Will Mild To Moderate Cervical Stenosis Get Worse

Phytosterols in Hypercholesterolemia

Agosto 29, 2007

Qué hacen los Fitosteroles ( Fitolip ®) en la Hipercolesterolemia ?

Qué hacen los Fitosteroles ( Fitolip ®) en la Hipercolesterolemia ?

Jaime Urdinola M.D.
Asociación Médica de los AndesBogotá D.C. Colombia
Teléfono 571 / 215 23 00
e-mail: jaimeurdinolamd@gmail.com
jurdinol@uniandes.edu.co
blogger: www.urdinola.blogspot.com
www.urdinolamenopausia.blogspot. com
www.urdinolamenopausia2.blogspot.com
Symposium / Luncheon on Women's Health Medical Association
Andes - Boardroom
Wednesday August 29, 2007

Cardiovascular disease (CVD) is the most prevalent serious diseases facing Colombian women in the early years of the century XXI. Affects mortality at 50.7 per 1 000 women with cerebrovascular disease and 67.1 per 1 000 women with ischemic heart disease 1.

interventions related to prevention of these problems are needed, such as measures to control dyslipidemia, whether pharmacological or not.

What are Phytosterols?

also called plant sterols, are steroid molecules that are abundant in the seeds of legumes and inhibit the absorption of cholesterol. Its cholesterol-lowering effect has been known since 1950.
The best known is the β-sitosterol, belonging to the group the 4-desmethylsterols, so do not have a methyl group at carbon 4, with campesterol and stigmasterol.

Cholesterol also is a sterol, but present only in animals and humans.

In its free form, phytosterols are insoluble in water and slightly soluble in fats. Are esterified to make them soluble, which also possess greater power Lovastatin. Precisely for esterification of vegetable oils is needed seed and soybean, sunflower, corn, canola, olive, etc..

Vegetarians consume in their diet about 500 mg daily, while the usual Western diet provides 150-350 mg of phytosterols, or is an amount almost equal to the intake of cholesterol. But these amounts do not produce significant reductions in cholesterol levels, since they require at least 1 g / day and ideally from 1.5 to 3 g / day to achieve 11-14% lower LDL cholesterol 2.

diet in preventing cardiovascular problems is essential, according to epidemiological studies and investigations of dietary intervention. If people consume plenty of carbohydrates and fats, cardiovascular mortality is lower than in the population who eat plenty of animal fats and cholesterol.

Moreover, the phytosterols alone or in foods enriched with them, could be considered as functional food, since they have proved scientifically, which are midway between food and medicines, nutraceuticals also consequently classified.

Phytosterols have been modified over time to make them more efficient. Initially administered in free form and in high doses. In a second stage is still administered in free form but at lower doses. Currently the administration is in esterified form and in small doses, and can be mixed with margarine or other fat products. Currently there is also the pharmaceutical.

Mechanism of action

Phytosterols and cholesterol are structurally similar, just different sterol ring the presence of a methyl group in the campesterol, sitosterol or ethyl, in the 24 carbon chain. Stigmasterol to sitosterol is similar, but with one more double bond in the carbon 22.

sterols are absorbed less cholesterol, depending on the length of the string. Campesterol is absorbed than sitosterol. This is the most abundant in nature and absorbs only a proportion of 5%. Stanols, sterols, saturated or is no double bond in the sterol ring and produced by hydrogenation of sterols, are absorbed below 1%.

Western diet contains phytosterols in quantities similar to cholesterol, but minimal absorption cause their blood levels are much lower than those of cholesterol. Phytosterols as cholesterol, are metabolized in the large intestine by bacteria to form coprostanol and coprostanonas.

But unlike cholesterol, phytosterols are not converted into bile acids. The molecular similarity of human and plant sterols is the reason why, when ingested in sufficient amounts, between 1.5 and 3 g daily, they compete with cholesterol for solubilization into micelles, which are compounds responsible for the intestinal transport polymolecular lipid insoluble, having greater affinity for these than the human cholesterol, which inhibit its absorption.

Remember that 30% of cholesterol comes from dietary intake, mainly from egg yolk, liver of mammals and crustaceans and 70% by training in liver and biliary excretion. Thus, cholesterol absorption in the intestine is reduced by about 50%, affecting the cholesterol from the diet and the bile enterohepatic circulation.

The decrease in intestinal cholesterol absorption induced by phytosterols liver promotes two regulatory effects. The first is the increase in endogenous synthesis cholesterol. The second is to stimulate the expression of LDL receptors, thereby increasing the uptake of circulating LDL. This is why the end result is a decrease from 10 to 15% of plasma LDL.

Recent studies suggest that cholesterol uptake by the micelles within the intestinal mucosa is mediated by Niemann Pick C1 Like Protein, a specific carrier that can be inhibited by ezetimibe 3.

should also be noted that cholesterol absorption is controlled not only by its input, or the inward flow (influx), but also for its output or flow out (efflux). This could explain why under normal circumstances, the efficiency of cholesterol absorption decreases as the amount ingested increases. For this reason might be the hyperresponders to absorb more dietary cholesterol than unresponsiveness 4 . Other findings indicate that phytosterols also influence cellular cholesterol metabolism within intestinal enterocytes 5 .

Interest in the effects of stanols in the diet to reduce cholesterol levels, motivated and in 2001 met in Stresa, Italy 32 experts in lipid nutrition and diseases heart 6, under the auspices of the Italian Foundation for Nutrition, to discuss the efficacy, safety and future of research into stanols. A meta-analysis of 42 clinical trials 7 showed that the intake of 2 g / day of stanols or sterols decreased low density lipoprotein (LDL) by 10%. Larger quantities added little to the effect obtained with the doses noted.

