Episode 101

NAD The Molecule of Life — and the Hype

Published on: 6th November, 2025

🧬 NAD: The Molecule of Life — and the Hype

How a lab coenzyme became the latest anti-aging obsession


What We Mean by Longevity and Healthspan

When people talk about longevity, they usually mean how long we live.

But healthspan — the years we live well — matters far more.

That’s the time before disease steals our energy, mobility, and independence.

Modern medicine has already doubled our lifespan in the last century.

Now the goal is to extend the healthy part — without falling for pseudoscience along the way.


When Marketing Meets Medicine

Longevity has become a booming business.

Some gurus, like Dr. Eric Topol, do real science.

Others, like Peter Attia, sell access: $150 000 per patient for lab tests, a VO₂ max treadmill run, and a few “optimized” workouts.

He’s also an investor in AG1 — the influencer’s green drink of choice.

Andrew Huberman promotes similar ideas under studio lights bright enough to sterilize a petri dish.

Both are clever, credentialed, and caught between data and drama.

Then there’s Dr. David Sinclair, who helped discover how cells age — and then helped turn that discovery into a supplement empire.

His company tried to patent NMN, an NAD precursor, as a drug.

The FDA briefly removed NMN from the supplement market, sending Reddit into meltdown.

It’s back now, but the episode showed how quickly science slides into sales.

And finally, we have the shirtless salesmen:

Paul Saladino, who went from carnivore crusader to “fruit influencer.”

Liver King, whose real secret wasn’t liver — it was injectable.

And Gary Brecka, who claims to predict your death date (for a fee).

These are subscription services disguised as sages.


What NAD Actually Is

Nicotinamide adenine dinucleotide (NAD⁺) is a molecule found in every living cell.

It helps convert food into energy and repair DNA.

As we age, NAD levels fall — metabolism slows and damage builds up.

So scientists asked: If we raise NAD again, can we slow aging?

In mice, the answer looks promising.

NAD precursors like nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) increase average lifespan by 5–15 percent and improve energy, insulin sensitivity, and activity.

That’s great for mice — but we don’t live in cages or eat lab chow.


Can You Get NAD from Food?

Not directly — but your body makes NAD from dietary precursors:

tryptophan and niacin (vitamin B₃).

You’ll find them in fish, poultry, beans, milk, and whole grains — basically, a Mediterranean-style diet.

So before spending $90 on capsules, you can spend $9 at the farmers' market.


What the Human Studies Show

Human trials of NR or NMN (usually 500–2000 mg per day for 6–12 weeks) show they are safe and well-tolerated.

They modestly raise NAD levels and sometimes improve lipid profiles and blood pressure.

But the effects are small and inconsistent, especially in healthy adults.

NAD precursors do not reverse aging.

They don’t prevent heart attacks or extend lifespan in people — at least, not yet.


NAD vs Statins: A Reality Check

Meta-analyses show NAD precursors, especially niacin, can lower LDL (“bad”) cholesterol by about 8–12 percent.

That’s fine, but compare it to rosuvastatin (Crestor):

DoseAverage LDL Reduction5 mg≈ 45 %10 mg≈ 52 %20 mg≈ 55 %40 mg≈ 63 %

That’s the difference between “interesting biochemistry” and “fewer funerals.”

So NAD may nudge your cholesterol; statins save lives.


Who Might Benefit

Older adults with metabolic syndrome, prediabetes, or early neurodegenerative disease could see modest improvements in inflammation or blood lipids.

Younger, healthier people mostly see lighter wallets.

No serious drug interactions have been documented, though theoretical ones exist with some chemotherapy or DNA-repair drugs.

As always, talk to your doctor before combining anything with prescription therapy.


Food Before Pharma

The best way to support NAD and longevity is still food, sleep, and movement.

A Mediterranean diet rich in legumes, vegetables, olive oil, and fish fuels NAD pathways naturally — and has proven benefits for heart and brain health.

No influencer code required.


A Note from the Galley

We’ll explore all of this — diet, longevity, and a little wine science — on next summer’s Mediterranean Longevity Cruise.

World-class physicians, scientists, and chefs will join me for ten days of evidence-based indulgence.

It’ll cost less than a Peter Attia consult — and no one will force you to drink AG1.

(For the record, I still do. It’s gentle on my stomach, but I’m hunting for less bougie vitamins.)


The Takeaway

Boosting NAD may someday help extend healthspan, but for now, the best evidence still supports:

  • Eat Mediterranean-style food.
  • Move daily.
  • Sleep enough.
  • Manage stress.
  • See your doctor before your supplement dealer.

