Extra-Virgin Olive Oil and Digestion: 11 Science-Backed Gut Health Benefits (2026 Update)

Medically reviewed and written by Heidi Moretti, MS, RD, CLT — a registered dietitian with 25+ years of clinical experience in functional nutrition and a Certified LEAP Therapist who has run MRT food sensitivity testing on herself and hundreds of clients, including for reactions to foods like olive oil that are typically considered universally healthy.

Extra-virgin olive oil’s digestion benefits go far beyond “healthy fat” — this antioxidant-rich oil carries gut-healing polyphenols, supports bowel regularity, and (according to newer research) even talks to your gut-brain axis.

But the amount you actually need to feel a difference in your gut may surprise you — and so might the fact that a food this well-researched can still be the wrong fit for an individual gut, mine included.

This post walks through the current research on olive oil and digestion, exactly how to use it for the biggest gut benefit, and an honest caveat most “olive oil is good for you” articles leave out.

Olive Oil Is Anti-Inflammatory for the Gut

Extra-virgin olive oil is rich in antioxidants that help dampen inflammation throughout the body by stopping free radicals from forming in the first place.

This is one reason a Mediterranean-style diet rich in olive oil is linked to lower rates of most gastrointestinal cancers, arthritis, and heart disease. Extra-virgin olive oil also has a documented ability to reduce gut and intestinal pain — the compound responsible, oleocanthal, has pharmacological effects similar to ibuprofen. Unlike ibuprofen, though, extra-virgin olive oil doesn’t damage the lining of the small intestine.

The antioxidants in olive oil also decrease inflammatory compounds, including tumor necrosis factor, interleukin-6, and cyclooxygenase-2 (COX-2) — markers that show up elevated in most chronic gut conditions.

Related post: The Best Oil for Air Frying and Sautéing

Olive Oil for Gut Healing

Beyond lowering inflammation, olive oil contains compounds that may actively help heal the gut when it’s a regular part of the diet. The antioxidants in extra-virgin olive oil, called polyphenols, act as prebiotics — feeding the bacteria you want more of.

A 2025 study in Biomolecules mapped this out in more detail than older research had: extra-virgin olive oil intake shifted both gut and saliva microbiota composition in ways associated with lower systemic inflammation, reinforcing that EVOO’s benefit isn’t just theoretical — it’s measurable at the microbial level, in more than one body site.

Olive oil antioxidants increase the number and diversity of healthy gut bacteria, and eating olive oil helps fuel the gut lining by boosting production of short-chain fatty acids.

Extra-virgin olive oil has even been shown to reduce symptoms of colitis, including bloating, constipation, incomplete evacuation, and fecal urgency.

Olive Oil, the Gut-Brain Axis, and Cognitive Health

One of the more interesting developments since this post was first published: olive oil’s gut effects may extend to the brain.

A January 2026 study in Microbiome followed over 650 older adults with overweight and metabolic syndrome, tracking olive oil intake, stool-sample microbiota, and cognitive testing over two years. Higher intake of virgin olive oil specifically (not refined) was associated with improved cognitive function over the follow-up period, and the researchers linked part of that benefit to olive-oil-driven shifts in the gut microbiome.

This fits the broader “gut-brain axis” picture I talk about across this site: a healthier microbiome doesn’t just mean better digestion, it appears to influence inflammation and signaling pathways that reach the brain too.

It also lines up with a larger, longer-running Harvard study. A JAMA Network Open analysis of over 92,000 adults followed for 28 years found that people consuming at least 7 grams of olive oil daily (a little more than half a tablespoon) had a 28% lower risk of dementia-related death compared to those who rarely or never consumed it — an association that held up regardless of overall diet quality or APOE ε4 genetic risk. That study didn’t test the microbiome mechanism directly, but between it and the newer Microbiome paper above, the brain-health case for olive oil is getting harder to write off as just “eat more Mediterranean food.”

