Histamine Impact on Regular High Intensity Exercise

Histamine is the primary mediator of allergy that causes itch and redness. As recently discussed, antihistamines are among the most commonly and incorrectly used medicines worldwide (Are you using Antihistamines Properly?). Antihistamines are best used to relieve symptoms of hay fever and outbreaks of hives, but not for asthma, eczema, coughs or insomnia.

However, in a recent study men given high doses of two antihistamine drugs did not experience the same benefits of high intensity interval training that men on a placebo which provides a clue to the molecular impact that histamine has on the effect of exercise. 

In general, regular aerobic exercise powerfully protects you from cardiovascular and metabolic disease. But the precise molecular mechanisms connecting regular activity to improved health have been unclear. When humans perform long-term training, histamine receptors are activated, improving a variety of cardiometabolic risk factors, from insulin sensitivity to aerobic capacity and blood vessel health.

Histamine is typically associated with allergic reactions and gastric acid secretion, but in recent studies have demonstrated that blocking the histamine receptors (H1 and H2) reduces

people’s muscular blood flow during recovery from a single bout of exercise (The Intriguing Role of Histamine in Exercise Responses) as well as altering gene expression expressed post exercise expressed post-exercise suggesting that histamine is a positive mediator of exercise’s effects.

 

In a study that enrolled 20 heathy men who didn’t exercise in a program of high intensity interval training (HIIT) three times a week for six weeks (Histamine H1 and H2 receptors are essential transducers of the integrative exercise training response in humans).  One hour before each exercise session, half the men received drugs that blocked the H1 and H2 histamine receptors, and the other half received a placebo. The histamine blockers were a combination of a common allergy medication, fexofenadine, which blocks the H1 receptor, and either ranitidine or famotidine, acid-reducing medicine, both of which block H2. Doses were higher than those taken to treat allergies or acid reflux. The team found that, after six weeks of exercise, men whose histamine receptors had been blocked experienced signficantly less improvement in several parameters related to exercise performance, as well as a smaller improvement in the ability of mitochondria to produce energy, than did those who received a placebo. Of specific note, when the men were given glucose tolerance tests before and after the six weeks of training, they found that, in men on placebo, insulin’s ability to move beneficial effects of exercise were impaired when the histamine receptors were blocked.

It would appear that chronic use of antihistamines (H1 and H2) may decrease the impact of exercise on health.

 Sinusol® Breathe Easy is a nonmedicated intranasal spray that may be considered as an alternative for the relief of allergy symptoms.