That’s how you live longer and better — no silver bullet, just science and common sense.


References

Effects of NAD+ Precursor Supplementation on Glucose and Lipid Metabolism in Humans: A Meta-Analysis. Zhong O, Wang J, Tan Y, Lei X, Tang Z. Nutrition & Metabolism. 2022;19(1):20. doi:10.1186/s12986-022-00653-9.

2 Niacin: An Old Lipid Drug in a New NAD+ Dress. Romani M, Hofer DC, Katsyuba E, Auwerx J. Journal of Lipid Research. 2019;60(4):741-746. doi:10.1194/jlr.S092007.

3.Nicotinamide Adenine Dinucleotide in Aging Biology: Potential Applications and Many Unknowns. Bhasin S, Seals D, Migaud M, Musi N, Baur JA. Endocrine Reviews. 2023;44(6):1047-1073. doi:10.1210/endrev/bnad019.

4. Crestor. FDA Drug Label. Food and Drug Administration Updated date: 2024-07-31

Transcript
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>> Dr. Terry Simpson: Hey, welcome back to 4Q. Today we are launching a

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new series about longevity and health span. Now,

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longevity is easy to measure because there's a

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date on every tombstone. But health span is

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different. Healthspan we define as the time when

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you're healthy, mobile, curious, and capable

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before disease or aging slows you down. That's the

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part we want to stretch out, because living longer

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isn't the same as living well. Now, the moment you

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step into the world of longevity, you meet a

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parade of gurus, pouters, and podcasts. There's

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some serious scientists in the field, like the

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founder of the whole field, Leonard Hayflick, who

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recently died at age 93. He was the one who

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defined cellular aging in the first place. Or Dr.

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Eric Topol, who actually advance his medicine. But

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then there are those who have turned longevity

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into a luxury brand. Take Peter Attia. In his many

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iterations of himself, he finally settled on

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building an empire where he can charge $150,000 or

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more for a patient to become a patient of his. And

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what do you get for that? You get a handful of

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basic lab tests. You get a VO2 max run. You get to

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hike with him with a rucksack, a weighted

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backpack. You learn a few yoga poses, and you get

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some lectures about how you should sleep better.

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Some of this you can get from your local primary

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care doctor and a local gym for about 30 bucks a

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month and copay. So remember, this is a man who

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never finished a surgical residency, but

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billionaires pay him because they can. He

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positioned himself exceedingly well. The man who

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has gone from being all pro keto to let's do all

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the exercise we can. By the way, he's also an

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investor in something called AG1, that bright

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green drink sold as nutrition in a scoop. And of

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course, there's Andrew Huberman. He is another AG1

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investor. He podcasts between studio lights that

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are bright enough to give you a tan, and he seems

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to always wear black. Now, both of these guys are

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smart, they are accomplished, but let's be honest,

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they live where marketing meets medicine. And

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sometimes the marketing wins. There's the other

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longevity star. You've probably heard of Dr. David

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Sinclair. He's a Harvard professor, and he turns

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something called nad, which is a supplement

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almost, into a religion. And the precursor

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molecules, these are initials you're going to

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hear. Nmn, M and nr. They sound like secret

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passwords to eternal health. You know David

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Sinclair's early work on aging and sirtuins? It

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was brilliant. But somewhere between Harvard and

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Hollywood, the science and the sales pitch,

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started to share a toothbrush. He even formed a

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company. And he tried to patent NMN as a drug.

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Now, when you try and patent a supplement as a

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drug, the FDA does what they would always do. They

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pulled it from the supplement market. Now this

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sparked all of these rhettic panics and these

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headlines that the government was hiding. The

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fountain of youth. You can buy NMN now. But that

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fiasco showed just how thin the line is between

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research and retail and, and how desperate people

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are for that fountain of youth. Now, no longevity

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carnival would be complete without the shirtless

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salesmen of supplements and scams, the ones who

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promise eternal youth. Everything from protein

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powder and ancestral vibes. Take Paul Saladino.

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Hasn't seen a patient in years, discovered that

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fruit is good for you, even after declaring steak

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with salvation. Or the liver King, his erstwhile

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partner, who discovered that, well, his secret

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wasn't liver, but it was ever he was injecting.

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Then, of course, no claim would be complete

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without mentioning Gary Breca, the guy who says

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he's a human biologist, whatever that is, and can

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predict the date of your death. Of course, all you

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have to do is buy some of his fancy amino acids,

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his hydrogen water bottles, and all of his scams

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in between. Those people aren't scientists.

