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25Jul/123

Uni update: year 2

So, around this time last year, I wrote a blog post on all the courses I'd taken during my first year. I figured I should keep you posted and do the same thing again this year.

As I explained last year, our school year is divided into six periods, three per semester. First period started off pretty heavy this year, with three different subjects. General Toxicology, where we learned about various toxins and how they affect different parts of the body; Integrated Human Physiology, which was essentially a continuation of last year's Principles of Human Physiology; and Introduction to Epidemiology and Public Health, which had far less to do with disease epidemics than you might think. It was mostly about the trends in diseases/conditions like diabetes and obesity, and involved quite a bit of statistics, history of epidemiological research etc. The second period has both the best and worst class of the year: there was Nutrition Behaviour, which I found really interesting because the behavioural/sensory aspects of nutrition are pretty much what I eventually want to focus on. And then there was Advanced Statistics for Nutritionists, which pretty much sucked. I had Statistics I and II last year and they turned out to be nowhere near as bad as I'd expected... and then Advanced Statistics suddenly delves into these rather complex statistical models and stuff, and I'm still not quite sure how I managed to scrape a pass in that class, because I was basically certain I had to have failed that exam. :P To finish off the semester, we had Pharmacology and Nutrition, which explained the workings of various types of medications and their interactions with food substances.

The second semester started off with the first (and only) subject that we got to choose for ourselves, rather than having a prescribed compulsory class schedule. Well, it still wasn't exactly a free choice, as there were only two subject to pick from. One was Practical Biochemistry or something like that and came with about 46829 lab sessions, so I went with Applied Data Analysis instead. I was a little worried about picking another statistics class after nearly failing my last one, but it was actually quite doable. We didn't so much learn any new stuff... it was basically a tutorial on how to apply all the different statistical methods in practice, that we'd learned in theory during the previous three courses. Quite useful and not even all that hard. Fourth period had Research Methodology I, where we were taught about various forms of nutrition research, standardised measurement methods etc., and Cell Biology and Health, which was basically the sequel to last year's Cell Biology I course.

Finally, we had Research Methodology II and Food & Health. In Methodology II, among other things, we measured our cholesterol levels in our own blood samples, which was pretty neat. Food & Health was probably the most intensive course I've had all year; we had to come up with a new and improved version of any food product, produce it ourselves, run a chemical analysis to establish the macronutrient composition, have it tested by a sensory panel, etc., and write a 50-70 page report on our findings, supported by literature. In fact, for the first time in my entire two-year study programme so far, this course didn't even have an exam; you simply get graded on said report. This also means I don't yet know my grade for this course; we had to edit two sections of our report after handing in the initial version (only 4 out of 19 reports immediately got accepted with no corrections necessary), so I'm not really expecting to receive a grade until the end of the summer holidays/start of the new semester.

That being said, here's my grades for all of the other courses:

Not as great as my first year marks, but still a 72% GPA for this year (77% overall), and I still passed all my exams on the first try. And now I get to relax for about five more weeks before the new year starts ;)

Filed under: Uni 3 Comments
11Apr/120

Phytoestrogens and cancer

I recently had to write a short essay for my Cell Biology & Health class, where we could pick any subject as long as it was related to breast cancer. Now, about a year ago I stopped drinking milk (dairy) after hearing some scare stories about growth hormones, and switched to soy milk instead. Then, a few months later, I heard additional scare stories about soy products causing cancer and being worse for you than actual dairy, and abruptly switched back. :P (Though to organic milk from grass-fed cows only.)

So, when this topic came up, I figured it would be a good time to actually check out the link between the phytoestrogens in soy and (breast) cancer for myself. I guess some of you might be interested in reading what I found, so I decided to post my essay here as well.

 

The role of phytoestrogens in the development of breast cancer

Phytoestrogens

Asian countries have a very low incidence of cancer (including breast cancer) compared to Western countries. (1) Is this simply because they have a healthy diet in general – their diet is typically low in fat and red meat, and high in fish – or because they consume a lot of soy products, which are especially rich in phytoestrogens?

Phytoestrogens are plants substances that comprise three main classes: the isoflavones, coumestans and lignans. The isoflavones are structurally similar to endogenous human estrogen, and can bind to the estrogen receptor. (2, 3)

Estrogen and the estrogen receptor (ER)

The estrogen receptors regulate transcription of target genes. Estrogen (or another ligand which is structurally similar) binds to the estrogen receptor; the estrogen-ER complex then binds to estrogen response elements (ERE), regulatory sequences in the target genes. In this way, the binding of estrogen to estrogen receptors stimulates the proliferation of cells in the mammary tissue. This increased proliferation increases the risk of breast tumor development. In addition, the metabolism of estrogen may lead to genotoxic by-products, which will also increase cancer risk. (4)

The effect of phytoestrogens: proposed mechanism of action

Because they are structurally similar to estrogen, isoflavones can bind to the estrogen receptor. They have a lower affinity for the estrogen receptor than endogenous estrogen, but can still compete with it if the phytoestrogens are present in sufficient quantities. Unbound phytoestrogen may be much more abundant in the bloodstream than estrogen, since it has a much lower affinity for binding to serum proteins like albumin. If a lot of phytoestrogen is able to displace estrogen in this way, the effect of estrogen will be much less potent, since phytoestrogen exerts a much weaker effect upon binding to the estrogen receptor. (2, 5)

There are two subtypes of estrogen receptors: ERα and ERβ. The ERβ receptor may have a protective role against breast cancer, by negatively regulating cell proliferation. Each receptor subtype has an affinity for particular ligands, and phytoestrogens show a stronger affinity for the ERβ receptor. (5)

Another way in which phytoestrogens may decrease breast cancer risk is through the estrogen biosynthesis pathway. Some of the key enzymes for estradiol biosynthesis – estradiol being the predominant estrogen in premenopausal women – are aromatase, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase. A bioassay has shown that various isoflavonols and flavonoid structures are aromatase, 3β-hydroxysteroid dehydrogenase and/or 17β-hydroxysteroid dehydrogenase inhibitors, thus decreasing estradiol synthesis. Lower levels of estradiol may also reduce the risk of developing breast cancer. (6)

Evidence supporting the effects of phytoestrogens

Most of the research on the effect of phytoestrogens in humans is observational rather than experimental, which makes it more difficult to establish a causative effect. Experimental studies using soy isoflavones on rodents did not show a significant protective effect against breast tumors. However, if the phytoestrogens were given neonatally or at least pre-puberty, they did have a significant protective effect against the development of breast cancer later in the animals’ life. (1)

In one study, rats were treated with genistein, an isoflavonic phytoestrogen. They developed their mammary glands faster and earlier on than controls, but at a later age their mammary tissue was actually less proliferative. (7) This can be compared to the effect of an early first pregnancy, which is a protective factor against breast cancer. (8) The rats showed increased levels of transforming growth factor alpha (TGF-α) and epidermal growth factor (EGF) at 21 days, but lower levels of TGF-α and EGF at 50 days. These growth factors have a proliferative effect, and upregulated TGF-α and EGF may play a role in the development of cancer. (7)

Most interventions with phytoestrogens or soy products in humans fail to show a protective effect of phytoestrogens against breast cancer. This could be due to the fact that the subjects are almost always adult women who have already gone through puberty. It may be that phytoestrogen intake is only effective at high doses, consumed at young ages (i.e. before the girl reaches puberty). (1, 2) Some studies have shown a decrease in genotoxic metabolites like estradiol, FSH and LH after intervention with soy in women, offering a possible protective effect against breast cancer. (2)

Several epidemiological studies show an association between soy and/or phytoestrogen intake and low breast cancer risk, but generally fail to conclude (with any significance) that phytoestrogens have a protective effect against breast cancer. (2) For instance, some studies on humans show that breast cancer patients have low levels of phytoestrogens, while people with high levels of phytoestrogens are usually in low breast cancer risk groups, but this is not enough information to draw a definitive conclusion on the effect of phytoestrogens. (1) It is also a problem that these studies are observational, so researchers are limited to studying existing populations and their intakes. Among the Asian population phytoestrogen consumption is homogenously high, while it is rather low among the Western population, making it more difficult to establish any significant effect. (2, 3)

Possible adverse effects of phytoestrogens

If a fetus is exposed to high levels of endogenous estrogen prenatally, this increases their risk of developing breast cancer later in life. In rats, a similar effect was observed when administering high levels of phytoestrogen prenatally. However, there has not been any evidence that phytoestrogens have the same effect in humans. (1) Epidemiological studies have not shown any evidence for increased breast cancer risk in populations that consume high levels of phytoestrogens. (2)

Conclusion

There is insufficient evidence to conclude that consumption of phytoestrogens has a protective effect against breast cancer in humans. More experimental research may be necessary to establish a causal association, for instance to test the effect of high phytoestrogen intake in young (pre-puberty) women.

