Old age, blindness, and light quality

Aging is a process that is as universal as a process can be.  Everything ages, all animals, plants, even planets and the universe as an entity age.  It is something we cannot avoid, despite the many searches for a fountain of youth.  And as we age, we may or may not become afflicted with the many complications that accompany getting old.  Our joints start to get stiffer, our muscles get a little weaker, and our memories might get a little worse.  However, these conditions aren’t all or none, and there are many things we can do during our lives to help decrease the amount of function we lose in old age.  These include eating a healthy diet, exercising regularly, and managing stress. 

One complication of aging I’d like to discuss today is our eyesight.  This one thing I am sure most people would like hang on to for as long as possible, since, as humans, we rely on our eyesight more than any of our other senses.  We have all seen eyesight that deteriorates in old age, many people start to need glasses when they never did before, or it might be getting harder and harder to see street signs while we are out driving.

This type of loss of sight is known as age-related macular degeneration (AMD), and is a phenomenon that plagues millions of people every year.  However, the exact causes and the development of this disease aren’t clearly known, so finding treatments and prevention plans for it is very difficult.  But, like many diseases of civilization, this one has inflammation as a root cause.

How AMD is an inflammatory condition 

There are many intersecting lines of evidence that help to show the inflammatory nature of AMD.  The first we will discuss is parainflammtion caused by ROS production. Since certain parts of our retinas are comprised of a large amount of neural cell types along with photoreceptors the energy needs of this tissue is very high (1).  This will create a high metabolism in these tissues, which can easily start to create ROS when energy is in constant excess.  As we have seen before, these ROS can then damage the retinal tissues, and cause inflammation.  Additionally, these ROS can be developed by a process called photooxidation, which the energy from the light itself excites the oxygen species, turning them into ROS. The presence of ROS causes new blood vessel growth to occur, and this can result in choroidal neovascularization (CNV), which is another form of AMD.

Next, certain components of our immune systems “complement system” have been implicated in AMD.  By far the most well known complement is CRP, or C-Reactive protein, which is a common biomarker for inflammation.  Another complement implicated in AMD is complement factor H (CFH).  An interaction between a certain genetic variant of CFH and CRP has been shown to be a main cause of AMD in over 50% of cases (1).  However, this interaction has been shown to be most dangerous at CRP levels >3mg/L.

There are several other additional lines of evidence that support the hypothesis that AMD is inflammatory in nature.  Most of these are based on anti-inflammatory treatments improving AMD in patients, or other diseases known to be inflammatory in nature increasing the risk of AMD.

One twin study found that smoking, which is known to drastically increase inflammation and the risk for a host of diseases, was highly correlated with AMD.  In fact, the risk factor was 32% greater in smokers than in non-smokers (2). 

The same study also looked at the effects of omega-3 consumption on AMD risk.  The omega-3 DHA is found in high concentrations in many of the photoreceptor layers of the human retina.  It is also an anti-inflammatory, which can help to reduce AMD risk.  In the twin study, they found a preventive effect of 22% by those who consumed the most omega-3s compared to those who consumed the least.  This effect was even amplified by those who consumed low omega-6s in their diet as well (2).

Since ROS production is on of the primary drivers of the inflammation implicated in AMD, supplementation with various anti-oxidants has been shown to help AMD (3).  Other lifestyle modifications such as quitting smoking, and losing weight if overweight or obese have been shown to lower the risk for AMD.

The effect of light on AMD

As many of us know, the light that comprises the visible spectrum in composed of many different wavelengths, with each color being its own distinct wavelength. Additionally, the visible spectrum leads into the infrared spectrum at its low energy end, and into the violets and ultraviolets at its high-energy end.  However, not all wavelengths of light are created equal to our photoreceptors.  It turns out that the blues, violets, and ultraviolets are actually damaging to our photoreceptors (4).  In fact, our eyes have developed a way to deal with this as we age, and that is to turn our lens slightly yellow in order to block out some of the blue light.  This study modeled the effects of adding certain filters to a model of the retina, and measuring the ROS production, beginning at age 70.  As we can see on the far right of the graph, when no filter is used we have fairly high rate of ROS production.  However, when a yellow filter is added to block out blue light, we get a decrease in ROS production.  An even greater reduction in ROS production is seen when we filter out UV light, as seen by the white diamonds that are virtually on the x-axis in the bottom right corner.

