In part two of this series, let’s take a gander at the biggest sole benefit that soy can deliver for the body. It can improve your overall cholesterol profile. That, of course, will help shield your heart from disease.
A decade back, a study in the “New England Journal of Medicine” showed that soy protein intake reduced total cholesterol by 9.3%, LDL (“bad”) cholesterol by 13%, and triglycerides by 10.5%. Meanwhile, it raised the “good” cholesterol, HDL, by 2.4%. In this study review, how much it lowered cholesterol depended on what the cholesterol levels were to begin with. Those with very high levels — over 335 milligrams per deciliter (mg/dL) — had the biggest reduction, at 20%. Yet those between 259 and 333 mg/dL had a seven-percent reduction. Those with levels below 255 mg/dL experienced no effect.
After this groundbreaking study, the U.S. Food and Drug Administration approved the claim that “25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”
Then a study came out analyzing 23 previous trials from 1995 through 2002. It covered about 1,800 patients. It proved that soy with isoflavones significantly lowered total cholesterol (four percent), LDL levels (five percent), and triglycerides (seven percent), while increasing HDL levels by about three percent. It had greater effects in men and in premenopausal women and people with higher initial cholesterol levels.
The American Heart Association acknowledges that, in most trials, soy protein with isoflavones lowers LDL levels to an average of three percent. They don’t think it has much effect on all the other items mentioned thus far. So why the different viewpoints, the unequal results? One factor is whether the person is or isn’t a good “equol-producer.” Equol is a chemical within isoflavones.
Some people can produce equol from soy and some can’t. An estimated 30% to 50% of all adults don’t produce equol. One study found major differences in patients with high cholesterol treated with soy foods. Of 23 women, eight were equol-producers. For them, five servings a day of soy for five weeks significantly lowered total cholesterol (8.5%), LDL levels (10%), and triglycerides (21%).
In part three I look at soy’s effects on diabetes and blood pressure. You can read part one of this series right here.