Featured Research

from universities, journals, and other organizations

Wake Forest Study Shows Soy Containing A Key Ingredient Is What Lowers Cholesterol

Date:
March 25, 1998
Source:
Bowman Gray/Baptist Hospital Medical Center
Summary:
The cholesterol-lowering effect of soy is the result of natural compounds in the soy known as isoflavones, Wake Forest University Baptist Medical Center researchers reported recently at an American Heart Association meeting in Santa Fe, NM.

WINSTON-SALEM, NC -- The cholesterol-lowering effect of soy is the result of natural compounds in the soy known as isoflavones, Wake Forest University Baptist Medical Center researchers reported March 20 at an American Heart Association meeting in Santa Fe, NM.

John R. Crouse III, M.D., professor of internal medicine (endocrinology/metabolism) and public health sciences (epidemiology), said the project was the first to dissect the effects of isoflavones in soy from the overall soybean.

Crouse and his colleagues studied 156 patients with moderately elevated cholesterol levels who were randomly assigned to receive a soy drink containing soy protein either with or without isoflavones. Another group of patients got a beverage containing casein, the principal protein of cow's milk, but no soy protein or isoflavones.

Soy drinks containing isoflavones reduced both total cholesterol and low-density lipoproteins, LDL, the so-called bad cholesterol, said Crouse. In patients who started with a high LDL cholesterol, the effect was even more dramatic -- a 10 percent reduction in just nine weeks. Soy protein from which isoflavones were removed by alcohol extraction had no such effect.

"The conclusion is that the active ingredient in soy is the isoflavones," Crouse told the AHA's 38th Annual Conference of Cardiovascular Disease, Epidemiology and Prevention.

Scientists have long known that cardiovascular deaths and illnesses were lower in people who lived in the Far East than in Western countries. They suspected that the soybean might be part of the difference, since soy consumption is high in the Pacific Rim countries and uncommon in the West. Naturally occurring soy contains high concentrations of isoflavones, also known as phytoestrogens.

Studies in monkeys, mostly conducted at Wake Forest, showed that soy containing these phytoestrogens had many of the same benefits as the standard estrogen replacement therapy, including lowering of cholesterol, reducing the risk of hardening of the arteries, and overall, improving the function of arteries.

Crouse said prior studies of the effects of soy on blood cholesterol in people had showed variable results, though overall these earlier studies did show a reduction in total cholesterol, LDL and triglycerides.

But none of these earlier studies attempted to determine whether the cholesterol-lowering effect came from the soy protein or from the isoflavones in soy.

Crouse's study gave patients 25 grams of proteins at each serving from identical containers with 25, 42, 58 or 4 milligrams of isoflavone or the inert casein. Neither patients nor staff knew which patients were on which treatment. The study produced stepwise results: the higher the concentration of isoflavones, the greater the reduction in both total and LDL cholesterol. The alcohol-extracted soy drink with just the 4 milligrams of isoflavone and the casein drink had no effect.

The study's 156 participants included 38 post-menopausal women, 24 pre-menopausal women, and 94 men, whose average age was 52. The average total cholesterol was 241, which is considered moderately elevated. The average LDL cholesterol was 164, also moderately elevated.

"Overall the soy product was extremely well tolerated and no participant dropped out of the study because of adverse effects of the soy product," Crouse said.

Though tofu is a soy product containing isoflavones, the Wake Forest investigators used soy drinks supplied by Protein Technologies International of St. Louis, Mo. Protein Technologies also paid for the study.


Story Source:

The above story is based on materials provided by Bowman Gray/Baptist Hospital Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Bowman Gray/Baptist Hospital Medical Center. "Wake Forest Study Shows Soy Containing A Key Ingredient Is What Lowers Cholesterol." ScienceDaily. ScienceDaily, 25 March 1998. <www.sciencedaily.com/releases/1998/03/980325074941.htm>.
Bowman Gray/Baptist Hospital Medical Center. (1998, March 25). Wake Forest Study Shows Soy Containing A Key Ingredient Is What Lowers Cholesterol. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/1998/03/980325074941.htm
Bowman Gray/Baptist Hospital Medical Center. "Wake Forest Study Shows Soy Containing A Key Ingredient Is What Lowers Cholesterol." ScienceDaily. www.sciencedaily.com/releases/1998/03/980325074941.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microneedle Patch Promises Painless Pricks

Microneedle Patch Promises Painless Pricks

Reuters - Innovations Video Online (Oct. 18, 2014) Researchers at The National University of Singapore have invented a new microneedle patch that could offer a faster and less painful delivery of drugs such as insulin and painkillers. Video provided by Reuters
Powered by NewsLook.com
Raw: Nurse Nina Pham Arrives in Maryland

Raw: Nurse Nina Pham Arrives in Maryland

AP (Oct. 17, 2014) The first nurse to be diagnosed with Ebola at a Dallas hospital walked down the stairs of an executive jet into an ambulance at an airport in Frederick, Maryland, on Thursday. Pham will be treated at the National Institutes of Health. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Raw: Cruise Ship Returns to US Over Ebola Fears

Raw: Cruise Ship Returns to US Over Ebola Fears

AP (Oct. 17, 2014) A Caribbean cruise ship carrying a Dallas health care worker who is being monitored for signs of the Ebola virus is heading back to Texas, US, after being refused permission to dock in Cozumel, Mexico. (Oct. 17) Video provided by AP
Powered by NewsLook.com
Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

Spanish Govt: Four Suspected Ebola Cases in Spain Test Negative

AFP (Oct. 17, 2014) All four suspected Ebola cases admitted to hospitals in Spain on Thursday have tested negative for the deadly virus in a first round of tests, the government said Friday. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins