EverydayArticle link

Extra virgin olive oil and cognitive function

Key points

  • A Harvard study of over 92,000 people found that consuming just half a tablespoon of olive oil daily was linked to a 28% lower risk of dying from dementia.
  • Extra virgin olive oil contains antioxidants that fight cell damage and reduce brain inflammation, which may help protect against cognitive decline.
  • Swapping just one teaspoon of margarine or mayonnaise for olive oil can make a difference—small changes add up.
  • Olive oil is most effective as part of a Mediterranean-style diet that also includes vegetables, fish, nuts, and whole grains.
  • Start with a small amount (1/2 tablespoon per day) and gradually increase if tolerated. Monitor for digestive issues.
  • Olive oil is not a cure or replacement for medical treatment—always discuss dietary changes with your loved one's healthcare provider.

General caregiving information, not medical advice. Check medications and major care changes with your clinician.

Step-by-step

  1. Begin with about 1 teaspoon of extra virgin olive oil daily and gradually work up to roughly 1/2 tablespoon (7 mL) over a week, slowing down or reducing the amount if your loved one develops loose stools or stomach upset.

  2. Swap out one less-healthy fat at a time—use EVOO instead of butter on toast, mayonnaise in tuna salad, or margarine on vegetables—so the change feels manageable and sustainable.

  3. Keep a simple journal of your loved one's memory, mood, and word-finding over several months, and bring these observations to their healthcare provider at visits.

What not to do

  • Don't treat EVOO as a cure for dementia or a replacement for prescribed medications—it is a supportive dietary choice that works best alongside medical care, physical activity, and other healthy habits.

  • Don't assume all olive oils offer the same benefit—choose extra virgin, check the harvest date for freshness, and store the bottle in a cool, dark place to protect its antioxidants.

  • Don't overheat EVOO—high heat degrades its beneficial compounds, so use it for dressings, drizzling, and low-heat cooking, and reach for avocado oil if you need a higher smoke point.

  • Don't force your loved one to consume olive oil if they dislike the taste or texture—blend it into familiar foods or pivot to other brain-healthy fats like avocados, nuts, and fatty fish.

  • Don't overlook potential interactions with blood thinners like warfarin—olive oil has mild blood-thinning effects, so discuss intake with the clinician, especially if you are increasing it significantly.

Practical tools

  • Half-Tablespoon Measuring Aid

    Keep a small measuring spoon or a marked glass jar in the fridge pre-portioned with 1/2 tablespoon (7 mL) of EVOO to ensure consistent dosing and eliminate guesswork.

  • Weekly Fat-Swap Checklist

    Create a simple list: Monday, swap butter on toast for EVOO; Tuesday, use EVOO instead of mayo in tuna salad; Wednesday, drizzle over vegetables instead of margarine. Check off each swap to build the habit.

  • Progress Journal Template

    Keep a small notebook to jot down brief notes on your loved one's memory, verbal fluency, and mood each week. After a few months, share these observations with their healthcare provider to guide care decisions.

Discuss with your clinician

If your loved one is on blood-thinning medication (e.g., warfarin), ask the doctor if increasing olive oil intake is safe, as it contains vitamin K which can affect clotting.

If your loved one has a history of pancreatitis or gallbladder disease, discuss whether adding more fat (even healthy fat like olive oil) is appropriate for their condition.

If your loved one is on medications for high blood pressure, cholesterol, or diabetes, ask how olive oil might complement these treatments and whether any dosage adjustments are needed.

If your loved one has swallowing difficulties (dysphagia), ask a speech therapist or doctor about safe ways to incorporate olive oil into their diet without risk of aspiration.

If you notice any new or worsening symptoms after starting olive oil (e.g., stomach pain, diarrhea, allergic reaction), stop use and consult a clinician.

Related guides

Sources