What Is Omega-7? The Palmitoleic Acid Harvard Researchers Called a Lipokine

A fat that behaves like a signal

Most dietary fats are either burned for energy or stored. In 2008, a research group at Harvard proposed that one of them does something different: it carries a message.

The team of Cao, Gerhold, Mayers, Wiest, Watkins and Hotamisligil, working in what is now the Department of Molecular Metabolism at the Harvard T.H. Chan School of Public Health, published work in the journal Cell identifying palmitoleic acid, an omega-7 fatty acid, as a lipokine. The term was coined by that laboratory to describe fatty acids that act as signalling molecules rather than simply as fuel or storage.

What the research describes

In the published account, palmitoleic acid is produced by fat tissue and then travels to the liver and muscle. In the liver it influences lipogenesis, the process by which the body creates and stores fat. In muscle it is associated with glucose disposal.

Subsequent observational work has reported that higher circulating palmitoleic acid levels correlate with better insulin sensitivity and a more favourable lipid profile.

The honest caveat

Correlation in observational studies is not the same as demonstrated effect in people, and this is where the science currently sits. A randomised placebo-controlled trial protocol using pure palmitoleic acid was published in 2023 to test its effects in overweight and obese adults with prediabetes.

That such a trial is being run is itself informative. It means the mechanism is considered interesting enough to test rigorously, and that the human evidence is still being gathered rather than settled. Anyone presenting omega-7 as an established treatment for anything is ahead of the literature.

Why sea buckthorn comes up in this conversation

Omega-7 is not widely distributed in food. Macadamia nuts and certain marine oils contain it, and sea buckthorn is among the notable plant sources, with the highest concentration in the fruit pulp rather than the seed.

This is the reason the berry appears in discussions of omega-7 more often than its overall profile might suggest. It is also why the distinction between pulp oil and seed oil matters when reading a label: they are different oils from the same fruit, with different fatty acid compositions.

Reading claims about it sensibly

Three things are worth holding on to. The lipokine finding is real, published and from a serious laboratory. The human clinical picture is still being established. And a nutrient being scientifically interesting is not the same as a product containing it doing something specific for an individual.

Good food is worth eating on the strength of what is known about it, without needing the claim to run ahead of the evidence.

Watch the full conversation

This article draws on Arjun Khanna, Managing Director of Biosash, in conversation with Amiett Kumar on the Readers Books Club podcast.

This article describes published research and is not medical advice. It does not claim that any product treats, prevents or cures any condition.