Clearing up the confusion over fat

We need good fat.

We need it not only for the health of body parts like skin, hair, and brains, but also to reduce the risks of diseases like diabetes, heart disease, dementia, and cancer.

  • Good fat is found in minimally processed whole foods like raw nuts and seeds, avocados, olives, extra-virgin olive oil, butter, homemade mayonnaise, eggs, and oil-rich fish, like salmon and sardines.
  • The two families of fats to avoid are hydrogenated oils and highly processed vegetable oils.  This even includes “cold pressed” vegetables like canola, soy, corn, peanut, avocado, and grapeseed, because most are extensively processed with chemicals and high heat (250-500 degrees F) after cold pressing.  This is necessary to create a neutral taste and a long shelf life, but it leaves them severely nutrient-depleted.
  • Don’t demonize saturated fat.  Naturally occurring fat in unprocessed meat, whole milk dairy, and eggs are all nutritionally valuable in moderation.
  • Use extra-virgin olive oil as your primary cooking oil.  Extra-virgin olive oil is really just fresh-squeezed olive juice, a simple, minimally processed food which can be produced today just as people have done for thousands of years: crush the olives, separate the oil from the solids, and it’s ready to eat.  Extra-virgin oil (from the first pressing) is the richest in nutrients, including oleic acid and a valuable family of antioxidants called phenols.
  • Coconut and other traditional oils:  Minimally processed traditional oils from seeds or nuts will be distinctively flavored and cloudy; these, including virgin coconut oil, enjoy the benefit of historical precedence, but lack the evidence for benefit that we see for extra-virgin olive oil.

Extra-virgin olive oil has the best data

No other fat has anything like the level of benefit associated with extra-virgin olive oil:

  • Lower total mortality1 and less cancer,2 dementia,3 heart disease, and stroke4
  • Reduced cholesterol oxidation
  • Reduced inflammation
  • Improved blood clotting function, blood pressure and endothelial function5
  • Lower risk of osteoporotic broken bones
  • Less atrial fibrillation7
  • Less macular degeneration8
  • Improved mood and activity levels9

Which extra-virgin olive oil?

In the U.S., we suggest choosing olive oil produced domestically rather than imported due to legitimate concerns about the purity and accuracy in labeling of imported olive oil — for example, whether it is truly extra-virgin.  More refined olive oils (regular and light) have had most or all of their valuable phenols processed out, so are second-best but still preferable to other highly refined vegetable oils.

Extra-virgin olive oil for cooking

Claims that extra-virgin olive oil shouldn’t be used for home cooking are incorrect.  We use it for all cooking purposes — sauteing, baking, and roasting — as cooks have been doing for millennia.  The smoke point issue appears to be irrelevant, and distracts from the crucial issue of quality and how oils are processed.  For stovetop cooking, add your vegetables before the oil smokes.  Vegetables roasted with extra-virgin olive oil are particularly delicious.  Even using extra-virgin olive oil for deep frying has been shown to be associated with less insulin resistance!10

More evidence for extra-virgin olive oil: Less cardiovascular disease, less diabetes, less premature death

A 24 year follow-up study from the Nurses’ Health Study suggested women with higher olive oil intake (>0.5 tablespoons /day or >7 g/day) had 14% lower risk of cardiovascular disease.11  A systematic review and meta-analysis of prospective studies and randomized controlled trials showed that participants with better adherence to the Mediterranean diet, primarily focusing on olive oil consumption, for adults with cardiovascular events cited a 16% reduced relative risk of cardiovascular disease for every additional olive oil consumption of 25g/d.  The review noted that an increment of 25g/d in olive oil consumption was associated with a significant 22% relative reduction in the risk of type 2 diabetes.  The summary estimated that for each 25 g/d of olive oil consumption, the overall relative risk of all-cause mortality was reduced by 11%.12

Selecting extra-virgin olive oil

We recommend domestic brands.  Look for a harvest date stamp (not to be confused with an expiration date), which tells you when the olives were pressed.  Extra-virgin olive oil is a fresh squeezed olive juice with valuable phenols that need to be protected from light and heat. was founded in Portland, Oregon, and we have been delighted to become familiar with Durant Olive Mill, the premier purveyor of Oregon milled extra virgin olive oil, home to the only olioteca in the Pacific Northwest.  Durant Olive Mill’s recipe box highlights opportunities to use extra-virgin as the primary cooking oil with whole-foods recipes at home.


Miles Hassell, MD