Food fortification to reduce vitamin A deficiency: International Vitamin A Consultative Group recommendations

In developed countries, food fortification has proven an effective and low-cost way to increase the micronutrient supply and reduce the consequences of micronutrient deficiencies. It has been rarely used in the developing world, but general conclusions can be drawn. The biological efficacy, but not the effectiveness, of fortifying oil and hydrogenated oil products as well as cereal flours and meals with vitamin A has been shown. Sugar has been fortified with vitamin A in Central American countries for years, and biological efficacy and program effectiveness are well established. Efficacy of fortifying monosodium glutamate with vitamin A was demonstrated but a program has not been established. Fortification with vitamin A in the developing world should satisfy certain elements for success. a) A potential food matrix (a food regularly consumed, produced by a few centralized factories, without sensorial changes compared with the nonfortified equivalent, and nutrient remains bioavailable and in a sufficient amount) is required. b) Fortified foods should provide at least 15% of the recommended daily intakes for the target group (e.g., individuals consuming the lowest amount of the fortified food). c) Voluntary fortification of processed foods should be regulated to prevent excessive consumption of vitamin A. d) Neighboring countries should harmonize technical standards, facilitate compliance and minimize conflicts over global trade laws. e) A practical monitoring system should be instituted. f) Social marketing activities should be permanent and aimed at industry, government and consumers. g) Food fortification should be combined with other strategies (e.g., supplementation) to reach those not adequately covered by fortification alone. Infants and small children, whose dietary habits differ from those of adults, require special attention. Fortification of food commodities is a very attractive and economic way to prevent and control vitamin A deficiency. Effective food fortification might make supplementation of postpartum women and older children unnecessary.

Dietary prenatal lipids affect myelin gene expression in postnatal undernourished rats

The effects on myelin gene expression of prenatal diets with a different lipid content and fatty acid composition were investigated in undernourished pups. Three groups of rats were fed ad libitum during gestation diets containing either 10% of margarine or 10% of microbial lipids or a standard diet containing 3.5% of lipids. After birth, all groups were switched to a reduced intake (60%) of the standard diet. A control group received ad libitum, the standard diet during pregnancy and throughout lactation. At birth no difference in body and brain weight was observed among the groups and the only significant difference in the brain fatty acid composition was the presence of odd-chain fatty acids in the group fed microbial lipids. Milk was removed from the stomach of pups at 1, 5 and 9 days of lactation for fatty acid analysis. During undernourishment, the monoenoic fatty acid and polyenoic fatty acid percentage was always higher and lower, respectively, in the groups fed 10% than in the group fed 3.5% of lipids during pregnancy. The expression of myelin genes at 11 days of undernutrition was determined in different brain regions by Northern analysis. In the standard group, the proteolipid protein and myelin oligodendrocyte glycoprotein transcripts were well detected only in the medulla whereas in groups fed 10% of lipids the transcripts were also visible in the cerebellum. These data suggest that the high lipid content of the prenatal diet independently from its fatty acid composition affects the myelin gene expression decreasing myelin susceptibility to postnatal undernutrition.

Short-term LDL cholesterol-lowering efficacy of plant stanol esters

BACKGROUND

The short-term cholesterol-lowering efficacy of plant stanol esters has been open to debate, and the data from different clinical studies with hypercholesterolemic subjects are variable, partly due to lack of systematic studies. Therefore, we investigated the time in days needed to obtain the full cholesterol-lowering effect of stanol esters in hypercholesterolemic subjects.

METHODS

Eleven mildly to moderately hypercholesterolemic subjects consumed stanol ester margarine (2.0 g/day of stanols) as a part of their habitual diet for 14 days and the changes in serum lipid values were measured three times at 4, 8 and 15 days after the initiation of test margarine consumption (0 day). The returning of serum lipid concentrations to baseline was measured two times after 2 or 3 days and after 7 days of the end of the test margarine consumption.

