Wheat germ policosanol failed to lower plasma cholesterol in subjects with normal to mildly elevated cholesterol concentrations

Wheat germ supplementation has modest effects on gut health markers but improves glucose homeostasis markers in adults classified as overweight: A randomized controlled pilot study

Wheat germ (WG), a by-product of flour milling, is rich in bioactive substances that may help improve health complications associated with increased adiposity. This study investigated the effects of WG on gut health, metabolic, and inflammatory markers in adults classified as overweight. We hypothesized that WG, because of its many bioactive components, would improve gut health and metabolic, and inflammatory markers in overweight adults. Forty adults (18-45 years old) and with a body mass index between 25 and 30 kg/m2 participated in this single-blinded randomized controlled pilot study. Participants consumed the study supplements containing 30 g of either cornmeal (control, CL) or WG daily for 4 weeks. Primary outcome variables were gut health markers including gut microbiota, gut integrity markers, and fecal short-chain fatty acids, whereas secondary outcome variables included metabolic and inflammatory parameters assessed at baseline and at the end of supplementation. Thirty-nine participants (n = 19 and 20 for CL and WG group, respectively) completed the study. The genus Faecalibacterium was significantly higher in the WG group compared to CL post-supplementation but no significant changes in other gut health markers, short-chain fatty acids, inflammatory markers, and lipid profiles were observed. Compared with baseline, WG improved markers of glucose homeostasis including insulin (P = .02), homeostatic model assessment of insulin resistance (P = .03), glycated hemoglobin (P = .07), and the pro-inflammatory adipokine, resistin (P = .04). However, these parameters after intervention were not different with control. Our findings suggest that WG supplementation have modest effects on gut health but may provide an economical option for individuals to improve glycemic control.

Cuban Policosanol (Raydel®) Exerts Higher Antioxidant and Anti-Glycation Activities than Chinese Policosanol (BOC Sciences) in Reconstituted High-Density Lipoproteins: In Vivo Anti-Inflammatory Activities in Zebrafish and Its Embryos

The present study compares sugarcane-wax purified policosanols sourced from Cuba (Raydel®) and China (BOC Sciences) and utilized following the synthesis of reconstituted high-density lipoproteins (rHDL). The two policosanols exhibited distinctly different ingredient ratios of long-chain aliphatic alcohols, particularly 1-octacosanol (C28) and 1-tetratriacotanol (C34). After synthesizing rHDL with apolipoprotein A-I (apoA-I), the two policosanols bound well with phospholipid and apoA-I to form the discoidal rHDL. Notably, rHDL-1, containing Cuban policosanol, displayed the largest particle diameter at approximately 78 ± 3 nm. In contrast, both control rHDL (rHDL-0) and rHDL containing Chinese policosanol (rHDL-2) exhibited smaller particles, with diameters of approximately 58 ± 3 nm and 61 ± 2 nm, respectively. Furthermore, rHDL-1 demonstrated enhanced anti-glycation activity, safeguarding apoA-I from degradation within HDL, and displayed the antioxidant ability to inhibit LDL oxidation. A microinjection of each rHDL into zebrafish embryos in the presence of carboxymethyllysine (CML) revealed rHDL-1 to have the strongest antioxidant activity with the highest embryo survivability and normal developmental morphology. Dermal application to recover the wound revealed rHDL-1 to have the highest wound-healing activity (75%) and survivability (92%) in the cutaneous wound area in the presence of CML. In adult zebrafish, injecting CML (250 μg) caused acute death and hyperinflammation, marked by heightened neutrophil infiltration and interleukin (IL)-6 production in liver. However, co-administering rHDL-1 notably increased survival (85%) and exhibited strong anti-inflammatory properties, reducing IL-6 production while improving the blood lipid profile. However, a co-injection of rHDL-2 resulted in the lowest survivability (47%) with more hepatic inflammation. In conclusion, Cuban policosanol (Raydel®) has more desirable properties for the in vitro synthesis of rHDL with stronger anti-glycation and antioxidant activities than those of Chinese policosanol (BOC Sciences). Moreover, Raydel-policosanol-integrated rHDL demonstrates a noteworthy effect on accelerated wound healing and robust anti-inflammatory properties, leading to increased survivability in zebrafish embryos and adults by effectively suppressing CML-induced hyperinflammation.

What is the influence of policosanol supplementation on liver enzymes? A systematic review and dose-response meta-analysis of randomized controlled trials

OBJECTIVE

Policosanol is a mixture of long chain alcohols refined from sugar cane. Significant reductions in liver enzymes have been observed in some studies. However, the impact of policosanol on liver enzymes remained controversial. The current meta-analysis aims to evaluate the effect of policosanol supplementation on the levels of alanine transaminase (ALT) and aspartate transaminase (AST).

METHODS

The literature was systematically searched for studies published up to November 2023 in PubMed/Medline, Google Scholar, EMBASE, and Scopus. Randomized controlled trial (RCT) studies were included to evaluate the intervention effect of policosanol compared to placebo on ALT and AST. DerSimonian and Laird models were used to calculate effect sizes.

