Podcast Transcript

Med diet prevents major disease

Back in July, Greek researchers working as part of EPIC, the largest study of diet and cancer ever undertaken, showed that the more Mediterranean a person’s diet is, the lower the risk of cancer. That’s a diet that contains lots of fruit, veg, grains, nuts and fish, along with a splash of olive oil, but is low in red and processed meat, alcohol, dairy and animal fats.

Now an analysis of 12 international studies of diet and disease published in the British Medical Journal has shown that a strict Mediterranean diet can help to reduce deaths from other diseases as well as cancer, including heart disease, Parkinson’s and Alzheimer’s.

Collectively, the studies covered more than 1.5 million people, whose diet and health were tracked from three to 18 years. All the studies used a score, to work out how “Mediterranean” a person’s diet was.  The researchers found that people sticking strictly to a Mediterranean diet had a 9% drop in overall death rate, including a 9% cut in deaths from heart disease, a 13% drop in the incidence of Parkinson’s and Alzheimer’s, and a 6% cut in cancer incidence.

The researchers suggest that a tool to help people to “score” their diets might be an effective way to help people cut the risk of these diseases and live longer. 

14th Sep 2008

Tackling post-natal depression in poorer countries

Researchers from Liverpool working in rural Rawalpindi in Pakistan have found a simple and effective way to cut depression in mothers in poorer countries.

Reporting their results in a special edition of the journal The Lancet this week, the researchers trained local village-based health workers in delivering the “Thinking Healthy Programme” to mothers in the final third of their pregnancy. The programme is based on cognitive behavioural therapy and involves listening techniques, guided questioning, and enabling mothers to practice techniques between sessions.  The researchers then measured the levels of depression in the mothers on the programme at 6 and 12 months, as well as monitoring the babies’ heights and weights.

In the trial, 463 mothers from 20 villages were given the programme, while 440 from another 20 villages acted as a control.  The team found that mothers in the control group were more than four times likely to be depressed than those given the programme. They also found that babies of mothers on the programme were less likely to have had diarrhoea, and were more likely to have had all their immunisations. They also found that mothers and fathers in the group on the programme played with their babies more often, and were also more likely to use contraceptives.

14th Sep 2008

Robotic Carrier Pigeons

As rural areas especially in developing countries are very spread out and often have an awful transport infrastructure clinics can be many hours if not days away from the nearest hospital with a lab able to do tests.  This means that any treatment that depends on the results could be delayed by days, which is obviously not good for the patient.

Barry Mendelow of the South African National Health Laboratory Service has a solution to this problem – spy planes...  Not the big ones costing millions of pounds, but the small Uncrewed Aerial Vehicles (UAVs) that have been developed for soldiers to be able to see over the next hill.  These are like radio controlled planes with a computer and GPS system so that they are essentially autonomous and able to fly a preprogrammed course of over 50km at 45km/hr and report back on their progress by mobile phone.

The first UAV they developed had a payload of 500g and is able to carry up to 20 blood or saliva samples or 2 units of blood or even life saving drugs such as rabies vaccines.  It can be given coordinates to drop off the samples and then instructed to fly back to base.  It is then landed manually by remote control.

While they developed this UAV, technology for doing tests has moved on and molecular diagnostics techniques have been developed that only need a spot of blood or sputum on a piece of paper.  This has lead the team to develop a much smaller and cheaper UAV with an only 10g payload which is small but still enough to carry 10-20 paper spot samples.  It only weighs 800g but can be launched and retrieved by hand and has a range of over 50km.

In tests they have sent a sample by UAV to a lab and got the results back to the clinic by SMS within 6 hours.

14th Sep 2008

Molecular help for heart attacks

Researchers in the US have discovered a chemical that could become a new treatment for heart attacks, as well as helping to protect the heart during open heart surgery or other traumatic events.

Writing in the journal Science, the researchers from Stanford and Indiana universities describe how jump-starting a particular enzyme called ALDH-2 using a compound called Alda-1 can reduce the amount of cell death caused by a lack of blood flow to the heart  - as is seen during heart attacks.

The key to the research was the team’s discovery that ALDH2 activity correlates with reduced levels of cell damage in heart attacks. ALDH2 is better known as an alcohol dehydrogenase enzyme, responsible for breaking down alcohol in the body – and it’s well known that small amounts of alcohol can help to protect the heart. So the scientists set about finding a molecule that could switch on ALDH2 without the need for booze, and that turned out to be Alda-1.