RESULTS

Serum LDL cholesterol concentrations were reduced from 0 day (4.51 +/- 0.66 mmol/l) by 3.5% (P = ns), 9.9% (p < 0.05) and 10.2% (P < 0.05) at 4, 8 and 15 days, respectively. Serum campesterol/total cholesterol ratio, an indirect marker of intestinal cholesterol absorption, was significantly reduced on day 4 already. After ending the stanol ester use serum cholesterol concentrations began to return rapidly and after 7 days serum LDL cholesterol was 5.3% less than the initial value (P = ns).

CONCLUSION

The specific effect of plant stanol esters on serum LDL cholesterol can fully be obtained within 1-2 weeks of the use of plant stanol ester-enriched margarine.

[Food phytosterol ester efficiency on the plasma lipid reduction in moderate hypercholesterolemic subjects]

OBJECTIVE

This study aimed at relating the pattern of response to dietary plant sterol ester (PSE) treatment of plasma lipids concentrations and apo E polymorphisms.

METHODS

Patients (20-60y old: 50 women; 10 men) with primary moderate hypercholesterolemia were fed margarine (20g/d), received no treatment (placebo), and were fed PSE (2.8g/d = 1.68 phytosterols), during 3 periods of 4 weeks each, in a crossover, double-blind study. DNA was extracted from white blood cells for the apo E polymorphisms.

RESULTS

PSE treatment significantly lowered TC and LDL-C 10% and 12%, respectively, in relation to the baseline, and 6% and 8% in relation to the placebo phase, but HDL-C and TG levels were not modified. In regard to the apo E genotyping, no significant difference occurred between apo E 3/3 and apo E (3/4).

CONCLUSION

Dietary plant sterol ester (PSE) treatment reduced cholesterolemia, and the reduction of LDL-C in absolute values was more pronounced when the initial LDL - C concentration were elevated.

The role of fats in the lifecycle stages. Adulthood--treatment: cholesterol-lowering with plant sterols

Margarines enriched with plant sterols are effective at lowering low-density lipoprotein (LDL) cholesterol levels when eaten as recommended. LDL-cholesterol level reductions of more than 10% are achieved in most people. Phytosterol-containing foods are valuable additions to other cholesterol-lowering treatments, including statins. They should be considered for all patients with increased cardiovascular risk factors in whom LDL reduction is desirable. The only recognised possible adverse effect is reduction in some carotenoids in plasma, but this can be overcome by eating an additional serving of a carotenoid-rich (yellow or orange) fruit or vegetable.

No changes in serum fat-soluble vitamin and carotenoid concentrations with the intake of plant sterol/stanol esters in the context of a controlled diet

Spreads enriched with plant sterol and stanol esters have been shown to possess similar cholesterol-lowering properties; however, their comparative capacity to alter circulating levels of other fat-soluble compounds has not been fully assessed. To compare actions of sterol and stanol ester consumption on serum fat-soluble vitamin and carotenoid concentrations, 15 hypercholesterolemic subjects were fed each of 3 fixed foods treatment diets over 21 days using a randomized crossover controlled design. Diets contained either (1) margarine (M), (2) margarine with sterol esters (MSE; 1.92 g/d), or (3) margarine with stanol esters (MSA; 1.76 g/d). No significant differences were found in initial or final serum fat-soluble vitamin and carotenoid concentrations among the 3 phases. Serum retinol and alpha- and gamma-tocopherol concentrations at baseline and endpoint and percentage changes relative to baseline for MSE and MSA were not significantly different from those of the M diet. After adjusting for total cholesterol reduction, no changes for alpha- and gamma-tocopherol were found. Serum vitamins D and K, lycopene, and lutein concentrations and percentage changes did not differ across diets. Serum concentrations at baseline and endpoint and percentage changes for alpha- and beta-cryptoxanthin and alpha- and gamma-carotene were not different among the diets, nor did serum alpha- and gamma-carotene concentrations to total cholesterol ratios differ. Serum lutein, beta-cryptoxanthin, and alpha-carotene concentrations increased over time. In conclusion, our results show no effect of consumption of esterified plant sterols or stanols on serum fat-soluble vitamin or carotenoid concentrations compared with a control diet.

