Researchers in Canada say that anti-anemia drugs, commonly used in place of blood transfusions to replace red blood cells in chemotherapy patients, may actually cause hematological issues such as blood clotting that could result in serious consequences.

They reviewed the findings of more than 12,000 patients in 52 clinical trials to further the information on cancer-related anemia, and found that the risk of death for those patients increased by about 15 percent when taking the drugs.

Although the treatments may still be warranted for situations where transfusions are not an option, researchers argue that policies should "recommend against the routine use of erythropoiesis-stimulating agents as an alternative to blood transfusion in patients with cancer," according to the study.

While iron is generally accepted as one way to limit the effects of anemia, several other supplements may help those at risk to maintain or improve heart health.

For example, scientists at the University of Porto found that certain antioxidants in olive oil helped maintain red blood cell function, allowing the cells that exist to work more efficiently.

Grapes and grapeseed extract may also minimize one effect of anti-anemia medications, according to researchers in Australia who found that the fruits limit blood clotting.