Dietary supplements. Natural remedies. Botanicals. Energy drinks. Wellness boosts. Health foods. Vitamins.

When choosing whether or not to use dietary supplements or other natural products, there are a lot of questions about the value of these products and their benefits. They often claim to be “all natural,” but that doesn’t necessarily make them safe for you. Natural products are not required to go through the same rigorous research and clinical trials as pharmaceuticals prior to marketing, so many potential health dangers are simply unknown.

Researcher Mary Paine, associate professor at Washington State University’s College of Pharmacy and Pharmaceutical Sciences in Spokane and a registered pharmacist, wants to uncover potential interactions that may cause health risks with products like the wheat grass and bee pollen in your smoothie, the echinacea in your natural cold remedy, and the licorice and catnip in your herbal tea.

Many people turn to natural products for health benefits but also take at least one prescribed conventional medication. According to Paine, there needs to be more definitive information available to health-care providers and patients about the risks of supplementing prescribed drug regimens with natural products. Interactions between natural products and conventional drugs are a concern because of their potential impact on drug effectiveness or toxicity.

“Patients often seek herbal and other natural products as a ‘natural,’ and therefore perceived as ‘safe,’ means to alleviate illnesses or supplement prescribed therapeutic regimens,” Paine says. “Co-consuming natural products with conventional medications—either prescription or over-the-counter—can lead to adverse interactions.”

For example, St. John’s wort is a flowering plant used as an herbal remedy for mild to moderate depression, but has several known drug interactions including some post-organ transplant medications, which renders them ineffective.

Adverse health effects could impact anyone looking to use natural products and conventional medications at the same time. According to the CDC, nearly half of the American population in 2016 had used at least one prescription drug in the past 30 days—nearly 158 million prescriptions, not even accounting for people taking multiple medications.

To explore the potential impacts, Paine helped create the Center of Excellence for Natural Product-Drug Interaction Research (NaPDI Center) at WSU Spokane. Through a $10 million, five-year grant from the National Institutes of Health National Center for Complementary and Integrative Health, experts in clinical pharmacology, natural products chemistry, health informatics, and health communications will study the interactions between natural products and conventional drugs.

The NaPDI Center will also recommend detailed steps for studying pharmacokinetic interactions between natural products and drugs—how a natural product can alter the absorption, distribution, metabolism, or excretion of a drug. Their work, already published in a number of journals, could help develop policy, regulations, best practices, and the individual adoption and integration of natural products into the medication therapy of patients.

In the future the NaPDI Center hopes to extend its online database to health-care practitioners to both proliferate quality science and offer useful data for the health-care community.

Paine and the center is also preparing for the next, and perhaps most challenging, natural product on its research list: cannabis. “The legal and regulatory hoops are substantial, but this is when we need the scientific information to be reliable,” says Paine.

Reliable, high-quality data on clinical interactions between cannabis and pharmaceuticals remains scarce, which makes the NaPDI Center’s recommended approaches to studying natural products important for rigorous study of the plant.


On the web

“WSU leads in expanding scientific knowledge on natural products”
(full version of this story)

Part 1: Expanding scientific knowledge

Part 2: The NaPDI Center

Part 3: The future of the NaPDI Center and the public health impact