake of soluble fiber, which probably favored the higher solubility and bioavailability of iron – a source similar to ferrous sulfate. The second study aimed to evaluate the effect of consumption of MC in body weight, body composition, blood pressure, bone health, control of satiety and nutritional status of iron and zinc in overweight women. It was conducted a randomized crossover clinical trial and two treatments were performed: a 15% energy restriction associated with the consumption of MC (test) or consumption of a placebo (control). Each treatment had a five-week period with a washout week between both. There were no significant difference in body weight, body composition, blood pressure and bone health. Likewise, we could not observe differences between treatments for the control of satiety. The weight loss was higher in the first period for control treatment (P = 0.0434) and for the test treatment in the second study period (P= 0.0086). There was a positive association between bone mineral density and body mass index (r= 0.3956, P= 0.0127). There was a significant increase in hemoglobin during the consumption of MC (P= 0.0001) and no losses on the absorption of zinc regarding the nutritional status of minerals. This work allowed the confirmation of data for iron bioavailability in animals and humans, which allows us to conclude that despite the vegetable components of the MC, it can be considered a good source of iron, and their daily consumption was not able to affect the nutritional status of zinc. The daily intake of MC, however, did not affect body weight, body composition, blood pressure and the control of satiety in overweight women.
The obesity epidemic has been a worldwide issue and the prevalence has increased mainly in urban areas of countries with medium or low income. In Brazil, the prevalence is higher for females, reaching about 16.5% of women. There are still many doubts about the effects of overweight on bone health. However, it is believed that during the weight reduction, potential bone loss may be caused. Among the treatments for overweight, the use of food rich in dietary fiber has been widely suggested and used. In this context, the food industry has launched several products on the market designed to help in weight loss, such as “Human Ration”. This is a mixture of cereals, seeds and grains (MC), composed by vegetable ingredients which present health benefits. These ingredients convey dietary fiber to the diet, however, the presence of antinutritional factors/phytochemicals such as phytate and tannins may impair the mineral bioavailability such as iron and zinc. Given the scarcity of studies addressing the actual effect of “Human Ration”, this study aimed to evaluate the iron bioavailability of a mixture of grain, seeds and grains (“Human Ration”) in Wistar rats, as well as its effect on body weight, body composition, bone health, the control of satiety and nutritional status related to iron and zinc minerals in overweight women. The first experiment aimed to evaluate the iron bioavailability in three types of a mixture of cereals, seeds and grains (“Human Ration”), light (LMC), regular (RMC) and homemade (HMC) through the depletion/repletion method, using a 12 mg·kg -1 iron level. The LMC and control group (CG) did not differ from hemoglobin gain, hemoglobin regeneration efficiency and relative biological value. Consequently it showed similar iron bioavailability, and 80.02 ± 36.63 99.99 ± 27.62, respectively. The other groups showed lower values. The RMC group showed a higher content of iron (23.2 mg·100 -1 ), however, the high tannin content (12.45 ± 1.2 mg·100 - ) may explain its lower bioavailability. The LMC group had a higher intake of soluble fiber (21.15 ± 0.92 g), and higher levels of propionate in fecal content (65.49 ± 11.08 μmol/g), and both variables were positively correlated (r= 0.5712, P = 0.0018). The LMC group had lower tannin intake and higher intake of soluble fiber, which probably favored the higher solubility and bioavailability of iron – a source similar to ferrous sulfate. The second study aimed to evaluate the effect of consumption of MC in body weight, body composition, blood pressure, bone health, control of satiety and nutritional status of iron and zinc in overweight women. It was conducted a randomized crossover clinical trial and two treatments were performed: a 15% energy restriction associated with the consumption of MC (test) or consumption of a placebo (control). Each treatment had a five-week period with a washout week between both. There were no significant difference in body weight, body composition, blood pressure and bone health. Likewise, we could not observe differences between treatments for the control of satiety. The weight loss was higher in the first period for control treatment (P = 0.0434) and for the test treatment in the second study period (P= 0.0086). There was a positive association between bone mineral density and body mass index (r= 0.3956, P= 0.0127). There was a significant increase in hemoglobin during the consumption of MC (P= 0.0001) and no losses on the absorption of zinc regarding the nutritional status of minerals. This work allowed the confirmation of data for iron bioavailability in animals and humans, which allows us to conclude that despite the vegetable components of the MC, it can be considered a good source of iron, and their daily consumption was not able to affect the nutritional status of zinc. The daily intake of MC, however, did not affect body weight, body composition, blood pressure and the control of satiety in overweight women.
Descrição
Palavras-chave
Dieta, Ferro, Fibra alimentar, Obesidade - Tratamento, Peso corporal - Regulação, Composição corporal, Ossos - Metabolismo, Taninos, Zinco, Nutrição
Citação
ENES, Bárbara Nery. Efeito de uma mistura de cereais, sementes e grãos (“Ração Humana”) no estado nutricional de ferro e zinco, na composição corporal e na saúde óssea. 2012. 153 f. Dissertação (Mestrado em Ciência da Nutrição) - Universidade Federal de Viçosa, Viçosa. 2012.