Nutrition in the elderly.

Nutritional modulation is one approach to successful aging. In animals, dietary restriction increases life span. Alterations in the macronutrient and micronutrient constituent of the diet can modulate gene expression. Anorexia is common in elderly persons. The results of studies in animals suggest that aging is associated with a decrease in the opioid feeding drive and an increase in the satiating effect of cholecystokinin. Unrecognized depression is a common, treatable cause of anorexia and weight loss in elderly persons. Protein synthesis decreases in elderly persons; nevertheless, nitrogen balance can be maintained in patients with fairly low intakes of protein. Carbohydrate intolerance is common and may be modulated by nutritional intervention and physical activity. The role of cholesterol in the development of heart disease in very old persons is controversial. Homebound and institutionalized elderly persons often do not expose their skin to sunlight; because the skin of older persons has a decreased ability to form vitamin D, the vitamin D status in these persons is precarious and they are at risk for osteopenia. Vitamins are often abused by elderly persons. Drug administration alters the vitamin requirements of persons. Borderline zinc state has been associated with deteriorating immune function, especially in persons who have diabetes mellitus or who abuse alcohol. Zinc administration appears to protect against the deteriorating vision associated with age-related macular degeneration. Selenium deficiency seems to be associated with an increased prevalence of cancer.

Fish oil supplementation results in decreased hypertriglyceridemia in patients with psoriasis undergoing etretinate or acitretin therapy.

Although retinoid derivatives are an effective treatment for severe psoriasis, they result in systemic toxicity, including hyperlipidemia. In an attempt to reverse this retinoid-related hyperlipidemia in patients with psoriasis, a prospective 4-week pilot study of fish oil supplementation was carried out in 25 patients with psoriasis vulgaris receiving etretinate (Ro-10-9359) or acitretin (Ro 10-1670). Daily fish oil supplements containing 3 gm of omega-3 fatty acids (1.8 gm of eicosapentaenoic acid 20:5 omega 3, and 1.2 gm of docosahexaenoic acid 22:6 omega 3) were found to be effective in reducing hypertriglyceridemia, with a significant mean reduction from 215.6 +/- 92.5 to 156.9 +/- 58.5 mg/dl (-27%) when compared with controls (203.6 +/- 46.9 to 204.1 +/- 54.3 mg/dl). High-density lipoprotein cholesterol levels increased from 41.4 +/- 10.5 to 46.1 +/- 10.8 mg/dl (+11%), and the ratio of total cholesterol to high-density lipoprotein cholesterol decreased from 6.6 +/- 1.9 to 5.9 +/- 1.7 (-11%). It is concluded that fish oil supplementation may prove a valuable adjunct to ameliorate the lipid changes secondary to retinoids.

Sugar and sugar substitutes. Comparisons and indications.

Public confusion and concern about the use of sugar and sugar substitutes are widespread. Physicians must be prepared to answer patients' inquiries about these substances. Some population groups should avoid certain sugar substitutes. In particular, pregnant women and young children should avoid saccharin, and phenylketonuric homozygous persons should avoid aspartame. In a varied, balanced diet, the use of aspartame and saccharin is one safe way for the general population to enjoy sweet foods with fewer calories and less cariogenic potential. Sugar substitutes may be helpful in dietary compliance for overweight and diabetic patients.

Effect of trans fatty acids on serum lecithin: cholesterol acyltransferase in rats.

An investigation was undertaken to study the effect of trans isomers of octadecenoic (18:1) and octadecadienoic (18:2) acids on serum lecithin:cholesterol acyltransferase (LCAT). Male rats of the Wistar strain were fed diets containing 15% fat for 9 months. The fat diets were either hydrogenated fat mixtures containing trans fatty acids, corn oil or lard. At the end of 9 months, rats were killed and serum cholesterol levels and LCAT activity were measured. It was found that free and total serum cholesterol levels were decreased when animals were fed trans fatty acids when compared with animals fed corn oil or lard. Although in vitro studies indicated that the percentage of cholesterol esterified in serum was not affected by the presence of dietary trans fatty acids, LCAT activity generally decreased when trans fatty acids were fed to rats for 9 months. In this study a negative correlation was found between serum free cholesterol and LCAT activity. Depressed total LCAT activity (mumoles of cholesterol esterified per hour per liter of serum) may have been related to a reduced amount of substrate (free cholesterol).

Incorporation and disappearance of trans fatty acids in rat tissues.

An investigation was undertaken to study the rate of incorporation and disappearance of trans isomers of octadecenoic and octadecadienoic acids from different tissues of rats fed 15% fat diets containing trans fatty acids for 3 months. At the end of 3 months some of the animals were killed and the remaining animals were changed over to a diet containing only trace amounts of trans fatty acids. Thereafter, representative animals were killed at 2, 4, 8, and 12 weeks. The fatty acid composition of tissue lipids was measured by gas liquid chromatography. Trans octadecenoate was primarily incorporated into phospholipids and triglycerides of plasma, liver, kidney, heart, adipose tissue, and red blood cells. Trans isomers of octadecadienoate accumulated in triglycerides of plasma, liver, kidney, heart, and adipose tissue while only small amounts accumulated in tissue phospholipids and cholesteryl esters. After removal of trans fatty acids from the diet, the time of disappearance of trans isomers of octadecenoate and octadecadienoate from tissues varied. With the exception of adipose tissue, 8 weeks after the trans fatty acid diet was discontinued, only negligible amounts of trans fatty acids were present in rat tissues, demonstrating that tissues studied can metabolize trans fatty acids.

