Thirsty Thursday: Cow’s Milk and Juvenile Diabetes Link

Overlooking some one’s Scientific American on the plane home last night I saw the heading “A Milk-Diabetes Connection” which brought back memories of evangelical vegans arguing that milk was bad for you and lead to the development of diabetes.  Continue reading

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Science Debate 2008

We need a president who moves science back into the White House. Today we do not have a presidential science adviser and there is no office of science in the White House (link).

Yesterday should have been the day of Science debate 2008 if only the candidates had agreed to participate. I am disappointed that they did not but also not surprised. Before becoming politicians Hilary and Barack were lawyers, and John was professional military. What do they know about science and technology? Nothing. Unfortunately by turning down the chance to debate and discuss science suggests that they do not have science advisors on their campaign staff either. So is this why they don’t want to debate the future of science in the USA?

The editorial quoted at the top of this post is very informative – kind of not surprising why so many scientists fail at their first academic position [takes a bow] if the average age of getting a grant is 42 years. So one or two brilliant people get them earlier and the rest of us…I always was a late developer.

Where are our future scientists and engineers coming from?  Can we get them from the US or do we need to import them? From what I’ve seen from some of the science labs in local high schools, it is not surprising that not many graduating high school seniors want to take up science.

It is a shame that the candidates did not debate science and they still need to prove their scientific credentials.

Now there is a second invitation to the candidates to debate science in Oregon on May 2, 9 or 16. Let us hope they attend.

science debate 2008 logo

And I thought I was nerdy…

Some one is knitting topographical surfaces:

Not sure I understand the mathematics involved, but these are very interesting. How do you think you wear it? Visit Dr Sarah-Marie Belcastro for information about her work and other information about mathematical knitting. There is even a book – hmm, now, I know what I want for my birthday. I think I’ll have to start with a basic mobius strip. I’ve made one the easy way – knitting a long strip and grafting together, but not this way where the mobius knit is part of the knitting.

[Hat tip M.O., thanx]

On Being a Grown Up Scientist

I have a couple of big posts coming – they just need to get out of my brain and on to the computer. In the meantime, Janet has a couple of great posts (part 1, part 2) about learning how to be a grown up scientist.

My only thought on this, at the moment, is remembering asking my PhD advisor, who was a great mentor, how he came up with ideas and how would I know that I had good ideas for my own research. I did not get a satisfactory answer and I still have not sorted it out for myself yet.

I also realize that good ideas are not enough, but you also need ideas that can be well presented to funding agents and committees.

Berries and Cancer

Dig those blackberries from last summer. Any excuse to reuse my photos! We all know we should be stuffing our faces with lots of fruits and veggies, but what is the evidence and which ones are the best?

In a recent article (1), Seeram reviewed the evidence that berries prevent cancer. This review was a little frustrating to follow, and I started wondering if it was a rewritten introduction to a grant application. For an article published in the Journal of Ag. and Food Chem., I personally could have done with a better overview. Some of the detail, while may be necessary in a cancer journal, lost me without careful concentration and then I lost myself in the acronyms. You may realize this from the discussion below. To be fair, they did explain quite a bit of the science and the subject knowledge might be all over the place with different researchers studying different berries and cancers.

In the USA, commonly consumed berries include blackberries, black and red raspberries, blueberries, cranberries, and strawberries. The active ingredients in berries includes Vitamins A, C, E and folic acid; calcuim and selenium; phytosterols; and phenolic molecules such as anthocyanins, flavonols and tannins.

So how good are berries at preventing and reversing cancer?

In vitro studies, with cell lines, have shown that berry phenolics in addition to being potent antioxidants, they also:

“[…]exhibit anti-inflammatory properties, are able to induce carcinogen detoxification (phase-II) enzymes, and modulate subcellular signaling pathways of cancer proliferation, apoptosis and tumor angiogenesis […].”

Coo. That sounds good, but as I am not a cancer researcher the details of the reviewed studies were difficult for me to follow. Raspberry, cranberry and lowbush blueberry juices showed the strongest inhibition of cell growth, which is good as we do not want cancer cells to grow. A red raspberry extract treated so it went through conditions that mimicked the digestive system decreased the number of colon cancer cells and protected against DNA damage induced by hydrogen peroxide. Blueberries induced apoptosis (cell death) of cancer cells and may influence prostate cancer cells [I assumed to the good]. Cranberry extracts inhibited the growth of human breast cancer.

Animal studies showed that rats fed berries and fruit juices showed a significant reduction in AOM-induced aberrant crypt foci, which is a leading indicator of colon cancer. AOM is azoxymethane and acts as a carcinogen to trigger colon cancer in rats and mice.