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They're basically services in human forms. Now

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here at 4Q, we're not selling miracle molecules or

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$150,000 wellness plans. We're bringing you the

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real science. What we know, what we don't, and how

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to tell the difference. Because understanding

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longevity shouldn't require six figure copay or a

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discount code. And as you will learn, you do not

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have to be a billionaire to learn about it and to

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implement it.

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But today, we're going to start with nad, which

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stands for nicotinamide adenine dinucleotide. This

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is the so called molecule of life. Now, does it

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actually work in humans? We're going to find out.

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I'm Dr. Terry Simpson, your chief medical

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explanationist, and this is Fork U Fork

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University, where we bust myths, make sense of the

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madness, and teach you a little bit about food and

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medicine. NAD is something that every freshman

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medical student learns in basic biochemistry about

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how the body works. It responsible for fueling

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energy production. It's in the Krebs cycle. It's

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responsible for DNA repair. And as we age, NAD

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levels drop, metabolism slows, inflammation rises,

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cells get sloppy, and blood, like Leonard Hayflick

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pointed out in the 1960s, senescent. So scientists

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ask the most obvious of all, can we top it up?

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Meaning can we Give external NAD or one of its

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precursors and kind of turn these cells back into

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powerhouses again, make those mitochondria shine.

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Well, it turns out in mice, the answer is yes.

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Boosting NAD in mice by using precursors such as

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NR or NMN extends the lifespan of the mice by 5 to

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15%. That translates to just a few months for a

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mouse. But if you're thinking about a human mouse,

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years in humans might work out to a couple of

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years. But in mice, we found that the mice moved

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better, they burned energy better, and as far as

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we could tell, they aged a little slower. But, uh,

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here's the catch. Human beings, we're not just

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mice with mortgages. Here's the thing. You cannot

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eat nad, but you can eat its precursors,

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tryptophan and niacin, which is vitamin B3. These

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are found in fish, poultry, beans, milk, and whole

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grains. Does this sound familiar? Yeah, we call

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that the Mediterranean diet. So before you drop 90

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to 100 bucks on a bottle of NMN or NR, maybe stop

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at the grocery store instead. The big supplement

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players, NR and NMN, can raise NAD levels and are

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generally safe up to about 2 grams a day. There's

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no major side effects beyond the occasional flush,

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but they don't reverse aging, and they don't

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replace real medicine. Now, a meta analysis shows

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that Some of these NAD precursors, especially

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niacin, can lower LDL cholesterol by about 8 to

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12%. That's a nice lab number, but let's compare

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that to, let's say, Crestor, which is

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rosuvastatin, which is the LDL lowering

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cholesterol agent. I use 5 milligrams, lowers

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cholesterol by about LDL cholesterol by 45%. 10

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milligrams, 52%, 20 milligrams. What? I take 55%,

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40 milligrams, same. So that's not a blip. That's

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the miracle of modern medicine. And no NAD

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supplement has ever been shown to prevent heart

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attacks or strokes. Statins have again and again

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shown that they can do that. Now, that's the

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difference between some interesting biochemistry

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and some actual medicine. But if we're looking at

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this, who might actually benefit from taking some

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form of nad? Well, maybe older adults with

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metabolic syndrome or prediabetes. The. Those

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small improvements in lipids or inflammation may

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be helpful. But imagine this. My bottle of Crestor

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cost me about 75 cents for a month. That bottle of

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NAD is going to be out 100 bucks a month, and the

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Crestor is going to do a little bit more for me.

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Now, there has been a hint of potential in

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patients with early Alzheimer's or Parkinson's

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disease, but that data is tiny and for all intents

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and purposes is statistically meaningless. Now, if

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you're young and healthy, the only thing NAD will

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reliably do is reduce your bank account. Safety

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wise, there have been no major interactions that

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have been found, although there are theoretical

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issues with certain anti cancer or DNA repair

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drugs. And even if your gut microbiome helps

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process NAD precursors, another reason to feed it

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well instead of flood it with pills, it may not

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actually help you that much. So what actually

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works NAD does drop. As we age, our cells enter

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into their cellular retirement. Or as Hayflick

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described it years ago, senescence. And whether

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topping NAD keeps them working longer is still

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really unknown. But what we do know is how to

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support your body's own NAD production on a plate,

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not in a capsule. The Mediterranean diet, which is