On the other hand, no adverse effects of phytoestrogen consumption on breast cancer development have been reported. Women may safely continue to eat soy products and other foods containing phytoestrogens.

References

  1. H. Adlercreutz: Phytoestrogens and breastcancer. The Journal of Steroid Biochemistry and Molecular Biology, 2002, vol 83(1-5), p 113–118.
    http://www.sciencedirect.com/science/article/pii/S096007600200273X
  2. P.H.M. Peeters, L. Keinan-Boker, Y.T. van der Schouw, and D.E. Grobbee: Phytoestrogens and breast cancer risk. Breast Cancer Research and Treatment, 2003, vol 77, p171–183.
    http://www.springerlink.com/content/g3g4u2j23157n842/
  3. L. Keinan-Boker, Y.T. van Der Schouw, D.E. Grobbee, and P.H.M. Peeters: Dietary phytoestrogens and breast cancer risk. Am J Clin Nutr, 2004, vol 79(2), p282-288.
    http://www.ajcn.org/content/79/2/282.short
  4. B.J. Deroo and K.S. Korach: Estrogen receptors and human disease. J Clin Invest, 2006, vol 116(3), p561–570.
    http://www.jci.org/articles/view/27987
  5. D. M. Harris, E. Besselink, S. M. Henning, V. L. W. Go and D. Heber: Phytoestrogens Induce Differential Estrogen Receptor Alpha- or Beta-Mediated Responses in Transfected Breast Cancer Cells. Exp Biol Med, 2005, vol 230(8), p558-568.
    http://ebm.rsmjournals.com/content/230/8/558.short
  6. J. Le Baila, Y. Champavierb, A. Chuliab, G. Habrioux: Effects of phytoestrogens on aromatase, 3β and 17β-hydroxysteroid dehydrogenase activities and human breastcancer cells. Life Sciences, 2000, vol 66(14), p 1281–1291.
    http://www.sciencedirect.com/science/article/pii/S0024320500004355
  7. N.M. Brown, J. Wang, M.S. Cotroneo, Y. Zhao, and C.A. Lamartiniere: Prepubertal genistein treatment modulates TGF-a, EGF and EGF-receptor mRNAs and proteins in the rat mammary gland. Molecular and Cellular Endocrinology, 1998, vol 144(1-2), p149–165.
    http://www.sciencedirect.com/science/article/pii/S0303720798001063
  8. K. Britt, A. Ashworth and M. Smalley: Pregnancy and the risk of breast cancer. Endocrine-Related Cancer, 2007, vol 14, p907-933.
    http://erc.endocrinology-journals.org/content/14/4/907.full

 

ETA: Wow, the WordPress font and spacing is tiny. This is nearly three pages in my original document... it looks so short here! Haha. Also, if you're a student and you've happened to stumble upon this blog post through a Google search or something, you probably want to look up those sources for yourself, instead of directly quoting another undergraduate's essay which is subject to error. I've even included handy links and everything! ;)

Filed under: Uni, Writings No Comments
9Feb/121

10 in 2012 goals

I know, I know, this is ridiculously late to be doing a "new year's resolutions" type post. But I kinda wanted to do 12 goals, to stick with the theme after last year's "11 in 2011", and I only came up with about 6 of them initially. :P I've been slowly expanding the list since, but I'm still only at 10 of them, and I really can't think of any more at the moment, so I figured I might as well post them now. So, here they are; some have been copied from last year's list, while others are all new.

