Factors affecting food absorption and digestion

As food plays a big part of my life, I often wonder about the process it goes through in my body. It would be cool to find out about what affects absorption of nutrients in the body from foods. A couple of factors I thought would be relevant is speed of eating, dispersion and density of eating and mixtures of different food types. Of course it is possible that these would not affect nutrient absorption but if they are they might be important in advising those wanting to improve their diets or tailor them to their needs.
An idea of investigating these would be to use a radioactive tracer built into certain food types to measure their absorption with varying factors. A radioactive material with 2 days or less half life should be used and gamma radiation to minimise ionisation damage and to maximise ease of detection. Obviously the same people will need to be used for different conditions as there are so many extraneous variables. Percentage change of absorption should be used as the presented data. My hypothesis would be that absorption would increase with an increase or dispersion of meal times and variety of food and with a decrease in speed and density of eating.

Pollution and noses

These are two completely unrelated topics today, but who says anything needs to associate.
Why is our nose red when it is cold?
This question is asked because I had learnt that when we are cold the body's response is to restrict blood to the extremities, nose included, which I assumed would result in a paler colour. Apparently, it s not so simple.The body will periodically dilate the constricted vessels to allow a brief burst of blood to flow into the area and then constrict the vessels again. This burst of blood causes the nose to turn red.


More people die as a result of air pollution than either alcoholism and obesity in Wandsworth, according to the Wandsworth Environment Forum. There are extremely high levels of Nitrogen oxide which damages lung tissue and can reduce lung function in those who are vulnerable, for example children and those with asthma. This is shocking becuse the risks of alcohol and obesity are widely publicised and air pollution dangers get little publicity. Perhaps there should be more attention on the personal risks of pollution which may help pursuade people to reduce their driving. The worrying thing is that it is the buses, which are always billed as the eco friendly vehicles, which, by burning diesel are contributing greatly to the nitrogen oxide. 

It is worth baring in mind though that this is only data from Wandsworth and it is always difficult to establish fully causal relationships in life because we cannot rule out different factors. 

Should smokers be allowed free NHS treatment?

There has been question about whether overweight and smoking individuals should be withheld treatment. Even though it is self inflicted, the NHS is for public health. It would be immoral and unfair to deny individuals who live in this country treatment. The NHS professionals are taught to be non-judgemental and the policies of the NHS should follow suit. The NHS should care for, not punish, sick people, after all overweight people and smokers have a far higher incidence of illness.

An aspirin a day keeps the cancer away

Aspirin, originally used as a painkiller and to combat fever, has other, perhaps more useful, uses. Daily low doses of the drug have been known to help prevent coronary heart disease, as it interferes with the clotting action. A series of papers in the lancet have also now found that aspirin can prevent the spread of cancer and after five years of taking cancer there was a 30-40% reduction in deaths from cancer.
But it is not an easy solution to all of these problems and it would be unwise to introduce a blanket scheme for example for everyone over the age of 45 because of the risks of serious excessive bleeding, especially gastrointestinal which can even cause death. It is also not as effective as Statins in CHD prevention and is no more effective than paracetamol in pain reduction.
Because of this I believe aspirin should be recommended to those in the risk categories for cancer and CHD but only on prescription or after advice from the chemist. This is because the risk of internal bleeding is so severe and after the recent headlines for the benefits of aspirin may cause a surge of people who shouldn't take aspirin putting themselves in danger instead of helping themselves stay in health.

here

http://www.dh.gov.uk/health/files/2012/02/A1-Overview-of-the-Bill.pdf

Cannabis memory effects examined

Cannabis floods the brain with a host of chemicals which lead to changes in mood and memory

Scientists believe they are closer to understanding how taking cannabis disrupts short-term memory.

The Canadian team from Ottawa University narrowed the effect down to a particular type of brain cell called an astrocyte.

Writing in the journal Cell, they said it might be possible to block it in medicines based on cannabis.

A UK researcher said it could reveal more about natural brain chemicals.

