What is inflammation?
You might be hearing more about inflammation and its role in overall health lately, but what exactly is inflammation and how does it happen?
Quite simply, “inflammation is the body’s response to something wrong,” explains Megan Wroe, wellness manager and registered dietitian at St. Jude Medical Centerin Southern California. For example, “when you get a paper cut, the area turns red and a bit swollen as the body initiates the healing process.”
Inflammation isn’t just a response to an external injury, though, Wroe notes. It kicks in inside the body in response to a number of issues, such as pathogens, irritants and allergens.
Inflammation’s purpose is to heal. “When inflammation occurs, the immune system’s cells release inflammatory mediators, which causes small blood vessels in the tissue of the affected area to dilate, allowing more blood to reach the injured tissue,” explains Janette Wong, a registered dietitian with Santa Clara Valley Medical Center in San Jose, California.
This cascade of events leads to redness and the sensation of feeling hot. “The immune system’s response also triggers an increase of white blood cells to fight the infection,” Wong adds. “This may irritate nerves, causing pain and increased fluid in the affected area, leading to swelling.”
When inflammation becomes chronic
Chronic inflammation is when the body’s inflammation lasts for a long time, usually several months to years. The effects of chronic inflammation depend on what caused the injury and how well the body can repair itself.
In the short run, inflammation can be helpful as a defense mechanism the body uses to heal injuries. But too much of a good thing can be problematic.
“(Chronic) inflammation is detrimental to the body because it increases the rate at which our cells age,” says Dana Ellis Hunnes, a senior clinical dietitian at UCLA Medical Center, assistant professor at UCLA Fielding School of Public Health and author of “Recipe For Survival.”
“Over time, the body may get less efficient at making inflammation subside,” explains Tracy Lockwood Beckerman, a registered dietitian based in New York City and author of “The Better Period Food Solution.” This can cause “inflammation to remain alive in the body” as chronic inflammation, she says.
Chronic inflammation may cause some noticeable symptoms, such as muscle soreness, joint pain or stiffness or frequent rashes. But chronic inflammation often has no discernible symptoms.
Chronic inflammation can linger long after the activating injury or disease has been resolved. According to 2019 research published in Nature Medicine, chronic inflammation has been linked to elevated risk for a variety of conditions, including:
— Stroke.
— Non-alcoholic fatty liver disease.
— Cancer.
— Neurodegenerative conditions, such as Alzheimer’s disease and other forms of dementia.
How diet affects inflammation
Certain lifestyle factors — specifically diet — may contribute to the development of chronic, low-grade inflammation, note researchers in a 2020 study published in the International Journal of Environmental Research and Public Health. It boils down to how the body negotiates nutrients, such as protein, fat and carbohydrates, and waste, which is excreted as a solid, a gas in the form of carbon dioxide or as a liquid in the form of urine and sweat.
“After food is consumed, the body has no other choice than to digest both the good nutrients and the not-so-good nutrients,” Beckerman explains. “Good nutrients, like vitamins, minerals, antioxidants and phytonutrients, are shuttled to cells that carry these helpful nutrients to areas that need energy, repair and reinforcement.”
That’s great, but the other ingredients that aren’t helpful can linger as the digestive system struggles to process them, “creating harmful conditions that can damage cells within the body,” Beckerman says.
Those foods can’t be recognized properly by the body, Wroe adds. “Foods that the body recognizes as damaging will signal the same inflammatory response” that the body produces when it senses you’re injured or sick. For example, if you have a peanut allergy, exposure to peanuts creates an inflammatory response that in severe cases could turn deadly.
Plant-based diets may help reduce inflammation.
Because of the role diet can play in chronic inflammation, people tend to look to dietary changes to reduce inflammation and promote overall health and immunity, says Whitney Linsenmeyer, an assistant professor of nutrition at Saint Louis University and a spokesperson for the Academy of Nutrition and Dietetics.
Dr. Weil’s Anti-Inflammatory Diet, based on the Mediterranean diet but with a few added elements, such as anti-inflammatory green tea and cooked Chinese mushrooms, is also OK. However, expert panelists convened by U.S. News didn’t rank the diet nearly as high as the Mediterranean or the DASH diet, which stands for dietary approaches to stop hypertension.
The good news is there are plenty of foods you can eat that don’t exacerbate inflammation. Simply, these are often plant-based foods.
