It's time to have "the talk"

Please enjoy this cuteness as a reward for reading this post

No, I'm not talking about the "birds and bees" talk. This "talk" is one you should have with your parents, or your partner, not your children. It's not an easy talk. You're not going to want to talk about it. They are not going to want to talk about it. But the discussion is important, and it should take place sooner than later. This "talk" is about advance health care directives.

Essentially, establishing "advance health care directives" (sometimes called a "living will") means deciding ahead of time how you want to be treated if you are no longer able to make decisions for yourself because you are ill (for example, with dementia) or incapacitated (for example, after a car crash). These decisions include things like whether you'd want to have a feeding tube, be treated with antibiotics, or be resuscitated with CPR if your heart fails (and many other decisions!). In general, people go about this in one of two ways: either by appointing someone to make decisions for them should it be necessary, or by writing down instructions for treatment, such as the kinds of treatments they would be ok with and the kinds they wouldn't want. Ideally, the advance directives should be a combination of both.

Now you're probably sitting there thinking "I'm way too young for this" (aren't we all), or "my parents are well, there's no need". And that's exactly the problem: by the time you need advance directives, chances are it will be too late. Our ability to make decisions for ourselves over our lifetime is like a bell curve: it's pretty low when we're young, still low-ish in our pre-teen/teenage years (hence the need for the "birds and bees" talk), then it peaks in adulthood, and starts declining again as we get older. So ideally we should start this discussion at our peak. I know I'm being a complete bummer suggesting we all sit down and talk about death and illness at our peak. But there's a good chance you'll thank me later.

I'm currently attending the Leadership Program for Physicians and Leaders in Long-Term Care in Vancouver (my talk is tomorrow and I should definitely be preparing for it instead of writing this!). There's a lot of discussion at the conference around advance directives. The main problem is that a lot of people don't have them!

There's some uncertainty over how much physicians actually follow advance directives. In some areas they have to and in others they don't. Really what it comes down to is everyone is better off if they have at least had the discussion - at the conference, one presenter mentioned how older adults who have advance directives tend to enjoy a better quality of life, and a better death. I know, I know. You're don't want to be reading about death on a Friday night. If you need a break, here are some kittens: click here.

As I said before, it's not an easy discussion. "Ah, ok, so, yeah, one day I might have dementia, or be in a car accident and suffer brain damage, and well I think I'd rather...". But hey, a lot of discussions are unpleasant ("Ah, ok, so, yeah, I dropped your brand new iPhone in the toilet"). So just do it. And don't just sit down and write this by yourself, either - speak to a loved one, or a relative, about what your thoughts are, and also involve your doctor - they can absolutely help with this, and may be able to provide you with useful tools. Advance directives should be an ongoing discussion, not a one-time thing - revisit your choices once in a while, and always keep someone in the loop.

I realize this isn't my most uplifting post, but as science moves forward, we face new choices that are important to talk about. So chatter away!

Go lift some weights and call me in the morning

In my last post I told you that I would reveal the one thing you can do to have a significant, positive and lasting effect on your brain health as you get older. See if you can spot it in the following list:

a) Learn to dance Gangnam style
b) Join a choir
c) Catch a wave
d) Pump some iron

Ok, that was a trick question. All of these answers are somewhat correct, but I was looking for the "most" correct answer (flashbacks to undergrad, anyone?): Pump some iron.

I realize I sound like a broken record - I've already written about how aerobic exercise can promote healthy aging here and here, and I've even already written about resistance training, or lifting weights, here.

So why am I at it again? Because it's important!
I'm fresh out of the 2012 Aging and Society Conference, where researchers came together to discuss what works and what doesn't when it comes to healthy aging. It turns out everyone pretty much agrees that exercise is hands down the most effective intervention to keep your brain cells happy into old(er) age. All sorts of different types of exercise, ranging from simply walking to attending resistance training classes, are associated with different types of improvements in cognition, memory, and even brain size. 

