Most replayed moment: Omega-3: heart health hero or overhyped? | Dr. Bill Harris and Professor Sarah Berry

**SPEAKER_1** (0:01)
Hello, and welcome to ZOE Recap, where each week, we find the best bits from one of our podcast episodes to help you improve your health. Omega-3 fats have been celebrated, scrutinized and debated for decades. While some research points to remarkable heart health benefits, other studies suggest they can actually raise the risk of cardiovascular disease. So where does the science stand today? Should we supplement, rely on food, or rethink our approach to Omega-3 completely? Dr. Bill Harris and Professor Sarah Berry join me to cut through the confusion, explain Omega-3's role in the body, and share an evidence-based approach to this fascinating fatty acid.
What are these Omega-3 fatty acids?

**Dr. Bill Harris** (0:50)
So Omega-3 fatty acids are fatty acids typically found in fish oils. They're made primarily by these little single-cell organisms in the ocean that convert sunlight and sugar into Omega-3 fatty acids, and then the little fish eat the little cells, and then the big fish eat the little fish. And so salmon, for example, doesn't really make Omega-3 any better than we do, but they eat it. So their levels are high because they eat a lot. Why are they essential?
You know, sitting here with Sarah, I can't really say essential because EPA and DHA, which are the two Omega-3s that are most important, that are in fish oils, fish and fish oils, are not actually essential in the diet because strictly speaking in a nutritionist's point of view, if you have an essential nutrient, if you don't eat it, you die. And there are plenty of people on this planet who are vegans who eat no preformed EPA and DHA. They eat the precursor and that apparently gives them enough to survive, grow up, reproduce and live a life. So I think of EPA and DHA omega-3s as very bioactive, very important for health, but not essential for life.

**SPEAKER_1** (2:11)
I've gone from omega-3s and now you've already mentioned DHA and EPA. Could you just help me to understand that?

**Dr. Bill Harris** (2:17)
Right, right. So omega-3 is like a class, a family. If you look at the chemical structure of it, they all have a similar last name, so to speak, which is omega-3. And then there are four or five fatty acids in that family. The three that we hear most about, one is called ALA, which is alpha-linolenic acid, which is a plant based omega-3. And then it's grown up super cousins are the two that we get in fish, which are called EPA and DHA.
EPA and DHA are the two that are in fish. ALA is the one that's in plants. And those are the three major ones in the family.

**SPEAKER_1** (2:54)
Why do they matter at all? You were saying they're not literally essential, so I can live without them, so they're not like sort of vitamin C, I don't get scurvy.

**Dr. Bill Harris** (3:02)
Correct, you don't get scurvy.

**SPEAKER_1** (3:04)
But I get the sense that they are doing something of importance.

**Dr. Bill Harris** (3:06)
They are important for many biological factors. They find their home and when we eat them, they end up getting into cell membranes.
And all our cells have a little or a lot of omega-3, depending on really how much you eat. And I think the way I like to explain why they're useful, and it's a little difficult in sometimes because it's not like you can say for vitamin C if you don't have vitamin C, your teeth fall out. Okay, that's a problem. Omega-3 is more subtle. But as the omega-3s get into the cell membranes, they sort of act like grease on a hinge on a door because every cell has doors that let good things in like nutrients. And the cell also has a door that opens up out to dump the trash.
And if you've got enough omega-3 in your cell membranes, those doors swing smoothly. If you don't, they don't swing so smoothly. And some of the good stuff doesn't get in. Some of the bad stuff doesn't get out as well. And the cell just gets older and unhealthy.

**SPEAKER_1** (4:14)
What is that affecting in somebody's health?

**Dr. Bill Harris** (4:17)
Every cell gets these signals from the body, from outside the body, saying, hey, we've got an inflammation we've got to deal with. And the cell has to respond and make certain chemicals. And if it responds properly, the inflammation comes and then it goes away.
And that's the way it's supposed to be. Cell membranes become more flexible. Stiff cell membranes don't respond very well. Flexible ones are able to be kind of fleet of foot.
You can move quickly. The general idea is just being flexible is a good thing. And the omega-3s help make that membrane more flexible.