Benefits of a plant-based diet
Plant produce contains a slew of helpful compounds that can reduce chronic inflammation, such as:
— Carotenoids. This type of plant pigment acts as an antioxidant when consumed. Antioxidants help prevent chronic diseases by protecting healthy cells from damage caused by free radicals.
— Anthocyanins. These anti-inflammatory phytochemicals give brightly colored produce their vibrant hues. They also act as antioxidants that combat inflammation and cellular damage.
— Quercetin. This antioxidant helps moderate the body’s histamine response, which may in turn lead to less chronic inflammation.
— Vitamin A. Another antioxidant, this vitamin helps regulate the immune system and keeps inflammation in check.
— Vitamin C. This vitamin can support a healthy immune system, but it’s also a powerful antioxidant that can combat cellular damage and keep inflammation from accumulating.
— Vitamin E. Another powerful antioxidant, vitamin E supports proper immune system function and fends off damage from free radicals.
— Fiber. Plant foods contain lots of fiber, the rough stuff that has been associated with improving digestion, lowering cholesterol and lowering inflammation levels. Fiber also helps support a healthy gut microbiome, which provides anti-inflammatory effects.
The following foods may help reduce chronic inflammation:
1. Asparagus
One stand-out piece of produce to add to your diet is asparagus. This spring vegetable is high in polyphenols, chemical compounds that research suggests could help protect against cancer, diabetes and heart disease.
Asparagus also contains a healthy number of anthocyanins, which is a type of flavonoid. Anthocyanins have antioxidant qualities. Antioxidants are molecules that ward off free radicals, which are unstable, naturally occurring compounds that can have harmful effects on your cells. Research suggests free radicals can contribute to the onset of such diseases as cancer, diabetes and heart disease.
This vegetable also contains fiber, which helps keep you regular, and quercetin, another flavonoid. Quercetin, according to 2016 research published in Nutrients, may help support a strong immune system.
Asparagus is great just simply steamed. For an added pop of flavor, though, try roasting with a little olive oil and your favorite seasoning.
Asparagus, however, isn’t the only game in town; many fruits and veggies may have, to varying degrees, anti-inflammatory properties. To maximize anti-inflammatory benefits, eat plenty of colorful fruits and veggies that are high in different types of antioxidants, such as:
— Kale.
— Red and orange peppers.
— Winter squash.
2. Leafy greens
Leafy greens like spinach and kale are a great source of fiber, vitamin E, vitamin C and the whole scope of antioxidants.
The category of leafy greens includes:
— Broccoli.
— Bok choy.
— Collard greens.
— Kale.
— Spinach.
— Swiss chard.
Add spinach and kale to smoothies and salads, and sauté as part of a side dish to nearly any type of meal. The bottom line: It’s hard to go wrong with veggies, especially brightly colored leafy greens.
3. Berries
Although they’re small in size, berries pack a nutritional punch. There are a wide array of tasty berries that are high in anthocyanins, which are responsible for berries’ red, blue and purple pigmentation. Berries’ high antioxidant content may also help prevent chronic diseases by protecting healthy cells from damage caused by free radicals.
You can add berries to cereal or yogurt or toss them in the blender with dairy- or plant-based milk for a smoothie.
Berries that can help you fight inflammation include:
— Blackberries.
— Raspberries.
— Strawberries.
4. Avocados
Besides being tasty, avocados are a great source of heart-healthy monounsaturated fat, which is protective against chronic inflammation, says Maggie Michalczyk, a registered dietitian based in Chicago.
Avocados are also powerhouse fiber foods. Fiber is a top anti-inflammatory nutrient because it feeds the beneficial bacteria that reside in the gut, the so-called gut microbiome. Ensuring that your gut microbiome is in balance and that the healthy bacteria can thrive is increasingly understood to support overall health and wellness, in part because these good strains can help regulate systemic inflammation levels.
Add avocados to your diet with:
— Avocado toast.
— Avocados as a base in your smoothies.
— Avocado slices on top of a sandwich or mixed into a salad.
5. Beans
Eating one cup of beans at least twice a week will help fight inflammation, says Amy Kimberlain, a registered dietitian based in Miami and spokesperson for the Academy of Nutrition and Dietetics.
Beans are loaded with prebiotic fiber — that’s the kind of fiber that the good gut bacteria love to chomp on and that results in the production of anti-inflammatory short-chain fatty acids. Beans are also rich sources of isoflavones and flavonoids, which are compounds in plants that help protect against bacteria, fungi and viruses.