RESULTS

Twenty-three trials including 2535 participants were included in the study. The combination of effect sizes, regarding the random-effects model, demonstrated significant changes in ALT serum levels after intervention (WMD: -1.48 U/L; 95% CI: -2.33 to -0.64; P = 0.001), and AST (WMD: -1.10 U/L; 95% CI: -1.70 to -0.51; P < 0.001). Subgroup analysis of AST and ALT showed that this reduction effect was most often observed at the dose of 20 mg/d. The dose-response analysis represented a non-significant non-linear connection between the dosage and duration of policosanol intervention in ALT and AST serum reduction.

CONCLUSION

Policosanol supplementation exerts a beneficial effect on liver enzymes as well as ALT and AST concentrations in adults. However, further long-term and well-designed RCTs with better quality are needed to further assess and confirm these results.

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet (MedD). In this narrative review, we synthesize and illustrate the various characteristics and clinical applications of EVOO and its components—such as oleic acid, hydroxytyrosol, and oleuropein—in the field of clinical nutrition and dietetics. The evidence is split into diet therapy, oleic acid-based enteral nutrition formulations and oral supplementation formulations, oleic acid-based parenteral nutrition, and nutraceutical supplementation of minor components of EVOO. EVOO has diverse beneficial health properties, and current evidence supports the use of whole EVOO in diet therapy and the supplementation of its minor components to improve cardiovascular health, lipoprotein metabolism, and diabetes mellitus in clinical nutrition. Nevertheless, more intervention studies in humans are needed to chisel specific recommendations for its therapeutic use through different formulations in other specific diseases and clinical populations.

Antioxidant Effect of Wheat Germ Extracts and Their Antilipidemic Effect in Palmitic Acid-Induced Steatosis in HepG2 and 3T3-L1 Cells

Wheat germ (WG) is a by-product of wheat milling and comprises many bioactive compounds. This study aimed to compare the antioxidant and antilipidemic effects of different WG extracts (WGEs) by analyzing candidate bioactive compounds such as carotenoids, tocopherols, γ-oryzanol, and biogenic amines by reversed-phase high-performance liquid chromatography. Antioxidant activity was determined using the ABTS, DPPH, and FRAP assays. The antilipidemic effect was evaluated in palmitic acid-induced steatosis in HepG2 hepatocytes and 3T3-L1 adipocytes. Cellular lipid accumulation was assessed by Oil Red O staining and a cellular triglyceride content assay. All analyzed WGEs showed significant antioxidant potential, although some bioactive compounds, such as carotenoids, tocopherols, and γ-oryzanol, were the highest in the ethanol extract. Correlation analysis revealed the antioxidant potential of all identified biogenic amines except for spermidine. Ethanol and n-hexane extracts significantly inhibited cellular lipid accumulation in cell models. These results suggest that WGEs exhibit promising antioxidant potential, with a variety of bioactive compounds. Collectively, the findings of this study suggest that bioactive compounds in WGEs attenuate plasma lipid and oxidation levels. In conclusion, WG can be used as a natural antioxidant and nutraceutical using appropriate solvents and extraction methods.

Effect of policosanol from insect wax on amyloid β-peptide-induced toxicity in a transgenic Caenorhabditis elegans model of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD), an age-related neurodegenerative disorder and a serious public health concern, is mainly caused by β-amyloid (Aβ)-induced toxicity. Currently, a limited number of drugs are effective against AD, and only a few are used for its treatment. According to traditional Chinese medicine, white wax is mainly composed of policosanol, hexacosanol, and octacosanol. Policosanol has been shown to reduce lipid levels in blood and alleviate the symptoms associated with diabetic complications and neurodegenerative disorders, such as Parkinson's disease and AD. However, the efficacy of policosanol depends on the purity and composition of the preparation, and the therapeutic efficacy of policosanol derived from insect wax (PIW) in AD is unknown.

METHODS

Here, we identified the main components of PIW and investigated the effects of PIW on Aβ-induced toxicity and life-span in a transgenic Caenorhabditis elegans model of AD, CL4176. Furthermore, we estimated the expression of amyloid precursor-like protein (apl-1) and the genes involved in various pathways associated with longevity and alleviation of AD-related symptoms in PIW-fed CL4176.

RESULTS

PIW mainly consists of tetracosanol, hexacosanol, octacosanol, and triacontanol; it could decrease the Aβ-induced paralysis rate from 86.87 to 66.97% (P < 0.01) and extend the life-span from 6.2 d to 7.8 d (P < 0.001) in CL4176 worms. Furthermore, PIW downregulated apl-1, a gene known to be associated with the levels of Aβ deposits in C. elegans. Additionally, our results showed that PIW modulated the expression of genes associated with longevity-related pathways such as heat shock response, anti-oxidative stress, and glutamine cysteine synthetase.

CONCLUSION

Our findings suggest that PIW may be a potential therapeutic agent for the prevention and treatment of AD. However, its effects on murine models and patients with AD need to be explored further.

