Tuesday, June 18, 2013

Want to Benefit from Plant Sterols? Eat Whole Food or Take Supplements With Meals. Plus: Do You "Benefit" at All?

This is not a joke by a blogger this is how Unilever advocates to use their Flora pro.active product to consumers, who "want to lower your cholesterol and follow a healthy diet and lifestyle."
Pharma companies and supplement producers are notorious for picking foods apart and providing you with concentrated extracts of the "active ingredients".

Aside from the fact that more often then not, the activity of those "active ingredients" is critically dependent on co-factors that are lost during the isolation and extraction processes, scientists from the Division of Gastroenterology-Hepatology at the Department of Internal Medicine of the Maastricht University Medical Center have now been able to show that the mere presence of the bulk in which plant sterols would come in the natural form is critically important to their effects.

Can you achieve a "healthily"(?) low cholesterol level by guzzling tuckloads of low-fat yogurt drinks!?

Based on the negative outcomes of previous studies into the benficial effect of "functional" foods or dietary supplements enriched in plant sterols, D. Keszthelyi had hypothesized  that
"100 mL drink, when consumed before a meal, would empty fast from the stomach and would not sufficiently trigger gallbladder emptying, whereas ingestion with or after the solid meal would enable the necessary physiological changes to aid inhibition of cholesterol absorption" (Keszthelyi. 2013)
To test this hypothesis the researchers recruited a total of 12 healthy male subjects (age, 25 ± 3 years; BMI, 23 ± 2 kg/m²) who reported the scientists' lab on three separate test days with one-week washout between test days.

Does the Paleo diet ruin your cholesterol levels as the conclusion to a recently published thesis would indicate (learn more)?
On each of the days, the participants consumed a Phytosterol (PS) containing yoghurt drink (100 mL, Becel Pro-Activ with PS added as their fatty acid esters (3.2 g, equivalent to 2.0 g PS), either
  • 45 min before (test condition A), 
  • during (test condition B), or
  • 45 min after (test condition C) 
the consumption of a 500 g macaroni meal (Macaroni Bolognese, Henri, Drunen, The Netherlands) at lunch time (I know not the ideal, but for the average Westerner a realistic test meal). T

he sequence of the test days had been determined by a random pre-selection prior to the start of the study. During each test day, gastric emptying of the test drink as well as the effect of the test drink on gallbladder volumes were determined (figure 1, left):
Figure 1: Gastric emptying (left) and gallbladder volume (right) depending on the time of ingestion of a phytosterol containing yogurt drink (Keszthelyi. 2013)
As the results go to show you the ingestion of the functional food before the meal resulted in the fastest gastric emptying. The ingestion with or after a solid meal, on the other hand, caused a significant contraction of the gallbladder.
"Accepting the postulate that concurrent presence of PS with dietary and/or biliary cholesterol in the small intestine is an important mechanism for the LDL cholesterol-lowering action (Ostlung. 2004), a significant stimulus leading to gall- bladder contraction with simultaneous delivery of the PS-containing food format from the stomach into the duodenum is required. It is therefore important to ascertain which stimuli are able to elicit this postprandial response to a sufficient and desirable degree." (Keszthelyi. 2013)
This is actually interesting, because in the end it means that cholesterol clearance, even when it's induced / supported by questionable supplemental phytoestrogens critically depend on fat intake! This in turn would explain why the rodents in the "optimal diabesity diet study" from one of the recent installments of the Short News found elevated cholesterol levels only in the high sugar and high fat + high sugar groups, yet not in the rodents on a high fat diet. One thing to keep in mind, though: The main reason I picked and posted this study is not to pimp the use of phytosterol-spiked imho dys-functional junk food. It's rather to raise your awareness of the importance of the whole nutrient matrix in terms of the effects of the individual agent.

If you want to do something for your blood lipids, you better eat more eggs than overpriced Frankenfood. The eggs will not only improve your cholesterol particle profile, the regular consumption of whole eggs will also increase HDL's ability to carry lipids out of the macrophages. If these accumulate, they will turn the macrophage into pro-atherogenic foam cells (learn more).
In how far the isolation is also behind the previously observed side effects of plant sterols and stanols, which are likewise used in functional foods remains questionable, but it is not unlikely that sides such as

  • abortion of pregnancy in animal models (Burckh. 1982)
  • reduced sperm concentrations & testis weights
  • neg. effects on the vascular system (Boberg. 1991)
  • increased intestinal tumor formation (Marttinen. 2013)
are eventually also a consquence of the absence of important co-factors, when the sterols and stanols are removed from their original food matrix and "transplanted" into yogurts, margarines and all sorts of overly expensive and at best useless Frankenfoods.

References:

  • Boberg KM, Pettersen KS, Prydz H. Toxicity of sitosterol to human umbilical vein endothelial cells in vitro. Scand J Clin Lab Invest. 1991 Oct;51(6):509-16.
  • Burck PJ, Thakkar AL, Zimmerman RE. Antifertility action of a sterol sulphate in the rabbit. J Reprod Fertil. 1982 Sep;66(1):109-12. 
  • Keszthelyi D, Knol D, Troost FJ, van Avesaat M, Foltz M, Masclee AA. Time of ingestion relative to meal intake determines gastrointestinal responses to a plant sterol-containing yoghurt drink. Eur J Nutr. 2013 Jun;52(4):1417-20.
  • Ostlund RE Jr. Phytosterols and cholesterol metabolism. Curr Opin Lipidol. 2004 Feb;15(1):37-41.

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