Beans are an excellent and inexpensive source of protein, Kimberlain says. They contain about 15 grams of protein per cup, which is important for muscle health.
There are a wide array of beans to choose from, including:
— Black beans.
— Kidney beans.
— Pinto beans.
— Red beans.
6. Citrus fruits
Most everyone knows that citrus fruits are high in vitamin C, which bolsters your immune system, promotes wound healing and fosters the development, growth and repair of body tissues. Citrus fruits also boast plenty of inflammation-fighting flavonoids.
Citrus fruits include:
— Clementines.
— Lemons.
— Limes.
— Oranges.
Beckerman notes that while citrus fruits usually get all the glory when it comes to vitamin C, another tasty fruit — watermelon — is an inflammation fighter. “Just 2 cups of watermelon provides 25% of the daily value of vitamin C per day,” she says. “Maintaining adequate vitamin C in the body is integral in suppressing inflammation because it helps to fight oxidative damage and stress in the body.”
7. Dark chocolate
Yes, you can reap some anti-inflammatory benefits by indulging in a little dark chocolate.
This satisfying treat contains flavonols, compounds that have antioxidant-like powers. Consumption of flavonols has been associated with increased antioxidant activity in the body, which reduces inflammation.
Some research has suggested that flavonols found in cocoa seem to exert an anti-inflammatory effect on blood vessels. A 2017 review study in Frontiers in Nutrition, for example, looked at results from 14 studies involving nearly 509,000 people and found that consuming chocolate in moderation — meaning less than six servings (of 30 grams each) per week — was associated with decreased risk of coronary heart disease, stroke and diabetes.
“It’s best to choose chocolate that’s at least 70% cacao because (that kind) contains higher concentrations of antioxidants, fiber, potassium, calcium, copper and magnesium,” Michalczyk says. It also has a lot less added sugar. Sugar is an inflammatory food.
8. Herbs and spices
In addition to keeping dishes flavorful, herbs and spices are also considered part of a dynamic anti-inflammatory diet.
In a randomized feeding study, published in the Journal of Nutrition in 2020, researchers at Penn State University examined participants who ate a meal high in fat and carbohydrates.Participants who consumed 6 grams of a spice blend added to their food had lower inflammation markers versus individuals who ate a similar meal with no or fewer spices.
Linsenmeyer especially recommends turmeric and ginger.
Other herbs and spices that are considered to have anti-inflammatory properties include:
— Chili peppers.
— Cinnamon.
— Clove.
— Cumin.
— Garlic.
— Oregano.
— Thyme.
— Rosemary.
— Sage.
9. Olive oil
Olive oil is loaded with heart-healthy fats, as well as oleocanthal, an organic compound that is part of the polyphenols family and has properties similar to nonsteroidal, anti-inflammatory drugs, Kimberlain says.
Olive oil also contains monounsaturated fatty acids, which research suggests reduces levels of chronic inflammatory markers, says Diane Javelli, a clinical dietitian at the University of Washington Medical Center in Seattle.
“Olive oil can be used in cooking and as a salad dressing,” adds Javelli, who’s also the owner of Belly by Javelli, a private practice for digestive nutrition assessment and counseling in Kent, Washington. “Try mixing extra-virgin olive oil with balsamic vinegar, and use (it) as a dip for a rustic, whole grain (loaf) of sourdough bread.”
It’s important to keep in mind that extra-virgin olive oil goes through less refining and processing, so it retains more nutrients than standard varieties.
“And it’s not the only oil with health benefits,” Kimberlain adds. Some research suggests that avocados and their oils could lower LDL cholesterol levels (that’s the bad kind), and safflower oils have been associated with improved cholesterol profiles. Avocado oil has also been demonstrated to have anti-inflammatory effects, such as in this 2022 Nutrients study on mice with obesity.
Meanwhile, walnut oil has 10 times the omega-3 fatty acids, which can fight inflammation, that olive oil contains.
10. Fish
There’s a reason why the Mediterranean diet features seafood: It’s full of immune system-supportive omega-3 fatty acids. Omega-3 fatty acids are polyunsaturated fatty acids the body needs to support healthy brain function, the immune system, cell repair and a range of other functions.
There are three main types of omega-3 fatty acids: ALA (alpha-linolenic acid), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These compounds are readily found in fatty cold-water fish like salmon and mackerel, as well as nuts, seeds and algae.
