Busting myths: Can a diet rich in herbs and spices prevent cancer and disease?

Do herbs and spices have clinical value?
Touting the health benefits of herbs and spices is a multibillion-dollar industry. But many health claims are, at best, inconclusive.

For centuries, herbs and spices have been used for more than just cooking. Egyptians used the ingredients to mummify the dead. Some cultures used spices as currency or as a way to establish trade with new lands. Herbs and spices were used to preserve meat before refrigeration. And some cultures used them for their purported medicinal properties.

While we no longer use aromatics as currency or to bury the dead, touting the health benefits of herbs and spices has become a multibillion-dollar industry. But before you turn your spice rack into a medicine cabinet, consider that the health claims associated with many seasonings and herbal supplements are, at best, inconclusive, according to the National Center for Complementary and Integrative Health (NCCIH). And most claims that herbs and spices may help prevent cancer are not backed by clinical evidence.

“Certain spices and herbs may be of value in symptom and side-effect management, such as in easing chemotherapy-induced nausea and vomiting,” says Maurie Markman, President of Medicine & Science at Cancer Treatment Centers of America® (CTCA). “But there is no evidence for a role for such products in the prevention or treatment of cancer.”

Science behind the spices

For some people, a little spice adds a dash of comfort and nostalgia to certain foods. When Mom sprinkled a touch of cinnamon into your hot cocoa or dropped a clove in your tea when you were sick, it made you feel better even if wasn’t actually making you better. But there is some  science behind many of the health claims associated with many seasonings. For instance:

Cloves contain the compound eugenol, which may be found in substances used to relieve dental pain. According to the U.S. National Library of Medicine, there is limited research to prove that cloves by themselves can relieve pain or reduce inflammation. Cloves are popular, however, for seasoning a baked ham and adding flavor to some teas and, of course, pumpkin pie.

Turmeric contains curcuminoids, which are believed to have anti-inflammatory properties. But, according the NCCIH, “claims that curcuminoids found in turmeric help to reduce inflammation aren’t supported by strong studies.” Turmeric can add a rich flavor to soup, sauces and stews.

Cinnamon and cinnamaldehyde, the substance that gives the spice it’s aroma and flavor, are subjects of research on Alzheimer’s disease and multiple sclerosis. But for now, according to NCCIH, “studies done in people don’t support using cinnamon for any health condition.” But many people use it to spice up their morning oatmeal and apple dishes.

Ginger contains several substances that give the root its signature flavor and pungency. And it has been researched, without conclusive evidence, to treat arthritis and cancer. But ginger may be used to help ease nausea.

“You see all sorts of claims about turmeric for its potential anti-inflammatory property,” says Carolyn Lammersfeld, Vice President of Integrative Care Services at CTCA®.  “The challenge is, after you dig into those claims, the amounts you’d have to consume in your diet to get the benefit isn’t realistic. Small studies reporting benefit use curcumin supplements, which have the potential for interactions with medications, and therefore should be discussed with your healthcare provider. This doesn’t mean it’s a bad idea to incorporate it into your diet. But the claims about health benefits may be hard to implement.

All about antioxidants

Many herbs and spices are highly touted for their high concentration of antioxidants and their ability to fight a process called oxidative stress, which can cause cell damage. Oxidative stress occurs when the body produces too many free radicals, which are unstable molecules that form when atoms with unpaired elections latch onto other atoms. Our bodies are constantly producing free radicals, and lifestyle choices and environmental factors—such as stress, smoking, a poor diet, and exposure to contaminants, pollutants or excessive sunlight—may lead to rapid free-radical production. Left unchecked, free radicals may quickly multiply, leading to oxidative stress, which may cause cell damage and lead to potential health issues. To fight free radicals, the body relies on antioxidants, which are compounds that can either disassemble unstable molecules or neutralize them. Just as the digestive system needs a balance of good and bad bacteria, the body requires an equilibrium between free radicals and antioxidants.

The debate rages, however, over the impact free radicals and antioxidants can have on disease and overall health, posing questions that have yet to be conclusively answered, like:

  • Can oxidative stress cause cancer or other diseases?
  • Can antioxidants help repair DNA and prevent cancer?
  • Can a diet that includes antioxidant-rich herbs, spices and other foods help prevent cancer and other conditions?

“There is ongoing research on the potential role of antioxidants in a variety of clinical conditions,” Dr. Markman says. “There is currently no evidence of a role for such strategies in the treatment or prevention of cancer.”

Know your supplements

Americans spend about $1 billion a year on herbs and spices, mostly for use in cooking. But in seeking more of a health boost, Americans spent more than $8 billion on herbal dietary supplements in 2017, nearly double the amount spent in 2000, according to industry sources quoted by the American Botanical Council. So, is money spent on herbs, spices and supplements being poured down the drain? Not necessarily. Like many foods, seasonings have nutritional value and can add rich flavors to healthy, well-balanced meals. “We turn to spices to add flavor to food without adding as much or any salt or sodium,” Lammersfeld says. “So, from a standpoint you are reducing sodium and may help to reduce blood pressure.” Seasonings may also encourage you to eat healthier by making vegetables tastier.

If you choose to try supplements, be aware of potential side effects and drug interactions and their purity and potency. Some supplements don’t interact well with prescription drugs. For instance, St. John’s wort, a popular herbal supplement touted to help treat depression, may weaken the potency of medications such as birth control pills and antidepressants. And studies show that St. John’s wort may interfere with cancer drugs, such as irinotecan, a chemotherapy drug used to treat colorectal cancer.

“One of the major concerns with the use of unregulated, orally ingested supplements is for potential interactions with established, effective treatment strategies,” Dr. Markman says. “This includes both increasing toxicity and accelerating the metabolism of an agent, potentially reducing its effectiveness. Patients interested in taking supplements should be encouraged to openly discuss their plans with their health care providers.”   

What’s the difference?

Herbs and spices come from different parts of plants or trees.

  • Spices are derived from the root, stem, bark or seed of a plant or tree.
  • Herbs are the plant’s leaves.

Some plants can produce both. For instance, coriander (the seeds) and cilantro (the leaves) come from the same plant–coriandrum sativum.

Get healthy recipes for savory main dishes and sweet desserts.