Policosanol profiles and adenosine 5'-monophosphate-activated protein kinase (AMPK) activation potential of Korean wheat seedling extracts according to cultivar and growth time

Policosanols is a health promoting aliphatic alcohol known as lipid-lowing agent. To enable maximising the functional properties of wheat, this research investigates the policosanol profiles and adenosine 5'-monophosphate-activated protein kinase (AMPK) activation potential of Korean wheat seedlings according to cultivars and growth times. GC-MS revealed six policosanols that differed markedly in content between 17 cultivars, especially, octacosanol (8) showed the most predominant component (49-83%), varying significantly in average concentrations with growth times as 361.4 (3 days) → 613.0 (6 days) → 203.1 (9 days) → 196.5 (12 days) → 50.9 mg/100 g (19 days). The highest average policosanol (738.7 mg/100 g) exhibited after 6 days, while the lowest was 104.4 mg/100 g on 19 days. Moreover, the wheat cultivars including Shinmichal 1, Anbaek, Namhae, and Joah at 6 days may be recommended as potential sources because of high policosanols (921.7-990.6 mg/100 g). Western blot analysis revealed markedly higher AMPK activation in cells treated with the hexane extracts (150-370% at 100 μg/ml) and octacosanol (8) possessed potent AMPK activator (control; 100 → 280% at 200 μg/ml). It is confirmed that the AMPK activation by wheat seedlings are positively related to the highest policosanol content at the 6 days of growth time, independent of the cultivar. Our results may be contributed to enhance the wheat value regarding development of new cultivars and functional foods.

Effect of wheat germ on metabolic markers: a systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis aim to evaluate the association of wheat germ interventions and metabolic markers. An electronic search was performed by mid-May 2019 in the PubMed, Google Scholar, and Web of Science databases. Quality was evaluated using the risk of bias assessment tools. Thirty-three randomized controlled trials (RCTs) were identified, among which ten were suitable and systematically reviewed based on biomarkers (cholesterol, triglycerides, glucose, and oxidative stress). Three biomarkers in five eligible studies were investigated by meta-analysis. Total cholesterol showed non-significant results (p = 0.98), with standard mean difference (SMD) of − 0.01 (95% confidence interval; − 0.17, 0.16). The SMD was − 0.06 (95% CI − 0.41, 0.29, n = 4) for triglycerides and − 0.09 (95% CI − 0.62, 0.45, n = 2) for glucose. No biomarkers showed heterogeneity (0%). This review revealed non-significant association between wheat germ interventions and metabolic markers. Sensitive analysis with high-quality RCTs may be worth trying.

Octacosanol and policosanol prevent high-fat diet-induced obesity and metabolic disorders by activating brown adipose tissue and improving liver metabolism

Brown adipose tissue (BAT) is an attractive therapeutic target for treating obesity and metabolic diseases. Octacosanol is the main component of policosanol, a mixture of very long chain aliphatic alcohols obtained from plants. The current study aimed to investigate the effect of octacosanol and policosanol on high-fat diet (HFD)-induced obesity. Mice were fed on chow, or HFD, with or without octacosanol or policosanol treatment for four weeks. HFD-fed mice showed significantly higher body weight and body fat compared with chow-fed mice. However, mice fed on HFD treated with octacosanol or policosanol (HFDo/p) showed lower body weight gain, body fat gain, insulin resistance and hepatic lipid content. Lower body fat gain after octacosanol or policosanol was associated with increased BAT activity, reduced expression of genes involved in lipogenesis and cholesterol uptake in the liver, and amelioration of white adipose tissue (WAT) inflammation. Moreover, octacosanol and policosanol significantly increased the expression of Ffar4, a gene encoding polyunsaturated fatty acid receptor, which activates BAT thermogenesis. Together, these results suggest that octacosanol and policosanol ameliorate diet-induced obesity and metabolic disorders by increasing BAT activity and improving hepatic lipid metabolism. Thus, these lipids represent promising therapeutic targets for the prevention and treatment of obesity and obesity-related metabolic disorders.

Potential role of phytochemicals in metabolic syndrome prevention and therapy

Metabolic syndrome (MetS) is a set of cardiovascular risk factors which severely increases the risk of type II diabetes, renal disease and cardiovascular disease. Over the last decades, the role of dietary bioactive substances in features of MetS has been extensively investigated. Due to their multiple properties, these plant-derived natural compounds have demonstrated to provide positive effects in obesity, diabetes, renal and in cardiovascular disease. Catechins of green tea and caffeine reduce body mass index and waist circumference. Catechins, anthocyanins and proanthocyanidins of cocoa reduce blood pressure and blood glucose. Curcumin and silymarin exert hepatoprotective effects. Monacolins of red yeast rice are effective cholesterol-lowering agents. However, inconsistent or conflicting results have been found in clinical trials when other promising compounds in vitro or in animal studies, such as policosanol, curcumin or silymarin, were used. Low oral bioavailability of substances, ineffective dosages, inadequate treatment duration and insufficient statistical approach may explain the lack of effectiveness observed in some human studies. Further clinical studies are needed to better understand the role of bioactive compounds in the prevention and management of MetS.

