Dietary aflatoxins, intelligence and school performance in southern Georgia.

In a region of southern Georgia known for poor school performance, the mothers of the mentally retarded children had diets that differed from the average in terms of foods, but did not differ in terms of critical nutrients. The consumption of large amounts of corn, rice, peanuts and milk (foods potentially high in aflatoxins) was significantly related to mental retardation of children in one county having high levels of aflatoxins in the food supply. However, no such relationship was found in a county having trivial levels of aflatoxins in the diet.

Maternal diet and mental retardation in southern Georgia, USA.

The diet of each of 250 mothers was correlated with the I.Q. (intelligence quotient) of her child. When the I.Q. was above 90, no systematic relationship was observed. Below an I.Q. of 70, all mothers consumed a similar diet--one with a smaller amount and variety of fruits and vegetables, but larger amounts of yams, greens, corn, rice and dry legumes. This diet was uniquely deficient in none of the common nutrients. It seems more possible, therefore, that the correlation with diet could be due to the presence of a toxicant, such as aflatoxin.

The effect of copper and protein on iron metabolism in rats fed a cereal diet.

Weanling male white rats were fed a diet containing a commercially available breakfast cereal. In 28 days they developed a mild anemia coupled with an increased amount of iron in the liver. In parallel work, this same diet was supplemented in a factorial fashion with casein, iron, copper and zinc. The zinc had no effect. Copper supplementation increased the hemoglobin level. Casein decreased liver iron. The copper and casein, when fed together, produced results approaching normal control levels. Supplementation of the diet with additional iron did not increase the hemoglobin or hematocrit but it did further increase iron storage in the liver. It is suggested that cereal enrichment programs might do well to consider copper and protein rather than focus total attention to additional iron and zinc.

Dietary aluminum and Alzheimer's disease--a review.

Current evidence suggests that dietary aluminum is neither an essential nutrient nor a toxic element causing neurological damage. The phosphate and fluoride salts of aluminum are very insoluble. When fed in excess, aluminum increases the dietary needs for these anions. Aluminum hydroxide is used as an antacid that can prevent the phosphatemia seen in severe kidney damage. In Alzheimer's disease there is progressive decrease in brain mass with the accumulation of phospholipid-rich cell debris. These membrane tangles tend to accumulate aluminum and are easily stainable with silver.

The three thiamin requirements of the rat.

Some nutrients are necessary parts of several different biochemical systems and are required for several different and measurable physiological functions. There are three measurable dietary requirements for thiamin in the rat. The largest is correlated with food intake and body weight gain data. A half-maximum response is produced by 7 micrograms of thiamin per day, and a maximum response is produced by a dose 2- to 4-times larger. The next requirement, showing a half-response at 1 microgram thiamin, relates to cardiovascular function. It is measured by the enlargement of the heart or by the rat bradycardia bioassay method for thiamin. The smallest requirement, occurring at 0.01 microgram thiamin, is associated with the nervous system responses characteristic of thiamin deficiency, and may be related to a variability in oxidative metabolism.

A comparison of sodium, chloride, thiocyanate, and sucrose spaces as estimates of extracellular fluid volume.

Sodium, chloride, thiocyanate, and sucrose spaces were measured in whole body and different tissues of rat. For each analytical method, when all tissue spaces were added the sum was in good agreement with corresponding total body fluid space obtained by dilution methods. There was surprisingly good agreement among the three ionic space measures in the total body, when one considers that there were discrepancies as large as 2- to 8-fold within certain of the different tissues. Some differences could be explained by the facts that sodium is a constituent of bond mineral and that there are marked differences between these four measures when observed in the water of the gastrointestinal contents.

Ratio of hemoglobin iron to liver in rats fed different amounts of iron.

Groups of young rats were fed diets containing amounts of iron designed to provide 0.1, 0.3, 1, 3, 10 or 30-times the iron requirement for the rat, and containing two different levels of protein. Iron deficiency anemia was most pronounced in rats receiving the larger amount of protein. In the case of most normal diets, the ratio of iron in the hemoglobin to iron stored in the liver was 26 +/- 6. This is in marked contrast with the ratio of 4.3 found in rats fed a common breakfast cereal.

Barbiturate and amphetamine activity in rats fed a magnesium-deficient diet.

Hexobarbital hypnosis and d-amphetamine toxicity were observed in rats fed a commercially available rat food preparation (lab chow) and in another two groups fed complete nutritionally defined diets with or without magnesium. Neither hexobarbital sleeping time nor hexobarbital blood concentration at awakening were affected after 4, 8 or 12 days of feeding the deficient diet. However, increased sensitivity to d-amphetamine was observed after 11 days of feeding the same magnesium deficient diet to other rats. The LD50 of d-amphetamine in magnesium deficient rats was less than 0.5 that recorded for the groups fed lab chow or the nutritionally defined diet with a magnesium supplement.

