The 5 best food swaps to lower cholesterol, protect your heart and to live longer | Dr. Alice Lichtenstein

**SPEAKER_1** (0:00)
Welcome to ZOE Science & Nutrition, where world leading scientists explain how their research can improve your health.
A ribeye steak marbled with fat hits a blazing pan. It crackles, spits, and releases a rich smoky aroma that fills the kitchen. It hits the plate, and the cook digs in with confidence, knowing he's eaten a whole food that his body has evolved to digest.
Meanwhile, across town, his friend peels the foil lid off a low-fat yogurt, reassured that she's protecting her heart by avoiding fat. How did one nutrient become both villain and hero? How can we scroll through social media and find one person feasting on beef tallow while sipping butter-infused coffee, convinced that fat is the ultimate health food, while another embraces the multitude of low-fat yogurts in the store? And more importantly, what should you be eating to protect your heart? Thankfully, there is an answer to this question. Today I'm excited to be joined by Dr. Alice Lichtenstein, who is widely regarded as America's leading researcher on fats and their impact on health, especially the risk of heart disease. Having published hundreds of scientific papers, she's ranked in the top 500 female scientists in the world. Together, we're going back to basics, unpacking what fat actually is, why our body is needed, and how what we eat influences our cholesterol levels and our risk of heart disease. For decades, fat has been blamed for clogged arteries and heart attacks. Yet high fat diets are booming. The supermarkets are now lined with shelves promising to be fat free, and more shelves claiming to be fat-fuelled. No wonder we're confused. But by the end of this episode, you will have all the information you need to navigate this fat-fuelled maze. And you'll understand what Alice's latest research tells you to eat to avoid premature aging.
Are there healthy fats we can eat to support heart health?

**Dr. Alice Lichtenstein** (2:05)
Yes.

**SPEAKER_1** (2:06)
If you removed all fat from your diet, would you die?

**Dr. Alice Lichtenstein** (2:10)
Yes.

**SPEAKER_1** (2:11)
Does grass-fed beef contain high levels of omega-3?

**Dr. Alice Lichtenstein** (2:16)
No.

**SPEAKER_1** (2:17)
If you have cholesterol in your blood, is that always a bad thing?

**Dr. Alice Lichtenstein** (2:21)
No.

**SPEAKER_1** (2:22)
The latest US guidelines say that beef, tallow, and butter are healthy fats. Do you agree?

**Dr. Alice Lichtenstein** (2:27)
No.

**SPEAKER_1** (2:29)
Finally, what is the most common myth that you hear about fat?

**Dr. Alice Lichtenstein** (2:33)
If I eat fat, I'm going to get fat.

**SPEAKER_1** (2:36)
That's not true?

**Dr. Alice Lichtenstein** (2:37)
No.

**SPEAKER_1** (2:38)
Of everything we eat, I think fat has the most confused reputation when it comes to health in general and heart health in particular. Many of my relatives still refuse to eat food that they consider fatty because they're convinced that it will damage their hearts, because their doctor has told them that their cholesterol is high, or because they're convinced it's calorie dense, and so it's going to make them put on weight. I have other relatives who swear that red meat is a natural whole food, and so another burger must be great for their health. Given how confusing this topic is, I'd really like to start at the very beginning.
What is fat?

**Dr. Alice Lichtenstein** (3:20)
Fat is one of three macronutrients. There's fat, carbohydrate, and protein. They're all made of carbon, hydrogen, and oxygen, but protein also has nitrogen in it. What distinguishes fat from the other macronutrients is that it's what we call apolar. It does not mix with water. So you know if you have vinegar and you have oil, you can shake it up, but then it'll separate, and that's because it essentially repels water. Therefore, our bodies have to handle it very differently than they handle carbohydrate and protein.

**SPEAKER_1** (3:56)
You mentioned that our bodies need fat. Why is that?

**Dr. Alice Lichtenstein** (4:01)
Well, there's a whole class of compounds that we refer to as essential nutrients. They're given the designation of essential because our bodies can't make them, but they're essential for our well-being, for growth, for maintenance, and for repair.
One of those essential nutrients is a fatty acid, linoleic acid. We can synthesize part of it, but we can't synthesize all of it. Therefore, for us, it's essential.

**SPEAKER_1** (4:30)
What does it do inside us?

**Dr. Alice Lichtenstein** (4:33)
Inside us, it is a very important component of things like our cell membranes.
All our cells have membranes, both external that hold the cell together and then internal. We also use it as what we call a precursor. We use it as a substance that we turn into something else. Our bodies can modify it, and then that other compound has biological functions. If we don't consume enough essential fatty acids, then they're going to be adverse repercussions because we don't have what the body needs to function adequately.