So in this lecture we're going to talk about healthy aging. We're going to start off with the description of our aging population. People are living longer than ever before. The oldest old, that is the demographic over the age 85 is the fastest growing segment of the US population per the National Institute on Aging or NIA. The challenge for the 21st century will be to make those added years as healthy and productive as possible. Now, I can tell you from my own experience here in Boulder Colorado, there are a lot of people who are very interested in this issue of healthy aging. That is how do people basically not only live longer but how they live healthier. So we're going to spend the next few lectures talking about that in relation to cannabis. So why the challenge? Well, with more people living to older ages comes a greater incidence of different diseases and disabilities. So for example, with increasing age also comes increasing risk of metabolic syndrome, osteoporosis, cardiovascular disease, Alzheimer's which we talked about a module or two ago, and of course there are also other more general issues like motor control, trouble balancing, increasing risk for falling. Even in the absence of physical disease or physical problems, quality of life can also be compromised. So as we get older even without Alzheimer's for example, we still experience age-related impairments and cognition. So our cognitive abilities change over time as we age. Executive function for example can be impaired with increasing age. There are also changes in social, emotional and economic functioning as well. So the good news, let's start off with some good news here. So the good news is that with increasing age there also comes preserved and improved abilities. So we don't just lose things, there are some things we actually gain and or preserve, wisdom obviously accumulates with time and age, verbal ability and fluency can be preserved, social functioning can be preserved or improved, and emotional well-being can be preserved. Now, the not-so-good news part of the equation. Certain cognitive tasks can become more challenging with increasing age. So in particular difficulties with memory and difficulties with executive function. If you're wondering what exactly do we mean by executive function, we're talking about things like reasoning and planning, multitasking and maintaining focus, maintaining attention in the face of distraction. So you can see here on the right-hand side is a figure taken from a paper published in 2004. Looking at performance on a number of different cognitive tasks which you see here and the different shapes and colors, still looking at performance on this task across age. What you see here is that basically they decline mostly most all of them with age. The one that's probably shows the least amount of change is the one here in the colored squares, and which are shown there, basically showing less server verbal buildup, showing less decline than the other tasks. So more not-so-good news, we look at physical issues and in this case we're looking at muscle atrophy or sarcopenia. Basically, that increases the older you get, bone density decreases the older you get. A risk of hip fracture increases dramatically with age, changes in muscle and bone. This is a really big deal. This is what we are talking about here, basically changes in muscle and bone density. That is an important factor in terms of losing independence. Obviously, for better quality of life we want to keep, stay independent as long as possible, and having reasonable muscle strength and bone density is super important for that. So when we look here at hip fracture incidence per 100 women over five years. We look at then that across age what you see here it's relatively increases somewhat in your fifties, increases much more dramatically in your sixties, and then you look into your seventies it's a huge increase. So this is super important and in terms of healthy aging. So how do we stay healthy? Well, there are a number of things that people can do to stay healthy both in terms of the cognitive domain and the physical domain, but doing things that are challenging, learning a new language, crossword puzzles, getting involved in the community, volunteering. But probably one of the most important things is staying physically active and that is super important. Not just for muscle strength and bone density but also for your brain as well, for your cognitive abilities. There are things that fit into this category, any aerobic activity. So walking, hiking, jogging, strength training is important, yoga, tai chi, these are all examples of things that people do to maintain that physical activity. Then what you see down here is this paper. Basically, that 10 minutes of daily exercise can help prevent disability in old age. So the reality is super important in terms of preventing some of the big problems that can develop with age, super important kinds of healthy aging. So why physical activity? Lets talk more about that. While physical activity in older adults does lead to psychological benefits as well as physicalogical benefits. But on the psychological side, we're talking about reduced levels of depression, increase satisfaction with life in terms of physiological benefits, improved insulin action, and cardiac function, decreased inflammation and blood pressure. We've talked already a lot about exercise in the context of these different issues, but long-term exercise is antiinflammatory, long-term exercise helps with mood and other issues helps with cognition. So the neurocognitive benefits have been documented in several papers, and more than several papers actually over the last couple of decades. But in older adults, regular physical activity leads to increased cerebral blood flow, increase gray and white matter volume, improvements in working memory. So we know it's good