Should extra-virgin oil be your default fat?

Investing in extra-virgin olive oil: is it worth it? Over years, the fats you use most often can influence long-term health,especially cardiovascular risk, because fats affect blood lipids, blood pressure, body weight (they’re calorie-dense), and the overall quality of the foods we eat.

Fats also play essential roles: they help absorb fat-soluble vitamins (A, D, E, K), form cell membranes, and support normal hormone production. The goal isn’t to “fear fat,” but to choose fats that fit your body, your cooking style, and your health priorities.

What the strongest human evidence actually shows

The most convincing evidence doesn’t come from isolated nutrients in a lab—it comes from diet patterns tested in people.

In the landmark PREDIMED trial (7,447 older adults at high cardiovascular risk), participants assigned to a Mediterranean-style diet supplemented with extra-virgin olive oil (EVOO) or nuts had fewer major cardiovascular events (heart attack, stroke, cardiovascular death) than those assigned to a reduced-fat advice group. This is outcomes-level evidence (real events, not just blood markers). (nejm.org)

This doesn’t prove that one oil is “magic.” It supports a practical message: fat quality matters, and benefits show up most clearly when healthier fats appear in a whole-food pattern (vegetables, legumes, fish, nuts, fruit, less ultra-processed food).

A second, complementary line of evidence comes from controlled trials and meta-analyses: replacing saturated fats with unsaturated fats lowers LDL cholesterol, and this pattern is consistent enough that major scientific reviews interpret it as a meaningful cardiovascular lever. (ahajournals.org)

How strong is the evidence? Where uncertainty honestly lives

Think of nutrition evidence as a ladder. Higher rungs are harder to do, but more convincing. Before deciding on which fat is healthier, let’s look at the most pertinent evidence:

1) Strongest (hard outcomes):
Randomized trials measuring heart attacks, strokes, and deaths. Example: PREDIMED, where adding EVOO or nuts to a Mediterranean diet pattern reduced major cardiovascular events. (nejm.org)

2) Strong (validated risk markers):
Randomized trials and meta-analyses showing fat swaps change LDL/apoB. These are “markers,” but they matter because atherosclerosis is driven by the number of LDL/apoB-containing particles. (ahajournals.org)

3) Suggestive (observational studies):
Cohort studies linking foods and oils to disease outcomes. Useful—but confounded by lifestyle patterns (for example, people who use olive oil often differ in many ways from people who use butter). (pubmed.ncbi.nlm.nih.gov)

4) Plausible but not decisive (mechanisms):
Oxidation, inflammation pathways, and “seed oil” hypotheses. These can generate ideas but rarely settle real-world effects on their own.

5) Value-based decisions (precaution zone):
GMO/pesticide residue concerns, solvent extraction worries, and “how much risk is acceptable.” Evidence can inform these choices, but personal risk tolerance plays a legitimate role.

A practical way to think about fats: “default fats” vs “flavor fats”

A useful approach for real life is to separate everyday default fats from occasional flavor fats.

Default fats (best supported as everyday choices)

Extra-virgin olive oil (EVOO) is a strong default for dressings, finishing, and low-to-medium heat cooking, especially when it’s fresh and stored well. PREDIMED provides outcomes-level support for a Mediterranean pattern where EVOO is central. (nejm.org)

Nuts and seeds (and nut/seed butters) are whole-food fats with one of the best overall evidence profiles. They provide unsaturated fats in a package that also includes fiber, minerals, and protein.

Canola oil is often controversial because it is a refined “seed oil.” If your goal is to judge it on human trial evidence, the most consistent finding is this: in randomized trials, canola oil tends to lower LDL and total cholesterol compared with saturated-fat sources when used as a replacement. (pubmed.ncbi.nlm.nih.gov)
A common claim is that omega-6 fats are automatically inflammatory. In randomized trials, higher linoleic acid (omega-6) intake does not reliably increase common inflammatory markers in healthy people. (sciencedirect.com)

Avocado oil is also monounsaturated-rich and is widely used for higher-heat cooking, but the strongest long-term outcomes evidence is for Mediterranean patterns and whole-food fats, not avocado oil specifically.