Functional foods and dietary supplements for the management of dyslipidaemia

Dyslipidaemia is characterized by increased blood levels of total or LDL cholesterol and triglycerides, or decreased HDL cholesterol levels, and is a risk factor for cardiovascular disease. Dyslipidaemia has a high worldwide prevalence, and many patients are turning to alternatives to pharmacotherapy to manage their lipid levels. Lifestyle modification should be emphasized in all patients to reduce cardiovascular risk and can be initiated before pharmacotherapy in primary prevention of cardiovascular disease. Many functional foods and natural health products have been investigated for potential lipid-lowering properties. Those with good evidence for a biochemical effect on plasma lipid levels include soy protein, green tea, plant sterols, probiotic yogurt, marine-derived omega-3 fatty acids and red yeast rice. Other products such as seaweed, berberine, hawthorn and garlic might confer some limited benefit in certain patient groups. Although none of these products can reduce lipid levels to the same extent as statins, most are safe to use in addition to other lifestyle modifications and pharmacotherapy. Natural health products marketed at individuals with dyslipidaemia, such as policosanol, guggulsterone and resveratrol, have minimal definitive evidence of a biochemical benefit. Additional research is required in this field, which should include large, high-quality randomized controlled trials with long follow-up periods to investigate associations with cardiovascular end points.

Joint position statement on "Nutraceuticals for the treatment of hypercholesterolemia" of the Italian Society of Diabetology (SID) and of the Italian Society for the Study of Arteriosclerosis (SISA)

AIM

Evidence showed that LDL-cholesterol lowering is associated with a significant cardiovascular risk reduction. The initial therapeutic approach to hypercholesterolemia includes dietary modifications but the compliance to recommendations is often inadequate. Some dietary components with potential cholesterol-lowering activity are present in small amounts in food. Therefore, in recent years the use of "nutraceuticals" (i.e., nutrients and/or bioactive compounds with potential beneficial effects on human health) has become widespread. Such substances may be added to foods and beverages, or taken as dietary supplements (liquid preparations, tablets, capsules). In the present manuscript, the cholesterol-lowering activity of some nutraceuticals (i.e. fiber, phytosterols, soy, policosanol, red yeast rice and berberine) will be discussed along with: 1) the level of evidence on the cholesterol-lowering efficacy emerging from clinical trial; 2) the possible side effects associated with their use; 3) the categories of patients who could benefit from their use.

DATA SYNTHESIS

Based on the current literature, the cholesterol-lowering effect of fiber, phytosterols and red yeast rice is consistent and supported by a good level of evidence. Over berberine, there is sufficient evidence showing significant cholesterol-lowering effects, although the results come from studies carried out almost exclusively in Asian populations. Data on the effects of soy are conflicting and, therefore, the strength of recommendation is quite low. The evidence on policosanol is inconclusive.

CONCLUSION

Although health benefits may arise from the use of nutraceuticals with cholesterol-lowering activity, their use might be also associated with possible risks and pitfalls, some of which are common to all nutraceuticals whereas others are related to specific nutraceuticals.

Triacylglycerols and aliphatic alcohols from fruits of three Tunisian Pistacia lentiscus populations

BACKGROUND

The search for other sources of vegetable oils by the exploitation and the enhancement of other oil plants will be needed to meet the demands of the international market. This study aims to determine the triacylglycerol (TAG) molecular species and aliphatic alcohol compositions of unexploited fruits of three Tunisian Pistacia lentiscus (lentisc) populations from the Korbous, Tebaba and Rimel areas of Tunisia.

RESULTS

Results show that the content of total TAG varies from 738.32 mg g(-1) of total lipid in the Tebaba population to 981.15 mg g(-1) of total lipid in the Korbous population. Furthermore, 14 species of TAG were detected in the three studied populations. In addition, 13 aliphatic compounds were identified and classified into two groups: (1) aliphatic alcohols with fewer than 20 carbon atoms (hexadecanol, heptadecanol, (Z)-octadec-9-en-1-ol, octadecanol and nonadécanol); and (2) the policosanol group (eicosenol, docosenol, docosanol tetracosanol, hexacosanol octacosanol and triacontanol). The Tebaba population showed a distinct composition compared to Korbous and Rimel where heptadecanol is the major compound.

CONCLUSION

Quantitatively, the most abundant TAG species are those constituted by palmitic, oleic and/or linoleic acid. Furthermore, the significant difference observed at the oil composition is associated with a remarkable station effect.

Effects of high molecular weight alcohols from sugar cane fed alone or in combination with plant sterols on lipid profile and antioxidant status of Wistar rats

The effect of feeding a mixture of high molecular weight alcohols derived from sugarcane (SCA), both alone and in combination with phytosterols (PS), on changes in plasma lipids, organ cholesterol accumulation, and antioxidant status of Wistar rats was undertaken. Three separate experiments were conducted and each experiment had 3 subsets. In experiment 1, rats were fed on an AIN-76, semi-synthetic diet supplemented with 0%, 0.5%, and 5% SCA w/w. The second experiment consisted of feeding rats an atherogenic diet (AIN-76+0.5% cholesterol) containing 0%, 0.5%, and 5% SCA w/w. The third experiment consisted of feeding rats an atherogenic diet that contained 2% PS in combination with 0%, 0.5%, and 5% SCA. Rats fed the atherogenic diet exhibited significant elevations in total and low-density lipoprotein cholesterol, and significant reductions in the high-density lipoprotein/total cholesterol ratio, regardless of the presence of 0.5% or 5% SCA mixture. Serum cholesterol increased 29% to 35% in these animals compared with animals fed the nonatherogenic diets. In contrast, animals fed atherogenic diets that contained 2% PS exhibited no difference in serum lipids compared with counterparts fed nonatherogenic diets. The combined presence of SCA with PS had no effect on further lowering plasma cholesterol. No changes in C-reactive protein were observed, but plasma oxygen radical scavenging capacity values significantly (p < 0.05) decreased when rats were fed the atherogenic diets that contained the combination of PS and SCA. This result corresponded to an apparent greater (p < 0.05) susceptibility of red blood cells to oxidative stress.

