There is much experimental but very limited clinical evidence that dietary restriction has a beneficial effect in reducing the incidence of naturally occurring and induced cancer formation. Restriction has also been suggested to be advantageous in other respects (Weindruch et al. 1986), including increasing longevity and improving the effectiveness of certain aspects of the immune system. The effect of dietary and caloric restriction on experimental carcinogenesis has been recognized for many years, the sentinel observations being due to Tannenbaum (1940a, 1942; Tannenbaum and Silverstone 1957). Many others have confirmed Tannenbaum’s initial observations (Andreou and Morgan 1981; White 1961; Ross and Bras 1973; Klurfeld et al. 1987). Information on the possible advantageous effect of dietary restriction in humans has proved much more elusive. Although Tannenbaum (1940b) obtained some evidence for a correlation between excessive body weight and cancer from human insurance records, further information has not been adequate to demonstrate this conclusively. In fact, there is a major controversy whether mammary and colonic tumorigenesis in humans is dependent on the high lipid content of the North American diet or on excess calories [National Academy of Sciences (USA) 1980, 1982].

ABSTRACTA more detailed pattern of the available carbohydrates in infant formulas, i.e., sugars, starch and total oligosaccharides (measured as oligosaccharide‐derived glucose) was obtained using ion‐moderated partition chromatography with fixed‐ion, resin‐based HPLC columns. Twenty‐five infant formula products were analyzed. Lactose, the main sugar in standard infant formula, was often associated with its non‐absorbed isomer, lactulose. Soy‐based formulas contained sucrose and many had substantial amounts of oligosaccharide‐derived glucose. Formulas for premature infants had less than half the lactose of standard formulas with oligosaccharide‐derived glucose supplying 35 to 57% total carbohydrate. Protein hydrolysate formulas had the highest amounts of starch.

Nutrition Research Division Food Directorate Health & Welfare Canada Banting Research Centre Tunney's Pasture Ottawa, Ontario K1A0L2 Canada

Weanling diabetes-prone BB rats were fed AIN-76 diets containing high (HE, 1 g/kg diet), basal (NE, 0.2 g/kg) or low (LE, trace) vitamin E and were killed at 21, 42 or 60 days of age. Plasma and tissues (adrenals, pancreas, spleen, thymus, liver, brown and white adipose tissue, muscle and testes) were analysed for vitamin E. Vitamin E levels reflected the level in the diet and no diabetic animals were detected at these times. In a second experiment, a total of 90 diabetes-prone BB rats were kept on diets LE and HE for 6 months or until they became diabetic. 11/45 on LE and 5/45 on HE became diabetic. Again, plasma and tissue levels of vitamin E reflected the levels in the diet with the exception of the thymus of diabetic rats fed the high vitamin E diet. Thymus vitamin E levels (microgram/g tissue) were 1.8 and 1.2 in LE-fed diabetics and asymptomatic rats, respectively; and 22.7 and 49.5 in HE-fed diabetics and asymptomatic rats, respectively. The last 2 values were significantly different (p less than 0.005). There were no other differences in plasma or tissue levels of vitamin E in these groups of animals. These findings suggest that high dietary vitamin E may decrease the incidence of diabetes in animals which are able to accumulate sufficient amounts of the vitamin in the thymus. Since the thymus plays a key role in the maturation of T cell populations, which appear to be altered in this disease, it seems possible that the protective effect may be exerted at this level.

1.1. Avian plasma was fractionated by sequential ammonium sulfate precipitation, and the carbohydrate composition of the fractions was determined and compared with fractions of porcine and bovine plasmas.2.2. The incorporation of radioactivity of labeled hexosamines into avian serum protein fractions, red blood cells and liver slices was investigated.3.3. Large differences in the degrees and patterns of association of radioactivity were found when labeled glucosamine, galactosamine and mannosamine were injected in fowl, or incubated with avian red cells or liver slices.4.4. The incorporation of labeled hexosamines by red blood cells in vitro may implicate these nucleated cells in glycoprotein synthesis.