The effects can be additional to the diet or drug interventions. If you eat food low in saturated fat and cholesterol and high in stanols, LDL can be reduced further, even 20%.

If added sterols or stanols to statin therapy, it is more effective than doubling the dose of statins 8.9.

In patients with diabetes mellitus, 3 g / day of phytosterols reduced LDL additional 6% when combined with pravastatin.

In patients with coronary disease and familial hypercholesterolaemia receiving simvastatin, the same dose of 3 g / day of phytosterols reduced LDL 16 to 20% compared with simvastatin alone 10 .

Of importance to the management of patients in middle age or old age, a meta-analysis 11 showed that plasma levels of vitamins A and D are not affected by the action of the sterols or stanols. Alpha carotene, lycopene and vitamin E levels remained stable in relation to its carrier molecule, LDL. The levels of β ̶ carotene decreased, but do not expect adverse health outcomes for this reason;, likewise, this could be corrected by adding additional fruits and vegetables to the diet.

Another of the concerns are fitosterolemia patients with homozygous, due to a marked increase in atherosclerosis in these patients, but it is considered that the risk is hypothetical, and that any increase due to the small increase in plasma plant sterols can be virtually ruled out by the decrease in plasma LDL.

are insufficient data to suggest that the sterols or stanols can prevent or promote colon cancer. This phenomenon is tracked, but the power of studies to capture the unusual increase of common diseases, is limited. A clinical study to analyze outcomes such as thickening of the intima media layer of the vessel might corroborate the expected efficacy in reducing the phenomenon of atherosclerosis.

But with the available data we may assume that the evidence is sufficient to promote the use of sterols and stanols in people with an increased risk for coronary heart disease. -

Long-term efficacy of phytosterols

Published studies suggest that the effect of cholesterol reduction by phytosterols is less marked in long-term studies compared with studies short term. There is a slight decrease in serum antioxidant soluble in lipids. Furthermore, phytosterols down regulate bile acid synthesis to 21%, which in turn attenuates the efficacy in reducing cholesterol, but further study is needed to confirm this effect and allow quantify the effects in time 12.

Highlights

● Cardiovascular Disease now kills thousands of women in Colombia

● hypercholesterolemia can intervene medically,
contributing to the prevention of this disease

● Phytosterols are plant sterols similar to cholesterol.
compete with this in their absorption in the intestine

● The administration of 1.5 to 3 g / day of phytosterols reduced by at least 10 to 14
% LDL cholesterol

● It is effective and safe for the patient, add phytosterols to
treatment with statins, doubling the dose of the latter

References 1 - Gender, Health and Development in the Americas - Basic Indicators 2005. Pan American Health Organization. Regional Office of World Health Organization.
2 - Plaza I. Phytosterols, cholesterol and cardiovascular disease prevention. Clin Invest Arteriosclerosis. 2001, 15:209 - 218.
3 - Altmann SW, Davis Hr Jr, Zhu LJ, Yao X, Hoos LM, Tetzloff G, Iyer SP, Maguire M, Golovko A, Zeng M, et al. Niemann ̶ Pick C1 Like protein is critical for intestinal colesterol absorption. Science. 2004; 303: 1201 ̵ 1204.
4- Thompson GR, Grundy SM. ­History and development of plant sterol and stanol esters for cholesterol-̵ lowering purposes. Am J Cardiol. 2005; 96 ( suppl ) : 3D ̶ 9D.
5- Plat J, Mensink RP. Plant stanol and sterol esters in the control of blood cholesterol levels: mechanism and safety aspects. Am J Cardiol. 2005; 96 ( suppl ) : 15D ̶̶ 22 D.
6- Katan MB, Grundy SM, Jones P, Law M, Miettinen T, Paoletti R, for the Stresa Workshop Participants. Efficacy and safety of plant stanols and sterols in the management of blood cholesterol levels. Mayo Clin Proc. 2003; 78: 965 ̶ 978.
7- Law M. Plant sterol and stanol margarines and health. BMJ. 2000; 320 : 861 ̶ 864.
8- Blair SN, Capuzzi DM, Gottlieb SO, Nguyen T, Morgan JM, Cater NB. Incremental reduction of serum total cholesterol and low ̶ density lipoprotein cholesterol with the addition of plant stanol ester ̶ containing spread to statin therapy. Am J Cardiol. 2000 ; 86: 46 ̶ 52.
9- Vuorio AF, Gylling H, Turtola H, Kontula K, Ketonen P, Miettinen TA. Stanol ester margarine alone and with simvastatin lowers serum cholesterol in families with familial hypercholesterolemia caused by the FH ̶ North Karelia mutation. Arterioescler Thromb Vasc Biol. 2000 ; 20 : 500 ̶ 506.
10- Thompson GR. Additive effects of plant sterol and stanol esters to statin therapy. Am J Cardiol. 2005; 96 ( suppl ) : 37D ̶̶ 39 D.
11- Raeini ̶ Sarjaz M, Ntanios FY, Vanstone CA, Jones PJ. No changes in serum fat ̶ soluble vitamin and carotenoid concentrations with the intake of plant sterol ⁄ stanols esters in the context of a controlled diet. Metabolism. 2002; 1 : 652 ̶ 656.
12- O'´Neill FH, Sanders AB, Thompson GR. Comparison of efficacy of plant stanol ester and sterol ester: short ̵ ̵ term and Long term studies. Am J Cardiol. 2005, 96 (suppl): 29D, 36D ̵.

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