Dr. Leff’s Guide to Living a Longer and Healthier Life

*Disclaimer: I’m NOT that kind of doctor. My PhD in business does not qualify me as a medical expert. I’m just a healthy guy in his older 60s who still runs half marathons, climbs mountains, skis, and does a lot of other active stuff who loves life and wants to keep enjoying it as long as possible.

I’m writing this because I’ve been following research on longevity for a while now – ever since I turned 65, really – and I hope that the research I’ve done may help some of my friends and family, or even other people, to live longer healthier lives. The people who know me I imagine trust me to have done my homework, with reliance on real science from real scientists as well as my personal experiences. I’m including links to research for those interested in seeing why I’m doing what I’m doing.


Now that most baby boomers are eligible for Medicare, and many tech pioneers who made boatloads of money are part of that generation, there has been an explosion of interest in how to slow down or even reverse aging. Until recently, medicine has been exclusively focused on treating particular diseases as they come up. Serious research on aging overall, and how to slow it down, is relatively new.

While there are billions of dollars going into discovering new drugs for longevity – a venture capital driven search for the fountain of youth – there are many products already available as either supplements or prescription medications that have proven longevity benefits. Many don’t have the “gold standard” large clinical studies supporting them; since they are already available, and mostly inexpensive, no one has the incentive to fund such studies. But evidence is there.


There are a lot of “snake oil salesmen” in the longevity business; I suppose there always have been. Just because something has interesting effects in mice, doesn’t mean it helps humans. For the most part, I’m following the regimen that Dr. David Sinclair, Professor in the Department of Genetics and co-Director of the Paul F. Glenn Center for Biology of Aging Research at Harvard Medical School follows. I also look at what other respected longevity researchers are putting into their bodies. I look for scientific studies in peer reviewed journals where possible.

Several of the things on this list are items I am just now adding to my routine. I’m cautious about what I put in my body. I don’t want to be a guinea pig for something completely unknown. I’m only taking stuff where there is good evidence supporting it, and negative side effects are limited or rare.

Summary – What I’m Taking for Longevity (detailed information will follow)

  • NMN – 600 mg/day
  • TMG – 750 mg/day
  • Pterostilbene – 250mg/day
  • Metformin – 425 mg/day (prescription required)
  • Vitamin K2 – 200 mcg/day
  • Vitamin D3 – 5000 IU/day
  • Fisetin – 200mg/day
  • Spermidine – 2.5 mg/day
  • Exercise almost every day
  • Things to keep my brain engaged

I also take B12, Magnesium, Potassium, Collagen, and AREDS-2, although those are not specifically for longevity related purposes, and a couple of prescription meds for my specific health issues.

Detailed Information


NMN, nicotinamide mononucleotide, is an NAD+ precursor that boosts NAD+ levels. NAD+ is essential for cellular functioning, and its levels decrease significantly with age. NAD+ has many anti-aging properties, as described in this article, The Science Behind NMN–A Stable, Reliable NAD+Activator and Anti-Aging Moleculethat appeared in “Integrative Medicine: A Clinician’s Journal.”

NR is another NAD+ precursor – I have been taking NR for a while, but Dr. Sinclair takes NMN, and NMN is reported to be better absorbed by the body than NR, so I’m switching to NMN. To get to the 1 gram/day dose Dr. Sinclair takes is expensive in capsule form, so I’m buying bulk powder from ProHealth. I’m taking a lower dose than Sinclair takes because I saw a study that found 600 mg to be an optimum dose, and it’s expensive stuff.


NMN uses up methyl groups as it is processed, so many recommend adding methyl donors, such as TMG if you are taking NMN.


You may remember there was talk some years ago about the health benefits of red wine because it contains the anti-oxidant resveratrol. You would have to drink an unhealthy amount of wine, however, to get the real health benefits. A lot of studies now show many benefits from resveratrol – as an anti-inflammatory, for example, as reported in this study reported in Complementary Therapies in Medicine. It is also reported to have an effect on preventing cancer, heart disease, and dementia. Also see this in Medical News Today.

I’m taking pterostilibene, and analog of resveratrol instead of the resveratrol Dr. Sinclair is taking because it is reported to be more easily absorbed by the body; see Resveratrol vs Pterostilbene in the Journal of Applied Pharmaceutical Science.

I’m getting capsules from ProHealth.


Metformin is one of the world’s most commonly prescribed drugs: 150 million people take it for treatment of diabetes. It has been around for 60 years, so it is long off patent protection, which means no one has a financial incentive to do expensive clinical trials on how it performs as an anti-ageing drug. But many studies show it seems to have powerful benefits in preventing cancer, heart disease, stroke, and Alzheimer’s – in other words aging related diseases. A recent study published in The Lancet finds genetic validation for its anti-ageing properties. See this article “Benefits of Metformin in Attenuating the Hallmarks of Aging” published in Cell Metabolism for a discussion of the topic.

