meta-analysis shows soy lowers cholesterol

In the U.S., the FDA is considering revoking soy protein’s official claim to lower cholesterol. While America questions soy’s heart healthy powers, Canada provides the answer.

In 1995, a meta-analysis of 38 placebo-controlled studies concluded that soy significantly lowers both total- and LDL cholesterol (NEJM 1995;3333:276-82). It lowered total cholesterol by 9.3% and the bad LDL cholesterol by 12.9%. It also lowered triglycerides by 10.5%. Soy protein also nonsignificantly raised the heart healthy HDL cholesterol by 2.4%.

Since the important 1995 study, several double-blind studies have added even more evidence to soy’s heart healthy claim (Am J Clin Nutr 1998;68:545-51; Arch Intern Med 1999;159:2070-76; Br J Nutr 1999;82:91-96; Am J Clin Nutr 2000;71:1077-84).

However, due to what University of Toronto researchers call “a perceived lack of consistent LDL cholesterol reduction in randomized controlled trials,” the FDA is considering revoking soy protein’s heart health claim. The “perceived” lack of consistency is because, though most studies of soy on cholesterol find benefit, the benefit does not always reach statistical significance. But what happens when you put all the studies together?

U of T researchers took all 46 studies upon which the FDA will base its ruling and put them together into a meta-analysis to determine what the data really says.

The studies included both men and women and compared the effect of soy protein with non-soy protein on total and LDL cholesterol. Of the 46 studies, 43 could be included in the meta-analysis for total cholesterol and 41 could be included for LDL cholesterol. The average study gave 25g a day of soy protein and followed people for up to six weeks.

The pooled data showed that soy protein reduced LDL cholesterol by a significant 4.76 mg/dL and total cholesterol by a significant 6.41 mg/dL compared to non-soy proteins.

About 75% of the studies, taken individually, showed that soy reduced cholesterol. Though not all the studies taken on their own produced significant results, the combines results were clearly significant and translated into a reduction of approximately 3-4%.

Since, at meal time, adding soy protein likely means that it replaces animal proteins that raise cholesterol, the real world effect of soy protein may be even greater. When an earlier study by some of the same researchers looked at the combined effect of replacing saturated fat and cholesterol from animal proteins with soy protein in eleven studies, they found that the real cholesterol reduction was actually between 7.9% and 10.3% (J Nutr 2010;140(12):2302S-2311S).

The researchers conclude that the data supports the advice to increase plant protein.

J Nutr 2019;149(6): 968-81


For the latest research to keep your family healthy, get The Natural Path delivered to your inbox each month: Subscribe!

For comprehensive help with cholesterolmake an appointment to see Linda Woolven now.

For much more on preventing and treating cholesterol, see our book The Family Naturopathic Encyclopedia or Chocolate: Superfood of the Gods, which contains a comprehensive chapter on the latest cholesterol research.


The Natural Path
 is intended for educational purposes only and is in no way intended for self-diagnosis or self-treatment. For health problems, consult a qualified health practitioner for a comprehensive program.

Comments (0)

There are no comments posted here yet

Leave your comments

  1. Posting comment as a guest.
Attachments (0 / 3)
Share Your Location
This Barrie website created by Piggybank Marketing