Plant Sterols for Cholesterol: Do They Really Work?

observational-study PMID: 12083314

Quick Summary: Research shows plant sterols, taken in a liquid form, can significantly reduce how much cholesterol your body absorbs. This study found that a specific type of plant sterol lowered cholesterol absorption by a significant amount in men with slightly high cholesterol.

How Plant Sterols Help Lower Cholesterol

Plant sterols, also called phytosterols, are naturally occurring substances found in plants. They're similar in structure to cholesterol, and when you eat them, they can help block cholesterol absorption in your gut. This study looked at a specific type of plant sterol (non-esterified stanols) in a liquid form.

What The Research Found

The study found that:

Plant sterols in a liquid form reduced cholesterol absorption by about 40%.

The plant sterols didn't significantly change how much cholesterol the body made on its own.

This suggests plant sterols could help lower "bad" LDL cholesterol levels.

Study Details

Who was studied: 12 men with slightly elevated cholesterol levels.

How long: The men took the plant sterol supplement or a placebo for just 3 days.

What they took: 3 grams of non-esterified plant stanols per day, mixed in a liquid emulsion.

What This Means For You

Plant sterols might be a good option: If you're looking for ways to lower your cholesterol, plant sterols could be a helpful addition to a healthy diet.

Consider the form: This study used a liquid form of plant sterols. You can also find them in foods like fortified spreads.

Talk to your doctor: Always discuss any new supplements with your doctor, especially if you're already taking medication for high cholesterol.

Study Limitations

Small study: The study only included a small number of men, so more research is needed.

Short duration: The study was only 3 days long, so we don't know the long-term effects.

No direct LDL measurement: The study didn't directly measure LDL cholesterol levels, so the impact is inferred.

Men only: The study only included men, so the results may not be the same for women.

Key Findings

The study demonstrated that non-esterified stanols (3 g/day) delivered in a liquid emulsion reduced cholesterol absorption by 40% (from 55.7% to 33.5%) in mildly hypercholesterolemic men. However, no statistically significant change in endogenous cholesterol synthesis was observed (0.074 pool/day vs. 0.0736 pool/day for control, p > 0.05). This suggests that stanols may lower LDL cholesterol by inhibiting absorption without compensatory synthesis increases, though longer-term studies are needed to confirm these effects.

Study Design

This was a randomized, double-blind crossover trial (described as observational in the source) involving 12 hypercholesterolemic men. Participants received either a phytostanol supplement or a control emulsion for 3 days, with a washout period before crossing over. Cholesterol absorption was measured using the dual isotope method (¹³C intravenous injection and ¹⁸O oral administration), while synthesis was tracked via deuterium incorporation from body water into cholesterol.

Dosage & Administration

Subjects consumed 3 g/day of free (non-esterified) phytostanols in three servings of an oil-in-water emulsion. The vehicle included lecithin to solubilize the stanols. The control group received the same emulsion without stanols.

Results & Efficacy

Cholesterol absorption: Decreased from 55.7 ± 6.5% (control) to 33.5 ± 5.3% (stanol treatment).
Cholesterol synthesis: No significant difference between stanol (0.074 ± 0.0015 pool/day) and control (0.0736 ± 0.0015 pool/day) groups (p > 0.05).
Efficacy: The absorption reduction aligns with prior evidence on esterified sterols but shows non-esterified forms in liquid emulsions are similarly effective.

Limitations

Small sample size (n=12) and short duration (3 days) limit statistical power and long-term conclusions.
Single-sex cohort (men only) restricts generalizability to women.
Lack of direct LDL measurements: The study inferred LDL-lowering potential from absorption/synthesis data but did not measure serum LDL levels.
Methodological constraints: Stable isotope tracers are precise, but variability in individual responses to stanols was not explored.

Clinical Relevance

The findings suggest that even low doses of non-esterified stanols (3 g/day) in a liquid emulsion can significantly inhibit cholesterol absorption, potentially lowering LDL cholesterol. This formulation may benefit individuals seeking alternatives to sterol esters (e.g., spreads). However, the lack of observed synthesis changes and absence of direct LDL data warrant caution in extrapolating clinical outcomes. Users should consider longer-term trials to validate these effects and monitor lipid profiles. The study highlights the importance of delivery vehicles (e.g., lecithin-emulsified liquids) in enhancing phytostanol bioavailability.

Note: The study’s observational label may conflict with its interventional crossover design, likely a classification error. All conclusions are specific to the described protocol and population.