Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Estrogens as antioxidants - reducing heart disease in younger postmenopausal women

07.07.2003


HRT could be used to protect younger postmenopausal women from heart disease. An article published in the journal Lipids in Health and Disease shows that estrogens commonly used in HRT reduce the build up of harmful oxidised lipoproteins, which can lead to heart disease, by acting as antioxidants.



It is well known that high-density lipoproteins (HDL) protect against heart disease while low-density lipoproteins (LDL) promote it. However, recent research has shown that the relationship is not that simple. The effectiveness of both types of lipoprotein change when they are oxidised by free radicals – highly reactive by-products of metabolism. If LDL becomes oxidised its ability to cause heart disease increases. If HDL becomes oxidised its ability to protect against heart disease is lessened.

Researchers from St. Michael’s Hospital, part of the University of Toronto, have shown that estrogens can act as antioxidants, which neutralise free radicals, and hence protect HDL from oxidation. In addition, high levels of HDL are able to protect LDL from oxidation, and this ability is strongly enhanced when estrogens are present.


Dr Bhagu Bhavnani’s team, who carried out the research, write, “The inhibition of HDL oxidation and the enhancement provided by estrogens toward the inhibition of LDL oxidation may be another way in which estrogens reduce the risk of coronary heart disease in healthy young postmenopausal women.”

Although recent randomised control trials have shown that HRT in older women may not reduce the incidence of coronary heart disease, Dr. Bhavnani believes that this is not the whole story. Although his team carried out experiments in test tubes rather than in human subjects they saw that estrogen had beneficial effects at concentrations lower than those found in women on HRT. He urges that, “randomised control trials using lower doses of HRT, different estrogens and progestins, and in younger postmenopausal women, from 50 to 60 years, are urgently needed to resolve the confusion created by recent studies”.

The research team used blood taken from men and postmenopausal women to carry out experiments in vitro. They measured the resistance of HDL to oxidation in the presence or absence of increasing concentrations of eleven different estrogens. All of these estrogens are components of a combined estrogen supplement that is commonly used for HRT by postmenopausal women. They then assessed whether the presence of HDL increased the resistance of LDL to oxidation, and if this resistance was further enhanced by the addition of estrogen.

They found that all the estrogens tested were able to protect HDL from oxidation and to enhance HDL’s ability to protect LDL from oxidation. They also found that different estrogens had different potencies as antioxidants, with an estrogen called Equilenin being the most effective.

According to recent data from the British Heart Foundation, women are five times less likely to suffer from coronary heart disease than men. This reduced risk can only partly be explained by differences in behaviour, such as smoking or stress levels. As women’s risk of heart disease increases after menopause it has been suggested that ovarian hormones such as estrogen play a role in protecting younger women from the disease. The research from Bhavnani’s team supports this idea.

Gemma Bradley | BioMed Central
Further information:
http://www.biomedcentral.com
http://www.lipidworld.com/content/2/1/4

More articles from Health and Medicine:

nachricht Hot cars can hit deadly temperatures in as little as one hour
24.05.2018 | Arizona State University

nachricht 3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>