Oxidative Stress: What It Is, Why It Happens, And How To Fight It

In the kitchen an off-kilter ratio may ruin a post-workout shake, but in your body it can cause something much more serious: oxidative stress. 

“Oxidative stress occurs when there are too many harmful molecules in your body compared to the antioxidants needed to clean them up,” says certified nutritionist and personal trainer Lisa Schultz C.N., C.P.T, creator of the Vendura Method for healthier eating. This imbalance—between unstable, damage-causing compounds known as free radicals and the antioxidants that neutralize them—can disrupt normal cellular function and set the stage for both short-term and long-term health concerns, she says.

Oxidative stress is no joke, and none of us are immune. “But the good news is that there’s plenty we can do to tip the ratio back in our favor,” says Schultz. In fact, the most effective way to fight oxidative damage is with your fork. 

Ahead, experts share more about what oxidative stress is and what causes it to build up in excess, plus four food-based strategies that can help restore balance one bite (or sip) at a time.

• ABOUT OUR EXPERTS: Lisa Schultz C.N., C.P.T, is a certified nutritionist, personal trainer and the creator of the Vendura Method. Jenna Volpe, R.D.N., L.D., C.L.T., is a holistic and functional registered dietitian and the founder of Whole-istic Living. 

What Is Oxidative Stress, Exactly? 

Simply put, oxidative stress is the consequence of cellular imbalance. It happens when the body’s internal cleanup crew, made up of antioxidants, is overwhelmed by the number of troublemaking chemicals, known as free radicals, says Schultz. 

Some free radicals are totally normal—even useful. As Schultz explains, “Your body naturally creates free radicals whenever it breaks down and digests food or exercises.” When things are running smoothly, the body is able to neutralize these chemicals on its own with its natural antioxidant defenses, keeping oxidative stress at bay. The problem arises when free radicals outnumber antioxidants, creating the kind of imbalance that leads to damage at the cellular level. 

Because oxidative stress leads to cellular damage, it can contribute to a range of health concerns over time, according to holistic and functional registered dietitian Jenna Volpe, R.D.N., L.D., C.L.T., founder of Whole-istic Living. 

Read More: 5 Antioxidant Supplements To Prioritize For Head-To-Toe Health

Common Causes of Oxidative Stress 

A little oxidative stress is actually beneficial. Your body relies on it to adapt and grow stronger after workouts, fight off pathogens, and build resilience, according to Schultz. “The key is balance,” she says. And unfortunately, modern life tends to tip the scales the wrong way.

“We’re exposed to extra free radicals every time we eat fried or ultra-processed foods, breathe in pollution or mold, smoke, drink alcohol, or get too much sun,” says Schultz. Skipping vegetables, staying sedentary, not drinking enough water, and chronic emotional and physical stress can all increase free radical load, too, she adds.

Signs and Symptoms of Excess Oxidative Stress 

Oxidative stress may start at a cellular level, but the effects can be felt head to toe. “When your body is overwhelmed with oxidative stress, it can start showing up in all sorts of ways,” says Schultz. 

Some research suggests that oxidative stress may contribute to or exacerbate symptoms like:

• Constant fatigue
• Frequent headaches or migraines
• Brain fog and memory loss
• Joint or muscle pain 
• Skin issues (like wrinkles, eczema, or breakouts)
• Digestive issues (IBS or constipation)
• Trouble sleeping or insomnia 
• Frequent colds 
• Slow wound healing

In lab work, oxidative stress might reveal itself through high levels of low-density lipoprotein (LDL) cholesterol and elevated levels of homocysteine and C-reactive protein, both of which are considered markers of increased biological stress and potential cardiovascular risk, according to Volpe.

Read More: The Surprising Food That Supports Heart Health

Long term, unchecked oxidative stress can lead to much more serious outcomes. “Over time, oxidative stress can translate to accelerated aging, reduced longevity, and an increased risk for a number of chronic diseases,” says Volpe. In fact, oxidative stress is linked with increased risk of diabetes, atherosclerosis (hardening of the arteries) cardiovascular disease, Alzheimer’s disease, Parkinson’s disease, and even cancer, according to a 2024 study in Human Antibodies. 

What To Eat To Reduce Oxidative Stress 

1. Eat The Rainbow 

When it comes to fighting oxidative stress, produce powers you up—while processed foods weigh you down. Fruits and vegetables are packed with antioxidants that help neutralize free radicals, says Volpe. Meanwhile, ultra-processed foods (think: fried snacks, sugary cereals, shelf-stable meals) contribute to your free radical count. Indeed, one 2023 Antioxidants study showed that people who ate a lot of ultra-processed food had higher oxidative stress levels compared to those who mostly ate plant-based foods like fruits, veggies, and whole grains. The researchers found that those who prioritized produce had stronger antioxidant defenses and lower levels of oxidative stress and related metabolic strain than those who leaned on processed foods.

With that, Volpe says that the goal is two-fold: “You want to increase your intake of antioxidant-rich foods while also minimizing your exposure to free radicals from processed foods. That’s one of the most straightforward and effective ways to reduce oxidative stress.”

