Can Humans Hibernate?

Can a State of Hibernation be Molecularly Induced in Humans?

by Bill Sardi by Bill Sardi


Could it be possible to create a state of molecularly induced hibernation in humans similar to that observed in certain animals? If so, damage to tissues from trauma, strokes and heart attacks could be treated or prevented. [Journal Neurochemistry 2007 Sep; 102(6):1713—26] Even more intriguing, if metabolic demand for oxygen can be significantly reduced, as observed in hibernating animals, athletes and military personnel could possibly achieve unusual physical performance and endurance.

The state of hibernation is a unique physiological state characterized by a profound yet reversible sleep-like state accompanied by a decline in body temperature and metabolism. In hibernating animals, metabolism declines to 2% of the normal state. The demand for oxygen declines and the heart rate slows. [Bioessays 2007 May; 29(5):431—40; Journal Neurochemistry 2007 Sep; 102(6):1713—26] Hibernating animals can also withstand extreme cold. [Medical Hypotheses, online 2007 Dec 3]

Researcher M Hashimoto of Japan asks: "Is hibernation a possible phenomenon in humans?" [Nippon Seirigaku Zasshi. 2006; 68(11):395—6] Researchers believe they are getting closer to understanding how to molecularly mimic a "physiologic" state of hibernation.


The first breakthrough came in April of 2005 when University of Washington researchers reported that hydrogen sulfide can induce a suspended animation-like state in non-hibernating species (in this case, a mouse) using a sulfur molecule called hydrogen sulfide. This state is readily reversible and does not appear to harm the animal. [Science. 2005 Apr 22; 308(5721):518]

Hydrogen sulfide decreases the metabolic rate of mice by approximately 90%. Mice normally cannot survive longer than 30 minutes when exposed to 5% oxygen (atmospheric O2 level is ~21%). However, when mice are pre-treated with hydrogen sulfide for 20 minutes they can survive for more than 6.5 hours in a low oxygen environment without apparent detrimental effects. [Shock 2007 Apr; 27(4):370—2]

Life extension

Recently researchers at the Fred Hutchinson Cancer Research Center put a roundworm into a state of hibernation using hydrogen sulfide, which resulted in significant extension of the worm’s lifespan.

The mean life span of worms grown in an atmosphere laced with hydrogen sulfide was 9.6 days greater than that of the untreated population, a longevity increase of 70 percent.

One theory is that exposure to hydrogen sulfide naturally regulates the activity of a gene called SIR-2.1, which has been shown to influence life span in many organisms, including the worm. [Proceedings of the National Academy of Sciences early online edition, reported in Science Daily, December 5, 2007]

Hydrogen sulfide: garlic

Hydrogen sulfide is that chemical that gives rotten eggs their sulfurous stench. It is a transient gaseous molecule. It takes the place of oxygen in transport mechanisms, thus reducing oxygen-derived free radicals.

So, would humans need to eat rotten eggs to obtain the same hibernation effect? No, but they might try another sulfur-rich food — garlic.

Researchers at the University of Alabama report that red blood cells convert garlic-derived sulfur molecules into hydrogen sulfide, which widens (dilates) blood vessels and helps to maintain blood flow. In fact, the production of hydrogen sulfide by garlic tablets can be measured in a breath test to determine if they actually produce the same potency as a fresh-crushed clove of garlic. [Proceedings National Academy Science U S A. 2007 Nov 13; 104 (46):17977—82]

Health benefits

Of great interest are experiments where asthmatic animals given hydrogen sulfide showed marked improvement in their condition. [Zhonghua Jie He He Hu Xi Za Zhi. 2007 July; 30 (7):522—6] The delivery of hydrogen sulfide after a heart attack, at the time when circulation is restored, has also been demonstrated to limit the size of a heart attack. [Proceedings National Academy Science U S A. 2007 Sep 25; 104 (39):15560—5]

Hydrogen sulfide is also being studied as an anti-inflammatory agent. [Trends Pharmacological Science 2007 Oct; 28(10):501—5] Hydrogen sulfide drugs are now considered a way to "build a better aspirin," since it reduces inflammation without the gastric side effects (ulcers) induced by non-steroidal anti-inflammatory drugs (aspirin, ibuprofen). [British Journal Pharmacology 2007 Oct; 152(4):421—8] In fact, hydrogen sulfide actually accelerates the healing of gastric ulcers. [FASEB Journal 2007 Dec; 21(14):4070—6]

Overcoming fatigue

Human studies show that garlic produces improvement in people who are physically fatigued. [Molecular Nutrition Food Research 2007 Nov; 51(11):1329—34] An animal study in Japan shows that aged garlic extract minimizes the impairments associated with physical fatigue by promoting oxygen supply via dilation of blood vessels, reduction of oxidation and control of sugar metabolism. [Biol Pharm Bulletin 2006 May; 29(5):962—6]

The Roman army (~100 BC) planted garlic in every land they conquered and marched into battle chewing cloves. It has popularly been thought that garlic was employed by the Roman soldiers because it inhibited waterborne parasitic infections that plague marching armies, or served as an antibiotic for battle wounds. But now we realize a different benefit may have been realized — greater endurance to fight an enemy in battle.