Of course, there are different levels of effort involved with different types of exercise, or even when talking about a single form of exercise. When my friend Jess asks me to go for a walk, she means a power walk: it usually involves going up hills, sweating like a pig (even though pigs, ironically, don't sweat much), and barely having enough breath for girl talk (though somehow we always seem to find it). When my friend Al and I go for a walk, what he means is a "mosey": we stop to look at the view, pet the dog, chit chat with strangers, and have more than enough breath for lengthy discussions about life, work, and the possibility of alien lifeforms. When it comes to brain health, whether you're walking or pumping iron, a little sweating and effort can go a long way. For example, resistance training has been proven to be most effective when the load, or how much weight you are working with, increases over time. So kick the intensity up a notch: there will still be plenty of time for chit chat around a post-exercise, antioxidant-rich mug of matcha (my new obsession - stay tuned).

Now that the obvious has been (re)stated, I want to take this opportunity to discuss the idea that perhaps lifestyle interventions such as exercise could be prescribed by your doctor. We know that exercise can improve cognition in aging but also conditions like depression. Should physicians prescribe lifestyle changes? Or are diet, exercise, and other lifestyle activities choices we should make ourselves? How would you feel if your doctor prescribed you exercise instead of pills? Would you be more motivated to exercise if the prescription came from your doctor instead of from your friendly Internet science blogger? Your thoughts in the comments!

If only I had a (better) brain: Part II

Can we "train" our brains to be brighter, sharper, faster? 

A while back I wrote a post about a big study looking at "brain training". The researchers wanted to know whether training programs that look like video games (like Brain Age and Lumosity) could significantly improve brain performance on various tests. The results, in a nutshell, showed that while participants improved on the tasks they trained on (e.g., if the game involved ranking balls from smallest to biggest, the participants got *really* good at ranking balls from smallest to biggest), the improvement didn't carry over to general brain function.Turns out ranking ball sizes doesn't help you remember where you left your keys this morning.

Two years later, what's the word?

I'm going to shift a little from how I normally do things (review a single article) and tell you about findings I learned about at the recent Aging and Society conference. At the conference, several researchers talked about brain training in the context of aging. We know that as we get older our cognitive abilities decline - we forget names and words, misplace our shopping lists, and process information a little bit more slowly. Wouldn't it be fantastic if we could just spend ten minutes a day playing games on our iPad and successfully counter this decline? Of course it would be fantastic. Not just for us, but also for the companies who are trying very hard to convince us to buy their products to improve our cognition.

The problem is that skills are specific. If you want to become a fabulous jazz pianist, you have to play the piano (preferably jazz songs, too). If you want to become a star ballet dancer, you have to practice ballet. If you want to become a better mountain biker, you have to mountain bike - road biking will improve your leg strength and fitness, but ultimately it won't make you a better mountain biker. So why should things be any different for brain skills?

As it turns out, they aren't. Two years later, nearly all the research conducted in the field of brain training is turning up the same results: people only get better at the tasks they trained on - the improvement doesn't cross over to more general skills, different skills, or everyday life. In one study, a researcher compared a commercially available brain training program with what she called an "active control" - a group that simply played regular video games like Tetris. She found that the group who spent time on the commercially available brain training program actually saw some aspects of their cognition decline compared with the control group. Bummer.

Now don't throw out your Brain Age game yet - everyone at the conference agreed that engaging your brain in training programs is better than not doing anything. And most of the researchers felt that while the programs don't work now, it's not to say they'll never work. We are increasingly more knowledgeable about how the brain works, what happens when we get old, and what different training tasks do. So it's quite possible that sometime in the near-ish future (don't ask me when) we could see the advent of brain training programs that do have a significant and lasting impact on cognition.

Until then, there is one thing you can do to have a significant and lasting impact on your brain health... And I'll tell you in the next post.

Healthy aging: As easy as do-re-mi ♪ ?

We’re all growing old – for all the recent advances in science and all the predictions of science fiction, this is still an inescapable fact. By 2050, there will be roughly 89 million older adults in the US, twice as many as there are now. While old age chases most of us down if we’re lucky, that doesn’t mean we’re entirely powerless in the process.