Even better than just eating fruits and veggies? Eating a wide variety of them. Different eats provide different antioxidants, which all work together to eradicate free radicals and support cellular health, explains Schultz. 

Green leafy vegetables like broccoli, kale, and Brussels sprouts, for example, boost your body’s production of an antioxidant called sulforaphane, she says. Meanwhile, orange and red vegetables like citrus, bell peppers, and berries are rich in antioxidant vitamin C, which helps protect your skin, immune system, and more. And “berries, grapes, red cabbage, plums, red apples, elderberry, and pomegranate seeds contain antioxidants called anthocyanins, which have been shown to have potent antioxidant activity and prebiotic properties,” says Volpe. 

2. Utilize Herbs and Spices 

Your best defense against oxidative stress might be hiding in your spice rack or herb garden. As it turns out, herbs and spices aren’t just flavor-boosters—they’re also antioxidant-rich ingredients that can help armor your cells against daily oxidative stress, according to Schultz. 

Read More: The Best Foods And Supplements For Longevity

One standout is turmeric, which contains an active compound called curcumin that’s been shown to significantly reduce oxidative stress, says Schultz. In fact, a 2025 review published in Frontiers in Pharmacology found that curcumin supplementation significantly decreased levels of markers associated with physiological stress (like C-reactive protein) while improving total antioxidant capacity.

You can easily incorporate turmeric into your diet by drinking golden milk lattes or adding half a teaspoon to curry, lentil dishes, soups, stews, or smoothies. Not a fan of cooking? A high-quality supplement works too. Just be sure to purchase one like Garden of Life’s Extra Strength Turmeric that includes black pepper extract (piperine), which can increase bioavailability of the curcumin by as much as 154 percent. 

Other players with powerful antioxidants include oregano, rosemary, sage, cinnamon, ginger, and cloves, all of which have proven efficacy at reducing oxidative stress, per one review in the Journal of Functional Foods. Consider keeping a rotating cast of fresh and dried herbs in your kitchen and adding them to every meal for taste. If you’re not sure where to start, try a sprinkle or oregano on scrambled eggs, rosemary on roasted potatoes, or cinnamon on oatmeal or sliced apple. 

3. Drink Your Antioxidants

The right morning beverage won’t just wake you up—it will also work overtime to defend your body against oxidative stress. 

Coffee is rich in antioxidants called polyphenols, which have been shown to neutralize free radicals and support cellular health. One 2025 review in Antioxidants even concluded that coffee may help slow biological aging, support longevity, and improve overall health span. Just note that most research is based on black coffee—adding excessive sugar or ultra-processed creamers may offset some of its antioxidant benefits by contributing to inflammation and metabolic strain.

Not a coffee person? “Green tea and matcha are other antioxidant-rich beverages,” says Volpe. Both drinks are high in catechins, a type of antioxidant known for their cell-protective and disease-fighting properties. One study in Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry found that drinking green tea was associated with protective effects against a variety of health concerns, including cancer, obesity, diabetes, cardiovascular issues, and neurodegenerative diseases. Other research has reported that regular consumption of matcha may positively impact both physical and mental well-being and help reduce the risk of chronic conditions.

Read More: Signs Your Electrolytes Are Off Kilter—And What To Do About It

Most studies look at the impacts of two to five daily cups, but even one cup is better than none. So if you’re looking to support cellular health and overall balance, consider swapping one of your daily beverages for a mug made with Aiya’s American Matcha Green Tea Powder. 

4. Consider Supplements

Even with a solid diet, your body may still benefit from backup—especially if you’re dealing with high stress, environmental toxins, or a demanding workout routine. “Antioxidant supplements such as vitamin C, NAC, CoQ10, and glutathione can all be very helpful in reducing and neutralizing oxidative stress in the body,” says Volpe. 

When your body is under chronic oxidative stress—whether from poor diet, environmental toxins, intense exercise, or infection—your antioxidant stores get depleted faster. “Your body is utilizing them to counteract the exposure to free radicals, which is good and ultimately results in low antioxidant stores,” Volpe says. 

Individuals who are exposed to mold, for example, have been shown to be low in an antioxidant called glutathione, due to the fact that the body is using it to detox mold-related toxins and protect cells from damage. Meanwhile, low levels of an antioxidant called CoQ10 are linked with low-nutrient intake, likely due to the fact that the body is tapping into stores to benefit health. 

For most people, antioxidant supplements are safe when taken in recommended amounts. But because a few can interfere with medications (like blood thinners and blood pressure meds), Schultz says that “it’s always best to talk to a healthcare provider.” They’ll be able to recommend the best options based on your symptoms or any deficiencies in your blood work, she explains.

The Bottom Line 

The effects of oxidative stress can sound intimidating, but the solution doesn’t require a total lifestyle overhaul, according to Schultz. “The body is smart and wants to stay in balance,” she says. So, a few consistent dietary choices—like loading up on produce, sipping smart, seasoning with purpose, and choosing quality supplements—can go a long way in supporting your body’s fight against oxidative stress.

This article was reviewed by Brian Tanzer, nutritionist and Director of Scientific and Regulatory Affairs at The Vitamin Shoppe.