BY THE OPTIMIST DAILY EDITORIAL TEAM
Every fall, the same conversation starts about how to stay well through cold and flu season. Most of the advice points to supplements: vitamin C, zinc, elderberry. Useful, but not the whole picture. The spice rack you walk past every morning has something to say about immunity too, and the research behind it is more substantial than most people expect.
Six common herbs and spices- turmeric, garlic, ginger, oregano, basil, and rosemary- contain bioactive compounds that support immune function through antioxidant, anti-inflammatory, and antimicrobial effects. They are not replacements for sleep, exercise, or a balanced diet, but as a regular part of how you cook, they do real work. Here is what registered dietitians say about each one.
Turmeric
Turmeric’s immune benefits come down to curcumin, its main active compound. “Curcumin promotes the health of T cells, B cells, and macrophages, the cells your immune system uses to fight germs and other threats,” says Mindy Haar, Ph.D., R.D.N., department chair of interdisciplinary health science at the New York Institute of Technology’s School of Health Professions. Haar also notes that curcumin “lowers the activity of proteins that trigger the production of inflammatory chemicals in the body,” which matters because chronic inflammation raises the risk of illness.
The catch is that the body does not absorb curcumin well on its own. Haar’s fix is simple: combine turmeric with a small amount of black pepper, roughly one-eighth to one-quarter teaspoon. Black pepper contains piperine, which slows curcumin’s breakdown in the digestive system and allows more to reach the bloodstream. Turmeric stirred into lentil soup, a golden milk before bed, or blended into a smoothie all work fine. Just do not forget the pepper.
Garlic
Garlic’s main bioactive compound is allicin. “Allicin has been found to be antifungal, antibacterial, antiviral, and antimicrobial, which is great for fighting the common cold and infections,” says Johanna P. Salazar, M.S., R.D.N., founder of Healing Nutrition. Registered dietitian Tammy Lomond, R.D., of JM Nutrition, points to a scientific review showing compounds like allicin can improve how the immune system performs, and notes it also has antioxidant properties that protect immune cells from oxidative stress.
The gut angle matters too. “Garlic is a great prebiotic, which helps feed the good bacteria in your gut,” Salazar says. A well-fed gut microbiome and a well-functioning immune system run on the same tracks.
Ginger
Ginger contains gingerol, a compound with anti-inflammatory and antioxidant effects that protect immune cells. “Gingerols do this by suppressing inflammatory processes and pathways,” says Seema Shah, R.D., owner of SeemaShahRD Whole Nutrition. Shah says the result is that “immune cells have increased stamina to fight infection and a more robust response to pathogens.” A study she cites found that gingerols elevated the responsiveness of neutrophils, a type of white blood cell, by 30 percent. Fresh ginger in a hot cup of tea or added to a vegetable broth is one of the easiest ways to use it regularly.
Oregano
Oregano contains carvacrol and thymol, two compounds that have shown protection against viruses and bacteria in lab studies, along with rosmarinic acid, which limits the production of inflammatory substances in the body. “Oregano supports immune health, as it contains several compounds that have antioxidant and antimicrobial properties,” Haar says. Fresh oregano is good stirred into sauces or scattered over a finished dish right before serving.
Basil
Basil brings more to the table than most people realize. It contains apigenin, linalool, and ursolic acid, all bioactive compounds with antiviral properties, according to Salazar, plus vitamins A and C, both antioxidants that fight free radicals and reduce oxidative stress.
It also has quercetin and anthocyanins. Quercetin helps the body absorb more zinc, another immune-supporting nutrient. Anthocyanins support a balanced gut microbiome, which Shah says is central to immune function: “the vast majority of our immune system resides in the gut.” Basil works well used as you would any leafy green, folded into salads or tossed with grains.
Rosemary
Rosemary contains linalool, carnosic acid, rosmarinic acid, and carnosol. Linalool has antimicrobial and anti-inflammatory activity. “Antioxidants such as carnosic acid and rosmarinic acid help reduce oxidative stress and inflammation,” Lomond says. Salazar points out that carnosic acid also helps the body produce glutathione, a powerful antioxidant it makes naturally, which adds another layer of immune support. Rosemary holds up well to heat, which makes it a natural fit for roasted proteins and vegetables.
Fresh or dried: does it matter?
Fresh herbs generally contain more antioxidants and anti-inflammatory compounds than dried, Lomond says. That said, dried herbs “contain more concentrated amounts of minerals and essential oils,” she notes, and last much longer in the pantry. When fresh is easy, use it. Dried is a perfectly good backup.
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