Heart attack

Women who take antibiotics over a long period of time are at increased risk of heart attack or stroke; according to research carried out in nearly 36,500 women. Women aged 60 or older who took antibiotics for two months or more had the greatest risk of cardiovascular disease; but the long duration of antibiotic use was also with an increased risk if taken during middle age (aged 40-59). The researchers could find no increased risk from antibiotic use by younger adults aged between 20-39.
Professor Lu Qi, says that a possible reason why antibiotic use is link to an increased risk of cardiovascular disease is that antibiotics alter the balance of the microenvironment in the gut, destroying “good” probiotic bacteria and increasing the prevalence of viruses, bacteria or other micro-organisms that can cause disease. “Antibiotic use is the most critical factor in altering the balance of microorganisms in the gut.

The macrobiotic environment

Previous studies have shown a link between alterations in the macrobiotic environment; of the gut and inflammation and narrowing of the blood vessels, stroke, and heart disease. After adjustments to take account of factors that could affect their results, such as age, race, sex, diet and lifestyle, reasons for antibiotic use; overweight or obesity, other diseases and medication use; the researchers found that women who used antibiotics for periods of two months or longer in late adulthood 32% more likely to develop cardiovascular disease than women who did not use antibiotics.

The study is the largest prospective study to investigate the link between antibiotic use and risk of heart disease and stroke; this is one of the strengths of the study, as well as the long follow-up and comprehensive information on factors that could affect the results such as lifestyle, diet, age, other diseases, and medication use. Limitations include the fact that the participants reported their use of antibiotics and so this could misremembered.

The information on medication

However, as all health professionals, they able to provide more accurate information on medication use than the general population. The researchers did not have information on the different classes of antibiotics used but believe that the most common type of prescription tends to depend on the infections it is treating, and information on these are in their analysis. As the study only looked at middle-aged and elderly women; the results cannot necessarily extrapolated to younger ages and to men.
Prof Qi concluded: “This is an observational study and so it cannot show that antibiotics cause heart disease and stroke; only that there is a link between them. It is possible that women who reported more antibiotic use might sicker in other ways that they are unable to measure; or there may other factors that could affect the results that they have not been able to take account of. “Their study suggests that antibiotics should used only when they are absolutely needed. Considering the potentially cumulative adverse effects; the shorter time of antibiotic use the better.”