Previous entries in my blog looked at various ways to promote healthy aging: walking and lifting weights, eating less, learning languages. Some of these lifestyle changes, like exercise, are easy to incorporate later in life, while others, like bilingualism, may depend on the environment you grew up in. Today’s new finding about healthy aging fits in the latter category. It's a bit like a lottery: were you one of the lucky ones who benefited from an anti-aging activity in your youth?

Researchers were interested in how the brain responds to sound. We already know that brain structures that lie at the base of your brain, called subcortical structures (sub > beneath, cortical > the outer layer of your brain) are important for detecting fast-changing sounds like the ones we make when we talk. The precise timing of your brain reacting to sounds degrades as you get older, and scientists believe this is why grandma sometimes doesn’t really follow what you’re saying.

In this study, the researchers measured the precision of this timing by putting electrodes on participants’ heads (the outside only!) and recording the signals their brains generated when they heard the syllable “da”. As expected, the older participants didn’t have as precise a timing as younger ones. More interestingly, however, was that this age-related decline wasn’t nearly as bad in participants who were musicians.

So the take-home message is that lifelong musical experience can help make your brain better equipped to deal with aging. No doubt it also comes with other benefits - my grandma, in her eighties, had forgotten much of her adult years but still delighted fellow residents of her care home with her flawless rendition of the "Sweet bye and bye". Now of course while this is an interesting article, the results don't come as a huge surprise – by now you probably have figured out that the whole “use if or lose it” saying has a lot of truth to it.

Conveniently, I just bought a piano. Now if only I could reap all the benefits just by looking at it…

Reference: Musical experience offsets age-related delays in neural timing (2012) Parbery-Clark A, Anderson S, Hittner E, Kraus N. Neurobiology of Aging 33:1483.e1-1483.e4.

Yet another reason to exercise

Last weekend I went for a bike ride and when I reached the bottom of the big hill leading to UBC, I noticed quite a bit of activity going on. I didn't pay too much attention at first, but once I was booting up the hill, I was passed by several senior citizens on top-notch bicycles and I started getting curious. I asked a person who seemed to volunteer for the event what was going on. As it turns out, I was cycling right in the middle of the BC Seniors Games. Now for those of you who might not know me, my thesis research has to do with aging and the brain and nothing warms my heart like witnessing older adults and seniors exercising. I had just hit the jackpot!

The reason I'm so enthralled to see seniors exercise is because it is the single best thing they can do to preserve their brains. Today's paper highlights recent research done in California that shows just that.

First, a bit of background. You have a gene called APOE (mice also have it). It comes in 3 flavors, and each person only has one of the three: APOE2 (not important for today’s article), APOE3 and APOE4. If you got lucky and scored the APOE3 kind, all is well. If you happen to be in the 20-25% of the population who has the APOE4 kind, you may be in trouble: APOE4 is a known risk factor for Alzheimer's disease. Does it mean you'll for sure get Alzheimer’s disease? No, but you are 10 to 30 times more at risk of developing Alzheimer's disease if you carry the APOE4 gene.

In this paper, researchers compared old APOE3 (normal) and APOE4 (at risk for dementia) mice. In general, aged APOE4 mice experience cognitive decline faster and earlier than APOE3 mice. The researchers were interested in studying whether exercise (running on a mouse wheel!) had any effect on this cognitive decline.

The researchers used cognitive tasks that rely on a part of the brain that's important for memory, the hippocampus. One of the tasks, called place recognition, involves putting a mouse in an arena with two objects. The mouse is then removed from the arena, one object is moved, and the mouse is put back in the arena. Presumably, a normal mouse will then spend more time exploring the object in the new location. For this task, the aged APOE4 mice were initially impaired compared with the APOE3 mice. This means that during the second trial of the task, they tended to explore both objects for similar amounts of time, instead of spending more time on the object at the new location. This result suggests that the APOE4 were unable to remember the initial object locations well. The good news? Mice who exercised did significantly better at this task. Interestingly, this was valid for both APOE3 and APOE4 mice. Even more interestingly, exercise improved the scores of both types of mice for all the tasks that tested the hippocampus.

