Soy Protein Helps Maintain Healthy Cholesterol Levels

by | Oct 16, 2009 | 2009, Blood Lipids, Cardiovascular Health, Diabetes, Proteins, Soy Isoflavones

Written by Greg Arnold, DC, CSCS. In 29 diabetic patients, forty grams of soy protein with 80 mg soy isoflavones reduced LDL cholesterol (bad) and total cholesterol more than the group taking milk protein without soy isoflavones.

According to the National Institutes of Health, high cholesterol is “a major risk factor” for cardiovascular disease (CVD) which affects nearly 81 million Americans (1) and is estimated to cost our healthcare system $448.5 billion in 2008 (2).  Two of the biggest manifestations of CVD, heart attack and stroke, cost our healthcare system $151.6 and $62.7 billion each year, respectively (3).

The NIH states that cholesterol levels less than 200 mg/dL are “desirable”, 200-239 mg/dL are “borderline high”, and greater than 240 mg/dL is “high” (4). Now a new study (5) has found that soy protein with isoflavones can help maintain healthy cholesterol levels in patients with type 2 diabetes. In the study, 29 patients with type 2 diabetes were given either 40 grams of soy protein containing 80 mg of soy isoflavones or milk protein (control) per day for 57 days, followed by 28 days without supplements and then switching to the other supplement for another 57 days.  The patients provided urine and blood samples at the beginning and end of each supplement period.

The researchers found that those in the soy protein group had a drop in LDL cholesterol that was double that of those the milk group (6% drop (2.98 to 2.75 mmol/L – p=0.04) vs. 3% drop (2.98 to 2.90 mmol/L)). There was a 40% greater drop in total cholesterol in the soy group vs. the milk group (5% drop (4.64 to 4.43 mmol/L) vs. 3% drop (4.67 to 4.53 mmol/L)), however the p-value was 0.21 and a little less certain.

For the researchers, “These data demonstrate that consumption of soy protein can modulate some serum lipids in a direction beneficial for CVD risk in adults with type 2 diabetes.”

Source: Pipe, Elizabeth A., et al. “Soy protein reduces serum LDL cholesterol and the LDL cholesterol: HDL cholesterol and apolipoprotein B: apolipoprotein AI ratios in adults with type 2 diabetes.” The Journal of nutrition 139.9 (2009): 1700-1706.

© 2009 American Society for Nutrition.

Posted October 16, 2009.

Reference:

  1. Cardiovascular Disease Cost” posted on The American Heart Association website.
  2. Chien-Hsun H.  Nattokinase decreases plasma levels of fibrinogen, factor VII, and factor VIII in human subjects. Nutr Res 2009; 29(3):190-196.
  3. American Heart Association Update.  Heart Disease and Stroke Statistics—2007 Update.  Circulation. 2007;115:e69-e171.
  4. High Blood Cholesterol: What You Need To Know” posted on the National Heart, Lung, and Blood Institutes website.
  5. Pipe EA.   Soy Protein Reduces Serum LDL Cholesterol and the LDL Cholesterol:HDL Cholesterol and Apolipoprotein B:Apolipoprotein A-I Ratios in Adults with Type 2 Diabetes.  J. Nutr. 2009 139: 1700-1706.