Both studies explore one particularly controversial aspect of the guidelines: a special formula
that predicts a person's cardiovascular event risk by taking into account risk factors such as age, blood pressure and cholesterol levels.
The guidelines were issued in an effort to save more lives by better management of cholesterol, but some experts have criticized them as giving too much leeway, thus needlessly treating people with cholesterol lowering medications.
One of the studies published Tuesday
found the 2013 cholesterol guidelines would prevent 40,000 to 60,000 more cardiovascular events over 10 years than the old rulebook for who should and shouldn't take statins. At least 40 million Americans currently take statins, which are medicines used to lower blood cholesterol levels.
"Statins are one of the most effective medicines, and this is reassuring that the new guidelines do work," said Dr. Udo Hoffmann, lead author of the study and professor of radiology at Harvard Medical School. Limitations of the study include that all the participants were Caucasian, which means the findings might not apply to the general population.
The other study published Tuesday
found the cardiovascular risk formula in the new guidelines is indeed cost-effective. Using a computer-generated model, researchers weighed the higher cost of prescribing more people statins against the health gains to see if it was worth it financially.
The lives saved were worth the extra cost, the study reports.
"In 2004, most statins were between one and two thousand dollars per year," said Dr. Thomas Gaziano, one of the study authors and assistant professor at Harvard Medical School. "Now most are generic, and only cost about 100 dollars for a year's supply."
Researchers took into account the psychological toll on patients of taking a pill every day, fluctuations in statin cost and the low risk that statins can cause diabetes.
"These drugs are really effective. They've been proven really safe," said Gaziano, adding that their findings back up the cardiovascular health risk formula set forth in the national guidelines
Dr Philip Greenland and Dr. Michael S. Lauer, believe these new studies settled the debate. "There is no longer any question as to whether to offer treatment with statins for patients for primary prevention, and there should now be fewer questions about how to treat and in whom," they wrote in an editorial
published with the two studies.
Critics of the cholesterol guidelines say they grossly overestimate the risk of people recommended to take statins. In terms of numbers, the new guidelines increase the number of Americans eligible for statins from about 40 million to 60 million people, according to a 2014 study
Not everyone is convinced these new studies are the final word on statin guidelines.
"I don't find these studies very compelling," said Dr. Steven Nissen, department chair of cardiovascular medicine at Cleveland Clinic. "In fact, many physicians consider the new  guidelines to be irrational," Nissen told CNN.
Nissen, an outspoken critic of the guidelines, has been involved in research of statin alternative drugs that were recommended by an FDA advisory committee in June
Nissen also questions the design of the two Harvard studies for not meeting the highest standards of scientific research. "The problem in this population [of the guideline accuracy study] is that they were selected to undergo calcium scanning." Nissen says this population isn't representative.
"We also don't place much stock in computer simulations," said Nissen.
Gaziano said he always encourages patients to change their lifestyle, including diet and exercise, before opting for a pill.
"If patients do not feel they are at the lowest risk they can be at with lifestyle modifications, statins can help lower their risk even more."