Green tea compounds can protect heart health
According to a new study, a molecule found in green tea might help protect against atherosclerosis, which is a common cause of heart attacks and strokes.
Atherosclerosis is the buildup of plaque inside the arteries.
Starting as fatty streaks on the walls of blood vessels, they slowly grow in size into hardened plaques; this makes the arteries narrower, reducing blood flow.
When vessels become blocked, certain body parts receive less oxygen-rich blood which keeps them healthy.
When atherosclerosis develops slowly, there are few symptoms. However, over the years, problems can begin to surface.
Depending on the location of the affected artery, atherosclerosis can cause a number of problems, such as coronary artery disease, which is a reduction in blood flow to the heart muscles, and stroke, which is characterized by reduced blood flow in part of the brain.
Several risk factors for atherosclerosis are known; they include being overweight, diabetic, and having high blood pressure or cholesterol levels.
As some of these factors increase in prevalence, there is a push to find innovative ways to tackle atherosclerosis and stop it in its tracks.
Add green tea
The list of health benefits of green tea is said to be almost endless. From cancer fighting powers to weight loss miracles, green tea has been considered the elixir of life. However, this research does not support many of these claims.
When speaking to the UK's National Health Service (NHS) about the health benefits of green tea, Alison Hornby - from the British Dietetic Association in Birmingham, in the UK - put it succinctly, saying, ''Evidence for the majority of these conditions is weak or deficient. "
However, because green tea contains so many compounds, scientists are still dissecting the components of the drink to tease out any potentially bioactive molecules.
One such chemical is epigallocatechin-3-gallate (EGCG). It is found in green, black, and white teas, but is most abundant in the dry leaves of green tea.
Scientists have shown that this compound binds to apolipoprotein A-1 (apoA-1), a protein that behaves similarly to the amyloid plaques found in the brains of people with Alzheimer's disease. Because of this, studies have explored the potential use of EGCG against Alzheimer's.
Recently, a team of researchers from Lancaster University and the University of Leeds, both in the UK, wondered whether EGCG might also be able to help fight atherosclerosis.
In atherosclerosis, apoA-1 attaches to plaques, making them larger and further restricting blood flow. If it could be dissolved, it might ease the condition.
As expected, they found that EGCG cleaved apoA-1 in the presence of heparin, a natural anticoagulant. The combination of molecules converts apoA-1 into a smaller, more soluble molecule that is less likely to restrict blood flow.
These results were published recently in the Journal of Biological Chemistry.
More work needed
It is important to note that, in order to get adequate levels of EGCG into the bloodstream, one must drink very large and possibly harmful green teas.
Researchers are interested in studying EGCG further; they hoped to find a way to increase its levels in circulation.
Prof Jeremy Pearson, associate medical director at the British Heart Foundation, explains, "Our bodies are very good at breaking down EGCG, so swapping your cuppa for green tea is unlikely to make a huge difference when it comes to your heart health."
"But," he adds, "with a little molecular engineering, we might be able to create new drugs to treat heart attacks and strokes."
The findings of this study are very encouraging. We now need to apply the best scientific techniques to discover how we can take the elemental molecule EGCG from green tea, and turn it into a working tool to combat life-limiting health problems.
-Co-author Prof. Sheena Radford
These are early days in green tea's battle against atherosclerosis, but researchers are excited about EGCG's possible future.