Olive Oil for Leaky Gut Healing

Leaky gut is an increasingly recognized condition according to Harvard Health. Not surprisingly, diet plays a major role in how well someone is able to heal a leaky gut.

By increasing the number of healthy Bacteroides bacteria in the gut, extra-virgin olive oil may decrease intestinal permeability, also known as leaky gut.

Olive oil improves the microbiome, and the protective barrier in the gut called the mucin lining may also thicken as a result. A stronger mucin layer further protects the body from foreign invaders like harmful bacteria and undigested particles that trigger immune reactions.

Olive Oil Helps Absorb Nutrients

Extra-virgin olive oil is rich in a healthy monounsaturated fat called oleic acid. Because of its fat content, olive oil enhances your digestive tract’s ability to absorb fat-soluble nutrients — vitamins A, D, E, and K among them.

Nutritious phenolic compounds in extra-virgin olive oil also help scavenge free radicals in the body, and research shows extra-virgin olive oil is likely the single most important part of the Mediterranean diet because of these compounds.

Extra-Virgin Olive Oil Is a Healthy Cooking Oil

Contrary to popular opinion, cooking with extra-virgin olive oil is healthy — research shows it’s stable under high temperatures and doesn’t oxidize or smoke at low temperatures like previously assumed.

Extra-virgin olive oil is also more stable in the pan than most other vegetable oils. Cooking with it even boosts the antioxidant availability of the foods it’s cooked with, like tomatoes, onions, and garlic.

Olive Oil Has Natural Laxative Effects

One of olive oil’s biggest digestion benefits is simple lubrication — it helps make passing stool much easier.

A newer 2025 double-blind randomized trial compared extra-virgin olive oil against refined olive oil head-to-head in 140 adults with chronic constipation. The EVOO group saw meaningfully better outcomes on stool frequency, hard-stool frequency, and straining — evidence that the polyphenols stripped out during refining aren’t just a nice-to-have, they appear to matter clinically.

Older research backs this up too: olive oil is an effective and very safe option for constipation because it simply lubricates the stool, without the stimulant properties or dependency risk of some over-the-counter laxatives. It also helps reduce symptoms of incomplete evacuation.

In summary, olive oil as a laxative is well-supported by research and a reasonable first step for occasional constipation.

Olive Oil May Reduce Diarrhea Symptoms

While olive oil helps with constipation, it thankfully doesn’t tend to cause diarrhea — because it lubricates the gut rather than pulling water into it. Some research even shows extra-virgin olive oil reduces bowel urgency, a common concern for anyone dealing with loose stools.

By supporting the gut microbiome, extra-virgin olive oil naturally helps regulate bowel movements in both directions. Of course, you can overdo anything — drinking several tablespoons of olive oil quickly can produce a laxative effect regardless of your baseline bowel habits.

Olive Oil Reduces Gallstone Risk

Although research is still developing, using extra-virgin olive oil daily may help reduce gallstone risk. Olive oil may help reduce stone formation in the biliary tract, and diets rich in olive oil and high-quality foods are linked to a lower gallstone risk overall.

Olive Oil Helps Stomach Health

Olive oil benefits stomach health, including helping increase stomach acid (gastric acid), which many people going through digestive issues actually need more of, not less. It also helps people digest foods better than sunflower oil does. As covered above, extra-virgin olive oil strengthens the gut lining by promoting the protective mucin layer, which ultimately supports stomach health as well.

Taken between meals on an empty stomach, olive oil may also help reduce stomach acid when it isn’t needed, according to Olive Oil Times. By reducing growth of H. pylori, extra-virgin olive oil may also help protect against stomach ulcers.

Olive Oil Curbs Appetite

One nice side effect of eating more olive oil: it helps fill you up so you’re less tempted by processed food. Eating olive oil helps slow stomach emptying, so you feel full longer — which is part of why it may also support healthy body composition.

Olive Oil Reduces Body Fat

Olive oil impressively reduced body fat by 80% more than soybean oil when combined with a low-calorie diet, in a study of overweight women — the same study also showed improved blood pressure in the olive oil group.

