Alpha phytosterol, a type of plant sterol, is used primarily for its cholesterol-lowering properties. The rationale for its use in metabolic syndrome is based on its ability to reduce intestinal absorption of cholesterol, which can help lower blood cholesterol levels—a key component of metabolic syndrome. Several randomized controlled trials and meta-analyses have shown that phytosterols (including alpha phytosterol) can reduce LDL cholesterol by about 8-10% when consumed at doses of 2 grams per day. This effect is recognized by major health organizations, including the FDA and EFSA, for cholesterol management.

However, direct evidence supporting the use of alpha phytosterol specifically for the broader metabolic syndrome (which encompasses dyslipidemia, elevated blood pressure, insulin resistance, and central obesity) is limited. Most studies focus on lipid parameters rather than the syndrome as a whole or its other components, such as blood pressure, glucose metabolism, or waist circumference. There is currently minimal evidence that phytosterols have significant effects on blood sugar control, insulin sensitivity, or weight loss.

In summary, the use of alpha phytosterol in metabolic syndrome is scientifically justified for addressing dyslipidemia, but evidence supporting broader benefits for all aspects of metabolic syndrome is weak. Therefore, the overall evidence rating for its use in metabolic syndrome is modest.