Soy Phytoestrogens Reduce Carotid Atherosclerosis As Much As Premarin

March 20, 1998

WINSTON-SALEM, NC -- Postmenopausal hormone replacement therapy markedly reduces the occurrence of atherosclerosis in the internal carotid artery in monkeys, a Wake Forest University Baptist Medical Center research team reported today at an American Heart Association meeting in Santa Fe, NM.

Blockage of the internal carotid artery is a leading cause of stroke.

The team found that hormone replacement therapy from soy protein with phytoestrogens provided equivalent stroke-prevention benefits to the standard Premarin therapy prepared from mammalian estrogens.

"Phytoestrogens were as robust as Premarin," said Thomas B. Clarkson, D.V.M., professor of comparative medicine at the Wake Forest University School of Medicine.

Clarkson and his colleagues presented their findings at AHA's 38th Annual Conference of Cardiovascular Disease, Epidemiology and Prevention.

Clarkson noted that several recent studies done elsewhere had reached differing conclusions regarding the benefits of hormone replacement therapy in preventing stroke. Stroke ranks third as a cause of death for middle-aged and older women. A 50-year-old white woman has a 20 percent probability of developing a stroke sometime in her remaining lifetime.

He said that one review of seven studies of stroke deaths among postmenopausal users of estrogen replacement therapy found a reduction of risk ranging between 20 and 60 percent compared to women who were not using estrogen replacement therapy. But an English study found no benefit, and a third hinted that estrogen replacement therapy might actually be making strokes more severe.

"Given the uncertainties about the effect of estrogens on stroke and stroke risk, it seemed to us important to place a major focus on the evaluation of internal carotid artery atherosclerosis, the lesion site most commonly associated with cerebrovascular symptoms of human primates," Clarkson said.

Clarkson and Mary Anthony, research associate in the Department of Comparative Medicine, compared the effects of treatment with mammalian estrogens -- Premarin -- with treatment with soy phytoestrogens in postmenopausal monkeys, all of whom had been fed a "non-prudent diet" -- a diet high in cholesterol.

The study was part of an overall program project which is looking at the potential benefits of soy phytoestrogens as a postmenopausal therapy. The program project is financed by the National Heart Lung and Blood Institute. The soy phytoestrogen used in the study was provided by Protein Technologies International.

The results showed that both forms of estrogen replacement therapy cut internal carotid artery atherosclerosis by more than half, compared to postmenopausal monkeys who did not receive estrogens. The results were statistically significant.

But the effect on the size of the atherosclerotic plaque was much less dramatic, though both forms of estrogen did reduce the size of the plaque.

"The primary effect of the intervention is in preventing atheroscerlosis from ever occuring," Clarkson said. "Once atherosclerosis begins to develop, there is only a small effect of the two interventions."

Clarkson and Anthony also concluded that the primary way that either form of estrogen replacement therapy works is by preventing the development of what they call an "atherogenic plasma lipid profile" -- or serum cholesterol levels that lead to atherosclerosis -- despite the high cholesterol diet.
-end-
Contact: Bob Conn or Jim Steele at 336-716-4587
-end-


Wake Forest Baptist Medical Center

Related Stroke Articles from Brightsurf:

Stroke alarm clock may streamline and accelerate time-sensitive acute stroke care
An interactive, digital alarm clock may speed emergency stroke care, starting at hospital arrival and through each step of the time-sensitive treatment process.

Stroke patients with COVID-19 have increased inflammation, stroke severity and death
Stroke patients who also have COVID-19 showed increased systemic inflammation, a more serious stroke severity and a much higher rate of death, compared to stroke patients who did not have COVID-19, according a retrospective, observational, cross-sectional study of 60 ischemic stroke patients admitted to UAB Hospital between late March and early May 2020.

'Time is vision' after a stroke
University of Rochester researchers studied stroke patients who experienced vision loss and found that the patients retained some visual abilities immediately after the stroke but these abilities diminished gradually and eventually disappeared permanently after approximately six months.

More stroke awareness, better eating habits may help reduce stroke risk for young adult African-Americans
Young African-Americans are experiencing higher rates of stroke because of health conditions such as high blood pressure, diabetes and obesity, yet their perception of their stroke risk is low.

How to help patients recover after a stroke
The existing approach to brain stimulation for rehabilitation after a stroke does not take into account the diversity of lesions and the individual characteristics of patients' brains.

Kids with headache after stroke might be at risk for another stroke
A new study has found a high incidence of headaches in pediatric stroke survivors and identified a possible association between post-stroke headache and stroke recurrence.

High stroke impact in low- and middle-income countries examined at 11th World Stroke Congress
Less wealthy countries struggle to meet greater need with far fewer resources.

Marijuana use might lead to higher risk of stroke, World Stroke Congress to be told
A five-year study of hospital statistics from the United States shows that the incidence of stroke has risen steadily among marijuana users even though the overall rate of stroke remained constant over the same period.

We need to talk about sexuality after stroke
Stroke survivors and their partners are not adequately supported to deal with changes to their relationships, self-identity, gender roles and intimacy following stroke, according to new research from the University of Sydney.

Standardized stroke protocol can ensure ELVO stroke patients are treated within 60 minutes
A new study shows that developing a standardized stroke protocol of having neurointerventional teams meet suspected emergent large vessel occlusion (ELVO) stroke patients upon their arrival at the hospital achieves a median door-to-recanalization time of less than 60 minutes.

Read More: Stroke News and Stroke Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.