What's going on in the brains of these exercising mice? It is thought that exercise increases the levels of a protein called BDNF (for Brain-Derived Neurotrophic Factor). BDNF regulates many important functions in the brain, including the making of new neurons and the making of new connections between neurons, and these effects are thought to be important for memory.

Regular readers of Scientific Chick know not to get too excited when I report about animal studies. Well, I'm happy to add that the results that were observed in those mice were also observed in humans. In fact, there are countless human studies out there that confirm that physical activity is a powerful way to improve and maintain your cognitive abilities.

When I try to urge certain people to exercise (you know who you are), I almost always hear the same excuse: “Well, my uncle so-and-so never got off his couch and he lived to be 100!” In some cases, heredity can be on your side, that's true. But genetics can be quite the lottery, and it's important to keep in mind that several forms of cognitive decline, including the most common form of Alzheimer's (called “sporadic” in scientific lingo) are not hereditary.

So to all my older readers out there, I'll see you on the road at next year's BC Seniors Games. And if you're not ready for cycling, there's always the cribbage category.

Winners from this year's BC Seniors Games, cycling event. This could be you!

Reference: Exercise improves cognition and hippocampal plasticity in APOE epsilon4 mice. (2009) Nichol K, Deeny SP, Seif J, Camaclang K, Cotman CW. Alzheimers Dement. 5(4):287-94.

Aging is optional! Take two of these pills and call me in the morning.

We’re getting older.

Not exactly a surprise, I know, but I didn’t mean you and me are getting older. I meant we are getting older, as a population. In 2001, one Canadian in eight was aged 65 or older. By 2026, one in five will be 65 or older. So what should we do with an increasingly aged population? Well, this being a North American consumer culture, the sensible thing to do is try to sell them stuff. I mean, think of the size of the market!

Right now, a significant amount of research is being devoted to aging. The main focus is to try to slow down aging (partly by developing marketable supplements and such). As some of you might know, even my own PhD thesis project is on how to slow aging in the brain. Loyal readers of ScientificChick.com will also be aware of recent articles about caloric restriction, a potential way to keep old age at bay. Thankfully, a recent publication in Nature suggests a much easier way to live longer: forget starvation, all you have to do is pop a(nother) pill!

In this article, American researchers show that mice that eat rapamycin supplements starting at 600 days of age (senior citizens in mouse years) live longer, up to 14% longer for females and 9% longer for males. What’s more, rapamycin supplementation did not change the causes of death. The researchers propose that this drug could be acting by postponing death from cancer, by delaying mechanisms of aging, or both.

How does rapamycin work? Well, as you might expect with a miracle drug like this, we’re not really sure. Rapamycin is an inhibitor of a pathway called mTOR. The mTOR pathway has many functions in your cells, like coordinating the survival response arising when there are changes in nutrient and energy availability, and dealing with potentially deadly stresses, such as oxidative stress (the kind of stress fancy juices packed with antioxidants are supposed to battle). Since the mTOR pathway acts kind of like a central sensor of cell health, it makes sense that it would be implicated in regulating lifespan. Exactly how rapamycin is working its magic, though, is probably what the researchers are trying to figure out for their next article.

Could the increase in longevity following rapamycin supplementation be related to the effects seen with caloric restriction (the “eat less, live longer” paradigm)? Well, mice on rapamycin show no change in body weight, so we know the drug is not acting through a caloric restriction mechanism. The converse, however, may be true: it is thought that the beneficial effects of diet restriction may also be due to an inhibition of the mTOR pathway.

So don’t throw out the double-stuffed Oreos just yet, but don’t eat half the box either: rapamycin pills for humans won’t be on the shelves tomorrow. While mTOR inhibitors are currently being used to treat a few conditions (transplant rejection and some cancers, for example), there’s still a lot of work to do to tease out all the potential interactions and side effects.

