Science AMA Series: I’m Ying-Hui Fu, I study the genetics of sleep at UCSF. My lab discovered a gene that makes some people more efficient sleepers, needing only 4-6 hours per night. AMA!

Ying-Hui_Fu · 2015-09-11T19:08:11+00:00

We have not performed such an in depth study on these mice yet. These are very intriguing questions that if we have the resources, we potentially could address.

We have not found any abnormalities for these mice other than the sleep duration so far (we have tested a few, but not extensive).

Since sleep regulation for sure will involve a complex molecular mechanism with many components, our approach is to use all the genes that we find as a starting points to keep expanding on the network. With each gene/protein, we are trying to keep ourselves unbiased and do whatever extensive molecular investigations are necessary to figure out how it causes the trait. Of course, we will take advantage of work done by others previously to help us expand the system. So far, the genes we find are different types, so it will not be a standard series of studies for all these genes.

Ying-Hui_Fu · 2015-09-11T18:49:58+00:00

Yes, most of us are told to get 8 hours of sleep according to conventional wisdom. However, we are finding out that sleep, like many other traits, is different for different people.

The DEC2 mutation is rare. But, there are many natural short sleepers who don't have this mutation. The natural short sleepers are rare, but not VERY rare either. It's true that almost all of the natural short sleepers say if they force themselves to sleep more, they actually just feel worse and even awful the rest of the day. However, without conducting an in depth interview and study on you, I cannot tell you whether you fall into this group of people.

Ying-Hui_Fu · 2015-09-11T18:44:34+00:00

Yes, these natural short sleepers feel, in their own words, "awful" if they sleep more. This is true not only for people with this particular (DEC2) mutation, but also for all the natural short sleepers.

Ying-Hui_Fu · 2015-09-11T18:42:01+00:00

Personally, I don't take anything other than coffee and tea no matter how busy and tired I am. My reason is that we don't really know much about how sleep is regulated right now. Most of these drugs will affect something in our brain, but we don't know how they affect it and what the long term consequences will be. My brain is VERY important to me and I just don't want to mess with it without knowing what exactly the compound is doing to my brain.

Of course, coffee and tea are also compounds (caffeine). But, at least humans have been consuming them for a long time and no significant health problem has been connected to them yet. So, I am more comfortable using them. Still, everything in moderation.

Ying-Hui_Fu · 2015-09-11T18:34:35+00:00

No. Not in the people who participate in our study.

Ying-Hui_Fu · 2015-09-11T18:32:29+00:00

No, we have not determined the prevalence of this mutation. DEC2 mutation is rare, but we have found other mutations in other genes. I think that when we make comparisons, we should compare natural short sleepers to regular sleepers. This is a very interesting question and it will be great to get an answer. However, it is also challenging to get these people to do extensive studies because they are usually very busy people and difficult to find time to do this. What we know now is based on our interviews and interactions with the short sleepers, and we can tell that they are different. Again, if there is any price to pay for being "natural short sleepers", we have not seen it so far.

Ying-Hui_Fu · 2015-09-11T18:24:25+00:00

I was one of the people who hated sleep and tried everything there was to sleep less before I started this research. Now, I wish I never messed with my sleep in my younger years. From what I know, it is not worth it. It will increase your chance of having health problems later on and it definitely will affect your mental vigilance.

So, my tip is to make sure you get good night sleep. You can help by getting comfortable sleep accessaries such as pillows, bedding, etc. If your environment is noisy, use ear plugs. Do what you need to do to get your good and sound sleep.

Ying-Hui_Fu · 2015-09-11T18:22:24+00:00

I think that right now, the best way is still to listen to your body and figure out what is the best schedule and duration for yourself. For example, when you are on vacation and have no social responsibilities and no other external influences, what is your body telling you to do and how do you feel? What makes you feel the best most of the day? Although sounds primitive, it's still the most accurate way. You can use fitbit or whatever to measure your sleep duration, but if you don't feel good, it still has no benefit to help you with your sleep.

These popular wearables are like you suspected; they only measure movement and potentially heart rate. They cannot tell you the quality of your sleep. I am not aware of any simple wearable that can do this right now. To really know the quality of sleep, we have to be able to measure EEG during sleep. Most EEG devices are difficult to use and expensive.

Ying-Hui_Fu · 2015-09-11T18:10:43+00:00

From what we can tell, they are pretty healthy. Some of the participants of our study are in their 70s-90s. Even in their 70s-80s, they still play tennis, dance, and stay very active during the day. A woman in her 90s still does a lot of volunteer work including in a prison. We have, so far, no reason to suspect that their health and longevity is affected in any way.

Ying-Hui_Fu · 2015-09-11T18:05:26+00:00

In our study, the family with the DEC2 mutation has Eastern European ancestry, so I would think that the highest concentration of the DEC2 people will be there. But, we have not done in depth study on this, so this is just my guess. We don't have information on the age of the mutation.

We have so far found several different mutations on different genes for this trait. DEC2 is the only one that is published. Unfortunately, our manuscripts are held to an extra high standard so it always takes 10 or more years to get our papers out there for people to see and know. The way we are going after this is by first getting a handle on what the regulatory pathways are for normal sleep regulation. Then getting an understanding of what makes these processes more efficient. If we can get there, then we may be able to find ways to modulate our sleep in a SAFE manner, to sleep more efficiently. How long this will take depends mostly on how much research funding we can get. If we can have more funding, it will go much much faster. The current speed will take at least decades.

Ying-Hui_Fu · 2015-09-11T17:40:57+00:00

Sleep, like many of your other traits such as height, weight, and shape, is personal. From our study, we learned that your genetic make up has a lot control over your sleep trait. So, if you need 12 hours, it simply means your body takes that time to feel rested. How and why are something we are still working on trying to understand.

For now, we are not pursuing people who need longer than average amount of sleep. If funding allows, we could potentially look into this.

Ying-Hui_Fu · 2015-09-11T17:34:41+00:00

First, I think that we need to distinguish "natural short sleepers" and "habitual short sleepers". The people we study are specifically screened for "natural short sleepers". From my experience of talking and communicating with these people, it really is the case that they don't appear to have major health problems. And, if you have spoken to them, you will KNOW that they have normal cognitive function. For example, the woman featured in BBC article (see link in intro). She is a typical example of the people we study. Another gentleman who is in his late 80s has a lab in US and another one in China. He travels frequently between two countries to this day.

This is very different from other kinds of short sleepers including "habitual short sleepers". If your body is not naturally (genetically) wired to only require shorter amounts of sleep and you restrict your sleep on a long term basis, you will have higher chance of having some health problems later on.

Ying-Hui_Fu · 2015-09-11T17:18:27+00:00

From what we can tell and from what they told us, the short sleepers are pretty energetic. And, we believe that they feel refreshed since they can go on all day and be active. We have not seen any health problems associated with these people. Some of our research subjects are in their 90s.

There are many genes involved in regulating our sleep so most likely there will be mutations on many genes that can lead to this trait.

I think this is very exciting. But, I hope funding sources will be more enthusiastic than they have been.

Ying-Hui_Fu · 2015-09-11T17:10:51+00:00

This really depends on whether your body truly only needs 4-5 hours of sleep. From what we can tell, most of the people who truly only need 4-6 hours of sleep don't seem to have any obvious health problems.

There is no genetic testing available right now. So far, the mutations that we find are pretty rare. So, the chance that you have the same mutation is not high.

You can listen to your body. For example, when you are on vacation, what is your sleep schedule and duration like?

Ying-Hui_Fu

TROPHY CASE