Cholesterol ester and free fatty acids are modulated by policosanol in CaCo-2 intestinal cells

OBJECTIVE

To investigate policosanol absorption by brush border membrane (BBM), metabolism in CaCo-2 enterocytes, and transport of policosanol metabolites across the basolateral membrane (BLM). It was hypothesized that policosanol is partially oxidized into fatty acids and then is incorporated into other lipids.

METHODS

Policosanol was emulsified with phosphatidylcholine in the culture medium. The viability of cells was assessed via an MTT (3-[4,5]dimethylthiazol-2-yl-2,5-diphenyltetrazolim) assay. Control cells received only the same amount of "vehicle" (phosphatidylcholine) without policosanol. CaCo-2 cell monolayer and medium were collected; lipid was extracted and analyzed by thin-layer chromatography (TLC) and gas liquid chromatography (GLC).

RESULTS

Eighty-six percent of policosanol added to the cell culture medium was absorbed after 48 hours' incubation. The amount of cholesterol ester fatty acid was significantly increased both in the cells and in the basolateral medium, and was reduced in the apical medium. Policosanol increased the quantity of free fatty acids in the basolateral medium and reduced the free fatty acid content of CaCo-2 cells. Further evaluation of lipid profiles indicated that policosanol modulated the fatty acid profile of cholesterol ester in the basolateral medium.

CONCLUSION

It was concluded that policosanol or policosanol metabolites may modulate lipid metabolism and/or transport following absorption by the BBM, partial oxidation by the intestinal epithelium, and transport of policosanol metabolites across the BLM.

New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as alpha-linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the 'whole-grain package', and the most promising ways for improving the nutritional quality of cereal products are discussed.

Policosanols as nutraceuticals: fact or fiction

Policosanols (PC) are very long chain aliphatic alcohols derived from the wax constituent of plants. In the early 1990s, researchers at Dalmer Laboratories in La Habana Cuba isolated and produced the first PC supplement from sugarcane wax. The original PC supplement has been approved as a cholesterol-lowering drug in over 25 countries throughout the Caribbean and South America. Cuban studies claim that 1 to 20 mg/day of the original PC supplement are effective at producing significant reductions in total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C). These studies also show that PC supplements are potent antioxidants, promote proper arterial endothelial cell function, inhibit platelet aggregation and thrombosis, and serve as effective treatments for intermittent claudication. However, for the most part, those studies reporting therapeutic efficacy of PC were carried out by one research group situated in Cuba. Conversely, research groups outside of Cuba have failed to validate the cholesterol-lowering and antioxidant efficacy of PC. Cuban researchers, however, continue to claim that the efficacy is attributed to the unique purity and composition of the original PC preparation, a mixture not found in PC products used by external research groups. The absence of independent and external studies confirming the therapeutic benefits of PC in disease prevention and treatment raises questions regarding their true efficacy.

Effect of sugar cane policosanol on lipid profile in primary hypercholesterolemia

Policosanol, a mixture of long-chain aliphatic primary alcohols, is used as a cholesterol-lowering supplement. The effectiveness of policosanol is still questionable. To determine the lipoprotein-lowering effects of Cuban sugar cane-derived policosanol a double-blind, randomized, placebo controlled trial was performed. Sixty-eight primary hypercholesterolemic subjects were enrolled and randomly assigned to the treatment or to the control group. The first group received sugar cane policosanol 20 mg daily for 8 weeks, while the control group was treated with placebo. All subjects followed a normocaloric diet. The content of policosanol in the supplement tablets was assessed by gas chromatography. A total of 32 subjects in the policosanol group and 31 subjects in the control group completed the study. Body mass index, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride plasma levels did not change significantly in either group. In conclusion, sugar cane policosanol at doses of 20 mg daily showed no lipid lowering effects in subjects with primary hypercholesterolemia.

Cholesterol-lowering nutraceuticals and functional foods

Epidemiological studies have demonstrated that elevated levels of plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) are the major risk factors for coronary heart disease (CHD), whereas high concentrations of plasma high-density lipoprotein cholesterol (HDL-C) and a low ratio of TC to HDL-C are protective against CHD. A relationship between plasma TC and the risk of CHD is well established at concentrations above 240 mg/dL. In addition to the use of three main classes of cholesterol-lowering medications, including HMG-CoA reductase inhibitors, anion-exchange resins, and fibrates, a nutritionally balanced diet that reduces saturated fat and cholesterol intake has traditionally been the first goal of dietary therapy in lowering plasma TC. In recent years, nutraceuticals and functional foods have attracted much interest as possible alternative therapies for lowering plasma TC, especially for hypercholesterolemia patients, whose blood cholesterol level is marginally high (200-240 mg/dL) but not high enough to warrant the prescription of cholesterol-lowering medications. This review summarizes the findings of recent studies on the production, application, efficacy, and mechanisms of popular cholesterol-lowering nutraceuticals and functional foods.