Flavor fats (can fit, but shouldn’t quietly become the default)

Butter and ghee are valued for taste and cooking traditions. They also contain saturated fats that tend to raise LDL more than unsaturated oils in controlled feeding studies—especially when they replace olive oil, nuts, or other unsaturated sources. (ahajournals.org)
At the same time, observational research suggests butter intake has small or neutral associations with CVD and diabetes overall—useful context, but not proof that butter is protective. (pubmed.ncbi.nlm.nih.gov)

Coconut oil contains some medium-chain fats, but it remains high in saturated fat overall. If LDL/apoB is high or cardiovascular risk is elevated, it usually makes sense not to use coconut oil as the main everyday fat. (ahajournals.org)

Lard and tallow are traditional cooking fats and can be useful for certain recipes. As with butter and ghee, the key question is what they replace. If they displace olive oil, nuts, seeds, and fish in a person’s pattern, their effect on LDL-related risk markers tends to be less favorable. (ahajournals.org)

Cooking method matters more than most people realize

A lot of “oil controversy” has less to do with the oil name and more to do with what people do to it.

Overheating oils to visible smoking and repeatedly reusing frying oil increases breakdown products. The most protective advice that applies to everyone is simple:

• avoid visible smoking,
• avoid repeated reuse of frying oil,
• store oils away from heat/light,
• and match the oil to the cooking method (use your best-tasting oils for cold/finishing, neutral oils for higher heat if needed).

Your Genes Matter (but lab results still matter more)

Genetics can influence how people respond to dietary fats, but it rarely overrides the basics.

• APOE ε4: Some diet trials suggest APOE genotype can modify LDL responses to fat swaps (the size of the effect varies). (pubmed.ncbi.nlm.nih.gov)
• FADS1/FADS2 variants: Influence conversion efficiency of plant omega-3 (ALA) into longer-chain omega-3s (EPA/DHA). Many people convert ALA modestly, so direct EPA/DHA sources (fatty fish or algae) can matter. (sciencedirect.com)

If you want true personalization, your measured results are usually more actionable than genetics: LDL or apoB, blood pressure, A1c/glucose, triglycerides, and your weight trend.

Practical swaps and daily habits

• Use EVOO for dressings, finishing, and low-to-medium heat cooking; use butter/ghee mainly as a finishing flavor. (nejm.org)
• Use a neutral oil you tolerate for higher-heat cooking without smoking or reusing oil repeatedly.
• If you love coconut oil, keep it as an occasional cooking fat rather than the daily default, especially if LDL/apoB is high.
• Favor fats that come with “built-in nutrients” (nuts, seeds, fish) more often than pure oils.

Daily habits: store oils in a cool, dark place; buy sizes you’ll finish while fresh; rotate 2–3 fats; measure instead of free-pouring; and focus on whole-food meals where fat enhances flavor rather than hiding ultra-processed ingredients.

Extra-virgin olive oil is certainly worth it, if you can afford a good one. But no matter what you choose, be sure to enjoy yourself and remember: No food is evil!

Want to see a ranking of fats? Read here

References

• Estruch R, et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. N Engl J Med. 2018;378:e34. (nejm.org)
• Sacks FM, et al. Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association. Circulation. 2017. (ahajournals.org)
• Ghobadi S, et al. Effects of Canola Oil Consumption on Lipid Profile: Systematic Review and Meta-analysis of RCTs. 2019. (pubmed.ncbi.nlm.nih.gov)
• Johnson GH, et al. Effect of Dietary Linoleic Acid on Markers of Inflammation in Healthy Persons: Systematic Review of RCTs. 2012. (sciencedirect.com)
• Pimpin L, et al. Butter Consumption and Risk of Cardiovascular Disease, Diabetes, and Total Mortality: Systematic Review and Meta-analysis. PLoS One. 2016. (pubmed.ncbi.nlm.nih.gov)
• Griffin BA, et al. APOE genotype and lipid response to dietary fat change (trial evidence). 2018. (pubmed.ncbi.nlm.nih.gov)
• Gillingham LG, et al. ALA conversion / fatty-acid metabolism and genetics (FADS). (sciencedirect.com