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rich in fish, legumes, olive oil, whole grains,

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naturally fuels the NAD pathway in your body and

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protects your heart in a dozen other ways. You

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don't need a subscription. You don't need a magic

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powder. You don't need this bougie price tag. You

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just need to eat better. Now, uh, here's the

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thing. If you want to learn a lot more about

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longevity the right way, we are going to actually

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work on, we're working on it now. A longevity

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cruise in the Mediterranean in the summer of 2026,

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next summer, maybe the second week of August. Our

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plan is to have world class physician, scientist,

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a food network chef with real conversations about

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living longer and better, all while sailing in the

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Mediterranean with shore excursions that will drop

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your socks off. You're not going to be fitted with

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a weighted rucksack. You're not going to have to

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pay a six figure fee. Um, unlike Peter Attia's

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program, this one includes shore excursions, wine

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and actual fun. And for the record, Yeah, I drink

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AG1, but. But not because I have an affiliate

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code. I don't get a kickback, I don't get stock on

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it. I just like how gentle it is on my stomach,

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which is why I take it. But I'm always looking for

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a less pricey, less bougie way to get in my

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vitamins. So come on. If you're interested, serve

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that time and consider about thinking about

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healthspan under the Tuscan sun, where we found 70

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years ago, people lived longer and lived better by

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eating simpler and developing immunity. This has

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been fork you, fork University researched and

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written by me, Dr. Terry Simpson, your chief

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medical explanationist. All things audio and

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editing were done by my friends at Simpler Media

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and the pod God himself who spent X amounts of

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time with me today and my new fancy equipment. For

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references and show notes, visit4q.com or

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YourDoctorsOrders.com or go to my

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substack@drsimpson.com now remember, I'm a board

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certified physician, but I am not your physician.

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If you have medical concerns, please see a real

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board certified doctor, not a chiropractor, not a

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wellness influencer. And please, you don't need to

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spend $150,000. This podcast is for education and

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entertainment, not personal medical advice. And

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until next time, stay curious, stay skeptical, and

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keep your diet Mediterranean. Have a great week,

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everyone.

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All right, Evo, we're getting old enough that our

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nad levels are dropping. I'm thinking that we

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should replace them. I just don't know how. More

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sunshine. An ocean. Happy? Uh, to hear your ideas.

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>> Speaker B: Well, I may be getting older, but I'm still

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perpetually 8 years old in my brain thinking about

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how my nads are dropping as I get older.

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About the Podcast

Fork U with Dr. Terry Simpson
Learn more about what you put in your mouth.
Fork U(niversity)
Not everything you put in your mouth is good for you.

There’s a lot of medical information thrown around out there. How are you to know what information you can trust, and what’s just plain old quackery? You can’t rely on your own “google fu”. You can’t count on quality medical advice from Facebook. You need a doctor in your corner.

On each episode of Your Doctor’s Orders, Dr. Terry Simpson will cut through the clutter and noise that always seems to follow the latest medical news. He has the unique perspective of a surgeon who has spent years doing molecular virology research and as a skeptic with academic credentials. He’ll help you develop the critical thinking skills so you can recognize evidence-based medicine, busting myths along the way.

The most common medical myths are often disguised as seemingly harmless “food as medicine”. By offering their own brand of medicine via foods, These hucksters are trying to practice medicine without a license. And though they’ll claim “nutrition is not taught in medical schools”, it turns out that’s a myth too. In fact, there’s an entire medical subspecialty called Culinary Medicine, and Dr. Simpson is certified as a Culinary Medicine Specialist.

Where today's nutritional advice is the realm of hucksters, Dr. Simpson is taking it back to the realm of science.

About your host

Profile picture for Terry Simpson

Terry Simpson

Dr. Terry Simpson received his undergraduate, graduate, and medical degrees from the University of Chicago where he spent several years in the Kovler Viral Oncology laboratories doing genetic engineering. Until he found he liked people more than petri dishes. Dr. Simpson, a weight loss surgeon is an advocate of culinary medicine, he believes teaching people to improve their health through their food and in their kitchen. On the other side of the world, he has been a leading advocate of changing health care to make it more "relationship based," and his efforts awarded his team the Malcolm Baldrige award for healthcare in 2018 and 2011 for the NUKA system of care in Alaska and in 2013 Dr Simpson won the National Indian Health Board Area Impact Award. A frequent contributor to media outlets discussing health related topics and advances in medicine, he is also a proud dad, husband, author, cook, and surgeon “in that order.”