Changes in cholesterol kinetics following sugar cane policosanol supplementation: a randomized control trial

Background

Sugar cane policosanols (SCP) have been shown to exert cholesterol-modulating properties in various studies conducted in Cuba by substantially reducing cholesterol synthesis. Independent research examining changes in cholesterol kinetics in response to SCP is limited to few studies, none of which was able to replicate findings of the original research. Moreover, no data are available on the effect of SCP on cholesterol absorption to date. The present study was undertaken to determine effects on cholesterol kinetics, namely synthesis and absorption, within hypercholesterolemic individuals consuming a SCP treatment. Twenty-one otherwise healthy hypercholesterolemic subjects participated in a randomized double-blind crossover study where they received 10 mg/day of policosanols or a placebo incorporated in margarine as an evening snack for a period of 28 days. The last week of the study phase, subjects were given ¹³C labelled cholesterol and deuterated water for the measurement of cholesterol absorption and synthesis respectively. Blood was collected on the first two and last five days of the trial. Cholesterol absorption and synthesis were determined by measuring red cell cholesterol ¹³C and deuterium enrichment, respectively.

Results

There was no significant change in LDL cholesterol levels as compared to control. In addition, the area under the curve for red cell cholesterol ¹³C enrichment across 96 hours was not significantly different in the SCP group as compared to control. Similarly, no difference was observed in the fractional rate of cholesterol synthesis over the period of 24 hours between the two treatment groups.

Conclusion

The findings of the present study fail to support previous research concerning efficacy and mechanism of action for policosanols.

Effects of emulsified policosanols with different chain lengths on cholesterol metabolism in heterozygous LDL receptor-deficient mice

Policosanol is a mixture of long-chain primary aliphatic saturated alcohols. Previous studies in humans and animals have shown that these compounds improved lipoprotein profiles. However, more-recent placebo-controlled studies could not confirm these promising effects. Octacosanol (C28), the main component of sugarcane-derived policosanol, is assumed to be the bioactive component. This has, however, never been tested in an in vivo study that compared individual policosanol components side by side. Here we present that neither the individual policosanol components (C24, C26, C28, or C30) nor the natural policosanol mixture (all 30 mg/100 g diet) lowered serum cholesterol concentrations in LDL receptor knock-out (LDLr(+/-)) mice. Moreover, there was no effect on gene expression profiles of LDLr, ABCA1, HMG-CoA synthase 1, and apolipoprotein A-I (apoA-I) in hepatic and small intestinal tissue of female LDLr(+/-) mice after the 7 week intervention period. Finally, none of the individual policosanols or their respective long-chain fatty acids or aldehydes affected de novo apoA-I protein production in vitro in HepG2 and CaCo-2 cells. Therefore, we conclude that the evaluated individual policosanols, as well as the natural policosanol mixture, have no potential for reducing coronary heart disease risk through effects on serum lipoprotein concentrations.

Octacosanol administration to humans decreases neutral sterol and bile acid concentration in feces

To investigate octacosanol (OC) metabolism in humans and its influence on cholesterol metabolism, two studies were conducted. In the first study ten healthy women received daily 30 mg OC for a period of 4 weeks. Blood and feces samples were collected at baseline and after the intervention. Serum concentrations of total cholesterol, LDL cholesterol, and HDL cholesterol were not altered following OC administration. Concentrations of excreted cholesterol end products decreased with the intervention (neutral sterols: 24.6 +/- 9.7 mg/g vs. 20.3 +/- 7.5 mg/g dry matter, P < 0.05; bile acids: 6.47 +/- 3.89 mg/g vs. 4.03 +/- 2.26 mg/g dry matter, P < 0.05). OC was not detected in serum samples, but the fecal OC concentration increased after the intervention period (11 +/- 7 microg/g vs. 817 +/- 179 microg/g dry matter, P < 0.05). In the second kinetic study on three participants, OC was identified in serums after oral application of 50 mg OC within 8 h. The decrease in the concentration of fecal cholesterol end products may underline a systemic effect of OC on cholesterol metabolism, even though the serum cholesterol levels were not influenced.

Comparison of composition and absorption of sugarcane policosanols

Policosanols (PC) exist as very-long-chain alcohols derived from sugarcane currently used in many countries as a cholesterol-lowering therapy. PC purity and relative percentage composition have been suggested as primary reasons why the original Cuban PC (OPC) supplements possess lipid-lowering efficacy. The purpose of the present study was, first, to compare the relative percentage purity and PC composition of both OPC and alternative sources of PC (APC). A second objective was to feed Syrian hamsters a diet containing 0.275 mg PC/g of either the OPC or an APC product (APC1) and compare subsequent tissue, plasma and faecal PC levels. Five animals from the APC1 dietary group received a diet containing ten times the original amount of PC. Results indicate that the APC formulations have a composition that is highly consistent with the OPC supplement, with octacosanol being present within the cited 60-70 % range. PC were undetectable in the small intestine, liver, adipose or plasma in animals fed either source. Hamsters fed OPC excreted octacosanol (C28) more rapidly (P < 0.05) than hamsters receiving APC1. If the cholesterol-lowering efficacy of PC mixtures is dependent on their purity and composition, then sugarcane-derived APC products should possess similar therapeutic properties as the OPC supplement.