  • Reduce weight to 62kg or less
    • Seeing as how I failed miserably at this last year, and am therefore still at least 20 pounds heavier than I want to be, it seemed like a good idea to keep this one on the list.
  • Do a workout at least 100 times
    • Rather than specifying various types of workouts like last year, I figured I'd just add "roughly 2 workouts of any kind per week" to the list. :P
  • Write at least 25 blog posts
    • I actually made this goal, last year, but that doesn't mean I suddenly want to stop blogging now! Haha.
  • Read at least 6 books (not counting school textbooks)
    • I only read a single book all last year, which is kind of pathetic. This year, I definitely want to free up more time for reading. (In fact, at the time of writing, I've already finished 2 books! And it's only February. So I'm quite well on track for this one.)
  • Finish at least 3 video games
    • I have this habit of buying/starting video games and then never actually finishing them. I own dozens of games and I've probably completed less than half of them! This is another thing I want to devote some more free/fun time to.
  • Travel outside of the country at least once
    • There are still a ton of places I haven't seen yet! I actually really really want to try and go to California this summer, but as that's kinda ridiculously expensive I have no idea if I'll end up getting there, yet. Failing that, there's lots of other fun places I'm considering: Scotland, Rome, Berlin, etc.
  • Complete Danish language course
    • So I kinda have my mind set on this Master's degree that partially takes place in Denmark. That's still a year and a half away, but if I do end up going there, I'd like to have at least a conversational grip on their language. If I don't, well, speaking another language never hurts, right? So I asked for, and received, a Danish language course for Christmas. I want to try and finish it by the end of the year.
  • Pass second year classes
    • Well. I don't think I really need to explain how this would be a good thing, right?
  • Pick third year classes
    • Up until now, I've never had to pick out my own class schedule. This probably sounds rather bizarre to the Americans reading this, seeing as you guys can go undeclared for years and just select "random" classes if you want to, but over here you actually declare your major before you even start at college/university. Then, I suppose the exact amount of compulsory classes kinda varies per major, but in my case it meant my entire first two years of classes were automatically selected. There's about 22 courses, which are all given at specific periods and time slots, so basically your whole schedule for those two years is already fixed. The only "choice" you have is to not enroll in a course, but that's fairly pointless since these are all compulsory subjects, and you'll just have to take it the next year before you can move on in your education.
      So all in all, it can be kind of restricting (you basically have no choice to drop classes that you find terribly uninteresting or are especially bad at), but it's also very easy, since you don't have to give any thought to what courses you want to pick. And then suddenly in the third year, boom, no more compulsory classes (at all!), just pick 60 credits worth of courses of your own choosing.  Again, this probably seems perfectly normal to at least half the people reading this, but to me, right now, it kind of feels like a daunting task to pick the "right" things. So I figured I might as well put it up here on the goals list, even though there's not really any way I won't have completed this one by the end of the year. :P
  • Actually keep track of goal progress
    • Yeah, so remember how I tried to write a blog post on how I'd fared regarding my 2011 goals and it was nearly impossible? There's not much of a point in formulating your goals in such a way that they're easily measurable, and then not actually keeping track of them. So this year, one of my goals is to keep track of my goals. How much more meta can you get? :P
Filed under: Personal life, Uni 1 Comment
22Jul/113

My first year of uni: a summary

I think I promised a uni update once my final grades for the year came in. Well, they did, almost a week ago, at this point. I just realized it's already been 9 days since I last blogged, not "just a few", as it felt like. Similarly, I can't believe I'm already three weeks into my summer holidays! Where did the time go? I'm just truly starting to feel like "the holidays have begun" rather than "ooh I think the school year's about over"; feel like I've had a week, maybe two off, by this point, and it's really been three weeks already! Craaazyyyy.

I was going to do tons of stuff during this vacation: do a completely revised version of the RoA script, create tons of cool drawings, read books, play games (I still have to finish Portal 2), maybe even write a little. Now it's been three weeks, and all I've done is hang out with friends a bit, watch tons of TV (complete rewatch of WhiCo 1x01-3x07, within a month of watching them all for the first time: done) and read tons of fanfic instead of actual books. Apparently, now that I don't have school work to procrastinate on, I'm actually putting off normal procrastinatory activities like blogging instead. Whoops.

So. An overview of all my classes. Our school year is divided into six periods; basically, the first semester has two long sections with 2-3 courses each, followed by a short section with only a single course, and then this is reversed for the second semester, which has a short one-course period followed by another two long bits with 2-3 courses each.

First period, I had General Chemistry (which is pretty much exactly what the name suggests), Bio-organic Chemistry (more of a focus on subjects related to our major, like sugar compounds etc.) and Nutrition I, which was mostly a broad series of introductory lectures, that our subsequent courses over these three years will tie into. Second period was Cell Biology, where we learned about the characteristics and interactions of all the different cellular components, and Nutrition II, which featured all the important macro- and micronutrients. I could go into detail, but why bother, when I might as well link you to the 34-page summary (PDF) I wrote at the time? ;) To finish off the first semester, we had Human Physiology, where I got to cut open a little piglet. Well, and learn all about organs and arteries and stuff, but really, the pig-dissecting bit is what stays with you the most. :P