Baseline intestinal absorption and synthesis of cholesterol regulate its response to hypolipidaemic treatments in coronary patients

Baseline cholesterol metabolism was hypothesized to regulate responses of cholesterol synthesis and absorption, and serum cholesterol lowering to hypolipidaemic treatment. Thus, serum cholesterol and non-cholesterol sterols were measured before and during long-term simvastatin treatment (inhibition of cholesterol synthesis) and subsequent combination of statin with plant stanol ester margarine (inhibition of cholesterol absorption) consumption in subjects with low (n=15) and high (n=15) absorption of cholesterol, defined by respective low and high baseline ratios of serum cholestanol to cholesterol. Cholesterol synthesis (defined by precursors of cholesterol) was markedly reduced by the long-term statin treatment in both groups, but more extensively in the low than high absorption group (P<0.05), yet the respective serum cholesterol reductions were similar. From among the absorption markers, sitosterol and cholestanol ratios were correspondingly increased more in the low than in the high absorption group. Plant stanol ester margarine consumption, combined with chronic statin treatment, further lowered the serum cholesterol level (P<0.001) only in the high absorption group. The sum of cholesterol absorption markers was reduced more (P<0.05) in the high than in the low absorption group, while the non-significant serum cholesterol reduction of the low absorption group was associated with relatively high increase of cholesterol synthesis. Thus, stanol ester margarine combined with chronic simvastatin treatment reduces cholesterol absorption and serum cholesterol more consistently in subjects with high than low baseline absorption of cholesterol. The profile of baseline cholesterol metabolism determines the changes in synthesis and absorption of cholesterol to hypolipidaemic treatments, but affects less differently serum cholesterol level.

Effects of phytosterol ester-enriched margarine on plasma lipoproteins in mild to moderate hypercholesterolemia are related to basal cholesterol and fat intake

Dietary phytosterols have been reported to lower total and low-density lipoprotein (LDL) cholesterol. However, less is known about the influence of cholesterol and fat intake on the cholesterol-lowering effect of esterified phytosterols in mild to moderate hypercholesterolemia. Sixty-three healthy subjects (38 women, 25 men, 42 +/- 11 years, LDL cholesterol > 130 mg/dL) were investigated in a randomized, double-blind, placebo-controlled, cross-over study. A total of 20 g/d of a phytosterol ester-enriched margarine (1.82 g/d of phytosterols) was compared with a control margarine (0.06 g/d of phytosterols). After 3 weeks of intake, participants crossed over to the other margarine. A 3-day dietary recall was performed at the beginning and at the end of the study to assess cholesterol, fat, and energy intake. Phytosterol ester-enriched margarine significantly changed total cholesterol (-3.4%, P <.005), LDL cholesterol (-5.4%, P <.001, 144 +/- 28 v 154 +/- 26 mg/dL), high-density lipoprotein (HDL) cholesterol (+3.4%, P <.05), apolipoprotein B (-4.0%, P <.005), and LDL/HDL cholesterol ratio (-7.8%, P <.001) compared with the control margarine. In the tertiles with the highest dietary intake of cholesterol, energy, total fat, and saturated fatty acids, and with the highest baseline proportion of campesterol to cholesterol, LDL cholesterol reduction was 11.6% (P <.001), 9.5% (P =.001), 9.4% (P =.001), 8.4% (P =.005), and 6.2% (P =.014), respectively. Triglycerides, plasma viscosity, and fibrinogen concentration did not change significantly. The improvements of LDL, HDL, total cholesterol, apolipoprotein B concentrations, and LDL/HDL cholesterol ratio during the daily consumption of a phytosterol ester-enriched margarine were most marked in those subjects with a high dietary intake of cholesterol, energy, total fat, and saturated fatty acids and with high baseline cholesterol absorption.

Enrichment of spreadable fats with polyunsaturated fatty acids omega-3 using fish oil