Effects of a policosanol supplement on serum lipid concentrations in hypercholesterolaemic and heterozygous familial hypercholesterolaemic subjects

Policosanol is a mixture of higher aliphatic primary alcohols that is extracted from purified sugar cane wax or a variety of other plant sources, and has been shown to have beneficial effects on serum lipid concentrations. The objective of this study was to investigate the effects of a policosanol supplement (Octa-60) on lipid profiles of hypercholesterolaemic and heterozygous familial hypercholesterolaemic subjects. Nineteen hypercholesterolaemic and familial hypercholesterolaemic subjects completed this randomised, placebo-controlled, double-blind study. The subjects received either a daily dose of 20 mg policosanol or placebo for 12 weeks. After a wash-out period of 4 weeks, the interventions were crossed over. Lipid levels were measured at baseline and at the end of each intervention period. No significant differences in total cholesterol and LDL-cholesterol from baseline to end or between policosanol and placebo were seen in the hypercholesterolaemic or familial hypercholesterolaemic groups. There were small reductions in total cholesterol and LDL-cholesterol from baseline to end in the hypercholesterolaemic group, but these changes did not differ significantly from the changes with the placebo, indicating that the observed decrease in cholesterol in the policosanol group was not due to the specific effect of policosanol treatment. The differences in response may be ascribed to the differences in composition of the higher aliphatic primary alcohols in the previously used products, compared with the local policosanol supplement. An intake of 20 mg/d policosanol for 12 weeks had no significant effect on serum lipid levels in hypercholesterolaemic and heterozygous familial hypercholesterolaemic patients when compared with placebo intake.

Policosanol is ineffective in the treatment of hypercholesterolemia: a randomized controlled trial

BACKGROUND

Policosanol is one of the fastest growing over-the-counter supplements sold in the United States. The use of policosanol to treat elevated cholesterol is based on clinical trials conducted in Cuba, which showed sugar cane-derived policosanol to be similar in efficacy to statins. Recent studies have challenged these findings, but there have been no trials conducted in North America that have examined the ability of sugar cane-derived policosanol to lower cholesterol.

OBJECTIVES

This study investigated the efficacy of sugar cane-derived policosanol in healthy adults with mild hypercholesterolemia. The primary outcome was the percentage change in LDL cholesterol after 8 wk of therapy. Secondary outcome measures included changes in total cholesterol, HDL cholesterol, triacylglycerols, C-reactive protein, and nuclear magnetic resonance-determined lipoprotein profile. Dietary habits, weight, and blood pressure were also monitored.

DESIGN

Ambulatory, community-dwelling healthy adults with mild hypercholesterolemia (n = 40) were assigned to receive oral policosanol (20 mg) or placebo once daily for 8 wk. This was a double-blind, randomized controlled trial conducted from January through August 2005.

RESULTS

No significant differences in the change in LDL cholesterol were observed between the placebo (n = 20) and policosanol (n = 20) groups. Also, no significant changes in secondary outcome measures, including total cholesterol, HDL cholesterol, triacylglycerol, C-reactive protein, and nuclear magnetic resonance spectroscopy-determined profiles were observed. Policosanol was well tolerated, and no significant adverse events were noted.

CONCLUSION

Policosanol does not alter the serum lipid profile over an 8-wk period in adults with mild hypercholesterolemia.

Lack of effect of sugar cane policosanol on plasma cholesterol in Golden Syrian hamsters

Policosanol is a mixture of higher aliphatic alcohols shown to have beneficial effects on plasma lipid levels in animals and humans. Over 50 studies have reported significant reductions in plasma cholesterol using policosanol obtained from Cuban sugar cane (Dalmer, La Havana, Cuba). However, other research groups using policosanol from alternative sources have failed to reproduce the efficacy of these alcohols observed in earlier studies. Therefore, the objective of the present study was to compare the cholesterol-lowering effect of the Dalmer sugar cane policosanol (SCP) product versus an alternative mixture of similar policosanol composition. Forty-eight male Golden Syrian hamsters were randomly assigned to four groups and fed experimental diets ad libitum for a period of 4 weeks: (i) non-cholesterol control, (ii) 0.1% cholesterol control, (iii) 0.1% cholesterol diet supplemented with 275 mg/kg diet of Dalmer Cuban sugar cane policosanol and (iv) 0.1% cholesterol diet supplemented with 275 mg/kg diet of alternative sugar cane policosanol. Hamsters were sacrificed and blood was collected at the end of the feeding period. Body weights and food intakes were similar across study groups. Neither of the two policosanol treatments had any significant effect on plasma lipid levels, as compared to cholesterol control. The outcome of the present study questions the clinical usefulness of policosanol mixtures as cholesterol-lowering nutraceuticals.