“High omega-3 foods will help the immune system to be strong and resilient to inflammation that is always happening simply due to living,” Wroe explains.
The American Heart Association generally recommends having two 3.5-ounce servings of non-fried fish per week, or around 200 to 500 milligrams of EPA or DHA total. Talk with a doctor about whether you should supplement your diet with omega-3s if you don’t eat fish.
Salmon also contains astaxanthin, an antioxidant carotenoid that produces bright yellow, red and orange colors in fruits, vegetables and plants. Salmon is the leading source of this carotenoid in the U.S. diet.
It’s also found in:
— Lobster.
— Red snapper.
— Red trout.
— Shrimp.
11. Pineapple
This tasty fruit is rich in an enzyme called bromelain, which may help fight pain and swelling that occur from tendonitis, sprains and strains and other minor muscle and joint injuries.
Pineapple also has plenty of:
— Fiber.
— Potassium.
“Try grilling fresh pineapple slices for a naturally sweet, caramelized flavor that is tasty on its own, on top of grilled fish or chicken, mixed with yogurt or as a topping for salad or pasta,” Javelli says.
12. Whole grains
Whole grains contain antioxidants and lots of prebiotic fiber, which helps your healthy gut bacteria flourish. One 2018 review study in the journal Medicine that included more than 800 participants noted that subjects who consumed more than 100 grams of whole grains per day had lower levels of inflammatory markers in their blood when compared with participants who consumed fewer whole grains.
This supports the theory that whole grains — and, more specifically, the prebiotic fiber they contain — may help lower systemic inflammation levels.
Healthy whole grain options include:
— Oats.
— Quinoa.
— Whole wheat.
13. Walnuts
Another anti-inflammatory food that’s high in a form of omega-3 fatty acids — ALA, or alpha-linolenic acid — is walnuts. In fact, just a small handful, or 1 ounce, of English walnuts contains more than 2.5 grams of ALA.
While nuts, in general, are a healthy feature of anti-inflammatory eating regimens like the Mediterranean diet, walnuts lead the pack in omega-3 content.
A 2020 study in the Journal of the American College of Cardiology that involved more than 600 people between the ages of 63 and 79 found that consuming walnuts on a daily basis reduced the concentration of several inflammatory biomarkers. Participants assigned to the walnut group consumed a diet that derived about 15% of its calories from walnuts (30 to 60 grams per day) for two years. That protocol resulted in a significant reduction in the concentration of six of the 10 biomarkers the researchers examined.
Beckerman points to a 2022 study in Antioxidants that found a correlation between walnut intake and reduced inflammation. “A recent systematic review found that diets enriched with walnuts may decrease inflammation and markers of metabolic syndrome, such as heart disease and type 2 diabetes. By eating just 1.5 ounces per day (about eight to 12 walnuts), the omega-3s in walnuts help to squash inflammation in the body,” she says.
She also likes almonds, which she calls “anti-inflammatory gems, thanks to their high fiber and high polyphenol content. A recent randomized control trial found that consuming almonds increased butyrate, a specific microbiota byproduct connected to fighting inflammation.”
14. Fermented foods
Fermented foods have also been found to help decrease inflammation and improve the diversity of food bacteria in the gut microbiome. They contain probiotics, a kind of bacteria that supports a healthy gut microbiome.
Fermented foods include:
— Kimchee.
— Miso.
— Pickles.
— Sauerkraut.
— Tempeh.
According to a small 2021 study, published in the journal Cell, that looked at 36 individuals, participants who increased their intake of fermented foods by an average of six servings per day over a 10-week period saw a boost in microbiome diversity and decreased activation of four types of immune cells. The levels of 19 inflammatory proteins also declined.
Stay away from foods and drinks that may worsen inflammation.
In addition to knowing which foods are good to keep inflammation at bay, it’s important to know which ones may exacerbate it. If you’re on an anti-inflammatory diet, you’ll want to avoid or limit your consumption of such foods.
The standard American diet, which often contains lots of excess sugar and ultra-processed foods, is often high in types of foods that contribute to inflammation.
These foods include:
— Foods that are high in added sugar (such as candy or sugary soft drinks).
— Fried foods.
— Packaged, processed foods (think snack chips, cookies and cakes).
— Red meat.
In addition, you should heed advice for limiting foods and beverages, such as the following:
Excess alcohol
While a glass of red wine with dinner can be part of the Mediterranean diet, excessive alcohol consumption is best avoided. Kimberlain says that “excessive use weakens liver function and disrupts other multi-organ interactions, and (it) can cause inflammation. Alcohol is best eliminated or used in moderation.”
