On paper, for cardiovascular disease, nuts are wonderful. Let's think of all the stages of atherosclerosis — hardening of the arteries, heart disease.

• High cholesterol: nuts lower your choelsterol.
• Inflammation: nuts are anti-inflammatory.
• Endothelial function — the function of your arteries: nuts improve, within hours, endothelial function.

You look through every single one, and it's like, "Wow! Nuts improve cardiovascular risk factors!"

So one would assume that if we put people on a Whole Food Plant-Based diet with nuts, they would reverse their heart disease even better than a low fat Whole Food Plant-Based diet. Has this ever been put to the test? Not in randomized controlled trials.

For example, Dr Joel Fuhrman has published case reports showing that "Look, I can reverse people's heart disease with a nut rich — nuts, avocados, seeds — whole food sources of fat, I can reverse heart disease just as well as Ornishes, Pritikins and Esselstyns of the world, with a Whole Food Plant-Based diet with added whole food sources of fat."

But the problem is that these are case reports. These are individual cases patients who did that. We are yet to have a randomized controlled trial where you randomize people to different diets.

I would love to study where you put people on a low fat WFPB versus a WFPB with some walnuts and see if they got better. My educated guess is that walnut group does better. That's what I would guess.

But if I had heart disease, if I had a patient that had heart disease, if I had a loved one with heart disease. You don't make them into guinea pigs. You don't mess around. We have data from these randomized controlled trials. You put people on a WFPB diet that's low in fat, you reverse heart disease. That's the data we have! So what do you do? You go on that diet. You go on a diet that's proven to work.

Theoretically, I think there's a diet that's even better - that same diet with walnuts. If you want to be the one to put that to the test, go ahead. But that's not where the available data is.

If it wasn't life & death, "hey, let's give it a trial!" It's life & death, so you do what works. If Esselstyn's diet said WFPB and only eat green M&M's, I would say, "that makes absolutely no sense!" but "only green M&Ms" — this is the diet that works — this is the proven diet. So we stick to what's been proven to work until we know otherwise.