Transcript: Inhibiting Platelet Aggregation with Berries
The Global Burden of Disease Study, funded by the Bill and Melinda Gates Foundation, is the most comprehensive and systematic analysis of causes of death undertaken to date, involving nearly 500 researchers from more than 300 institutions in 50 countries, starting out with almost 100,000 data sources. What did they find? Here in the U.S. they determined our #1 killer was our diet. #1 on their list of the most important dietary risks? Not eating enough fruit, responsible for an estimated 4.9 million deaths a year around the world.
The Union of Concerned Scientists laid it out. A set of dangerous, often lethal, illnesses continues to wreak havoc in the United States. Hundreds of thousands of Americans laid to waste. Yet there is a straightforward way to reduce the rates of these eminently preventable disorders, including stroke and heart disease. One antidote for individuals is easy, painless—even pleasurable: exploit the protective benefits of fruits and vegetables. If Americans increased their consumption of fruits and veggies just to meet the dietary recommendations, that alone could save the lives of over 100,000 people every year in the United States.
But how? One way may be because of their antiplatelet effects. Platelets are what trigger the blood clots that cause heart attacks and most strokes. But beyond their obvious function in blood clotting, platelets are now considered to play a pivotal inflammatory role in the hardening of the arteries in the first place, as well as allergies, rheumatoid arthritis and even cancer.
Now it’s important to realize that normally, under healthy conditions, platelets circulate in a quiescent, dormant, inactive state. But once they become activated they can emerge as culprits in inflammation. Platelets transport a vast amount of inflammatory chemicals. Upon activation, they release these chemicals, which can recruit the inflammatory cells that form the pus pockets within our arterial walls that can burst and kill us.
This involvement of platelet activation in atherosclerosis development is well established. We've long recognized the platelet's role in the final stages, however, a growing body of data indicates that platelets may also play an important role in the initiation and propagation of atherosclerosis in the first place, which is our nation's leading killer. So how can we prevent the excessive activation of platelets? Well, it’s generally recognized that platelet hyperreactivity is associated with high levels of cholesterol circulating in the blood, so we can cut down on foods that have trans fats, saturated fats, and dietary cholesterol, and we can eat more fruits and vegetables. For example, different varieties of strawberries have shown a significant antiplatelet effect in a petri dish and in people. Here’s how they figured it out. This is a platelet in a resting state, packed with little round granule grenades of inflammatory chemicals, which fuse together when the platelet gets activated and the delivery system dilates, before it releases its payload. Because resting and activated platelets look so different you can just take blood from people and count how many are resting and how many are activated before and after people eat more than a pint of strawberries every day for a month, and there’s a small but significant drop in the percentage of activated platelets circulating throughout their bodies after the strawberries.
Other berries had a similar effect, and at a more modest two servings a day. Drinking orange or grapefruit juice didn't seem to help, but purple grape juice successfully reduced platelet activity on the same order that aspirin does.
Studies have shown daily aspirin can reduce heart attacks and strokes, however, aspirin can also cause severe gastrointestinal disturbances and bleeding problems, so should not be used for the primary prevention of heart attacks and stroke, as the benefits don't clearly outweigh the serious risks, so it’s nice to have safe, side-effect free alternatives.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
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