As for human studies:

Increased fruit and vegetable consumption has been associated with the decreased risk of a number of cancers of epithelial origin, including esophageal cancer.

As an aside, I prefer the British spelling for oesophagus, the oe looks more dignified and I do say “oh-sophagus” or “oo-sophagus”

It is hard to know how much bioactives we are consuming. This is partly, as this article reports, because the amount of phytochemicals present in foods is not known and changes dramatically depending on growing conditions. Organic strawberries had a greater effect on human colon and breast tumor cells than conventionally grown strawberries. Organic berries were more effective probably because they contain more secondary metabolites than conventionally grown fruit.In addition:

Studies have shown a high variability in phenolic intake based on variations in individual food preferences. A high daily intake of fruits and vegetables is estimated to provide up to 1 g of phenolics.

Unfortunately, “high daily intake of fruits and vegetables” is not defined in the article.

Even if we know how much of the bioactive compounds we consume, we still do not know how bio-available these phenolics in berries or other fruit.

I find it amusing that articles always end up with a statement which in effect says “more research is needed, I am the best person to do it and I need funding now“. In this article the concluding paragraph goes:

In conclusion, it is strongly recommended that this area of research for berry fruits continue to be explored, as this will lay the foundation for the development of diet-based strategies for the prevention and therapy of self types of human cancers.

My conclusion?

Eat lots of berries, now and forever more. Fortunately, I have lots in my freezer. Yum.


Reference:

(1) Seeram, N.P. (2008). Berry Fruits for Cancer Prevention: Current Status and Future Prospects. Journal of Agricultural and Food Chemistry DOI: 10.1021/jf072504n

ResearchBlogging.org

Eating Broccoli Protects Your Heart

A recent study published online by the Journal of Agriculture and Food Chemistry reports on the role of broccoli as a cardioprotector. Broccoli contains high concentrations of selenium (65 nanograms/g broccoli) and glucosinolates, especially isothicyanate sulforaphane (23.6 micrograms/g broccoli). Both selenium and sulforaphane are shown to protect the heart and the cardiovascular system. Sulforaphane induces the redox regulator protein, thioredoxin, which has a cardioprotective role by reducing oxidative stress.

A clinical study reported that eating fresh broccoli sprouts for a week lowered serum low density lipoprotein levels (LDL is the so-called “bad” cholesterol) and a prospective study in Iowa showed a strong association between broccoli consumption and a lowering of the risk of coronary heart disease.

In the study reported in JAFC, rats were either feed, on top of regular rat chow, a broccoli slurry or water for a month before slaughter. At which time the hearts were isolated, stabilized and then subjected to 30 minutes of total ischemia followed by reperfusion*. Heart function was assessed 10, 30, 60, 90 and 120 mins after ischemia finished.

Hearts from rats fed on broccoli slurry showed faster recovery in left ventricular function and aortic flow. Heart rate was not affected by treatment. In addition, hearts from broccoli-fed rats had a smaller myocardial infarct size and the number of cardiomyocytes which under went cell death (apotosis) was reduced.

Hearts from broccoli-fed rats showed a similar response to ischemia as hearts in which thioredoxin had been upregulated. Broccoli possibly limits heart damage by inducing the production of thioredoxin and related proteins. These proteins play important roles in maintaining the inner cell redox potential. Selenium is required as part of the enzymes glutathione peroxidase and thioredoxin reductase, and sulforaphane up-regulates thioredoxin reductase stimulating thioredoxin production and reducing oxidative damage in the cell.

Reference:

Mukherjee, S.; Gangopadhyay, H.; Das, D. K. Broccoli: A Unique Vegetable That Protects Mammalian Hearts through the Redox Cycling of the Thioredoxin Superfamily. J. Agric. Food Chem. 2007. (online)

Notes:

From what I scan-read in Wikipedia, ischemia occurs by preventing blood flow to the heart and reperfusion is when blood is allowed back. Reperfusion can cause injury because the sudden influx of oxygen and blood can cause oxidative damage and inflammation.

Nutritional Properties of Beer

An interesting abstract just published online by the Journal of Food Science got me thinking. I have not read the whole article as I lack online access to JFS. The researchers at UCDavis:

[…] used surveys to compare beer and wine consumers’ perceptions of alcoholic and nonalcoholic beverages. The consumers ranked 7 beverages based upon perceived healthfulness both before and after they were exposed to nutritional information about the beverages.

