Do Ice Baths Improve Sperm Health & Fertility? | Dr. Andrew Huberman
00:00:00.000 | [silence]
00:00:02.420 | So any discussion about heat and sperm
00:00:04.380 | and how heat is detrimental to sperm
00:00:06.220 | has to raise this issue of whether or not cold
00:00:09.740 | is good for the testicle.
00:00:11.060 | Okay, well now there's a lot of data starting to come out
00:00:14.320 | about the positive effects,
00:00:16.060 | the positive biological effects of deliberate cold exposure
00:00:20.540 | on different aspects of brain biology,
00:00:23.540 | such as the release of dopamine and norepinephrine,
00:00:25.740 | and on the biology of the body,
00:00:27.860 | to some extent metabolism,
00:00:29.080 | but more so the impact on brown fat stores,
00:00:31.440 | which are good for us, so-called brown fat thermogenesis.
00:00:34.400 | There's a lot related to deliberate cold exposure,
00:00:37.080 | and we've done entire episodes on deliberate cold exposure.
00:00:39.700 | Again, you can find that at hubermanlab.com.
00:00:41.560 | We did a guest episode with an expert
00:00:43.680 | on the use of cold for health and performance
00:00:46.320 | with my colleague Craig Heller
00:00:47.340 | from Stanford Department of Biology.
00:00:49.000 | We also have a toolkit on how to apply
00:00:52.220 | deliberate cold exposure for health
00:00:53.840 | for both females and for males,
00:00:56.040 | for sports performance, cognitive performance,
00:00:57.800 | mood, sleep, et cetera.
00:00:59.080 | You can find all that, again, hubermanlab.com,
00:01:00.960 | totally zero cost.
00:01:02.760 | Just go into the menu, go to newsletter,
00:01:04.280 | and scroll down, and you'll find those.
00:01:06.240 | When thinking about sperm quality,
00:01:09.920 | we want to remember that excessive heat is bad.
00:01:12.680 | Now, does that mean that deliberate cold is good?
00:01:15.440 | Well, it turns out that one of the major causes
00:01:18.400 | of lowered sperm count and overall reduced sperm quality
00:01:23.400 | that's quite common is the presence
00:01:25.400 | of what's called a varicella.
00:01:26.560 | A varicella is kind of like varicose veins
00:01:29.040 | of the veins that innervate the testicle.
00:01:32.400 | And what it essentially does is it means
00:01:35.800 | that blood will pool in the testicular region.
00:01:39.880 | It can't circulate back to the body quickly enough,
00:01:42.200 | and therefore the temperature of that environment increases.
00:01:44.400 | There's some other things that varicellas do
00:01:46.320 | which can be obstructive at the physical level,
00:01:48.360 | so they're not just temperature related.
00:01:50.440 | It's pretty clear that using deliberate cold exposure
00:01:54.160 | can be healthy for the sperm
00:01:55.720 | because of the ways not that cold
00:01:58.240 | directly supports testosterone or sperm quality,
00:02:01.880 | but rather because cold reduces heat, okay?
00:02:04.760 | So you will find available online,
00:02:08.140 | I think they're actually called,
00:02:10.560 | forgive me, but that's what they're called.
00:02:11.920 | I didn't name them, called Snowballs.
00:02:13.280 | These are, they're sort of like gel pack cold briefs
00:02:18.200 | that you can buy and men will wear for some period of time.
00:02:21.280 | I don't think you wear them all day.
00:02:22.520 | You wear them for some period of time.
00:02:24.640 | A lot of people are now using cold showers
00:02:26.600 | and ice baths and circulating cold baths
00:02:29.000 | or going into a cold ocean or lake
00:02:30.640 | for any number of different reasons I talked about earlier.
00:02:33.080 | I myself start every day
00:02:34.720 | with either a one to three minute cold shower
00:02:37.400 | or one to three minute immersion up to my neck
00:02:40.160 | in a cold bath, cold water,
00:02:43.720 | circulating water or a cold shower.
00:02:45.600 | I do that mainly for the psychological effects
00:02:47.320 | related to the long lasting increases
00:02:49.080 | in dopamine and epinephrine,
00:02:50.840 | but there are other data starting to come out
00:02:52.340 | showing that that sort of approach or similar approaches
00:02:56.200 | can increase testosterone levels
00:02:58.020 | and maybe even sperm counts
00:02:59.080 | can reduce cortisol late in the evening
00:03:00.860 | if the cold exposure is done early in the day,
00:03:02.640 | so on and so forth.
00:03:03.480 | So a lot of interesting data coming out
00:03:05.240 | in really good journals that are peer reviewed
00:03:08.360 | and so on in humans.
00:03:10.480 | I should mention those studies are done in humans
00:03:12.680 | to support the use of deliberate cold exposure.
00:03:14.640 | But again, if you're going to use deliberate cold exposure
00:03:16.620 | to improve sperm quality, can it work?
00:03:18.960 | Yes, indeed it can work,
00:03:20.380 | either indirectly by increasing testosterone
00:03:22.840 | or directly by improving sperm quality,
00:03:24.920 | but both of those effects are likely to be indirect
00:03:27.560 | by virtue of reducing the temperature
00:03:29.540 | of the testicle overall,
00:03:31.240 | not because there's any sort of magic effect of cold
00:03:34.160 | on the testicle.
00:03:35.160 | Now I have to imagine that a number of you,
00:03:36.600 | in particular females listening to this,
00:03:39.200 | are going to say, is deliberate cold exposure,
00:03:42.160 | and for that matter, is deliberate heat exposure
00:03:44.000 | like sauna or hot tub, good or bad for the ovary,
00:03:47.300 | for eggs and for fertility?
