The Brain and Ageing

Neurologica blog is a blog site maintained by the producer of my favorite podcast, "The Skeptic's Guide to the Universe." I read a lot of articles on their site, and one article last week just happened to relate to ageing.

Dr. Novella writes a brief introduction about what happens to the brain as we age, focusing on Alzheimer's Disease. This is essentially a degenerative disease in the brain that can happen in older people, and causes dementia. (Any disorder that impairs cognition and/or memory) Later on he talks about new, potential breakthroughs, in detecting Alzheimer's Disease without having to perform a biopsy.

This article reveals an interesting perspective on the prospect of extending the human lifespan. Even if we can develop techniques to slow the body's ageing, there are still numerous problems with the brain and ageing. Living to 200 years won't do us any good if we're only mentally cognizant for a little over half the time.

Financial Aging

I calculated my retirement income with several assumptions in mind, as in wouldn’t be very accurate since most of my summer-earned income goes to paying for college. I used my age as 28, which will be when I complete graduate school. I put my estimated yearly income at $100,000. This is fairly average for a physicist post-grad school, if not below average. It all depends on the job, though. I put my future spouse down for $80,000 as post psychology grad school. Once again, the lower end of the average.

To compensate for inflation and a cushy retirement for retiring at age 75 until 90 (wishful thinking I know), I would need to save 4.6% of my yearly income. I extended the retirement age because I’d like to keep teaching into my old age instead of retiring early to give me something to do, as well as ease off the burden of having enough money to retire. The total I would need to save is $5,512,071; which is quite a lot, even with inflation added. Obviously investing heavily at a young age is a good idea.

Centenarian Study

Content:
The information in the Centenarian video was like seeing things that we’ve learned in class applied to the real world. The study went deep into the lives of the Centenarians and uncovered a lot about their lifestyle, diet, and relations.

Self:
I found the information found on diets of Centenarians very interesting. The oldest Centenarians had typical Southern diets, consisting of lots of vegetable and fried chicken. This could be incidental, but diet does play a huge role in one’s health.

World:
I think people who would benefit from this video series the most would be people afraid of old age, or see centenarians through a stereotyped view as incompetent or worthless. Seeing an in-depth, comprehensive analysis of their lives is definitely something that can remove past judgments in favor of a more positive outlook.

Practice:
I can use the information that I learned from the Centenarian videos to get a better outlook on growing old. Living past one hundred is an extreme example, at least for now, but it is interesting to see what people did and how they were doing in this age group.

Life Expectancy

According to the Living to 100 Life Expectancy Calculator (http://calculator.livingto100.com/calculator) my approximate expiration is at 87 years. I think, as of right now, this is an accurate estimate, although I was expecting low eighties.

However, these calculators are only useful assuming a static timeline, as in nothing is changing. It's likely that when I turn 21 I will have a few drinks a week, as opposed to now where I have none. It also doesn't predict future technologies which may increase my lifespan.

I thought that all of the questions were pretty fair, except the ones that can change drastically over time (drinking and dietary habits). I expected I will live until sometime in my eighties, so the calculator wasn't too big a surprise; unless Aubrey de Gray has his way and I live until my late four hundreds.

As for alcohol shortening life expectancy, which is what I assume this calculator took into effect, I have this study to show it. It's summed up nicely in this WebMD article.

http://www.webmd.com/food-recipes/news/20100824/moderate-drinking-may-prolong-life

Essentially people who drank a moderate amount of alcohol (a serving or two a day) have a greater life expectancy than those who drink heavily OR those who abstain entirely.

Here is the meta-analysis being referred to:

http://www.acsh.org/docLib/20040401_Moderate_Alcohol1993.pdf

What Processes Cause Aging?

The reading thoroughly discussed two consequences of the metabolic process and their relation to aging, simply put: “rusting,” and “browning.”