Another interesting experiment into the effects of light used photobiomodulation, or providing specific wavelengths of light to elicit certain signaling effects, on mice (5). In this they exposed mice to a “damaging light”, which, interestingly, was just a regular 18W fluorescent light. They then treated this light damage with three different near-IR light treatments, one that was only done before the damaging light, one during, and one after.  They then looked at the number of immune cells in various parts of the eye, and you can see what an effect the damaging light (the LD treatment) had on the mice.

I think with these studies on the effects of light on our eyes we can see just how important it is to limit our blue light exposure.  This is a very common type of light emitted from our computer screens, phones, TVs, and almost all other electronics.  You can pick up some nifty yellow tinted glasses to help block out the light, and as geeky as they might seem now, being able to see when you’re 70 or 80 is probably worth it!  Otherwise, just trying to limit the amount of time we are exposed to these sources that emit mainly this type of light is something we should all try to do.  You can also download F.lux for your computer screen, but I haven’t yet found a good app for my phone for it (I have an android, it looks like you can jailbreak iPhones to get it on there).

Another important thing to note is just how important crubing inflammation and supporting our immune systems are to all facets of health.  By doing this and keeping our energy levels in check we can help ourselves age more gracefully, and avoid many of the complications of our current industrialized way of life.

(D)efense

Vitamin D is a well known nutrient, however, I think few people really understand the significance of this important vitamin.  To  begin with, vitamin D should hardly be classified as a vitamin at all, since it is really hormone that helps to signal our bodies calcium status (1).  However vitamin D (VD) has been implicated in a range of processes including obesity, renal disease, cardiovascular disease, male fertility and even sex hormone production (2,3).  With all these different actions of VD it is tough to know where to start, as there is so much research on how VD affects so much of our lives.  I do think these many actions are very interesting, and well deserving of a post in their own right, but I would like to focus this post on VD’s interactions with the immune system, as that is a topic consistently on my mind these days.  To do that we will first go over a quick look at VD metabolism, and then get into its effects on immunity, and finish up with some thoughts about our own VD status.

Vitamin D Metabolism

As humans there are two main ways we can get VD: through sun exposure and supplementation.  We will go over the optimal VD levels at the end of the post, but first lets see how sunlight affects our VD status.

Absence, and future posts!

Well, I know it has been a long time since I have done significant posting, I have been pretty busy since Thanksgiving with projects, tests, and just general wrapping up of the semester.  However, I completed the last final of my undergraduate career this morning, so regular posting will continue soon.  Some topics to look forward to in the coming weeks include:

• Vitamin D
• Antioxidants
• Fructose
• More on cooking
• Clock genes

And many more!  As always, if you have a good idea for a post, or would like to learn more about a topic send me an email or write it in the comments!  One of the hardest parts is coming up with good topics to write about, so suggestions are always welcome.

The Signal and the Noise: What does it mean for science?

I just finished reading Nate Silver's excellent book The Signal and the Noise.  This book is all about statistics, and how often misguided we are when hear statistics get thrown out for everything from weather predictions, to earthquakes, even baseball.  It is very well written and engaging, he has quite the sense of humor, and gives funny descriptions of the people he met to interview for the book (to the reader at least, I doubt some of these scientists appreciated how he depicted them!).

In the book he talks about his own personal journey.  He began as an economist for a big accounting firm, but developed a baseball sabermetric program that he sold to another company and struck it big.  From there he turned to political forecasting, and has done quite well, he correctly predicted the results of the presidential election in all 50 states!  They guy is what I would call a "genius"  so the book is a must read.

However, this blog is about science, and what can a scientist take away from this book?  Well, I think there is quite a bit for us, especially since statistics are the basis of our profession (statistically significant anyone?).