Lack of cholesterol-lowering efficacy of Cuban sugar cane policosanols in hypercholesterolemic persons

BACKGROUND

More than 50 studies have reported substantial reductions in plasma lipid concentrations in response to 2-40 mg Cuban sugar cane policosanol (SCP) mixtures/d. However, several animal and human trials conducted outside of Cuba that used non-Cuban mixtures have failed to reproduce the efficacy of policosanols observed in earlier studies.

OBJECTIVE

The objective was to evaluate lipid-modulating actions of the authentic Cuban SCPs on plasma lipids in healthy hypercholesterolemic volunteers.

DESIGN

Twenty-one volunteers consumed, under supervision, 10 mg SCPs/d or a placebo incorporated in margarine as an afternoon snack, for a period of 28 d with the use of a randomized, double-blind crossover study design. Subjects maintained their habitual diet and physical activity and were weighed daily throughout the study period. Blood was collected at days 1, 2, 28, and 29 of the feeding trial, and lipid concentrations were measured.

RESULTS

Body weights did not vary significantly throughout the trial and did not affect plasma lipid values. No significant difference was observed between treatment and control groups in plasma total, LDL-, HDL-cholesterol, and triacylglycerol concentrations.

CONCLUSION

Present results show no beneficial effects of Cuban SCPs on lipid indicators in hypercholesterolemic persons and question the clinical usefulness of policosanol mixtures as cholesterol-lowering neutraceutical agents.

Comparative lipid-lowering effects of policosanol and atorvastatin: a randomized, parallel, double-blind, placebo-controlled trial

BACKGROUND

Policosanol, commonly derived from purified sugar cane wax, has been reported to exert lipid-lowering effects. Policosanol is available in the United States as a nutritional supplement despite no US research clinical experience. This trial was designed to rigorously establish the lipid-lowering efficacy of policosanol as monotherapy and its potential additive and possibly synergistic effects when added to statin therapy.

METHODS

A randomized, parallel, double-blind, double-dummy, placebo-controlled design was used. Patients with low-density lipoprotein cholesterol (LDL-C) levels from 140 to 189 mg/dL were assigned into 1 of 4 groups to receive policosanol 20 mg, atorvastatin 10 mg, combination therapy, or placebo for 12 weeks.

RESULTS

A total of 99 patients were examined. Baseline characteristics were similar among all treatment groups. Policosanol (20 mg/d for 12 weeks) did not significantly change plasma total cholesterol, LDL-C, high-density lipoprotein cholesterol, or triglyceride levels when compared with baseline values or with values of placebo-treated patients. Atorvastatin (10 mg/d for 12 weeks) reduced total cholesterol by 27% and LDL-C by 35%. Addition of policosanol to atorvastatin failed to produce any further reduction in lipid levels above that of atorvastatin alone. Policosanol was safe and did not affect liver enzyme or creatinine phosphokinase levels.

CONCLUSIONS

Policosanol did not reduce LDL-C or total cholesterol levels either alone or in combination with atorvastatin. This observation supports the need for systematic evaluation of available products containing policosanol to determine their clinical lipid-lowering efficacy under rigorous experimental conditions. We propose that policosanol should be added to the list of nutritional supplements lacking scientific validity to support their use.

Complementary and alternative therapies for the management of dyslipidemia

OBJECTIVE

To review the literature on select alternative therapies for the management of dyslipidemia.

DATA SOURCES

Searches of MEDLINE and PubMed (1965-March 2006) were conducted using the key terms omega-3-fatty acids, policosanol, plant stanols and sterols, flaxseed, red yeast rice, guggulipid, garlic, fiber, almonds, and cholesterol and/or lipids.

STUDY SELECTION AND DATA EXTRACTION

Meta-analyses, published in English and involving adults, that incorporated randomized, controlled trials on alternative therapies for dyslipidemia were reviewed. Additionally, trials published subsequent to the meta-analyses were reviewed. Articles deemed relevant were included in this review.

DATA SYNTHESIS

Of the aforementioned alternative therapies, randomized controlled trials were found for omega-3-fatty acids, policosanol, plant stanols and sterols, flaxseed, red yeast rice, guggulipid, garlic, fiber, almonds, and soy. Studies for each of these agents report varying degrees of lipid reduction. Based on published data, effective therapeutic options for lipid-lowering include intake of fiber, intake of plant stanols/sterols, replacement of animal protein with soy protein, and substitution of foods high in saturated fat with those with monounsaturated fatty acids (eg, dry roasted almonds). Adding omega-3-fatty acids is effective for reducing triglycerides in patients with hypertriglyceridemia. Well-designed studies with long-term outcome data are necessary to further define the role for guggul, red yeast rice, policosanol, garlic, and flaxseed in the management of dyslipidemia.

CONCLUSIONS

Alternative therapeutic approaches with complementary therapies are becoming increasingly popular among patients. It is important for healthcare providers to be familiar with the safety and efficacy of these agents to facilitate optimal outcomes for patients with dyslipidemia.