Another study confirmed this benefit, showing olive oil not only reduces body fat but also helps improve muscle strength and walking speed in adults with severe obesity.

Other Olive Oil Benefits

Beyond digestion, extra-virgin olive oil has a long list of proven and emerging health benefits, including:

• Reduces blood pressure
• Helps with heart health
• Decreases stroke risk
• Helps manage blood sugar — a 2026 20-year ATTICA cohort study of 2,000 Greek adults found exclusive olive oil use was linked to roughly 51% lower odds of developing type 2 diabetes over 20 years, with an even stronger association in participants who were overweight or obese
• Reduces arthritis pain
• May help boost mood
• May reduce anxiety
• Anti-aging support
• Reduces cancer risk by helping turn off cancer genes
• Supports gut-microbiome-linked cognitive function (new 2026 research)

Most of these benefits kick in at intakes of roughly 4 tablespoons per day.

Make Sure to Choose Extra-Virgin Olive Oil

Extra-virgin olive oil is cold-pressed — made simply by crushing olives to extract the oil. Because of this, most of the natural antioxidants from the olives stay in the oil, giving it a rich green color.

If the label says “light” olive oil or “refined” olive oil, it won’t provide the same level of health benefit. Light and refined olive oils are processed to remove most of the beneficial compounds — the same compounds the 2025 constipation trial above found actually drove the digestive benefit.

The Olive Oil Purity Problem: How to Avoid Fake or Adulterated Oil

Here’s an uncomfortable truth that most “olive oil benefits” articles skip entirely: everything in this post assumes you’re actually getting extra-virgin olive oil. A meaningful share of what’s sold as “extra virgin” on grocery shelves isn’t.

The landmark UC Davis olive oil study found that a large share of imported extra-virgin olive oils sold on U.S. supermarket shelves failed international standards for the extra-virgin grade — some due to age and poor storage, some diluted with cheaper refined olive oil or seed oils like sunflower or canola, and some simply mislabeled on origin or harvest date. Large-scale enforcement actions in Europe have periodically seized tons of adulterated or mislabeled oil, so this isn’t a fringe concern; it’s a structural issue in a high-value commodity that’s easy to dilute and hard for the average shopper to verify by eye.

Why this matters for everything above: the digestive, anti-inflammatory, and gut-microbiome benefits covered in this post are tied specifically to extra-virgin olive oil’s polyphenol content. Refined, adulterated, oxidized, or blended oil has little to none of it — so a bottle that says “extra virgin” but isn’t may look identical on your counter while delivering almost none of the research-backed benefit.

Practical ways to buy real extra-virgin olive oil:

• Check for a harvest date, not just a “best by” date. Real, transparent producers print when the olives were pressed. No harvest date at all is a yellow flag.
• Look for third-party certification — seals like the California Olive Oil Council (COOC), the North American Olive Oil Association (NAOOA), the Australian Olive Association, or EU/international PDO and PGI (Protected Designation/Geographical Indication) marks mean an independent body has actually tested the oil rather than taking the label’s word for it.
• Be skeptical of vague origin claims. “Imported from Italy” or “Product of Italy” can legally describe oil that was only bottled there after being sourced from several countries. Single-estate or single-region oils with a named mill are harder to fake.
• Watch the price. Real extra-virgin olive oil is genuinely expensive to produce. A large bottle priced dramatically below comparable EVOO is very likely refined, old, or cut with a cheaper oil.
• Buy in dark glass or tin, and use it up quickly. Polyphenols degrade with light, heat, and time — even genuine extra-virgin olive oil loses much of its benefit if it sits, clear-bottled, on a sunny shelf for a year.
• Trust your nose and palate somewhat. Real extra-virgin olive oil should taste fresh, slightly bitter, and peppery at the back of the throat (that’s the oleocanthal). A flat, greasy, or “crayon-like” flavor with no bite at all is a sign of an old, refined, or adulterated oil — though a full sensory panel evaluation is the only way to confirm this with certainty.