Effect of major nutrient substitutions on body weight gain, blood glucose and cholesterol levels, and the rate of drug metabolism in the liver.

Rats were fed diets resembling a normal human diet, except that, in a complete factorial fashion, safflower oil and/or mineral oil were substituted for part of the fat, while fructose, lactose and/or cellulose were substituted for carbohydrate, and zein was substituted for milk protein. Food intake and weight gain were not influenced by cellulose and mineral oil, but zein decreased both substantially. Plasma cholesterol was unchanged by safflower oil or mineral oil but was decreased by fructose. Plasma glucose was reduced as the starch-to-sugar ratio increased. The rate of aniline metabolism was increased by lactose and/or zein, but the rate of ethylmorphine metabolism was decreased by safflower oil or mineral oil.

Effect of essential and nonessential fatty acids in complex mixture on fatty acid composition of liver lipids.

Linoleate, linolenate, arachidonate, docosahexenoate and six other fatty acids were major components of 24 ester preparations fed as 5% of the diet for 60 days to groups of male white rats. The experiment was designed so as to provide that all major fatty acid components were independent of each other in the sense that the intake of each was poorly correlated with the intake of any of the others. Fatty acid compositions of liver lipids were determined and were related to the composition of the diet lipids. Linolenate and docosahexaenoate contents of diet and tissue revealed the same relationships reported previously from experiments in which individual pure acid esters were added to a fat-free diet. Linoleate, when fed in lipid mixtures, was more effective in raising the linoleate concentration in liver lipids than when fed alone, but this increase did not change the shape of the dose-response curve or the estimated nutritional requirement. Large amounts of fish oil in the diet tended to depress the arachidonate concentration in tissue lipids.

Growth, hemoglobin, cholesterol, and blood pressure observed in rats fed common breakfast cereals.

Most of the common breakfast cereals tested were unable to support growth or promote health in young rats that consumed these products as their only food. An anemia, accompanied by fatty liver and large concentrations of iron stored in the liver, was observed with cereals having the lowest protein content. Some cereals produced a marked elevation of systolic blood pressure at certain times. Low cholesterol levels were invariably associated with fatty livers, whereas high cholesterol levels seemed to be associated with hypertension at the 45-day period. When only the ready-to-eat cereals were considered, there was a positive correlation between the dietary zinc/copper ratio and the plasma cholesterol concentration.

Effect of dietary palmitate, stearate, oleate and linoleate on the tissue lipid and systolic blood pressure of the rat.

The nutritional effects of palmitate, stearate, oleate and linoleate were correlated with the percentage of each fatty acid in the dietary lipid but were found to be largely independent of the total amount of fat in the diet. Increasing the proportion of linoleate in diet fat to levels as high as 52% of the fat, increased theproportion of fat observed in the carcass. Increased linoleate and/or oleate resulted in increased concentrations of cholesterol in body fat deposits. The maximum weight of the perirenal fat pads occurred when diet fat contained about 43% oleate and 19% stearate. Increasing the stearate decreased the cholesterol concentration in plasma. The systolic blood pressure was decreased slightly when the amount of diet fat was increased.

Dietary effects of the esters of butyric, caproic, caprylic, capric, lauric, myristic, palmitic, and stearic acids on food intake, weight gain, plasma glucose, and tissue lipid in the male white rat.

Eight saturated fatty acid esters were fed to male white rats for 30 days in a 1/81 fractional factorial experiment in which diets contained 12-38% of their total energy as lipid. Marked increases in food intake, feed efficiency, and weight gain were achieved when lipid provided 36% of diet energy, and when that lipid was more than half caproate, caprate, myristate, and/or stearate. Caproate was the only saturated fatty acid to increase plasma glucose levels. The feeding of stearate or caprylate decreased plasma and liver cholesterol. Caprate increased liver fat. The short-chain fatty acids (butyrate to myristate) increased the concentration of fat in the carcass.

Hyperglycemic effect of amino compounds structurally related to caproate in rats.

The chronic feeding of small amounts (0.3-3% of diet weight) of certain amino derivatives of caproate resulted in hyperglycemia, an elevated glucose tolerance curve and, occasionally, glucosuria. Effective compounds included norleucine, norvaline, glutamate, epsilon-aminocaproate, methionine, and leucine.

Electrocortical activity characteristic of vitamin B6 deficiency in the rat.

Vitamin B6 deficiency is characterized by a variety of changes in the central nervous system. Weanling male white rats, fed different levels of pyridoxine for 60 days, showed consistent differences in both amplitude and frequency of their electrocortical activity. The more deficient animals displayed higher EEG voltages and a higher dominant frequency. These two effects were systematically related to pyridoxine intake and provided similar dose-response curves. The nutritional requirement for vitamin B6, as estimated from the EEG data, was in good agreement with that estimated from growth response data.