Lowering the glycemic index of white bread using a white bean extract

<p>Abstract</p> <p>Background</p> <p>Phase 2^®is a dietary supplement derived from the common white kidney bean (Phaseolus vulgaris). Phase 2 has been shown to inhibit alpha-amylase, the complex carbohydrate digesting enzyme, in vitro. The inhibition of alpha-amylase may result in the lowering of the effective Glycemic Index (GI) of certain foods. The objective of this study was to determine whether the addition of Phase 2 would lower the GI of a commercially available high glycemic food (white bread).</p> <p>Methods</p> <p>An open-label 6-arm crossover study was conducted with 13 randomized subjects. Standardized GI testing was performed on white bread with and without the addition of Phase 2 in capsule and powder form, each in dosages of 1500 mg, 2000 mg, and 3000 mg. Statistical analysis was performed by one-way ANOVA of all seven treatment groups using unadjusted multiple comparisons (t tests) to the white bread control.</p> <p>Results</p> <p>For the capsule formulation, the 1500 mg dose had no effect on the GI and the 2000 mg and 3000 mg capsule doses caused insignificant reductions in GI. For the powder, the 1500 mg and 2000 mg doses caused insignificant reductions in the GI, and the 3000 mg dose had a significant effect (-20.23 or 34.11%, p = 0.023)</p> <p>Conclusion</p> <p>Phase 2 white bean extract appears to be a novel and potentially effective method for reducing the GI of existing foods without modifying their ingredient profile.</p> <p>Trial Registration</p> <p>Trial Registration: ISRCTN50347345</p

Velocidade crítica como um método não invasivo para estimar a velocidade de lactato mínimo no ciclismo La velocidad crítica como un método no invasivo para estimar la velocidad de lactato mínimo en el ciclismo Critical velocity as a noninvasive method to estimate the lactate minimum velocity on cycling

A velocidade de lactato mínimo (VLM) representa o ponto de equilíbrio entre produção e remoção do lactato sanguíneo (lac). Com objetivo de analisar a validade da velocidade crítica (VC) como método não invasivo de estimar a VLM no ciclismo outdoor, 15 ciclistas (67,9 ± 5,7kg; 1,70 ± 0,1m; 26,7 ± 4,2 anos) percorreram as distâncias de 2, 4 e 6km em velódromo no menor tempo possível. A VC foi identificada pelo modelo distância-tempo a partir das combinações de séries preditivas de 2 e 4km (VC2/4), 2 e 6km (VC2/6), 4 e 6km (VC4/6) e 2, 4 e 6km (VC2/4/6). Para identificação da VLM foi realizada uma série de 2km à máxima velocidade, seguida de seis séries incrementais de 2km com 1 minuto de pausa para dosagem de lac. A VLM foi identificada visualmente (VLMv) e aplicando-se função polinomial (VLMp). Não foram observadas diferenças entre VLMv (33,3 ± 2,5km.h¹) e VLMp (33,1 ± 2,6km.h¹). Com exceção da VC4/6 (34,6 ± 3,5km.h¹), os valores de VC2/4 (38,0 ± 2,2km.h¹), VC2/6 (36,1 ± 2,4km.h¹) e VC2/4/6 (36,1 ± 2,5km.h¹) diferiram da VLMp e VLMv. Os autores concluem que, apesar de ser ~1km/h acima da VLM, a VC identificada a partir de séries preditivas de maior duração (4 e 6km - aproximadamente 6 e 10 min) não diferem estatisticamente e apresentam alta correlação e concordância com a VLM. No entanto, é necessário investigar se a VC representa um equilíbrio entre remoção e produção de lac durante exercícios de longa duração no ciclismo outdoor.<br>La velocidad de lactato mínimo (VLM) representa el punto de equilibrio entre la producción y la remoción de lactato sanguíneo (lac). Con el objetivo de analizar la validez de la velocidad crítica (VC) como método no invasivo de estimar la VLM en el ciclismo "outdoor", 15 ciclistas (67,9 ± 5,7 kg; 1,70 ± 0,1 m; 26,7 ± 4,2 años) percorrieron distancias de 2, 4 y 6 km en velódromo en el menor tiempo posible. La VC fue identificada por el modelo distancia-tiempo a partir de las combinaciones de series predictivas de 2 y 4 km (VC2/4), 2 y 6 km (VC2/6), 4 y 6 km (VC4/6) y 2, 4 y 6km (VC2/4/6). Para la identificación de VLM fue realizada una serie de 2km a máxima velocidad, seguida de 6 series incrementales de 2km con 1 minuto de pausa para dosaje de lac. La VLM fue identificada visualmente (VLMv) y aplicando función polinomial (VLMp). No se observaron diferencias entre VLMv (33,3 ± 2,5km.h¹) y VLMp (33,1 ± 2,6km.h¹). A excepción de VC4/6 (34,6 ± 3,5km.h¹), los valores de VC2/4 (38,0 ± 2,2km.h¹), VC2/6 (36,1 ± 2,4km.h¹) y VC2/4/6 (36,1 ± 2,5km.h¹) difirieron de VLMp y VLMv. Concluimos que, a pesar de ser ~1km/h por encima de VLM, la VC identificada a partir de series predictivas de mayor duración (4 y 6km - aproximadamente 6 y 10 min) no tienen diferencia estadística y presentan alta correlación y concordancia con VLM. A pesar de esto, es necesario investigar si la VC representa un equilibrio entre remoción y producción de lac durante los ejercicios de larga duración en ciclismo outdoor.<br>The lactate minimum velocity (LMV) represents the equilibrium point between blood lactate (lac) production and removal. With the purpose of analyzing the validity of critical velocity (CV) as a non-invasive method to estimate the LMV on outdoor cycling, 15 cyclists (67.9 ± 5.7 kg; 1.70 ± 0.1 m; 26.7 ± 4.2 years) performed all-out tests on distances of 2, 4 and 6 km on velodrome. The CV was identified by distance-time model from combinations of 2 and 4 km (CV2/4), 2 and 6 km (CV2/6), 4 and 6 km (CV4/6) and 2, 4 and 6 km (CV2/4/6). The LMV was identified during 6 x 2 km incremental bouts after a latic acidosis induced by the all-out 2 km. The lower lac during test identified the LMV visually (LMVv) and by applying a polynomial function (LMVp). No differences were observed between LMVv (33.3 ± 2.5 km.h¹) and LMVp (33.1 ± 2.6 km.h¹). Apart from CV4/6 (34.6 ± 3.5 km.h¹), the values of CV2/4 (38.0 ± 2.2 km.h¹), CV2/6 (36.1 ± 2.4 km.h¹) and CV2/4/6 (36.1 ± 2.5 km.h¹) differed from LMVp and LMVv (P < 0,001). The authors concluded that, besides being ~1 km/h above the LMV, the CV determined through predictive series of longer duration (4 and 6 km approximately 6 and 10 min) did not differ statistically from LMV and presented a high correlation and agreement to each other. However, it is necessary to investigate whether the CV reflects the balance between lac production and removal during long-term exercise on outdoor cycling