None of this means you need to become a suspicious olive oil detective at every trip to the store. It just means “extra virgin” on the label is a starting point, not a guarantee — and for a food this central to gut and metabolic health research, it’s worth buying from a producer transparent enough to earn that trust.

Extra-Virgin Olive Oil Is Flavorful

At first, you’ll notice the stronger flavor of extra-virgin olive oil, but like fine wine, it grows on you. There really isn’t a dish that can’t handle it — don’t be shy about baking with it either.

To get the most benefit from olive oil for gut healing, pair it with a broader gut-healing diet.

Related: The Best Fiber Supplements for IBS-D.

How to Use Extra-Virgin Olive Oil for Your Gut

Use more than you think you should. If your food is swimming in olive oil, you’re on the right track. Keep a bottle out to add to everything.

Good places to start:

• Eggs
• Rice
• Vegetables
• Fruit dishes and fresh fruit
• Meat dishes and chicken
• It tastes great on popcorn

When it comes to cooking and baking, the sky’s the limit. If a recipe calls for a tablespoon, go ahead and use three.

• Tapenade
• Basil pesto
• Marinara
• Baked fish
• Guacamole (also helps prevent browning)
• Gluten-free olive oil bread
• I add it to my no-sugar-added blueberry muffin recipe in my book, The Whole Body Guide to Gut Health

Olive oil’s gut benefits only show up if you use it consistently and generously, so don’t be shy with the amount.

A note for anyone who dislikes the taste or struggles to get enough in food form: a concentrated olive polyphenol extract can be a practical bridge. I keep a small set of professional-grade options in my Fullscript store for clients who want the research-backed polyphenol dose without the tablespoons.

Myths About Cooking With Olive Oil

One myth worth clearing up: you absolutely can cook and even sauté with olive oil. Research shows it doesn’t smoke in the pan the way people assume, making it an excellent all-purpose cooking oil.

That said, it’s still worth using cold-pressed extra-virgin olive oil raw at the table sometimes, since it retains all its antioxidants that way.

Other Tips for Using Olive Oil

Use up your olive oil relatively quickly — like all oils, it goes rancid if it sits on the shelf too long. If you can’t see yourself adding it to that many dishes, a spoonful straight is a perfectly good way to get the benefit. A reasonable goal, matching Mediterranean intake patterns, is around a liter of extra-virgin olive oil per week for a household.

How to Use Olive Oil for Constipation

Using olive oil for constipation is simple. Start with around 1.5 teaspoons of extra-virgin olive oil per day (about 4 ml) and work up from there. Many people land around 2–3 tablespoons a day for relief — consistent with the 2025 constipation trial dose above. There’s no harm in using olive oil this way, so the right amount can be individualized to your response.

You can take it straight, in food, or in drinks. Remember, Mediterranean intake patterns run around a liter a week — over 9 tablespoons a day — so don’t be afraid to use a generous amount.

When Olive Oil Isn’t the Answer: A Caveat From My Own MRT Results

Precautions With Olive Oil

If you have a known allergy to olives or olive oil, don’t eat it — that one’s straightforward.

Beyond true allergy, watch for a pattern of bloating, fatigue, joint pain, skin flares, or GI symptoms that track with olive-oil-containing meals (dressings, sautéed vegetables, dips) even though nothing seems obviously “wrong” with the food. As covered above, this is the kind of delayed, non-IgE reaction that standard testing misses, and it’s worth investigating with a qualified provider rather than assuming a “healthy” food can’t be the culprit.

If you take medication for blood pressure or blood sugar, talk to your provider before significantly increasing olive oil intake, since it can modestly affect both.

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body and is shared for educational purposes only. While The Healthy RD’s posts are backed by research, you are unique, so you must seek care from your own dietitian or healthcare provider. This post is not meant to diagnose or treat any conditions. Consult your doctor or healthcare provider before making changes to your supplement regimen or lifestyle.

FAQ: Extra-Virgin Olive Oil and Digestion