Soy Won't Reduce Cholesterol After Menopause

From Reuters Health Information

Apr 02 - Eating extra soy for one year doesn't help postmenopausal women cut their cholesterol levels, new research shows.

The findings support the Food and Drug Administration's 2007 move to reevaluate its decade-old decision allowing soy product makers to claim heart benefits, Dr. Sara Chelland Campbell of Florida State University in Tallahassee and her colleagues say.

In an online paper in Menopause March 3rd, the researchers noted that recent studies investigating soy and cholesterol levels in postmenopausal women have been short, or have only looked at individual soy components. They conducted the current study to investigate the long-term effects of soy protein in food, specifically 25 g of soy protein and 60 mg of isoflavones every day for a year, in women after menopause.

They enrolled 87 overweight postmenopausal women who were younger than 65, 62 of whom completed the study. Study participants had moderately high total cholesterol levels (236 mg/dL in the control group, 231 mg/dL in the soy group) and were randomly assigned to eat soy products, or comparable products containing casein, for a year. The products included a snack bar, drink mix, and cereal.

Total cholesterol and HDL levels increased slightly in the women given soy products, the researchers found, but soy had no effect on LDL cholesterol or triglyceride levels.

Average total cholesterol rose by 18 points (to 254 mg/dL) in the control group and by 12 points (to about 243 mg/dL) in the soy group. HDL levels increased from 58 to 63 mg/dL in the control group, and from 57 to 60 mg/dL in the soy group.

Since 1999, Dr. Campbell and her colleagues note, the FDA has allowed soy product labeling to claim that diets low in saturated fat and cholesterol, along with 25 g of soy protein daily, "may reduce the risk of heart disease."

Other recent studies have called this benefit into question, the researchers add, and the AHA in 2000 changed its position to say that the benefit of soy protein or isoflavones is "minimal at best."

The researchers conclude: "Our results support the large body of literature showing no favorable alterations in the lipid profile as a result of the incorporation of 25 g/day of soy protein in the diet."

Menopause 2010.