Cannabis floods the brain with a host of chemicals which mimic one of its own subtle signalling systems, leading to pronounced changes in mood and memory. Scientists are trying to harness the power of these chemicals, called cannabinoids, in pharmaceuticals aimed at conditions such as multiple sclerosis and chronic pain. The doses of cannabinoid are carefully controlled to avoid the "high" feeling. The work by the Ottawa University researchers may shed light on how one of the best known cannabinoids, THC, acts on the brain.

Memory matters

Their work suggests that, when it comes to affecting memory, THC is acting not, as might be expected, on the brain's neurons, but on a brain cell called an astrocyte.

We may find a way to deal with working memory problems in Alzheimer's.”

They bred mice whose astrocytes could not be affected by THC, and found that their spatial memory was unaffected by the dose. This discovery could help drug companies reduce the risk of unwanted side effects when using THC in their products, they suggested. However, possibly more importantly, it could shed light on the brain's own chemical pathways, the "endocannabinoid" system.

Dr Xia Zhang, one of the researchers, said: "Just about any physiological function you can think of in the body, it's likely at some point endocannabinoids are involved."

Understanding how this system works could lead to ways to make it work better, he suggested. "We may find a way to deal with working memory problems in Alzheimer's," he said.

Prof Heather Ashton, from the University of Newcastle, said that memory problems were an established feature of cannabis use, and understanding the mechanism behind them was "interesting".

She said: "When someone is taking cannabis, in some cases you find that they cannot even remember starting a sentence by the time they reach the end."

But she agreed that the practical benefits of such research might ultimately lie in a better understanding of the body's own endocannabinoid system, rather than the effects of cannabis itself.

Cannabis may actually be useful in helping to understand a lot about our brains. If we study cannabis and

Cannabis acts on astrocytes

A couple of non medical-related questions

These are just 2 questions which I have been wondering recently.


Why does salt melt ice?
Water and ice are at equilibrium at 0°c, adding solute to the system will disrupt this equilibrium. They dissolve into the water and do not pack uniformly into a solid, so the rate of freezing decreases, along with the melting point of ice. Any solute could be used, but salt is used on roads in icy conditions because it is cheap and readily available.


How is coffee decaffeinated?- (My Dad drinks decaf coffee as otherwise he gets heart palpitations)
Coffee is decaffeinated using 2 main methods: Water extraction and supercritical carbon dioxide extraction. Water extraction involves soaking the beans in hot water and passing this over hot charcoal before restoring the flavour by soaking the beans in this water again. Supercritical carbon dioxide involves heating CO_{2 under high pressure, forming a supercritical fluid which is like gas and liquid, when forced through coffee beans this absorbs up to 99% of the caffeine as it is gas-like and can penetrate deeply into the beans. Caffeine extracted using these methods can be used for soft drinks and medicines.}
However caffeine extraction is expensive and loss of some flavour is common. So as an alternative, there is potential to inactivate the gene in tea and coffee plants which codes for the caffeine synthase, which catalyses the synthesis of caffeine. 
Well now I know!

'The immune response to infection

I attended a lecture last night on microorganisms and their effect on our everyday lives. It was very interesting to see the special adaptations that bacteria and viruses have which allow them to alter the way the body's cells work to their favour, like using the cells contents to replicate. Whilst we can harness microorganisms for our own good; there is potential for producing highly nutritious food aid for developing countries using fungi, the majority of the time the microorganisms that we notice most are harmful.
There are loads of different points in the infection's cycle that it would be possible to develop treatments to stop it from progressing, including: the binding to the cell, the markers on it's surface, the replication and assembly. However we should really focus on treatments available now and to make sure they are effective we should educate the public so that they know the importance of taking their antibiotics to full term and keep all their vaccinations up to date. This could be done via a variety of mediums including schools, workplaces and media. Research is ongoing into treatments for other illnesses which we currently have no cure for, and hopefully when these are released they will be used by the public as instructed, so that all the effort developing them is not wasted.

http://www.bbc.co.uk/news/world-europe-17230102