for the brain, we know it's good for your cognitive function, we know it's good for the physiology, and it certainly some mood benefits to it as well. This is definitely true across the board age wise, but even more so for older adults. So physical activity in cognitive function is just a couple of quick figures taken from a scientific paper published by Kilgore in 2013. But what you see here on the left-hand side, is you get the left hippocampus, right hippocampus, and we're looking at gray matter. Volume in hippocampus across minutes exercise per week. Bottom line is you see a positive relationship. The more minutes exercise per week you get, the better the gray matter and healthier the gray matter is in the hippocampus both left and right. So the problem or the difficulty, I guess it'd be a better way to put it with exercise and aging. So there is no doubt that exercise is good for you both mentally and physically as you age, and of course, it's true for every age, but especially true for older adults in terms of wanting to maintain independence and quality of life. But what else comes along with aging? Well, this is true in general, exercise can hurt, we talked about this in the exercise module, intense exercise can be uncomfortable, and it's especially uncomfortable for aging adults, right? So that makes exercise difficult. So in general, as you age, you hurt more in general, and it makes it difficult to exercise. Then also as you age, sleep is compromised, we know that in seniors, and we actually talked about this in a seat module, showing you some data looking at how sleep changes with age, sleep gets more difficult the older we get. Maybe it's related to physical problems. Maybe it's related to medications. Again, all these things can tie together, right? If you're more likely to be in pain, pain makes it more difficult to sleep. Loss of sleep makes the pain more intense. So all these things work synergistically or additively. So also, of course, as we get older, risks for disease increases and there is all this also can make exercise difficult. So this is a quick snapshot showing the relationship between aging and pain, breaking down different pain types with an older population, taken from a paper which is cited down here at the bottom of the screen, and you can see that 40 percent of older adults talk about musculoskeletal pain, 65 percent osteoarthritic pain in the neck and back, 15, 25 percent report chronic joint pain, and 35 percent report neuropathic pain. So pain definitely increases, the experience of pain increases as we age. This is another figure showing how these things combine in terms of inflammageing. So this combination of inflammation and aging, as we get older, our body shows greater signs of inflammation just as a function of aging. But how does that work? Well, inflammations have all been cognitive decline in mental health. It's involved in body composition and mobility, susceptibility to infections, cancer, cardiovascular disease, and type 2 diabetes. Most of the things that go wrong as we age are the direct or indirect effect of inflammation. In some ways, aging is characterized by a chronic inflammatory state which some people referred to as inflammageing. So putting it all together, aging is characterized by chronic inflammatory or chronic inflammation, and it's an addition to its numerous other benefits that we talked about, exercise are also anti-inflammatory over the long term. But the problems that characterize aging make it difficult to exercise, right? So again, if you're more likely to have joint pain and makes a hard exercise when you're older, if you're more likely to have muscle atrophy or loss of bone density, it makes it more difficult to exercise. On the other hand, exercise is super important for maintaining that muscle density and that bone density, and the same thing with sleep, right? So again, where situation that all these things get worse as we age, and makes it more difficult to exercise. On the other hand, it makes even more important that we do exercise as we age. So how does cannabis use fit into this? This is an interesting figure here, I'm looking at cannabis use over different years, and how the views have changed in older adults. So this is looking at adults over the age of 65 in the US between 2002 and 2014, and this is data from the National Survey on Drug Use and Health. You can see here is that the views have definitely changed. They're relatively stable from 2002 to 2008, and then we see from 2008 really all the way to 2014, and wish we had more data to show here for 2015, '16, '17. But the reality is the views have been changing in terms of cannabis use. Again, this graph basically suggest that views on marijuana use have become more positive over the years in this older adult population, and of course, we also know that this demographic has also been increasing the most in terms of their use of cannabis compared to other demographic groups. So in summary, we're living to older ages. This is much more true now than ever before. The challenge is to make sure that we are adding quality of life in addition to quantity of life. Inflammageing, so inflammation gets worse as we age, it's called inflammageing, and its associated conditions, that is, changes in cognition, increases in disease, and pain, difficulty sleeping make it difficult to do things that we help us to stay healthy. Older adults may be turning to cannabis as a way to feel better and get healthier. This is a working hypothesis here, and certainly we're trying to collect some data on this question. But assuming for a second that might be the case, why would cannabis help? Is actually working? Those are two super important questions for future research. In the next two lectures, we're going to consider some of the different pieces of evidence that lead to these hypotheses and talk about this some more.
