An evolutionary secret to longevity

Healthy Aging

Longevity is a resilience game

Over the past 5 weeks, we have covered the science behind our cell membranes and aging, including: 1) how our diets determine the make-up of our cell membranes, 2) how strong cell membranes support survival in extreme environments, 3) how red blood cell membrane fragility (aka lower hemoglobin) is a measurement of our aging rate, and 4) how those fragile red blood cells over time can advance to a condition called ‘anemia of aging.’

Whew! For the final part of this series, let’s talk about the role that cell membranes play in the longevity game – including a smart & simple evolutionary trick that explains how we humble humans live 23 times longer than mice.

So, how do we live longer than mice?

One solution to longevity in mammals is actually quite simple.

You see, oxygen is a bit of a Jekyll & Hyde molecule. While oxygen is essential to life, it also – slowly, over time – creates damaging reactive oxygen species that break down our cells, resulting in our inevitable demise.

The secret to long life? The longer we can stave off the damaging effects of oxygen, the longer we (as mammals) live.

Okay, I’ll bite. How do we hold off damaging oxygen species?

Chances are, you have heard of antioxidants. Inherently, antioxidants are molecules that protect against oxidative damage. As described in a thorough review by Nwozo et al., there are many molecules that have antioxidant properties. So, there’s that.

A.J. Hulbert, however, discovered something bigger than just antioxidants in blueberries. He found that mammals with the highest saturation of fatty acids in their cell membranes had the lowest body levels of damaging oxygen species. Most importantly, he found that these mammals lived the longest.

Meet the “Cell Membrane Pacemaker Theory of Aging”

This discovery, which Hulbert coined the Cell Membrane Pacemaker Theory of Aging, includes the following three important points:

1. Fatty acids with the least double bonds were the most stable and protected cell membranes against oxidative damage. In contrast, polyunsaturated fatty acids with multiple double bonds were the most unstable and made cell membranes more susceptible to oxidative damage.
2. Long-lived mammals (like humans and elephants) have more stable fatty acids in their cell membranes, while short-lived mammals have more unstable polyunsaturated fatty acids in their cell membranes.
3. The more stable the fatty acids in a mammal’s cell membranes → the less oxidative damage is present → the slower that mammal ages → and the longer that mammal lives.

Take home point: By shoring up the stability of fatty acids in our cell membranes, we support a key mechanism to longer life.

But will this fun fact really help to extend human longevity?

We had the same question. That is why – upon understanding a few secrets to longer life among mammalian species – our fatty15 team spent a decade studying molecules that might just help humans (and dolphins) live even healthier and longer.