Oleocanthal Alters Alzheimer’s Proteins in Lab Tests
Oleocanthal, the compound that makes fresh extra virgin olive oil sting the back of your throat, changed the structure of the toxic protein clusters linked to Alzheimer’s disease and made them less likely to latch onto nerve cells, in laboratory tests reported yesterday by the Monell Center and Northwestern University. This note covers what the researchers actually did, what they did not show, and what it means for the oil on your shelf.
What happened
On September 29 the Monell Chemical Senses Center in Philadelphia announced the results of a study it ran with Northwestern University, due in the October 15 issue of the journal Toxicology and Applied Pharmacology. The work was co-led by Paul Breslin, a sensory psychobiologist at Monell, and William Klein, a neurobiologist at Northwestern whose group identified the proteins in question in 1998.
Those proteins are called ADDLs, short for amyloid beta-derived diffusible ligands. They are small, soluble clusters of amyloid beta, different from the larger plaques most people have heard of, and they bind at the synapses where nerve cells pass signals to each other. Klein’s view is that this binding is a crucial first step in Alzheimer’s disease. In a series of test-tube and cell-culture experiments, the team found that incubating ADDLs with oleocanthal made the clusters larger, and that the altered clusters were less able to bind to synapses of cultured hippocampal neurons, the brain region that handles memory and is hit early in the disease. They also report that oleocanthal made ADDLs easier targets for antibodies, which they suggest could help immunotherapy research.
The funding came from the National Institute on Aging and the National Institute on Deafness and Other Communication Disorders. Klein’s own caveat was plain: translational studies are needed to link these laboratory findings to clinical treatment.
Why oleocanthal keeps making news
Oleocanthal is not new to anyone who tastes oil for a living. It is the source of the peppery catch that makes a panel of tasters cough over a young oil. Monell scientists put it on the map in 2005 when they reported in Nature that it acts on the same enzymes as ibuprofen, a story this site followed in Extra Virgin: a Pain Killer? and Extra Virgin Anti-Inflammatories. The link between Mediterranean eating and brain health has also been studied for years, as we noted in Mediterranean diet helps against Alzheimer’s. This new work tries to name one possible mechanism.
| What the study did | What it did not do |
|---|---|
| Exposed ADDLs to oleocanthal in the lab | Test olive oil in people |
| Measured binding to cultured nerve cells | Show any effect on memory or disease |
| Used purified oleocanthal | Establish a dose you could get from food |
What it means for buyers
Nothing in this study tells you to eat more olive oil to protect your brain, and the researchers do not say that. What it does do is add weight to an old point about quality. Oleocanthal is found in extra virgin olive oil, and the amount varies a great deal with the olive variety, how green the fruit was at picking, how the oil was milled and how old it is. Refined olive oil, including the pale “light” bottles, has little of the compounds that give extra virgin its bite. If a researcher’s compound of interest is the one that makes you cough, a flat, sweet, tired oil is not the one they were studying.
- The results come from test tubes and cultured cells, not patients.
- Oleocanthal levels differ widely from one bottle to the next.
- A peppery throat catch is a rough sign that the oil still has it.
For years buyers at trade fairs asked us to find oils that were “smooth, no bite”, because the pepper put some customers off. The market rewarded mild oil, and many blenders built soft, easy oils to order. Now the lab work points at the very sting that the trade spent years sanding away. Taste before you believe any health line on a label: if it does not tickle your throat at all, it is probably not the oil the scientists had in mind.
This is general information, not medical advice. Anyone worried about memory loss, or about Alzheimer’s disease in the family, should talk to a doctor rather than rely on diet alone.