Polyunsaturated fatty acids of the omega-3 series, especially very long chain--eicosapenta- and docosahexaenoic acid (EPA, DHA)--exert a strongly desirable influence on health. However, their intake with the western-style diet is usually too low which favours development of many diseases (CVD, cancers, allergies, etc.). Nowadays elevation of EPA and DHA intake is commonly recommended, but almost the only dietary source of them is seafoods, especially fish. A new way to increase the intake of long-chain omega-3 without radical changes of eating patterns is enrichment of regularly consumed foods with unhydrogenated fish oil. The aim of this study was to establish sensory and nutritionally acceptable enrichment level of low-calorie spreadable fats (soft margarine and mix of butter and vegetable oil) with EPA and DHA by addition of fish oil preparations (ROPUFA--30% EPA, DHA and MARITEX--10%), and evaluation of the stability of enriched spreads during storage (sensory and chemical). It was shown that tested spreadable fats might be enriched up to 1% EPA, DHA (i.e. 3% ROPUFA, 8% MARITEX), and that this had no significant influence on sensory acceptability. Both used fish oils which exerted similar influence on the quality of fats. An enriched mix of butter and vegetable oil and margarine may be stored up to 3 and 6 weeks respectively without significant decrease of quality. Peroxide value and acid numbers were not much affected by enrichment and storage. Daily portion (25-30 g/day) of spreadable fats enriched on the level established in the study may provide 0.2-0.3 g EPA, DHA, significantly increasing the amount of long-chain omega-3 in the diet above those eaten normally.

Hydrogenated fat consumption affects acylation-stimulating protein levels and cholesterol esterification rates in moderately hypercholesterolemic women

To determine whether hydrogenated fat consumption alters triglyceride metabolism and cholesterol esterification rates, 14 women (65-71 years of age) were provided with each of four diets for 5-week periods according to a randomized cross-over design. The experimental diets contained either soybean oil (SO), low trans squeeze (SQM), medium trans tub (TM), or high trans stick (SM) margarines. Triglyceride uptake by adipose tissue was determined by measuring plasma acylation-stimulating protein (ASP), FFA, glucose, and insulin levels, while rates of transfer and esterification rate of newly synthesized cholesterol (ER) were derived by using plasma CETP levels and the deuterium incorporation methodology. Plasma ASP levels were lowest (P < 0.05) in subjects on the SM diet (33.4 +/- 12.7 nM) compared with the SO (48.7 +/- 17.0 nM) and SQM (50.7 +/- 15.7 nM) diets. Conversely, FFA were highest (P < 0.05) on the SM diet (0.86 +/- 0.45 mM) relative to all the other diets. No differences were observed in plasma glucose and insulin levels among diets. A trend toward higher CETP levels after consumption of the SM diet was observed. However, the ER was lowest (P < 0.05) after the SM (0.111 +/- 0.062 g x day(-1)) diet and highest after consumption of the SQM (0.216 +/- 0.123 g x day(-1)) diet. In addition, ASP levels were negatively correlated with FFA (r = -0.63, P < 0.05), LDL cholesterol (r = -0.56, P < 0.05), and TG (r = -0.41, P < 0.05), whereas FFA was positively correlated with apolipoprotein B-containing lipoproteins (r = 0.58 and 0.47, for VLDL and LDL cholesterol, P < 0.05), and negatively correlated with HDL cholesterol (r = -0.51, P < 0.05). The ER was found to positively correlate with HDL cholesterol and HDL2 subfraction (r = 0.53 and 0.45, respectively, P < 0.05). Taken together, these data demonstrate that the alterations in circulating lipid levels, commonly observed with consumption of hydrogenated fat-rich diets, can be explained in part by changes in ASP activity as well as newly synthesized cholesterol ER.

Oral stimulation influences postprandial triacylglycerol concentrations in humans: nutrient specificity

OBJECTIVE

To determined whether the nature of the lipid in an oral stimulus modifies postprandial triacylglycerolemia.

METHODS

Sixteen healthy adults (eight male, eight female) participated in six test sessions conducted weekly. The test sessions were administered randomly after overnight fasts and included: ingestion of 50 grams of butter in capsules (to avoid oral stimulation with lipids) and 500 mL of water in 15 minutes followed by oral stimulation with one of the following foods on a cracker: butter, unsaturated fatty acid (UFA) margarine, jelly, UFA margarine + jelly, cracker alone or no oral stimulation. Sensory stimulation entailed masticating and expectorating approximately 5.0 g samples of each stimulus every three minutes for 110 minutes. Blood was drawn immediately after preload ingestion and at minutes 35, 85, 200, 320, and 440 post loading and analyzed for serum triacylglycerol (TAG), insulin and glucose concentrations.

