Heart protection with ASA: 100 mg are only enough for slim people

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

More posts by Christiane Fux All content is checked by medical journalists.

Acetylsalicylic acid (ASA) is not only a popular pain reliever, it also thins the blood. This has advantages: taken daily, ASA is said to protect against strokes and heart attacks. Many people at an increased risk of cardiovascular disease swallow 75 to 100 mg a day. But that is often not enough.

A team led by Peter Rothwell from the University of Oxford has now investigated how well the protective effect of low doses of ASA works in people of different body weights.

For this purpose, the researchers evaluated a total of nine studies on this topic in which the participants had not yet experienced a serious cardiovascular event, as well as four studies in which the subjects swallowed ASA after they had already suffered a heart attack or stroke. In total, the researchers recorded data from more than 117,000 participants.

The result: The daily ASA tablet with 75 to 100 mg of active ingredient only developed the hoped-for effect in those participants who weighed less than 70 kg. Their risk of premature death from heart attack or stroke decreased by 25 percent if they swallowed low-dose ASA daily.

For many, 100 mg is not enough

All participants who were heavier benefited less or not at all from the blood-thinning pills. With them only a much higher dose of 325 mg ASA daily or more worked reliably. However, such a high dose is associated with a greater risk of bleeding, for example gastric bleeding. For very light people who weigh less than 50 kilograms, the low dose could already be too high.

ASA not only protects against heart attacks and strokes, it also lowers the risk of developing colon cancer. Here the magic limit of the low dose is 80 kilograms of body weight. Those who are heavier do not benefit from the low ASA dose in this respect either.

But there is another limit to the anti-cancer effect of ASA: age. Participants over 70 years of age who took ASA daily were even 20 percent more likely to get sick - especially if they weighed less than 70 kilos.

Each dose has its therapeutic window of action

"There seems to be a therapeutic window in which a certain dose, depending on the weight, has the optimal effect," the authors write. The “one-dose-for-all” application of ASA is therefore not optimal. Instead, you need a strategy that is better tailored to the individual, write the authors.

Tags:  laboratory values tcm hair