If you take niacin, you must exercise

We use a lot of niacin in the Track Your Plaque program.


--Increases HDL and shifts HDL towards the large, protective fraction

--Reduces small LDL--In fact, niacin is the best treatment we have to reduce small LDL after wheat elimination and carbohydrate reduction.

--Reduces fasting and postprandial (after-eating) triglycerides

--Reduces heart attack risk by 20-28%--even as a sole agent.

But . . . niacin also triggers higher blood sugar because it partially blocks the effects of insulin (insulin "resistance").

While the net effect of niacin remains positive, the provocation of insulin resistance is not such a good thing. Can it be minimized or eliminated?

Yes, through exercise. Here's one interesting observation in obese (BMI 34.0), sedentary men given placebo, exercise, niacin (1500 mg Niaspan, once per day), or niacin + exercise:

From Plaisance et al 2008.

Blood was drawn following a high-fat meal challenge. (Yes, a high-fat challenge, not a carbohydrate challenge. In this study, there were only 17 grams carbohydrates in the test meal, but 100 grams fat. More on this in future.) Exercise consisted of walking for 50 minutes at a moderate pace one hour prior to the meal challenge.

You can see from the graph that exercise partially corrected the increased insulin level provoked by niacin.

Judging from this and other studies, exercise can help minimize the insulin-blocking effects of niacin. It doesn't take much, just moderate exercise for at least 30 minutes.

Adequate sleep can also help, since sleep deprivation is a potent trigger for insulin resistance, only worsened in the presence of niacin. Vitamin D supplementation to achieve desirable blood levels (which I define as 60-70 ng/ml) is also an effective means to minimize this effect.

Comments (23) -

  • karl

    12/29/2009 11:16:55 PM |

    What about adding P-5-P to the Niacin?

    I've heard things about cinnamon lowering Blood sugar, but I'm not convinced.

  • Grandma S.

    12/30/2009 1:59:12 PM |

    Thank you for posting this.  I am exercising everyday sometimes twice a day to equal 45-60 minutes and see some help with the glucose level.  My LDLs continue to be around 100 and my Dr. wants to increase the Niacin.  Will that help?  It's a fine line, keep the sugars down and get the LDLs down. I appreciate your blog!

  • Renrew

    12/30/2009 2:42:42 PM |

    Cinnamon does reduce blood sugar but the effect is minimal, even at higher doses.

  • Adolfo David

    12/30/2009 3:06:07 PM |

    About Karl comment, you can add many supplements to niacin to counteract this effect. Chromium, resveratrol, standarized cinnamon, green tea extract... Life Extension has launched a niacin with quercetin for example (but now out of stock).

  • Nigel Kinbrum BSc(Hons)Eng

    12/30/2009 3:19:47 PM |

    Would reducing sugary/starchy carbohydrate intake be an effective way to reduce hyperglycaemia?

  • Anonymous

    12/30/2009 10:00:47 PM |

    Thanks for posting Dr. Davis.

    Is splitting 1500 mg of Niacin to two 750mg doses,one in morning, one in evening ok?
    Or should  the 1500 be taken all at once?

  • Anonymous

    12/31/2009 1:13:38 AM |

    Both times I started Niacin, I developed Gout.
    The second time I cut the tablets in half hoping to avoid another bout but still, Gout in a different joint.

  • Mark

    12/31/2009 4:56:24 AM |

    It has been my experience that over time (2-3 Months)the Slo-Niacin I use has less effects on raising blood glucose levels like it does at the onset. It is well advised that everyone should get in the exercise regardless of niacin intake.

  • Boris

    1/1/2010 3:48:15 PM |

    I took 500mg of Niacin every day to get my HDL up. Plus, there was niacin in my multivitamin. My HDL didn't go up at all. I exercise plenty too. All I got out of it were a few itchy flushes that made my ears feel clogged. I'm going to finish my bottle of Slo-Niacin and try a red yeast rice that was tested by Consumerlab.com.

  • Anonymous

    1/1/2010 8:29:23 PM |

    Regarding splitting the dose of Niacin.  I am pretty sure I have seen a post from Dr.D saying to take all at once.  

    I used to split my dose. I thought I was being smart by distributing the Niacin over the day.  My local pharmacist told me not to split the dose because of impacts to Liver function.

  • Anonymous

    1/2/2010 2:10:06 PM |

    I avoid sustained release niacin.

    I get around 80 mg niacin per day in a multivitamin and don't want to add extra.