Some people have cited a study, “Comparison of long-term effects of metformin on longevity between people with type 2 diabetes and matched non-diabetic controls” in which metformin didn’t help patients with type 2 diabetes live longer, but those concerns likely don’t apply to people who do not have type 2 diabetes. 

Other longevity scientists, including Dr Nir Barzilai at the Albert Einstein School of Medicine who is conducting a clinical trial of the drug and longevity, continue to believe in the benefits and are taking Metformin.

There is some evidence that metformin can interfere with the benefits of exercise, so I’m going to follow the advice of another longevity scientist, Peter Attia – take metformin at night, use a lower dose, and don’t take it on the days when I exercise hard. I also may drop it completely when I’m in peak training period for a half marathon. I’ll experiment and see what feels good.

Since it’s such a well-known and well tolerated drug, my primary care physician had no issue with prescribing it off label for longevity. It’s also very inexpensive. A 90-day supply for someone on Medicare costs $3.76.

Vitamin K2

See “Vitamin K2—a neglected player in cardiovascular health: a narrative review” in openheart.  K2 also helps with calcification of bones, see “Vitamin K2: Everything You Need to Know.” 

Vitamin D3

The benefits of D3 are well known, my doctor checked my D3 levels and recommended supplementation years ago. I’m taking 5000 IU a day. Desired level in your blood is above 30, you should have it checked when you have annual blood work done.


Fisetin is a senolytic – a substance that can selectively remove senescent cells, which are cells that are no longer replicating properly. Fisetin is a natural substance, an anti-oxidant found in many foods, especially strawberries. It’s related to resveratrol (the stuff in red wine that is supposed to be good for you), but seems more readily used by the body, This 2018 study published in The Lancet brings evidence it can extend health and lifespan.


Spermidine is another naturally occurring substance, this one commonly found in wheat germ. It is a caloric restriction mimetic – it provides some of the same benefits you get from calorie restriction, without the diet. It’s an autophage-inducing substance, a process by which cells repair themselves. A paper reported in the journal Aging brings evidence it provides health benefits for humans.

Know What You Need

Everyone is different. Since I have a mostly plant-based diet, I generally don’t get enough B12, so I supplement. I’ve had electrolyte issues, so I take magnesium and potassium. You need to understand your individual health issues and make the appropriate adjustments.

Use it or Lose it

Anything designed to move – cars, motorcycles, airplanes, people – suffers if it sits unused too long.

If the health benefits of exercise could be bottled, it would be hailed as a “wonder drug.” Exercise can prevent all kinds of diseases from heart disease to diabetes, helps control weight, helps you sleep better and can provide mood benefits as well. If I’m feeling down or grumpy a run will usually get me out of the dumps.

No doubt your doctor has been telling you this for years. See this article “Real-Life Benefits of Exercise and Physical Activity” from the National Institute on Aging for more.

The important thing is to find something you actually enjoy doing. I’m blessed in that I actually enjoy working out, so it’s not a chore I have to push myself to do. Well, if it’s cold and raining, I do have to push myself to get out the door on a run, but on a normal day, no problem.

It’s important to include cardio, strength training, and flexibility stuff in your routine – all have different benefits. My current routine includes running (I typically run in two half marathons a year), biking, mountain biking, strength training, yoga, walking, and swimming. In the winter I also ski.

Use it or lose it also applies to the brain. Take up a new hobby. Learn a new skill. Learn a new language. Reading, writing, and studying Torah helps keep my brain busy.

Use it or lose it also applies to sex. If you are not blessed with a partner with whom you enjoy an active sex life, masturbate. It keeps everything in working order should you later get a partner, and for men it can also help keep your prostate happy, so you don’t have to pee in the middle of the night so often. Having more frequent orgasms is also associated with a lower risk of prostate cancer. Besides, it’s a great stress reducer.

Speaking of stress reduction, meditation and/or prayer is also beneficial. See “The Science of Prayer” and “Meditation: A simple, fast way to reduce stress.” I try and pray meditatively, with mindfulness. Some days I’m more successful than others.


Of course, you can do everything right, and still get hit by a truck, or be the unlucky one that gets a stroke or cancer despite doing everything right. But you might as well do what you can to stack the deck in your favor.

Longevity research is a new thing. If you’re going to adopt a regimen like this, it’s important to stay up to date on the research – it could be longer term studies will show something you’ve been taking is not useful, or the negative effects outweigh the good, or some new thing could come along that’s even better than what you’ve been doing.

As to when to start an anti-ageing regimen, Dr. Sinclair is 54 and is on it, so it seems by the time you’re in your 50s you might want to get on board. You don’t have to wait until you’re officially a “senior citizen.”

I’d love to hear from you if you have something to add or found this useful.

B’vracha (with blessings),

Rav Barry

Barry Leff

Rabbi Barry (Baruch) Leff is a dual Israeli-American business executive, teacher, speaker and writer who divides his time between Israel and the US.

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