The main thing I would like to discuss here is this paper by John P Ioannidis.  Nate talks about this in his book, and the title of it is "Why most published research findings are false".  Woah, that's quite the mouthful for any scientist to swallow.  How does he come to these conclusions?  Well he uses a lot of statistics that, to be honest with you, mostly went over my head.  I was able to understand most of the article when the numbers were absent and he used words, though!  What I got out of the article was that most of our published research findings are suffering from some of the most basic problems that the scientific method is supposed to sort out.

The first, and obviously most occurring problem, is bias.  Ioannidis uses math to show that as bias increases the probability of a research finding being actually true goes down.  I feel like bias is definitely as issue in a lot of journal articles, and we see it all the time.  I think many people will remember an article published not long ago that said that eggs were just as deadly as cigarettes?  Well, it turned out these guys had connections to the cholesterol drug market, obviously they are going to find that the high cholesterol eggs are very bad for you.

This is just one type of bias though.  Another type would be purposely designing an experiment to get a result you want.  This can be done in many ways, by how you ask the question, to the statistical methods you use to present your data.  Ioannidis talks about many studies that will use statistics to develop results that have a p<.05 (the standard in most scientific literature) when they previously did not meet that criteria.  This is obviously poor science, if you modify your data so it looks how you want.

Another way we introduce error into our scientific studies is by saying that just because a difference is small, but statistically significant, it is a meaningful finding.  I struggled with this principle myself when I was writing the How to build muscle post.  There were many studies that showed certain associations, but they were so very small.  However, the study said it had a statistically significant finding, so I assumed it was true and used it as a source to back my claim.  Significant or not, are these small gains enough to say something is important enough to publish a paper about it?  Maybe we just need to be more selective about what gets published these days.

The most funny problem that Ioannidis points out is the competition between groups that can lead to exaggerated findings.  If one group doing similar research to yours publishes a finding,  one that is "statistically significant, and you can make the opposite finding in a "statistically significant" way, you should publish your finding immediately!  Why?  Well, mainly its just to be a dick, and say you're wrong!  This great for you and your career, and can help grab headlines for your field, but is very damaging to science as a whole, where consensus needs to be found on topics.  If you have opposite finding you need to work together to find and modify your experiments so that you can reach a consensus answer that benefits science.

Nate talks about this consensus view at length, and recommends that "Bayesian" thinking is the solution to this problem.  He throws out the situation where you are in a world where all your predictions are depicted on a sandwich board, and when you meet someone with a differing prediction, you must either make a bet with them about who is right, or come to a consensus.  This type of bayesian thinking is the core of Nate's book, and is quite the insight for those of who might have differing views, especially us scientists who seem to be rarely trained in this bayesian thinking.

All in all, I think both Nate's book and Ioannidis' paper are very good reads, I would recommend both of them to anyone.  I think the main thing we get out of both of these is that we need to be better at critically analyze the data.  We need to be sure we are finding signals, and not just noise.

Competition Culture: What have we done?

Wow, what a sad,sad story coming out of Kansas City this weekend.  My thoughts and prayers go out to anyone affected by this tragedy.

An event like this makes me call into question our competitive culture.  Now, obviously this young guy must have had some problems.  And I'm sure stuff like this happens to people all the time and it doesn't get as much notice because they are in the position this kid is.  But, my question would be, do you think this would have happened to this kid if he had not been a pro football player?

Most of these players a essentially just kids, from the time they reach about sophomore year in high school they begin to come under intense scrutiny.  They are immediately thrust into the spotlight, and many of them continue to stay there through college ball, and into the pros.

Cam Newton is 23, and is almost exactly one year older than I am.  He regularly has articles published about him on a national level that call into question every aspect of his character.  Can you imagine being that young and having have those things read about you?  I can't, in fact I'm right up there with the other people saying they hate him most of the time.  I'm 22, and I spend most of my time wondering why my funny facebook status didn't get more likes, not thinking about whether or not all of my basic values are right or not.