Longevity in pill form? To me, it would feel like cheating the system. And if there’s one thing we keep learning over and over in the life sciences, it’s that trying to cheat Mother Nature always has some unintended consequences.

A great illustration of the aging mouse by TS Rogers

Reference: Rapamycin fed late in life extends lifespan in genetically heterogeneous mice. Harrison DE, Strong R, Sharp ZD, Nelson JF, Astle CM, Flurkey K, Nadon NL, Wilkinson JE, Frenkel K, Carter CS, Pahor M, Javors MA, Fernandez E, Miller RA. Nature 2009 16;460(7253):392-5.

The secret to eternal youth? Say goodbye to brownies.

You’ve heard of Atkins. You’re familiar with Weight Watchers. You probably know about the South Beach Diet. Well, there’s a new diet in town, and it’s called the “Longevity Diet”. It’s inspired by a relatively new hot topic in the life sciences called caloric restriction. As the name implies, it essentially means eating less, and it's hailed not so much as a weight loss strategy as an anti-aging solution. While I’m usually excited about new simple ways of changing daily habits to live a healthy life, this one I’m not sold on yet. You may remember that I like cheese. You may also remember that I like brownies. So obviously, I’m not too excited to hear that eating less is extra healthy. Especially since most caloric restrictions studies suggest you have to cut back anywhere from 30% to 60% of what you eat to see an effect.

So far, most of the really convincing data on caloric restriction slowing down the aging process have been carried out in model organisms that fit in your pocket: rats, mice, worms, all the way down to the tiny yeast. I personally would be reluctant to extrapolate those findings to humans. Surely worms don’t have the same kind of relationship with brownies that I do. However, one recent study looks at caloric restriction in healthy humans, and it’s hard not to take notice.

Researchers from Germany took 50 normal-to-overweight elderly subjects (sorry, Mom, in this case, “elderly” means 60ish, but the important thing is to be young at heart!) and divided them into groups. One group was told to not change their eating habits, and one group was put on 30% caloric restriction for 3 months. Before the study and after the 3 months, everyone’s memory was tested using simple tests like remembering a list of words. Well, I’m very sorry to say, but after 3 months, the group who ate less did significantly better at the memory tests. Sad but true.

During the study, the volunteers were monitored for many different biological indicators (such as cholesterol, insulin, inflammation, and cellular stress), in hopes of identifying the mechanisms responsible for the effects of caloric restriction. The one mechanism that really stood out and that showed a solid correlation with the memory improvements is insulin: the group on caloric restriction had lower insulin levels. Insulin is a hormone responsible for taking the sugar out of your blood and storing it in your liver and muscles to use when energy is needed, but it also plays an important role in keeping your brain healthy. When you have less insulin circulating in your body, you become more sensitive to it, and this sharpens and improves how your body (including your brain!) reacts to insulin. This may be why the group who ate less performed better on the memory tests.

So, throw out the cheesecake? I’m going to wait a little before I draw any solid conclusions, as there is still a very ongoing debate over caloric restriction. One side is claiming significant benefits like longevity, healthy aging and protection against age-associated diseases (think Alzheimer’s). The other side is critical of the methods and models used, as well as the contradictory results, and points to the downsides of caloric restriction, especially during the reproductive years. Not eating enough can also lead to the breakdown of muscles (and remember, your heart is a muscle), which is very important to consider if you have an active lifestyle. Interestingly, in this study, the authors show that the caloric restriction group lost a significant amount of weight, but did not lose body fat. Healthy? I think the jury is still out, but hopefully more well-controlled human studies will shed some light on this potentially exciting and easy way to fend off the effects of the ticking clock.

Learn to make these, shorten your healthy life expectancy?

Reference: Caloric restriction improves memory in elderly humans. Witte AV, Fobker M, Gellner R, Knecht S, Flöel A. Proc Natl Acad Sci U S A. 2009 Jan 27;106(4):1255-60.