RESULTS

Only the oral samples containing the UFA margarine led to significant elevations of serum TAG concentration compared to baseline (p < 0.05). Maximum change of TAG concentrations were greater following orosensory stimulation with UFA margarine compared to orosensory stimulation with butter, jelly or UFA margarine + jelly. No differences were observed relative to vehicle alone or no orosensory stimulation, but this is due to lower nadir values for these treatments. Insulin and glucose concentrations were not different between treatments.

CONCLUSION

Oral exposure specifically to an unsaturated dietary lipid augments the postprandial rise of TAG, compared to baseline.

Phenolic extracts from meadowsweet and hawthorn flowers have antioxidative properties

From the flowers of meadowsweet and inflorescence of hawthorn the whole set of phenolic acids and flavonoids was analysed by TLC. Phenolic compounds were determined both as free ones and those liberated by hydrolysis. Moreover, ethyl ether and ethyl acetate extracts obtained from the analysed plants before and after alkaline and enzymatic hydrolyses were evaporated under reduced pressure and residues were analysed for their antioxidative properties. The weakest antioxidative activity was observed with the remaining residue after evaporation of ethyl ether extract obtained from enzymatically (beta-glucosidase) hydrolysed hawthorn inflorescence water extract. The strongest antioxidative activity was noticed with the remaining residues after evaporation of ethyl ether extracts obtained from non-hydrolysed and hydrolysed in alkaline conditions of meadowsweet flower water extracts. The residues from meadowsweet flowers exhibited stronger antioxidative properties than residues obtained from hawthorn inflorescence and can be recommended as margarine preservatives.

Lipid responses to plant-sterol-enriched reduced-fat spreads incorporated into a National Cholesterol Education Program Step I diet

BACKGROUND

Plant sterol esters reduce cholesterol absorption and lower circulating blood cholesterol concentrations when incorporated into the habitual diet.

OBJECTIVE

This randomized, double-blind, 3-group parallel, controlled study evaluated the influence of esterified plant sterols on serum lipid concentrations in adults with mild-to-moderate primary hypercholesterolemia.

DESIGN

Subjects incorporated a conventional 50%-fat spread into a National Cholesterol Education Program Step I diet for a 4-wk lead-in period, followed by a 5-wk intervention period of the diet plus either a control reduced-fat spread (40% fat; n = 92) or a reduced-fat spread enriched with plant sterol esters to achieve intakes of 1.1 g/d (n = 92; low-sterol group) or 2.2 g/d (n = 40; high-sterol group).

RESULTS

Subjects in the low- and high-sterol groups who consumed > or = 80% of the scheduled servings (per-protocol analyses) had total cholesterol values that were 5.2% and 6.6% lower, LDL-cholesterol values that were 7.6% and 8.1% lower, apolipoprotein B values that were 6.2% and 8.4% lower, and ratios of total to HDL cholesterol that were 5.9% and 8.1% lower, respectively, than values for the control group (P < 0.001 for all). Additionally, triacylglycerol concentrations decreased by 10.4% in the high-sterol group. Serum concentrations of fat-soluble vitamins and carotenoids were generally within reference ranges at baseline and postintervention. Serum plant sterol concentrations increased from baseline (0.48% of total sterol by wt) to 0.64% and 0.71% by wt for the low- and high-sterol groups, respectively (P < 0.05 compared with control).

CONCLUSION

A reduced-fat spread containing plant sterol esters incorporated into a low-fat diet is a beneficial adjunct in the dietary management of hypercholesterolemia.

Plant sterol-enriched margarine lowers plasma LDL in hyperlipidemic subjects with low cholesterol intake: effect of fibrate treatment