00:03:48.840 | Now there are fewer data to look to, unfortunately,
00:03:53.140 | but what we do know is that deliberate cold exposure
00:03:56.100 | done in the way that I just described,
00:03:57.720 | one to three minutes a day,
00:03:58.820 | ideally early in the day through cold shower
00:04:01.060 | or immersion up to the neck,
00:04:02.180 | doesn't have to be an ice bath,
00:04:03.140 | could be cold circulating water
00:04:05.100 | or even non-circulating cold water.
00:04:07.220 | And people will say, well, how cold?
00:04:08.820 | I should have mentioned that before.
00:04:10.060 | How cold?
00:04:10.900 | There is no way I can tell you
00:04:13.580 | exactly how cold the water should be
00:04:15.100 | because for some people, 60 degrees Fahrenheit
00:04:17.460 | will be exceedingly cold, for other people,
00:04:19.460 | 40 degrees is going to be more appropriate.
00:04:21.220 | How cold should you make it?
00:04:22.620 | If you're going to embrace these practices,
00:04:24.620 | you want to, according to the literature,
00:04:26.820 | what you want to do is make it uncomfortably cold,
00:04:29.420 | such that you really want to get out, but safe, right?
00:04:31.960 | You don't want to go into 30 degree water immediately.
00:04:34.940 | You can actually have a heart attack and die if you do that.
00:04:37.260 | So you want to progress gradually into the cold.
00:04:40.580 | So you don't want to shock your system too much,
00:04:42.660 | although it is the adrenaline evoked by that [gasps]
00:04:45.740 | that quickening or shortening or elimination of the breath
00:04:48.120 | for a short period of time
00:04:48.960 | when you get into uncomfortably cold water
00:04:51.100 | that correlates with, or is actually the reflection of,
00:04:54.300 | would be more accurate to say the release of adrenaline
00:04:56.620 | and then dopamine and so forth,
00:04:58.340 | which has been very well-documented.
00:05:00.380 | So uncomfortably cold, but safe to stay in.
00:05:03.820 | And I cannot tell you an exact number
00:05:06.400 | that is uncomfortably cold, but safe for you.
00:05:08.640 | It's going to differ person by person.
00:05:10.060 | You want to figure that out.
00:05:10.980 | Just like I can't tell you how much weight
00:05:12.280 | that you should squat in order to achieve
00:05:14.340 | some effective resistance training for the legs.
00:05:16.860 | It's going to differ depending on your strength
00:05:19.680 | and your prior experience and so forth.
00:05:21.300 | So ease into it, be safe.
00:05:23.060 | But it does appear that both for men,
00:05:25.020 | for reasons I talked about a few minutes ago,
00:05:26.940 | and for women, that deliberate cold exposure
00:05:30.940 | can be beneficial for fertility and for hormone production,
00:05:35.380 | but in particular for females
00:05:37.020 | in terms of regulating cortisol and for hormone production.
00:05:39.840 | Now you might say, okay, getting into cold is stressful.
00:05:41.960 | How can that be helpful for regulating stress?
00:05:43.740 | Well, it turns out when you get into the cold,
00:05:45.560 | you get a big surge in adrenaline and then dopamine,
00:05:47.820 | which is very long lasting,
00:05:49.140 | provided that's done in the early part of the day.
00:05:51.220 | So I would say, you know, not too close to sleep.
00:05:53.820 | Then what you do is you restrict
00:05:55.380 | your maximum cortisol release to a period earlier in the day
00:05:58.700 | that buffers, reduces, that is the likelihood
00:06:02.880 | that you would have excessive amounts of cortisol
00:06:05.300 | later in the day, which not only can disrupt sleep,
00:06:07.420 | but is correlated with a number of other hormonal effects
00:06:10.940 | that are not good for us
00:06:11.960 | and therefore not good for fertility.
00:06:13.780 | So here, what I'm describing are positive
00:06:15.540 | yet indirect effects of a cold on hormone levels,
00:06:20.020 | both in males and in females.
00:06:22.660 | So for men, we talked about increased testosterone,
00:06:25.300 | improved sperm quality that was indirect, right?
00:06:27.300 | You're reducing the temperature of the testicle,
00:06:29.700 | but it's not that cold itself
00:06:31.020 | is positively impacting those things.
00:06:32.680 | Does that make sense?
00:06:33.520 | Heat is bad, therefore reducing temperature is good.
00:06:36.040 | Likewise with females,
00:06:37.980 | deliberate cold exposure can be good
00:06:39.440 | for the overall fertility process.
00:06:41.780 | Not because cold is good for the ovary
00:06:44.300 | or being cold is good for the ovary
00:06:46.600 | or for luteinizing hormone or for follicle stimulating
00:06:49.580 | hormone or anything else like that,
00:06:51.260 | but rather that using deliberate cold exposure
00:06:54.580 | as a way to restrict stress in a deliberate way
00:06:57.100 | to a particular time of day,
00:06:59.300 | increases the release of cortisol then
00:07:01.420 | and indirectly reduces the amount of cortisol
00:07:03.980 | that's released at other times along the 24-hour cycle.
00:07:07.340 | Okay, so these are positive yet indirect effects.
00:07:09.940 | So if you're a woman who really is interested
00:07:12.700 | in exploring deliberate cold exposure
00:07:14.240 | or who enjoys it or is already doing it
00:07:16.380 | and you're wishing to conceive, great, explore it,
00:07:19.660 | do it safely of course,
00:07:20.500 | but explore it and continue to do it.
00:07:21.860 | However, if you're somebody who just hates the cold
00:07:23.900 | and doesn't want to go anywhere near it,
00:07:25.340 | there's no reason to think that you absolutely need it
00:07:27.140 | provided that your stress, your sleep and other factors
00:07:29.620 | are all being carried out properly.
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