How Saturated Fat is Gumming Up Your Cellular Membranes

close up of a slab of soft butter

Remember the microscopes you used in biology class? Well, they’ve gotten a lot more powerful since then, and some exciting new microscopy research just breathed new life into the familiar (and overused) expression, “you are what you eat.” Advanced microscopic techniques have been used to examine the individual molecules that form the outer membrane of cells… and what’s there might surprise you.

We have long known that cell membranes are made of fat, but  these new techniques show how saturated fats in the diet can impair the function and undermine the health of your cellular membranes. (I promise you, you’ll think twice before reaching for butter or cream after reading this piece).

This turns out to be a really huge deal because it demonstrates (right down to the intracellular level) why saturated fats are so bad for you. In the past, scientists have established a clear link between the excessive consumption of saturated fats and cardiovascular disease, obesity, and cancer. But now researchers can actually see how these types of lipids gum up the works and disrupt the health of your cellular membranes.

New Insight Into Health on a Cellular Level

In a moment, I’ll discuss what these findings mean for your health, but first a quick word about the science that led to this breakthrough (I promise it’s not too geeky).  It starts with a team of scientists at Columbia University who were able to “tag” saturated fatty acids with a molecular label that did not alter the chemical properties of lipids they wanted to track. These researchers  then used a very sophisticated imaging method, called stimulated Raman scattering (SRS) microscopy, which allowed them to observe how saturated fat molecules affected the structure, function, and integrity of cellular membranes.

What they observed was extraordinary, and it has very important implications for your health. Normally, healthy membranes are flexible because there is a fluidity at the molecular level. But when you consume excessive saturated fat over an extensive period, your cellular membranes become more rigid, inelastic, and solid-like.

The results came as quite a surprise to the researchers. As lead investigator Dr. Wei Min, a professor of chemistry explained, For a long time, we believed that all cell membrane is liquid-like, allowing embedded proteins to change their shape and perform reactions. [A] solid-like membrane was hardly observed in living mammalian cells before. What we saw was quite different and surprising.”

Saturated fat accumulation in a cell alters the integrity of the membrane while interfering with cellular health in multiple ways. Internal dynamics are adversely impacted, but so is cell-to-cell signaling. That’s because cells communicate using chemical signals that are received by a receptors that are like satellite dishes that are anchored within the membrane. If that outer membrane is faulty (because it’s too rigid) then it’s a lot like a satellite dish that is stuck in one position… it will not do as good of a job receiving a signal and the communication is bound to be disrupted.

That’s just what the evidence suggests — when people consume excessive amounts of saturated fats, the serotonin receptors (which are critical to mood regulation) do not function optimally. Saturated fat is not just bad for your heart’s health, but also your mental health.

Healthy Sources of Fats Promote Health at the Cellular Level

On the other hand, studies show that eating unsaturated (healthy) sources of fat, such as omega-3 fatty acids, have precisely the opposite effect — they help maintain and restore health at the cellular level. As Yihui Shen, a graduate student who was part of the team at Columbia explains, “We found that adding unsaturated fatty acids could ‘melt’ the membrane islands frozen by saturated fatty acids.”


The way unsaturated fats can benefit health is a story I’ve been telling my patients for more than fifteen years. Great sources of essential omega-3 fatty acids include:

  • Wild-caught cold water fish like salmon, tuna, mackerel, or sardines.
  • Avocado
  • Olive oil
  • Nuts like walnuts, pecans, almonds, cashews, and macadamia nuts
  • Seeds like flax, hemp, sesame, pumpkin, or chia seeds

The recent study on how saturated fats damage cells, which was recently published in the Proceedings of the National Academy of Sciences, is further confirmation of my view that replacing unhealthy fats with the right kinds of lipids (those high in omega-3 fatty acids) can pay enormous health dividends. I hope this information helps you make better choices.

Take good care,

Dr. Josh