Monday, July 12, 2010

An active social life can help you fight cancer, researchers say

Once again this generalizes from the mouse brain to the much more complex human brain -- a highly dubious proposition. And in a rather fun twist, the results below could also be interpreted to show that stress is good for you!

A good social life can help beat cancer, scientists say. Tests on diseased mice found their tumours shrank dramatically when they were brought into contact with many more other animals than normal - with tumours even disappearing completely in a few cases.

It means human patients should be encouraged to meet up with friends and family, or stay in as close contact as possible with them by email or phone, to maximise their chances of recovery.

Geneticist Professor Matthew During said his findings published in the journal Cell offer powerful new evidence of the critical role that social connection and an individual's mental state may play in cancer. He said: 'Animals' interaction with the environment has a profound influence on the growth of cancer - more than we knew was possible.'

Mice, naturally sociable creatures, are typically housed in groups of five or so for laboratory experiments, where they can have all the food they want and play all day. But when those with tumours were placed in 'enriched environments' with 15 or 20 and provided with more space and more things to play with and do - including toys, hiding places and running wheels - their disease often went into spontaneous remission.

Tumor mass shrunk by an average 77 per cent and the volume by 43 per cent. And one in 20 of the cancer ridden mice remarkably showed no evidence of the disease after three weeks in their new home. That never happened in control animals kept in standard housing.

Prof. During, of Ohio State University, said the more complex social dimension in the new living arrangements was apparently key. The same improvements weren't seen in animals who only exercised more, so physical activity in and of itself wasn't the answer.

The animals did show lower levels of a hormone produced by fat called leptin, indicative of a significant shift in metabolism. Their immune systems also appeared to be 'ramped up a bit' which was traced by the researchers to a brain chemical known as BDNF (brain-derived neurotrophic factor).

Manipulating the mice to produce increased levels of BDNF, which can be increased by exercise, also reduced their tumours, whereas the benefits of an enriched environment evaporated in those lacking the molecule - suggesting low levels of stress, or certain kinds of it, can be beneficial.

Prof. During said: 'A lot of people think stress is bad, but our data show the animals aren't just happy. Antidepressants won't give you the same effect.' In fact, the animals show higher levels of stress hormones known as glucocorticoids.

Added Prof During: 'The goal isn't to minimise stress, but to live a richer life, socially and physically. You want to be challenged.'

The findings could ultimately lead to new treatments for cancer and other diseases as well, whether through environmental modifications that offer mental and social stimulation or perhaps via a drug that mimics those experiences on a molecular level.

It will be important to find out what it takes in humans to turn BDNF on. Prof During said: 'We're really showing that you can't look at a disease like cancer in isolation. For too long, physicians and other have stuck to what they know - surgery, chemo, radiotherapy. Traditionally working on the area of lifestyle and the brain has been a "soft area".

'This paper really suggests if we look at people more in terms of their perceptions of disease, their social interactions and environment, we could realise a profound influence on cancer. There is no reason to suspect our findings in mice won't be generalisable.'


A regular chocolate treat 'could halve a woman's risk of giving birth prematurely'

I hate to spoil the fun but this is even more rubbishy "correlation is causation" epidemiology than usual -- in that it involves retrospective self-reports. At least that aspect is acknowledged below.

The finding is probably just data dredging anyway. Chocolate is such an unremitting subject of research that correlations will arise by chance alone

It is a sweet revelation for every mother-to-be. Pregnant women have the perfect excuse to give in to their cravings - because chocolate is good for both mother and baby. Expectant mums who regularly snack on chocolate bars are less likely to develop pre-eclampsia, according to a study.

One of the most common causes of premature birth in the UK, pre-eclampsia affects 70,000 British women a year and claims the lives of up to 1,000 babies and ten mothers. It is characterised by high blood pressure and can cause convulsions, blood clots, liver damage and kidney failure.

But after asking 2,500 women about their dietary habits during pregnancy, researchers from Yale University in the U.S. found that those who consumed higher rates of chocolatey snacks - including hot chocolate drinks - were less likely to develop the potentially fatal complication, the journal Annals of Epidemiology reports.

It is thought that theobromine, the bittertasting chemical in cocoa, keeps blood pressure steady by helping blood vessels to dilate. Researchers stressed the results may have been skewed by women being asked to remember what they had eaten during pregnancy.

The study also failed to examine if the benefits are confined to dark chocolate. Some research suggests milk or white chocolate does not have the same health benefits, as they they are higher in sugar and have a lower content of flavanols, the disease-fighting ingredient in cocoa used to make chocolate.

In a report on their findings researchers said: 'Women who reported regular chocolate consumption of more than three servings a week had a 50 per cent or greater reduced risk of pre-eclampsia. 'Regular chocolate intake during the first or third trimester was equally protective.'

Last year, Swedish scientists found heart attack survivors who snacked on chocolate at least twice a week could slash their risk of dying from heart disease by up to 70 per cent.

And in 2008, a team at Georgetown University in Washington DC discovered a chemical found in chocolate could hold the key to stopping bowel cancer in its tracks. They tested a man-made version of the naturally-occurring ingredient and found it halved the rate at which tumours grew, while leaving healthy cells untouched.


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