| Abstract: | The consumption of CN? containing foods (particularly cassava) is pervasive among millions of humans throughout the tropics, yet very little is known about the long-term implications of this dietary pattern on growth. In this study Liberian (West African) levels of dietary cyanide (CN?) intakes were replicated in juvenile swine for 24 weeks to quantify the effects of specified, chronic, sublethal doses of this metabolic poison on body weight. Twelve female and male littermates were partitioned into a control (Ø mg CN?) and 3 treatment groups (1.2, 0.7, or 0.4 mg CN? per kg body weight per day). CN? treatments depressed absolute weight gain in a dose-dependent manner with significant differences apparent as early as week 12. Thyroid hormones T3 and T4 and fasting blood glucose values were evaluated at 6-week intervals. T3 levels were ostensibly suppressed and blood glucose values elevated with increasing CN? ingestion. Serum thiocyanate (SCN?), the major metabolite of sublethal CN? ingestion, was positively correlated with CN? intake loads (r = 0.83, P < 0.01). Hypothesized physiological foundations for these observations and theoretical implications for human growth are elaborated. |