Phytosterols, found in fat-soluble fractions of plants, chemically resemble cholesterol and inhibit cholesterol absorption in the small intestine. Phytosterol consumption in human subjects reduces plasma total and low density lipoprotein-cholesterol (LDL-C) levels. The primary aim of this study was to determine the efficacy of a low-fat spread enriched with plant sterols in reducing total and LDL-C concentrations in primary hypercholesterolemia. The secondary objective was to evaluate whether patients receiving a lipid-lowering drug (fibrate) might differ in their response to plant sterols. The study was a randomized, double-blind, placebo-controlled two-period cross-over trial with two treatments and three periods. Both treatment periods lasted 2 months, with a washout period (2 months) between them. Spread enriched with plant sterols was compared to non-enriched control spread. Fortified fat spread provided 1.6 g/day of plant sterols derived from edible vegetable oils and fatty acids from sunflower seed oil. The plant sterol content consisted of sitosterol esters (50%), campesterol esters (25%), stigmasterol esters (20%) and 10% of other esters. Data in 53 hypercholesterolemic patients (31 females and 22 males) who completed the study were as follows: patients were 58+/-12 years of age with mean body mass index 23.5+/-2.8 kg/m2 (mean+/-SD). No adverse side-effects of the diet were reported. Plasma total cholesterol and LDL-C concentrations were significantly reduced by 6.4% and 8.8%, respectively, after using the spread enriched in plant sterols, as compared to controls (0.0% and 1.3%, respectively). No effect on high density lipoprotein-cholesterol (HDL-C) and lipoprotein(a) concentrations was detected. When subjects were divided in two subgroups according to fibrate treatment, supplementation with phytosterols decreased plasma cholesterol and LDL-C by 8.5% and 11.1%, respectively in the subgroup of patients treated with fibrates. In the group of patients who did not receive fibrates, consumption of plant sterol margarine reduced plasma cholesterol and LDL-C by 5.5% and 7.7%, respectively. Spread enriched with plant sterol esters significantly lowers blood total and LDL-C levels without affecting HDL-C concentrations, in a hypercholesterolemic population following a strict low cholesterol diet (NCEP step1). In addition, a combination of fibrate treatment and plant sterol ester-supplemented spread offers a safe and effective measure to significantly decrease abnormally high cholesterol levels. We conclude that phytosterol-enriched spread is a useful adjunctive therapy for hypercholesterolemic patients.

Replacement of dietary saturated fatty acids by trans fatty acids lowers serum HDL cholesterol and impairs endothelial function in healthy men and women

We tested whether trans fatty acids and saturated fatty acids had different effects on flow-mediated vasodilation (FMD), a risk marker of coronary heart disease (CHD). Consumption of trans fatty acids is related to increased risk of CHD, probably through effects on lipoproteins. Trans fatty acids differ from most saturated fatty acids because they decrease serum high-density lipoprotein (HDL) cholesterol, and this may increase the risk of CHD. We fed 29 volunteers 2 controlled diets in a 2x4-week randomized crossover design. The "Trans-diet" contained 9.2 energy percent of trans fatty acids; these were replaced by saturated fatty acids in the "Sat-diet." Mean serum HDL cholesterol after the Trans-diet was 0.39 mmol/L (14.8 mg/dL), or 21% lower than after the Sat-diet (95% CI 0.28 to 0.50 mmol/L). Serum low density lipoprotein and triglyceride concentrations were stable. FMD+SD was 4.4+/-2.3% after the Trans-diet and 6.2+/-3.0% after the Sat-diet (difference -1.8%, 95% CI -3.2 to -0.4). Replacement of dietary saturated fatty acids by trans fatty acids impaired FMD of the brachial artery, which suggests increased risk of CHD. Further studies are needed to test whether the decrease in serum HDL cholesterol caused the impairment of FMD.

Dietary plant sterols alter the serum plant sterol concentration but not the cholesterol precursor sterol concentrations in young children (the STRIP Study). Special Turku Coronary Risk Factor Intervention Project

Plant sterol supplementation reduces serum cholesterol concentration but may increase serum plant sterol concentrations, especially in children. We determined whether natural dietary plant sterols derived mainly from vegetable oil or margarine in early childhood affect serum concentrations of plant sterols (campesterol and sitosterol) and cholesterol precursor sterols (Delta-8 cholestenol, desmosterol, and lathosterol), reflecting endogenous cholesterol synthesis. We measured the serum sterol concentrations using gas liquid chromatography in 20 healthy 13-mo-old intervention children in a randomized, prospective study designed to decrease exposure of the children to known environmental atherosclerosis risk factors and in 20 control children. The diet of the intervention children was rich in plant sterols due to replacement of milk fat with vegetable fat, whereas the diet of the control children contained only small amounts of plant sterols. The intervention children consumed twice as much plant sterols as the control children (P < 0.001). Their serum concentrations of campesterol and sitosterol were 75% and 44% higher, respectively, than those in the control children (P < 0.001 for both), but serum cholesterol precursor sterol concentrations did not differ between the two groups. We conclude that doubling dietary plant sterol intake almost doubles serum plant sterol concentrations in 13-mo-old children, but has no effect on endogenous cholesterol synthesis. Relative intestinal absorption of natural plant sterols from the diet in early childhood is similar to that in adults.