Rusting is essentially the buildup of damaging products, called free radicals, caused by oxidation. Whenever I used to hear about this theory, it was used as complete scientific evidence that free radicals will kill you. Companies then use this as a basis to sell anti-aging cures, usually in the form of “all-natural” herbs and remedies. It was really interesting to read about the theory coming from a credible source that cited experiments and empirical evidence. The oxidation theory was viewed as a doorway into understanding aging, like one more piece of the puzzle.

The buildup of glucose causing browning in our bodies (exactly what happens to meat when cooked) was totally new to me, and relates to aging much in the same way that the oxidation theory does. That is, that the buildup of free radicals causes damage to our cells and collagen. I thought this was really cool and it lends support to the idea that metabolism; the process we go through to live, also causes us to age.

Why Do We Age?

There are many different theories as to why we age. In truth, it is a complicated process. There isn’t one theory out there that can adequately explain all the factors. Indeed, even logical sounding theories have been proven false, or simply don’t apply.

The first theory I’d like to talk at is the ‘Good of the Species’ theory. It states that aging occurs as a renewal, to get rid of the elderly in a population to make room for the new generation. The theory explains it as a group advantage. Although not really getting into the technical processes behind aging, this theory backs itself up using evolution. However, evolution dictates that advantageous characteristics of individuals will be carried on through their genes. This runs contradictory to a group advantage. Assuming this, we would expect to see an increase in longevity in individuals: the increased life span of the species creating more genes of their type, since they would be able to reproduce more often. The genes controlling for an increase in longevity would prosper. This would be worse for the group, but favors the individual, which is what evolution is all about: survival of the fittest. The ‘Good of the Species’ theory just doesn’t hold up.

The ‘Rate of Living’ theory explains aging like a ticking clock. There are a lot of different explanations within the theory. Some pin aging on metabolism, some on cellular division, and even some outdated versions on number of breathes! The theory speculates that a higher metabolic activity accelerates aging. There is a lot of support for this as a general rule, although there is still a lot of variation. It’s based around the idea that all organisms are born with a certain amount of energy. Larger organisms, or more active ones, will use it up faster and therefore age quicker. A kind of sub-theory of this is the idea that the eventual inability for cells to reproduce will eventually cause aging. Once again, we can find examples for and against. The strongest proof runs counter to the theory of a cell division limit. As we age, the muscles in our body become weaker. This isn’t due to the cell’s inability to reproduce, but rather the cells losing their ability to contract.  Though The ‘Rate of Living’ theory cannot explain the entire process, it does help us understand many factors.

A theory that I believe holds up relatively well, and also accurately describes biological and mathematical models, is the ‘Reliability’ theory of aging. What it essentially says is that system failure causes an increased mortality rate in organisms, based on flaws and defects.

-A site which explains the metabolic factor in the ‘Rate of Living’ theory: http://courses.cit.cornell.edu/psych527_nbb420-720/student2005/nrb26/Page_2.htm

-Paper written on the Reliability Theory, by Leonid and Natalia Gavrilova: http://longevity-science.org/JTB-01.pdf

-I also used Wikipedia as a basis for my research, as well as the assigned reading “Why We Age.”

What is Healthy Aging?

Age occurs in all of us, since the beginning of our lives, all the time. Only later on do we see the negatives of this. Negative factors in aging can include less mental acuteness, increased chance of contracting diseases like cancer, and worse physical shape. (Just to name a few) However, there are plenty of ways to age healthier, and diminish the impact. 

Healthy aging can be defined as one's efforts, both mental and physical, to stay sharp and in shape to maintain an ideal way of life. Aging is a slow process, not a disease. Through determination and work, we can reduce many of its effects.

Examples of healthy aging practices:

-Regular physical exercise (the amount and type depends heavily on the individual) 

-A nutritious, balanced diet

-Working your brain (such as word puzzles, reading, taking classes)

-Visiting your doctor and being aware of potential illnesses that could affect yo

Examples of non-healthy aging practices, essentially the opposite:

-Laziness, long periods of inactivity

-A poor diet filled with 'junk food,' or restrictive diets