While consumers perceived red wine to be the healthiest of seven beverages, the abstract does not answer the question as to whether beer and wine have any nutritional value.

We’ve all read the information that red wine contains compounds that reduce heart disease. This is meant to be part of the French paradox. In Britain, women just after child birth, were recommended to drink stout because it is rich in vitamins and minerals. However, as this Nutritional Facts panel shows, an American pint (16 fl oz) contains a whopping 196 calories.

Guinness Nutritional Facts

One of the problems is that alcohol is a source of calories. Whereas sugar and protein give 4 calories/g and fats give 9 calories/g, alcohol yields 7 calories/g. Unlike carbohydrates, protein and fat, which are used for maintenance and repair, alcohol only goes for energy production.

According to the USDA’s food composition tables, which only has “average” beer light beer or Budweiser, beer does not provide many minerals and it is helpful for B-vitamins especially niacin and folate. Red wine is slightly better providing some iron and a little B6, but 16 fl oz of wine, which I used to compare with beer, contains a whopping 1999 calories.

At least both are fat-free!

Dark beers, like dark chocolate, contain antioxidants, which make have beneficial health effects. These are formed, along with the color and flavor, by my favorite reaction: The Maillard reaction. Unfortunately, I cannot find any detailed nutritional facts for dark beers to prove if they are better nutritionally than lighter beers. Guinness has also been shown to prevent clots from forming. These clots increase the risk of heart disease.

So beer does not really add any nutrition to the diet – it sure tastes good though. Drinking one beer or one glass of wine per day has been shown be good for you. The drink helps you relax and may be sleep better at night. It is over drinking and binge drinking that are the problem.

References

C.A. Wright, C.M. Bruhn, H. Heymann, C.W. Bamforth. Beer and Wine Consumers’ Perceptions of the Nutritional Value of Alcoholic and Nonalcoholic Beverages,Journal of Food Science (OnlineEarly Articles).doi:10.1111/j.1750-3841.2007.00606.x

beer.about.com

Guinness at Wikipedia

Books: Your Brain on Music

I am reading lots of books about music at the moment. It is becoming a bit of an obsession. I read Eric Clapton’s autobio [bleuh] and followed that up with Bob Dylan’s [wow]. I might review them in the future and explain my asides. For now I am reading Oliver Sack‘s Musicophilia and last month I read This is your brain on Music by Daniel J. Levitin. There is too much information in this book to write just one post about it. So this is my first. Do not hold your breath for the second. Just in case you have not noticed, science posts are sporadic around here.

The major elements that Levitin considers to make up music are pitch, timbre, key, harmony, loudness, rhythm, meter and tempo.

A discrete musical sound is usually called a tone. Tone and note typically refer to the same thing unless you are a scientist or musician when “note” refers to the thing on a score of music.

Pitch is the primary way that music can convey emotions – a single high note can trigger excitement and a single low note may trigger sadness. Different instruments have different ranges in pitch available to them. For example, the piano keys range from 27.0 hertz as its lowest note to 4186 htz at the high end. These images show the ranges for different instruments and the human voice.

 

musical ranges

another musical range image

Arranging pitches in particular ways leads to the formation of scales and these also can effect our moods. Major scales are happy and triumphant and minor scales are sad or defeated. Key is related to the hierarchy of importance that exists between pitches within a musical piece and harmony is the relationship between pitches being played at the same time.

The most important feature about music is timbre as it is the principal feature that separates the voices of the different instruments. Timbre is caused by presence of the overtones, which in turn are influenced by the material making up the instrument. For example, wood is less dense than metal so gives lighter overtones. I was always proud of the fact that I could do this as a child – I was especially delighted because I could tell an oboe from a clarinet, apparently difficult instruments to tell apart. Timbre also allows us to recognize the voice of a friend from that of some one unknown.

 

Loudness is purely a psychological construct that relates to the physical amplitude of a tone. Loudness is partly the volume and also how the dynamics change within a musical piece. Brahms, who I am singing at the moment, deliberately changes the dynamics from loud (forte) to soft (piano) from note to note to emphasize his point. He’ll build up a crescendo to forte and the next note is sung piano. Beethoven is another composer who uses contrasting dynamics in a similar way.

Rhythm refers to the durations of a series of notes and to the way they are grouped together (duplets, triplets). Tempo is the overall speed of a piece of music and meter is created by our brains by extracting information from rhythm and loudness cues, refering to ways in which tones are grouped with one another across time. For example, waltzes have meters in three and a march has a meter of either two or four.

Introduction to music and neuroscience to follow.