The role of n-6 polyunsaturated fat in stable asthmatics

We investigated in a clinical setting whether increased intake of linoleic acid alters respiratory function in 26 mild asthmatics. Subjects completed a 16-week-dietary intervention comprising 8 weeks eating an enriched n-6 polyunsaturated fat diet (9.2% energy from linoleic acid) and consuming either a high monounsaturated or saturated fat diet in a random cross-over resign for 8 weeks. Neither FEV1 nor PC20 values changed significantly after increased linoleic acid consumption when compared with the other diets. Increased consumption of linoleic acid caused a 20% rise (p < or = 0.01) in plasma linoleic acid, a 38% decrease (p < or = 0.01) in plasma eicosapentaenoic acid, but no change in arachidonic acid. There were no changes in symptom scores or bronchodilator use.

Randomised controlled trial of use by hypercholesterolaemic patients of a vegetable oil sterol-enriched fat spread

Plant sterols may be a useful additive therapy in the treatment of hypercholesterolaemic patients. The purpose of this study was to determine the effect of a fat spread enriched with vegetable oil sterols on plasma lipid, lipoprotein and apolipoprotein concentrations. A randomised double blind placebo-controlled crossover trial with two consecutive periods of 8 weeks was conducted. 30 patients with heterozygous familial hypercholesterolaemia treated concurrently with an HMG-CoA reductase inhibitor (statin) and 32 patients with type IIa primary hypercholesterolaemia with a total cholesterol concentration >6.5 mmol/l not taking lipid-lowering drug therapy were recruited from a hospital lipid clinic. The active treatment was a fortified fat spread (25 g/day) providing 2.5 g of plant sterols. The control spread was indistinguishable in taste and appearance. Comparison at the end of the two 8-week trial periods showed a statistically significant reduction in total and LDL-cholesterol with use of the fortified spread but the results were confounded by a carry-over effect, which was partly explained by changes in the background diet. Because a carry-over effect was present, further analyses were restricted to the parallel arms of the first treatment period and were conducted on an intention to treat basis. After 4 weeks, LDL-cholesterol had decreased by 0.04 mmol/l ([0.8%] 95% confidence interval -0.44-0.37 NS) in the placebo group and decreased by -0.76 mmol/l ([15.0%] 95% CI -1.03--0.48, P<0.0001) in the active treatment group. After 8 weeks, the corresponding results were 0.0 mmol/l ([0.0%] 95% CI -0.26-0.24 NS) and -0.51 mmol/l ([10.0%] 95% CI -0.73--0.29 P<0.0001). There were no significant changes in apolipoprotein AI or B concentrations in the placebo group, but there was a small but statistically significant increase in apolipoprotein AI and a decrease in apolipoprotein B in the active treatment group. HDL cholesterol and triglyceride concentrations were unchanged. There was no difference in response between patients with statin-treated familial hypercholesterolaemia and patients with type IIa hyperlipoproteinaemia. We conclude that a fortified fat spread enriched with vegetable oil sterols reduces LDL-cholesterol by 10-15% with no difference in response between hypercholesterolaemic patients prescribed statins and those not taking lipid-lowering drug therapy.

