Why I’m Not Worried about NAD “Causing” Cancer

  • This article is copyright © Nils Osmar 2019 and 2021.
  • It’s intended solely for informational purposes, and is not meant to be taken as, and should not be construed, as medical advice. Any changes to your lifestyle or diet should be done in consultation with your doctor or health care professional. 
  • For more information, check out the Facebook Group: Anti-Aging

Updated 4/7/2021


Many people nowadays are taking supplements such as NR, NMN, niacin, apigenin and other NAD boosters in the hopes of improving the quality of their lives and (perhaps) living a few years or decades longer.

But could we be doing damage to our health by taking them?


NAD is essential to the body, and levels of it decrease as we age. There is evidence that increasing its levels through diet and other interventions may facilitate DNA repair, slow aging, and have other benefits to the body.

There has also been some recent evidence suggesting that some types of cancer (including brain cancer and colon cancer) may be fueled by having an internal environment high in NAD.  Could boosting NAD levels, whether it’s by supplementing or exercising or fasting,  be setting us up for health problems down the road?

The truth is that we don’t know. More research is needed. But we do know that many of the activities which increase levels of NAD+ in the body tend to strengthen our immune systems, and appear to be protective against cancer. 

Activities with these benefits include:

  1. HIIT exercise (or any exercise that creates a temporary oxygen deficit)
  2. Intermittent fasting and time-restricted eating (stressing the body by giving it a break from the constant intake of food)
  3. Prolonged fasting (for 3-5 days) (or fasting-mimicking diets of a similar length)
  4. Heat exposure (spending some time in the sauna, generating heat shock proteins)
  5. Cold exposure (cold showers or ice baths, generating cold shock proteins)
  6. Contrast showers  (showers that go from hot to cold, hot to cold, hot to cold, ending on cold)

Again, all of the above activities, which increase NAD and activate the sirtuin genes, are associated with lower, not higher, levels of cancer.

We also know that:

  1. Athletes who engage in vigorous physical exercise have higher NAD and tend to live longer, not shorter, lives than many others in the general population. (There are some exceptions, like competitive bodybuilders and pro wrestlers, but this appears related to the constant activation of mTOR and drugs that keep them continuously in an anabolic state.)
  2. Children, whose levels of NAD are much higher than adults’, have much lower levels of cancer than adults.
  3. Lab animals whose NAD levels were raised through giving then dietary NAD boosters also tend to live longer and appear younger than their litter-mates that were not.
  4. Many, many studies have suggested that vitamin B3 (from which most NAD boosters are derived) is protective against cancer. Niacin, for example, does raise NAD,  but it appears to be decrease, not increase, our odds of succumbing to cancer.

B3 and other vitamins

Some NAD boosters, like NMN and NR and niacin, are forms of vitamin B3. My own feeling is that if all that we do is pop capsules of this sort while eating bad diets, raising our insulin and blood sugar, accumulating excess body fat, and living sedentary lives, then we probably are heading for trouble. 

But if we eat healthy diets (at the minimum, ones that are high in nutrients but low in sugars), take supplements designed to support our health, get out and exercise once in a while, and do a little fasting now and then, then bolstering our NAD levels through supplementation seems far more likely to be helpful than harmful.

It’s similar, perhaps, to the question of nutrients and nutritional supplements. To use one nutrient as an example, human beings need the B vitamin folate. We’ll have all kinds of health problems if we don’t have it in our diets. If we’re healthy, eating a diet rich in folate, such as one including lots of leafy greens, will likely be beneficial to our health. (It’s a main reason nutritionists recommend eating a lot of greens.) 

But certain types of cancer also love folate, and thrive in a high folate environment. If we have those types of cancer, and they’ve gotten a foothold in our bodies, we may need to avoid folate for a while (or eat diets extremely low in it).

Zapping cancer before they can grow

Cancer has the potential to be starting in our bodies all of the time. This is because cells with damaged DNA can become cancerous.

This relates to NAD in two ways. One is that NAD is essential to DNA repair.

Another is that strong immune systems kill cancer cells. Taking NMN or NR while doing other things to keep our immune systems strong is likely to be of benefit. This is because NAD regulates immune function.

If you have cancer (not just a cell or two floating around in your bloodstream, but a cancer which has taken hold and is growing and causing health problems, it makes sense to my mind to avoid NAD boosting supplements. If you’re trying to prevent it and prolong your life, in my opinion, it makes good sense to take them.

NAD boosters aren’t magic pills that will make us live forever even if we sit around nibbling potato chips all day. But as part of a regimen designed to support our health and longevity, the benefits of taking them likely outweigh the risks.

That’s my POV, after looking at the evidence I’ve seen. You’ll have to decide for yourself what makes sense to you. If you decide not to take them, there are many other things you can go on doing to support your health and long life.

Some more thoughts about fasting

Doing fasting is one of the ideal ways of accomplishing what many of us are trying to do when we take NAD precursors. I’ve done several 4-5 day fasts for the purpose of triggering autophagy, apoptosis, and the creation of new stem cells at the end of the fast. And unlike taking NAD-boosting supplements, fasting is free.

Short fasts (skipping breakfast or dinner now and then and “fasting” till the next meal have some benefits. But doing occasional 4-5 day fasts or fasting mimicking diets have more profound ones.

A long fast will clean your cells of debris; kill and cannibalize your senescent cells; kill and cannibalize senescent mitochondria; then at the end of the fast, our bodies will create new stem cells and new, “young” mitochondria to replace the dying ones that were cannibalized. 

Like taking supplemental NAD boosters, fasting does have some dangers and drawbacks. Some people have caused organ failure (kidney failure in particular) by overly long fasts. And it’s possible that we may reach an age at which fasting no longer has benefits.

Things like HIIT exercise, hot/cold showers, saunas, ice baths, and other things that stress the body just the right amount, work along similar pathways to fasting, and also raise NAD+ levels. There are so many health benefits to activities like these, that they likely more than make up for the slight possibility of increased NAD production fueling cancer. 

NAD boosters and the sirtuins

Whatever method you use to increase NAD levels (if you choose to), it appears to be helpful to take a sirtuin gene such as quercetin, resveratrol or fisetin, so that our bodies can make good use of the NAD+ being created.