Effect of administration of alpha- and gamma-tocopherol on tissue distribution and red cell hemolysis in rats.

Four groups of rats fed a tocopherol-free diet from weaning were administered, orally, 1.5 mg/day of either alpha- or gamma-tocopherol for 12 weeks or 5 mg/day of these compounds for 6 weeks. The fifth group was continued on the tocopherol-free diet. At the end of the experimental period the concentration of the two tocopherols was measured in plasma, RBC, liver, kidney, heart, spleen, muscle, testes and lungs. At the lower dose levels alpha-tocopherol, but not gamma-tocopherol, protected the RBC from hemolysis. At the higher levels both compounds were effective in this respect. While liver and spleen appeared to be the preferred storage tissues for both alpha- and gamma-tocopherols, a considerable amount of these compounds were found in RBC, muscle, heart and lung. The content of alpha-tocopherol in the liver was significantly greater than that of gamma-tocopherol. Whether this difference is the reflection of preferential utilization of gamma-tocopherol remains to be determined. The other tissues showed a more or less equal accumulation of the two compounds. At the higher levels of supplementation with the tocopherols the accumulation of gamma-tocopherol in most tissues was significantly greater than that of alpha-tocopherol.

Effect of an oral contraceptive on alpha-tocopherol levels in rat tissues.

PIP: The distribution of alpha-tocopherol was studied in female rats receiving .052 mg/day Enovid E for 4 days, and maintained on Vitamin E deficient, adequate, or enriched (10%) diets. The administration of Enovid produced slight increases of alpha-tocopherol in the liver and ovaries of Vitamin-E-deficient animals, and decreases of alpha-tocopherol in the plasma, erythrocytes, adrenals, and kidneys of Vitamin-E-supplemented rats. The magnitude of response of different tissues varied with increasing levels of dietary tocopherol. The results support previous findings on the effects of oral contraceptives on plasma cholesterol levels and lipoprotein distribution.^ieng

An evaluation in rats of nutritional status and reproduction performance post oral contraceptive therapy.

Adult female rats were orally administered either 0.052, 0.26 mg of Enovoid E (OC) or the vehicle, propylene glycol. Thereafter they were mated six, thirteen or twenty-seven days after the discontinuation of the drug. Chemical analyses i.e. cholesterol levels in plasma, liver and adrenals; tocopherol levels in plasma and liver; fatty acid patterns of cholesteryl esters of plasma liver, and adrenals, and plasma lipoproteins distribution, were performed on the pre-breeding (post-OC) females, mothers (following weaning of the young) and young female progeny, 10 weeks after weaning. Weanlings derived from mothers previously exposed to OC weighed more than their counterparts from mothers who had not been given the drug. A slight decrease of the survival time of the young during lactation was also observed in groups treated with higher levels of OC. Liver weights were increased in mothers as a result of pregnancy and lactation. Observed elevations of plasma cholesterol levels and cholesteryl arachidonate in the livers of the progeny were probably due to prolonged exposure to the 15% corn oil diet. In addition, previously reported metabolic effects of OC, such as increases in liver cholesteryl oleate, decreases in plasma and adrenal cholesteryl arachidonate, decreases in the alpha/beta lipoprotein ratio and alpha-tocopherol levels in plasma were confirmed.

PIP: The effects of Enovid E on nutrition and reproductive function were studied after discontinuation of the drug in adult female rats. The ani mals received either .052 or .26 mg of Enovid, and were mated 6, 13, or 27 days after cessation of treatment. Post-Enovid females (prebreeding) , mothers, and female offspring (10 weeks after weaning) were examined for plasma, liver, and adrenal concentrations of cholesterol, plasma and liver tocopherol levels, plasma, liver and adrenal fatty acid patterns of cholesteryl esters, and the distribution of plasma lipoproteins. Weanlings of treated mothers weighed more than those whose mothers were not treated. The higher dose tended to slightly decrease survival time of the young during lactation. Pregnancy and lactation increased liver weights in mothers. Increases in plasma cholesterol levels and liver cholesteryl arachidonate concentrations were observed in the offspring. Increases in liver cholesteryl oleate, decreases in plasma and adrenal cholesteryl arachidonate, and decreases in the plasma alpha/beta lipoprotein ratio and plasma alpha-tocopherol levels were observed.

Effect of oral contraceptives on plasma lipoproteins, cholesterol and alpha-tocopherol levels in young women.

PIP: The effects of oral contraceptives (OC) on plasma lipoprotein, cholesterol, and alpha-tocopherol levels were studied in 400 women volunteers. OC use caused plasma cholesterol levels to increase by about 7% and tocopherol levels to decrease by about 20%. The changes in cholesterol and tocopherol levels were significantly greater in women receiving vitamin E supplements (p less than .03; p less than .04, respectively). Plasma alpha-lipoproteins increased by 16%, while beta-lipoprotein levels decreased by 20%, resulting in a 30% decrease in the alpha-beta ratio. OC use diminished the usually high correlation between tocopherol and beta-lipoproteins. Plasma triglyceride and total lipid levels were significantly increased among OC users (p less than .05). Since the most pronounced changes occurred in the early stages of OC treatment, an adaptation with time is suggested.^ieng