Leggo spesso che i grassi sono sopravvalutati e che arrivare anche a basse dosi (30-40 gr/day) non porterebbe abbassamenti del testosterone (a pari calorie ecc..) ma tengo conservato questo studio da un pò:
Diet and serum sex hormones in healthy men. [J Steroid Biochem. 1984] - PubMed - NCBI
mi sapreste dire dove hanno cannato con l'esprimere quella conclusione?
---------- Post added at 18:59:14 ---------- Previous post was at 18:48:58 ----------
http://jap.physiology.org/content/82/1/49.full
The primary finding from this investigation was that dietary nutrients may influence resting concentrations of T in young athletic men. However, the resistance exercise-induced increase in T does not appear to be affected by nutritional variables averaged over 17 days. Because of the variation in nutrient intake from day to day within individuals (especially dietary cholesterol and PUFA/SFA values), 2–3 wk of diet information appears to be required to obtain reliable data (21). Most other studies have used much shorter time periods to obtain individual food intake information; thus their reliability and accuracy may be questionable. Our results demonstrated that dietary protein, fat, SFA, MUFA, PUFA/SFA ratio, and protein-to-carbohydrate ratio were all significantly correlated with preexercise T concentrations. However, none of these dietary variables were significantly correlated with C concentrations. These data are consistent with the findings of several other investigations that have reported a decrease in T in individuals consuming a diet containing ∼20% fat compared with a diet containing ∼40% fat (7, 9, 13, 25). Vegetarians also consume less fat, SFA, and a higher PUFA/SFA ratio compared with omnivores, and vegetarians exhibit lower concentrations of T compared with omnivores (3, 11, 12, 15, 24). These data suggest that alteration in dietary energy and/or dietary composition has the potential to modify T concentrations.
The results from several investigations strongly suggest that dietary fat has a significant impact on T concentrations; however, the influence of different types of lipids on T is not as clear. In the present investigation, dietary fat, SFA, and MUFA were the best predictors of resting T concentrations. Interestingly, Tegelman et al. (28) observed a significant positive correlation (r = 0.76) between percent energy fat and T in young athletic men, which is very similar to the correlation (r = 0.72) obtained in this study. Also, Adlercreutz et al. (1) reported significant positive correlations between T and dietary fat, SFA, MUFA, and cholesterol in postmenopausal women. The same nutrients were positively correlated with T in the present investigation except for cholesterol, which showed a correlation of r = 0.53 (P = 0.07) with T. In contrast to the results obtained in this study, Key et al. (15) reported a significant positive correlation (r = 0.37) between PUFA and T in male vegetarians and omnivores. Our results showed a nonsignificant correlation between PUFA and T and a significant negative correlation between the PUFA/SFA ratio and T. Thus dietary lipids appear to have a significant influence on resting T concentrations; however, the effect of different types of lipids on T regulation and metabolism is complicated and most likely influenced by a complex interaction of several nutritional and metabolic factors. This complexity is illustrated by the findings of Sebokova et al. (26,27), who reported that alteration in the testicular plasma membrane and changes in the responsiveness of Leydig cells and subsequent T synthesis occur as a result of ingestion of different compositions of lipids.
Diet and serum sex hormones in healthy men. [J Steroid Biochem. 1984] - PubMed - NCBI
mi sapreste dire dove hanno cannato con l'esprimere quella conclusione?
---------- Post added at 18:59:14 ---------- Previous post was at 18:48:58 ----------
http://jap.physiology.org/content/82/1/49.full
The primary finding from this investigation was that dietary nutrients may influence resting concentrations of T in young athletic men. However, the resistance exercise-induced increase in T does not appear to be affected by nutritional variables averaged over 17 days. Because of the variation in nutrient intake from day to day within individuals (especially dietary cholesterol and PUFA/SFA values), 2–3 wk of diet information appears to be required to obtain reliable data (21). Most other studies have used much shorter time periods to obtain individual food intake information; thus their reliability and accuracy may be questionable. Our results demonstrated that dietary protein, fat, SFA, MUFA, PUFA/SFA ratio, and protein-to-carbohydrate ratio were all significantly correlated with preexercise T concentrations. However, none of these dietary variables were significantly correlated with C concentrations. These data are consistent with the findings of several other investigations that have reported a decrease in T in individuals consuming a diet containing ∼20% fat compared with a diet containing ∼40% fat (7, 9, 13, 25). Vegetarians also consume less fat, SFA, and a higher PUFA/SFA ratio compared with omnivores, and vegetarians exhibit lower concentrations of T compared with omnivores (3, 11, 12, 15, 24). These data suggest that alteration in dietary energy and/or dietary composition has the potential to modify T concentrations.
The results from several investigations strongly suggest that dietary fat has a significant impact on T concentrations; however, the influence of different types of lipids on T is not as clear. In the present investigation, dietary fat, SFA, and MUFA were the best predictors of resting T concentrations. Interestingly, Tegelman et al. (28) observed a significant positive correlation (r = 0.76) between percent energy fat and T in young athletic men, which is very similar to the correlation (r = 0.72) obtained in this study. Also, Adlercreutz et al. (1) reported significant positive correlations between T and dietary fat, SFA, MUFA, and cholesterol in postmenopausal women. The same nutrients were positively correlated with T in the present investigation except for cholesterol, which showed a correlation of r = 0.53 (P = 0.07) with T. In contrast to the results obtained in this study, Key et al. (15) reported a significant positive correlation (r = 0.37) between PUFA and T in male vegetarians and omnivores. Our results showed a nonsignificant correlation between PUFA and T and a significant negative correlation between the PUFA/SFA ratio and T. Thus dietary lipids appear to have a significant influence on resting T concentrations; however, the effect of different types of lipids on T regulation and metabolism is complicated and most likely influenced by a complex interaction of several nutritional and metabolic factors. This complexity is illustrated by the findings of Sebokova et al. (26,27), who reported that alteration in the testicular plasma membrane and changes in the responsiveness of Leydig cells and subsequent T synthesis occur as a result of ingestion of different compositions of lipids.
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