Nathan Scheelhaase (for those of you who don't know who this is, he is/was the quarterback for the University of Illinois. Go Illini!)  is 22, in fact, he is about 7 months younger than I am.  He regularly is referred to as talentless on certain sites around the web.  What?  Can you imagine what that would be like?  I get stressed out when I have two exams in one week, I can't imagine how would feel if I could also pick one of a number of sites to read why random people think I have no worth.

The pressure most of these kids are under by choosing to be stars in this culture of competition that we have is just unreal.  It is not just the injuries these athletes are sustaining that will have lifelong side effects, it the emotional and phychological damage that comes from this culture as well.

I am reminded of Peter Gray's talk from AHS this year in times like these.  He talked about how in most traditional societies around the world there is very little competition.  One thing that really stuck with me was when he said that if you give kids a soccer ball in these societies they don't play a competitive game with it, they play something like seeing how long they can collectively keep it up in the air.

This competition culture isn't just present in athletics though.  It can be seen in almost any industry in America these days.  Who can get promoted faster, who can publish more papers, who can earn more money.  All the time we are constantly bombarded with competition, and it just doesn't seem natural to me.

Stress also plays a big role in this.  When you are in an intense competition like this all the time you are under quite a bit of stress.  Not only are these kids under stress during actual games that millions of people watch, but their actions throughout their lives are more stressful than ours. I think play can be a great way to reduce stress, and everyone should have multiple different stress reduction strategies they can turn to when things start to build up.

I think we could all benefit from some extra play in our lives.  Even if that play comes in the form of a competitive, taking the competition element out if it can make it that much more enjoyable.  For instance, one of my roommates and I enjoy playing racquetball, or course someone ends up winning, but we don't go out there with the intention of winning or losing, we just play a couple games so we have something more to do than just hit the ball for 45 minutes.

When you look at the multitude of factors that are contributing to our current health epidemics, both physical health and mental health, I think it is hard to say that our competitive culture is not helping to cause it.  Through the stress this competition causes we are slowly broken down, and stress reduction strategies need to be implemented to help us reclaim our health.

How to Build Muscle

Alright guys, I’ll admit it.  I’m vain.  I would like to be bigger.  Maybe not Arnold big, but I would like to add a few more pounds to my 5’ 10” frame.  However, many people struggle with the herculean task of adding muscle mass, and for many there doesn’t seem to be any solution.  Any one who has looked into the topic knows that there are a few basics you need to follow: Lift heavy weights often, and EAT!  These two things will get people on the right track, and they should be able to add a considerable amount of muscle, especially if they are new to weight training. 

Yet, these two suggestions are somewhat vague, especially the eating part.  Some people will tell you just to eat everything in sight, and gain as much weight as possible then after the weight is put on you can look at cutting down on the fat you have gained.  Who really wants to get fat like that though? 

Another question people have about the eating part is how much protein should they eat?  While getting in enough energy to grow through healthy fats and whole food carbohydrate sources such as potatoes is certainly needed, protein remains kind of an anomaly in the diet for many.  If we follow what the body builders have been preaching for half a century or more we would think that the way to put on weight is to consume massive amounts of protein 8 times a day or more!  Another question mark is when to consume this protein, especially around a workout.  Well the science in this particular area has come a long a way in the past decade or so, and since a friend asked me many of these questions and more a week ago, I thought I should dig into the research to see if my own thoughts on the subject were valid, or if I needed to revise some of them.

The Central Problem of Gaining Muscle: Net Protein Balance

Ummm, that was a hoax, right?

Well people are talking, so I'll talk back.  Have your heard about these Raspberry ketones that Dr. Oz is making famous?  Someone in my 400 level nutrition class asked about these today, and I had already looked into them this week after first hearing about them on Monday or Tuesday.

They are supposedly a "magical" fat burner, and Dr. Oz is apparently pretty high on them.  Also, stores can't keep these bad boys in stock!  But is there really any science to back this holy grail of fat burning up?

No.