Researchers at St. Michael’s Hospital in Toronto conducted a meta-analysis of 46 existing trials that evaluated soy and determined whether the proposed move aligns with existing literature. Of the 46 trials, 43 provided sufficient data for meta-analysis. Forty-one trials examined the protein’s effects on low-density lipoprotein (LDL, or “bad”) cholesterol. All 43 studies provided data about “total cholesterol,” which reflects the overall amount of cholesterol in the blood.
The researchers found soy protein reduced LDL cholesterol by 3 to 4 percent in adults—a small but significant amount, said David Jenkins, M.D., Ph.D., lead author of the study, director of the Clinical Nutrition and Risk Factor Modification Centre, and a scientist in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital.
“When one adds the displacement of high saturated fat and cholesterol-rich meats to a diet that includes soy, the reduction of cholesterol could be greater,” he said. “The existing data and our analysis of it suggest soy protein contributes to heart health.”
A limitation of this study was that it exclusively analyzed the 46 trials the FDA had referred to previously, as opposed to casting a wider net. The researchers hope the work is taken into account in FDA’s current evaluation of soy protein as it pertains to heart health. “We hope the public will continue to consider plant-based diets as a healthy option,” Jenkins said. “It is in line with Health Canada’s recently released Food Guide, which emphasizes plant protein food consumption by Canadians.”