The federal government’s 2020-2025 Dietary Guidelines for Americans recommend that individuals either not drink alcoholic beverages or limit their consumption to two drinks a day or less for adult men and one drink daily or less for women. Less is more when it comes to alcohol.
Saturated fats
Wong recommends avoiding foods that are high in saturated fats and trans fats. One way to do this is by cooking with heart-healthy oils, such as olive oil, instead of butter. Or, “choose avocado or nut spread instead of margarine-type spread where the main ingredient is palm oil,” she says.
Again, fresh versus processed wins, Wong says, noting that it’s best to avoid highly processed protein sources like deli meat, bacon and sausage.
“Instead, choose meats that are low in fat, such as lean beef or pork, skinless chicken or turkey,” Wong adds. Plant-based protein sources, such as tofu, lentils, peas and beans, are naturally fat-free and may reduce inflammation levels.
Omega-6 fatty acids
Omega-6 fatty acids are an essential fatty acid that the body needs for normal growth and development, Kimberlain says. “The body needs a healthy balance of omega-6 and omega-3 fatty acids.”
However, excessive consumption of omega-6 fatty acids may trigger the body to produce inflammatory chemicals, so it’s a good idea to consume such foods in moderation.
Foods that contain high levels of omega-6 fatty acids include:
— Corn oil.
— Mayonnaise.
— Many salad dressings.
— Peanut oil.
— Safflower oil.
— Soy oil.
— Vegetable oil.
Refined carbohydrates
Refined carbohydrates are another type of ultra-processed food to watch out for, and they can include:
— Many sugary and frosted cereals made with refined white flour.
— White bread, crackers and rolls.
— White potatoes (instant mashed potatoes or French fries).
These foods may be problematic because of the refining process. During refining, they’re stripped of the fiber and nutrients that make whole grains so healthy, leaving behind a processed item that can elevate blood sugar levels.
“Too many simple/processed carbohydrates induce inflammation in the body by increasing hormone production — specifically insulin — and/or being ‘toxic’ to the body,” Hunnes says. “This leads to inflammation, and over time, this inflammation increases the risk of chronic diseases.”
Instead of reaching for a loaf of white bread, select whole grains that are full of fiber, minerals and vitamins.
“(These will) lower inflammation in the body because we’re not inducing a high insulin response or stress within the system. We are actually tamping it down,” Hunnes explains. “The insulin response can be a form of stress in the body, and stress is inflammatory.”
Kimberlain recommends aiming “to include half of your grains as whole grain, and (switch) out some of the refined carbohydrates for the whole versions.”
The takeaway
A balanced diet full of fresh fruits and veggies, lean protein sources and whole grains can help you keep inflammation at bay and reduce the risk of chronic illness. It doesn’t have to be complicated, Wroe says, just consistent.
“Focus less on fancy supplements and ‘fixes,’ and focus more on simply eating less processed foods,” she says. “If it’s a whole food, or a food made of real food ingredients, the body will recognize it and inflammation will not be its response.”
On the other hand, if a food contains “synthetic, denatured ingredients that the body does not recognize, it will view it as a danger,” Wroe adds. “Read ingredient labels, and cook more, and I promise you will significantly reduce any inflammatory concerns!”
It’s also important to note that while “inflammation in the body from bad food choices typically happens over time, it’s never too late to add anti-inflammatory foods into your diet to achieve positive health outcomes,” Beckerman notes. “Each meal and snack is a new chance to add something colorful or healthy to your diet.”
14 anti-inflammatory foods (and 4 to avoid):
Anti-inflammatory foods to add to your diet:
1. Asparagus.
2. Leafy greens.
3. Berries.
4. Avocados.
5. Beans.
6. Citrus fruits.
7. Dark chocolate.
8. Herbs and spices.
9. Olive oil.
10. Fish.
11. Pineapple.
12. Whole grains.
13. Walnuts.
14. Fermented foods.
Inflammatory foods to avoid:
— Excess alcohol.
— Saturated fats.
— Omega-6 fatty acids.
— Refined carbohydrates.
More from U.S. News
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Anti-Inflammatory Diet: The Best and Worst Food for Inflammation originally appeared on usnews.com
Update 03/31/23: This story was previously published at an earlier date and has been updated with new information.
