An epidemic neuropathy that broke out in Cuba in late 1991 has exhibited clinical manifestations similar to those of other polyneuropathies of nutritional origin. To investigate its possible association with diet, a study was conducted on the Isle of Youth in 1993, at the start of an outbreak there. Thirty-four subjects with cases and 65 controls were interviewed regarding their diets, measured anthropometrically, and evaluated. As a whole, the subjects with cases demonstrated greater weight loss before the onset of disease, lower body mass indexes (BMI), lower percentages of body fat, and more deficient diets than the control subjects. Analysis of individual variables found associations between occurrence of the disease and the following: weight loss, low BMI, a broad range of specific dietary deficiencies, a sugar intake exceeding 15% of total caloric intake, alcohol consumption, and smoking. Also, protective associations were found between absence of the disease and regular consumption of certain foods at or above specified levels. Multivariate analysis indicated that while smoking and alcohol consumption reinforced the effects of the dietary deficiencies, they did not account for occurrence of the disease by themselves. Overall, the results indicate that diets which are deficient in caloric energy, protein, fat, and the micronutrients included in the study, and which reflect an imbalance resulting from a relative excess of sugar, with consequent effects on body weight, are strongly associated with, and causally related to, the occurrence of epidemic neuropathy in Cuba.

Background. From 1991 to 1993, epidemic optic and peripheral neuropathy affected more than 50,000 people in Cuba. The number of new cases decreased after the initiation of vitamin supplementation in the population. In September 1993, Cuban and U.S. investigators conducted a study to characterize and identify risk factors for the optic form of the syndrome.Methods. We conducted ophthalmologic and neurologic examinations, assessed exposure to potential toxins, administered a semiquantitative food-frequency questionnaire, and assessed serum measures of nutritional status in 123 patients with severe optic neuropathy, matched for sex and age to randomly chosen normal subjects.Results. In the case patients, prominent clinical features were subacute loss of visual acuity with field defects, diminished color vision, optic-nerve pallor, and decreased sensitivity to vibration and temperature in the legs. Tobacco use, particularly cigar smoking, was associated with an increased risk of optic neuropathy. The risk was reduced among subjects with higher dietary intakes of methionine, vitamin B-12, riboflavin, and niacin and higher serum concentrations of antioxidant carotenoids, The risk was also reduced among subjects who raised chickens at home or had relatives living overseas - factors that may be indirect measures of increased food availability.Conclusions. The epidemic of optic and peripheral neuropathy in Cuba between 1991 and 1993 appears to be linked to reduced nutrient intake caused by the country's deteriorating economic situation and the high prevalence of tobacco use.

The epidemic of neuropathy that arose in Cuba in late 1991 has clinical manifestations similar to those of other neuropathies that are nutritional in origin. In an effort to identify its possible association with the diet, a case-control study was conducted at the beginning of the epidemic in Isla de la Juventud. Dietary intake was assessed through a semi-quantitative survey of consumption frequency obtained by direct personal interviews, and measurements were taken of the weight, height and skin fold thickness of 34 cases and 65 controls. As compared to controls, cases showed more pronounced weight loss prior to becoming ill, a lower body mass index (BMI), a lower percentage of body fat, and a poorer diet. According to odds ratios (OR) resulting from the separate analysis of each variable, factors associated with illness were weight loss, low BMI, low weight for height, a lower consumption of bread and rice, a less balanced diet, lack of milk intake, an intake of sugar greater than 15% of total energy consumed, consumption of alcohol, and smoking. The association was protective in the case of beans, tubercles, starchy roots, oil, and meat substitutes made from soy. Multifactorial analysis revealed higher OR values, adjusted for smoking and alcohol consumption, for intakes of less than 50% of the recommended daily allowance of protein, pyridoxine, thiamine, energy, vitamin E, niacin, folic acid, fat, riboflavin, and vitamin A. The results of this analysis show that tobacco and alcohol promote the effects of a deficient diet, but do not in and of themselves explain the association. A global analysis of these results leads to the conclusion that a diet poor in energy, calories, fats, and those micronutrients that have come under study, and that is unbalanced because of a relative excess of sugars, with its resulting effect on body weight, is strongly associated with and causally related to epidemic neuropathy.