    Despite the patients’ advanced atherosclerosis, ingesting pomegranate juice produced statistically significant reductions in the thickness of their carotid artery walls, which is correlated with decreased risk for heart attack and stroke. After only three months, the average thickness declined by 13%, and after 12 months, the thickness dropped 35% compared to baseline. During this same 12-month period, the average carotid artery thickness of the placebo group increased by 9%.

  • Anonymous

    1/2/2010 2:39:54 PM |

    Thank you so much for posting this!  I have bee na niacin devotee for about 15 years, and wanted to get my LDL back up after a dx of T2D (with Antibodies) ... and having my niacin "taken away" by my internist.  MY Endo put me back on a lower dose of slo-niacin ... exercise is helping but I may need to up my anti-IR meds.

  • Anonymous

    1/4/2010 4:14:05 AM |

    When is the best time to take niacin?

    morning or night?

    before or after exercise or meals?

  • Dr. William Davis

    1/4/2010 11:27:02 PM |

    We've had best results dosing niacin with dinner or the largest meal of the day.

  • Anonymous

    1/12/2010 2:37:54 PM |


    Just asking this again, could you could please help me out.

    Is splitting 1500 mg of Niacin to two 750mg doses,one in morning, one in evening ok?
    Or should the 1500 be taken all at once?

  • Anonymous

    3/19/2010 4:24:19 PM |

    I had a terrible time with Niacin and insulin resistance.

    I tried exercising but to keep my BG down, I would have to exercise 3 or 4 times a DAY, which is simply not feasible.  Oh, and I am a low-caber, too.

    I would exercise extreme caution in starting to use this, with any Diabetes. (I am a T1.5).

  • lnoonan

    5/19/2010 4:14:15 PM |

    Dr Davis,

    What kind of exercise would you recommend for a Senior lady who is handicapped?  It is difficult for her to do any exercise, so do you know of something she would be able to do while she is taking niacin?  Or, would it be better for her to stop the niacin since exercise is difficult and try other supplements?  Thanks for your help.

  • Anonymous

    5/27/2010 5:00:58 AM |

    Assuming your recommended Slo-niacin...is it better to split your doses up (500 mg morning and 500 mg at night) or take all 1000mg at once? If its better to take all at once is night or morning better?

  • kimberly

    8/11/2010 5:57:09 PM |

    I love to practice exercise, i think this activity is the best option to keep our total welfare and it is very fun. When we exercise frequently we can notice a change not only in our shape but in our mood too. Actually we can improve our sexual performance. When some cases when the erectil dysfunction present like a problem  to buy viagra is a great alternative, how ever you must to combine it with exercises and a good feed.

  • buy jeans

    11/4/2010 5:11:30 PM |

    While the net effect of niacin remains positive, the provocation of insulin resistance is not such a good thing. Can it be minimized or eliminated?

  • Anonymous

    12/15/2010 1:49:29 PM |

    Taking niacin before vigorous exercise has one benefit for me.  The flusing is minimized or even eliminated.

    I've seen different recommendations for dosing frequency.  Three times a day is the "standard" dosing regimen.  However, when I haved switched to three times a day dosing, I have experienced elevated liver enzymes.  I've never had a problem with twice a day dosing.

  • bob

    2/7/2011 4:55:57 AM |

    I am not aware of any data to support 24% risk reduction for MI with the use of Niacin, can you provide citations?

    Primary or secondary prevention?

    Bob Hansen MD

  • John

    6/2/2011 5:01:34 PM |

    Cinnamon doesn't lower blood sugar per se.  The apparent mechanism occurring here is a slowing down of carbohydrate absorption in the gut.  The mechanism is believed to involve a class of molecules known as flavonoids, which either reversibly compete for the glucose receptor or have their own receptor on the GLUT 2 (glucose transport 2) protein.  This action only slows down the absorption of carbohydrates, but all (that's 100%) sugar is absorbed into the body.  It is the only thing you intake that is absorbed 100% and it doesn't matter if it's glucose, sucrose, fructose, or a complex carb.  Anywho, not that I want to debate the finer points of carbohydrate biochemistry.  For more on flavonoids and GLUT2 you can look up this paper (Kwon O., Eck P., Chen S., Corpe C., Lee J-h., Kruhlak M., Levine M. (2007) Inhibition of the intestinal glucose transporter GLUT 2 by flavonoids. FASEB Journal 21, 366-77.).