We started our second semester with Social Psychology, which I thought was a really interesting course. (I'm not sure if I've mentioned this on the blog before, but I'm seriously considering doing a minor in consumer psychology in my third year.) It was also lectures-only, which was a nice change of pace from having tons of labs and tutorials to go with each course, as was pretty much the first semester-standard. Fifth period was another three-course one: Statistics I, Statistics II and Metabolic Aspects of Nutrition. MAoN was basically "Workings of the Digestive Tract 101", while Statistics was mathy hell. Actually, it really wasn't. That's what I was expecting it to be, considering Math was my worst high school subject and we'd never even covered that much statistics related stuff to begin with... but apparently, that's the type of Math I'm actually halfway decent at, considering I barely studied for those exams and pretty much aced them. Finally, this last period we had Nutrition III, which I already wrote plenty about in another blog post, and Microbiology, which was basically a continuation of Cell Biology, plus studying a whole bunch of different micro-organisms, especially those relevant to food spoilage and such.

I think what you're all really waiting for is the promised grade overview, right? So, without further ado, in reverse chronological order:

I managed to pass all my exams on the first go, and the list above comes down to a 81% GPA. I think that means I'm on track for cum laude graduation, should I manage to keep this up for another couple years. Whelp. That's something I never quite expected when I started this whole "back to uni" endeavour about a year ago. O.o

Filed under: Uni 3 Comments
27Jun/112

10,000 words on chocolate sprinkles

Okay, I lied. It's actually only 9694 words.

I can't believe the school year is already nearly over! In just two days I have my final exams (this is me pretending I already know all the material super well, hence having time to write blog posts. Of course I'm not blogging to procrastinate on studying. Pshah. What a silly notion) and then, vacayyy...! :D This final period, I'm taking Nutrition III: Knowledge of Foods, and Microbiology & Biochemistry. Microbiology basically consisted of a ton of lectures and labs that I'll not bore you with. (Though, did you know that the botulinum toxin produced by Clostridium botulinum is about a gazillion times more deadly than, say, cyanide, and yes, this is what people voluntarily get injected with to get rid of wrinkles?)

Nutrition III was a lot more fun, though. We had relatively few lectures this period, and instead mostly did our own research and experiments. Each group (2-3 students) got assigned a certain food product (in our case -- you guessed it -- chocolate sprinkles), and you had to do three kinds of analysis on it: a sensory test where you had to find a bunch of test subjects and make them taste test/analyse it, a nutrient analysis (lab work), and researching the health status of the product & any claims on its packaging (literature research). All of this had to be reported in a fifteen-page minimum article of the sort you might find in a scientific journal. In addition to that, you also had to write a simpler two-page article aimed at the average consumer, of the sort you might find in a magazine like De Consumentengids, based on your own research.

It was quite a bit of work, obviously, but also actually quite a lot of fun! I almost felt like we were writing a sort of mini-thesis to finish off of first year of studies. In case I've managed to pique your curiosity, feel free to read the whole thing here. Oh, it's in Dutch, though. It had to be, for the assignment, and I figure probably at least half the people who read this blog understand Dutch anyway, so... I'm not really about to translate the whole 24-page thing into English for you all. Sorry :( Besides, the conclusion can be summed up in a couple words anyway: chocolate sprinkles contain lots of fat and sugar and are therefore not really all that good for you, but people love them anyway.  There, I just spared you about 9673 words. ;)

Once my grades for these final exams come in (should be around mid-July somewhere), I'll do another post where I'll tell you a little more about all the different courses I took this first year, and the grades I got for them. And to prevent the embarrassment of having to show you two very low final grades, I better get back to studying right around now. Yeah.

ETA: I just ran the whole PDF through Google Translate to see if that could provide a solution for you non-Dutch folk. Nope, it doesn't, but some of these lines are outright hilarious. My favourites...

  • "Chocolate sprinkles: almost every Dutch person has a suit in the closet." Now there's a non-sequitur if there even was one. It's perfectly grammatically and semantically correct, and yet, makes absolutely no sense. The problem arises from the fact that the Dutch word for "suit" and "package" is the same, as well as "closet" and "cupboard". So obviously, this was supposed to read "chocolate sprinkles: almost every Dutch person has a package in their cupboard." So close, Google, and yet...
  • "If you have fully completed the questionnaire, consult your manual to stabbing." ...I was completely unaware we'd handed out such violent instructions to our test subjects. This originally read, "if you have fully completed the questionnaire, please raise your hand." Consult your stabbing manual? Wtf I don't even :O
Filed under: Personal life, Uni 2 Comments