Effects of diets enriched with two different plant stanol ester mixtures on plasma ubiquinol-10 and fat-soluble antioxidant concentrations

Plant stanols lower intestinal cholesterol absorption. This causes a decrease in serum low-density lipoprotein (LDL)-cholesterol, despite a compensatory increase in cholesterol synthesis. We therefore hypothesized that plant stanols also change LDL-cholesterol-standardized concentrations of ubiquinol-10 (a side product of the cholesterol synthesis cascade) and of those fat-soluble antioxidants that are mainly carried by LDL. To examine this, 112 nonhypercholesterolemic subjects consumed low erucic acid rapeseed oil (LEAR)-based margarine and shortening for 4 weeks. For the next 8 weeks, 42 subjects consumed the same products, while the other subjects received products with vegetable oil-based stanols (2.6 g sitostanol plus 1.2 g campestanol daily, n = 36) or wood-based stanols (3.7 g sitostanol plus 0.3 g campestanol daily, n = 34). Consumption of both plant stanol ester mixtures increased cholesterol synthesis and lowered cholesterol absorption, as indicated by increased serum cholesterol-standardized lathosterol and decreased plant sterol concentrations, respectively. Compared with the control group, absolute plasma ubiquinol-10 concentrations were lowered by 12.3% +/- 18.9% (-0.14 microg/mL v. the control group; P =.004; 95% confidence interval [CI] for the difference in changes, -0.05 to -0.22 microg/mL) in the vegetable oil-based group and by 15.4% +/- 13.0% (-0.17 microg/mL v. the control group; P <.001; 95% CI for the difference, -0.08 to -0.27 microg/mL) in the wood-based group. Changes in LDL-cholesterol-standardized ubiquinol-10 concentrations were not significantly changed. The most lipophylic antioxidants, the hydrocarbon carotenoids (beta-carotene, alpha-carotene, and lycopene), decreased most, followed by the less lipophylic oxygenated carotenoids (lutein/zeaxanthin and beta-cryptoxanthin) and the tocopherols. These reductions were related to the reduction in LDL, which carry most of these antioxidants. The decrease in the hydrocarbon carotenoids, however, was also significantly associated with a decrease in cholesterol absorption. LDL-cholesterol-standardized antioxidant concentrations were not changed, except for beta-carotene, which was still, although not significantly, lowered by about 10%. We conclude that the increase in endogenous cholesterol synthesis during plant stanol ester consumption does not result in increased LDL-cholesterol-standardized concentrations of ubiquinol-10, a side product of the cholesterol synthesis cascade. Furthermore, decreases in absolute fat-soluble antioxidant concentrations are related to decreases in LDL-cholesterol. However, for the most lipophylic carotenoids, some of the reduction was also related to the decrease in cholesterol absorption.

Cholesterol-lowering effect of spreads enriched with microcrystalline plant sterols in hypercholesterolemic subjects

BACKGROUND

Plant sterols have been shown to reduce serum lipid concentrations. The effectiveness is highly dependent on the physical state of the plant sterols. By means of a new crystallizing method, plant sterols can be added into dietary fats and oils homogeneously. In this fat ingredient, plant sterols are in a microcrystalline form.

AIMS OF THE STUDY

We investigated the cholesterol-lowering effect and possible side effects of vegetable oil-based spreads fortified with two different doses of microcrystalline plant sterols.

METHODS

This double-blind randomized, placebo-controlled study consisted of a 6-wk run-in and a 6-month experimental period. During the run-in period, all 155 hypercholesterolemic subjects received rapeseed oil-based control spread. In the beginning of the experimental period subjects were randomly assigned into one of three experimental groups. The control group continued to use control spread, and the two test groups used spreads with added plant sterols of either 1.5 g/d or 3.0 g/d. The subjects consumed test spreads as a part of their normal diet without any restrictions in lifestyle and diet.

RESULTS

Plasma total- and LDL-cholesterol concentrations were significantly reduced by 7.5-11.6% (0.46-0.62 mmol/1) in groups consuming margarine enriched with free plant sterols, compared with the control group. The effects were similar between the two groups consuming either 1.5g or 3.0 g plant sterols per day. No effect on HDL-cholesterol or triacylglycerol concentrations occurred. The test spreads did not induce any adverse effects in blood clinical chemistry, hematology or decreases in serum concentrations of lipid soluble vitamins.

CONCLUSIONS

Microcrystalline plant sterols are effective in lowering serum total- and LDL-cholesterol concentrations without obvious side effects. The daily dose of 1.5 g plant sterols is enough to reach the maximum effect.