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 Cancer cells make blood vessels drug resistant during chemotherapy
02.07.2020 | Hokkaido University

nachricht Novel potassium channel activator which acts as a potential anticonvulsant discovered
02.07.2020 | The Mount Sinai Hospital / Mount Sinai School of Medicine

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: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

Im Focus: AI monitoring of laser welding processes - X-ray vision and eavesdropping ensure quality

With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.

Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

 
Latest News

Rising water temperatures could endanger the mating of many fish species

03.07.2020 | Life Sciences

Risk of infection with COVID-19 from singing: First results of aerosol study with the Bavarian Radio Chorus

03.07.2020 | Studies and Analyses

Efficient, Economical and Aesthetic: Researchers Build Electrodes from Leaves

03.07.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>