Effect of olive oil-fried sardine consumption on cholesterol content in the serum, lipoproteins, spleen and adipose tissue of hypercholesterolemic rats.

BACKGROUND: The information about the effect of fried-oily fish consumption on cholesterol metabolism is rather scarce. AIM: To test the effect of olive oil-fried sardine consumption on cholesterol content in the serum, lipoproteins, spleen and adipose tissue of hypercholesterolemic rats. METHODS: Hypercholesterolemia was induced for 3 weeks by a casein + olive diet containing cholesterol and bovine bile (COC). Rats were later switched for 2 weeks to diets containing casein + olive oil (CO), olive oil-fried sardines (S), and olive oil-fried sardines-cholesterol-bovine bile (SC) while one rat group continued on the COC diet. Cholesterol was determined in serum, lipoproteins, adipose tissue and spleen. RESULTS: The SC diet markedly blocked the hypercholesterolemic induction of the cholesterol-raising agents. Dietary cholesterol withdrawal decreased serum cholesterol levels, with the S diet inducing the highest decrease in serum and VLDL + LDL-cholesterol levels. Cholesterol withdrawal decreased spleen total cholesterol content and weight but the S diet was unable to reduce spleen cholesterol content (micromol/g) more than CO diet. Adipose tissue of S rats displayed the lowest cholesterol values. Cholesterol (mmol/g) of adipose tissue correlated very significantly with total serum cholesterol (r = 0.9225, p < 0.0001) and VLDL + LDL-cholesterol (r = 0.9313, p < 0.0001). CONCLUSIONS: Cholesterol in adipose tissue was very sensitive to variations in plasma cholesterol. Consumption of fried sardines interacts with cholesterol withdrawal, accelerating serum cholesterol normalization and reduction of cholesterol levels in adipose tissue.

Thermally oxidised sunflower-seed oil increases liver and serum peroxidation and modifies lipoprotein composition in rats.

Peroxidation of LDL and other lipoproteins is thought to play a central role in atherogenesis. Dietary thermally oxidised oils may increase atherogenic risk in consumers by increasing their oxidative status. The present paper compares the effects of two diets containing unused sunflower-seed oil (US) or sunflower-seed oil repeatedly used in frying (FS) (both 15 g/100 g diet) on weight gain, food efficiency ratio, serum lipid levels and lipoprotein composition, and the content of thiobarbituric acid-reactive substances (TBARS) in the liver, serum, and lipoproteins in growing Wistar rats. After sixty potato fryings the FS contained 27.7 g polar material/100 g oil and 16.6 g oligomers/100 g oil. The FS-fed rats had a significantly lower weight gain and food efficiency ratio. Liver-TBARS increased due to the consumption of the highly altered oil and showed a significant linear relationship (all r > 0.68; P < 0.002) with the ingestion of thermally oxidised compounds. Serum-, VLDL-, LDL- and HDL-TBARS were significantly higher in the FS-fed rats (all P < 0.001). Concentrations of serum total and non-esterified cholesterol and phospholipids were significantly higher in the FS-fed rats (P < 0.05, P < 0.05, and P < 0.001, respectively). Serum triacylglycerol concentrations did not vary between the two dietary groups. Total and esterified cholesterol and phospholipid levels increased significantly in the HDL fraction (P < 0.05, P < 0.05, and P < 0.001, respectively) of the FS-fed rats. HDL-cholesterol and HDL-phospholipids were significantly correlated with liver-TBARS (r > 0.747; P < 0.0001), VLDL-TBARS (r > 0.642; P < 0.003), LDL-TBARS (r > 0.475; P < 0.04), and HDL-TBARS (r > 0.787; P < 0.0001). The data suggest that the rat increases HDL as a protecting mechanism against the peroxidative stress induced by the consumption of a diet containing the thermally oxidised oil.

Mineral and vitamin status in elderly persons from Northwest Spain consuming an Atlantic variant of the Mediterranean diet.

AIM: To assess dietary intake and serum mineral and vitamin levels in elderly people from Northwest Spain consuming a Mediterranean diet, rich in vegetables, fruit, meat, fish, olive oil, dairy products and moderate in wine. METHODS: Cross-sectional observational study in four retirement homes. Forty-five men and 65 women participated. Dietary intake and serum calcium, magnesium, iron, retinol, alpha-tocopherol, albumin, cholesterol, glucose and hematological parameters were determined. RESULTS: Mean consumption of fruit plus vegetables was 600 g/day. Men consumed significantly more legumes, fruit, meat, and alcoholic beverages, but fewer vegetables than women. Women presented higher carbohydrate and lower alcohol energy contributions. Men consumed significantly more thiamin, niacin equivalents, riboflavin, retinol equivalents and iron. Vitamin D intake was 2.2 +/- 1.2 microg/day and folate intake was 204 +/- 47 microg/day without gender differences. Prevalence of anemia was 6.7% and that of high ferritin, 1.8%. Serum cholesterol and retinol were higher in women. Mean serum alpha-tocopherol/cholesterol ratio in the whole population was 6.3 +/- 2.3 mmol/mol without gender differences. CONCLUSION: This elderly population consumes an Atlantic-Mediterranean diet that appears, according to biochemical and hematological parameters, appropriate. However, more fatty fish and leafy green vegetables and the inclusion of fortified foods in the diet might optimize micronutrient status.

Fat and protein from olive oil-fried sardines interact to normalize serum lipoproteins and reduce liver lipids in hypercholesterolemic rats.

Fatty fish consumption has been recommended due to its high (n-3) PUFA content. However, an effect of its protein on serum lipids and lipoproteins has also been suggested. The present study was designed to determine the acceptability of diets containing sardines fried in olive oil or the fat extracted from those sardines and the normalization of serum lipids and lipoproteins, the hepatic lipid profile, and the fatty acid composition of the liver of growing Wistar rats fed these diets after dietary loading of cholesterol. Hypercholesterolemia was induced for 3 wk by feeding rats a casein/olive oil/cholesterol diet. Rats were then switched for 2 wk to cholesterol-free purified diets containing casein plus olive oil (CO), sardines fried in olive oil (S) and casein plus the fat extracted from sardines fried in olive oil (CSF). The S and CSF diets were well accepted by the rats. Withdrawal of dietary cholesterol markedly reduced (P < 0.05) serum cholesterol level in all of the groups, but the S group had the greatest decrease and the CO group the smallest decrease. The S group had a more normal lipoprotein profile, in which HDL was the major lipid carrier, whereas rats of the CO group still had beta-VLDL particles. CSF-fed rats had an intermediate profile. Liver fat and total, free and esterified cholesterol levels were lower (P < 0,05) in the S group than in the other two groups. The S and CSF diets increased (P < 0.05) the (n-3) PUFA content in hepatic triacylglyceride, cholesterol ester and phospholipid fractions. The liver fatty acid profile of the S group was more normalized than those of the other two groups. These findings suggest that the inclusion in the diet of whole sardines fried in olive oil normalizes cholesterol metabolism in hypercholesterolemic rats more quickly than consumption of their extracted fat.