At the moment, the experiments have only been done in rats, so several more years of work will be needed, to turn the chemical Alda-1 into a drug that’s safe and effective in humans.

Millions of people of East Asian origin aren’t suitable for the most common heart treatments, such as nitroglycerin, due to their genetic makeup – around 40% of people from that background have a faulty version of ALDH2. But the team found that Alda-1 was particularly effective at kick-starting this form of ALDH2, which offers hope for a treatment for this group of people.

14th Sep 2008

The Super Solar Power Tower

Meera -   Providing the cities and villages of Africa with a good supply of electricity has long been a challenge for African governments.  With many of the smaller countries relying on larger ones to connect them to the grid.  But a recent proposal approved by the government in Namibia could provide vast amounts of power from a natural, renewable source.  With me this week is Christina Scott from the Science and Development Network to tell me more.

Christina -   There's a proposal to build an absolutely massive solar energy tower outside the capital of Namibia which is Windhoek.  Historically they've always got their electricity from their neighbours, only South Africa basically ran out of electricity and it's having this terrible knock on effect on all the knock on countries.  The good side is that now there's a renewed interest in renewable energy and there's this proposal to build an absolutely massive solar tower, and it's going to be one of the first ones in the world, it's one and an half kilometres high!  I have trouble actually imagining how they're going to persuade planes to go around it, it's going to be so big!

Meera -   That's extremely high, actually, and how wide is it going to be?

Christina -   Well basically it's one very boring looking chimney, straight up, straight down.  But at the base of it there's going to be a transparent disk stretching for about half a kilometre into the distance around, a bit like a doughnut.  The idea is that this will trap the solar energy and it will get funnelled into the tower into wind turbines.  At the same time, there's research that's been done here in South Africa at the University of Stellenbosch which says that you can use that transparent disk to actually at the same time create really big greenhouses and do two things at the same time.

What worries me is that there are no prototypes.  We had one tower which was a lot smaller in Spain, which was used as a test run, but between then and now there's been almost nothing else.  What's happening with this proposal is that they're arguing that because these things work so much better the bigger they are, they want to go past the intermediary steps and build what will basically be the world's biggest man made structure.  So it will be incredibly expensive to build, on the other hand it will be very, very inexpensive to run and they're particularly good for areas that don't have a lot of water because some solar power designs require water as a back-up, and quite frankly places like Namibia just don't have the water to be able to cope.

Meera -   But at the same time, you've mentioned that it's going to be very expensive to build this tower, so how much money are we looking at here?

Christina -   Well, the pre-feasibility report on it's own is $780,000 and there are other countries that are looking at it as well, so presumably the cost will come down if we get quite a lot of solar chimneys being built in countries like Australia, Egypt, India, Morocco.  But right now, they're proposing something that's going to be $900 million to construct.

Meera -   That's a lot of money, so is it actually worth that amount to go this way?

Christina -   I think the Namibian government is interested because they are situated really well for using solar power, and they are extremely vulnerable to what happens in their neighbouring countries.  We've got electricity here in South Africa but we're using it all ourselves.  They want to become more independent.  This is just one of the things that they're looking at, for example Namibia has uranium and rather than exporting it they're now considering nuclear power as well because their economy wont expand without power, it is an issue across the continent.

Meera -   Where are we, currently, with this situation?  Is it going to be built soon or is it just in discussions?  What's the current position?

Christina -   Right now they're still in discussions.  We interviewed the permanent secretary for the ministry of mines and energy in Namibia and he says that they are basically prepared to work with serious investors.  They're interested in this one because the solar tower, the tower of power, can actually work at night, which they're quite interested in.

Meera -   It is going to provide 24 hour power then?

Christina -   It can provide 24 hour power and it can provide power at peak times, which is something that doesn't always happen with other versions of solar power.  They had a study for a similar solar chimney in the Kalahari desert on the South African side of the border, and that was dropped.  That was dropped because they considered that it's power was too expensive compared with the coal power that South Africa relies on quite heavily.  But given the fact that we've got global warming, it makes a lot of sense for countries that have a lot of sun to wean themselves off oil.  I think we're going to find a lot more work going into these solar towers in the future.

September 2008