DDT linked to Alzheimer's

A new post in my series dedicated to my students, we will have a look at an interesting article about the connection between DDT, a banned pesticide in most countries, and the current epidemics of Alzheimer's disease.

See below the link to the original article. Thanks to BBC News and the article's writer for the excellent work!

http://www.bbc.co.uk/news/health-25913568

HEALTH

28 January 2014 Last updated at 00:32 GMT

DDT: Pesticide linked to Alzheimer's

By James GallagherHealth and science reporter, BBC News

Exposure to a once widely used pesticide, DDT, may increase the chances of developing Alzheimer's disease, suggest US researchers.

A study, published in JAMA Neurology, showed patients with Alzheimer's had four times as much DDT lingering in the body as healthy people.

Some countries still use the pesticide to control malaria.

Alzheimer's Research UK said more evidence was needed to prove DDT had a role in dementia.

1. Exposure: contact with something, like a chemical product or radiation or UV rays...
2. once: in the past
3. widely used: many/most people used it.
4. researchers: scientists looking for some information.
5. four times: a multiplying factor. e.g. He earns four times as much as I do: I earn 20,000 he earns 80,000.
6. evidence: something that proves a theory or a crime, etc... in this context "scientific evidence".

DDT was a massively successful pesticide, initially used to control malaria at the end of World War Two and then to protect crops in commercial agriculture.

However, there were questions about its impact on human health and wider environmental concerns, particularly for predators.

It was banned in the US in 1972 and in many other countries. But the World Health Organization still recommends using DDT to keep malaria in check.

1. massively: very widely and in big quantities.
2. crops: plants grown by humans in a systematic way.
3. concern: if you are concerned about something, you are interested, usually because you are affected. Also a little worried.
4. to keep (malaria) in check: to control malaria, to keep it under control.

Not clear

DDT also lingers in the human body where it is broken down into DDE.

The team at Rutgers University and Emory University tested levels of DDE in the blood of 86 people with Alzheimer's disease and compared the results with 79 healthy people of a similar age and background.

The results showed those with Alzheimer's had 3.8 times the level of DDE.

However, the picture is not clear-cut. Some healthy people had high levels of DDE while some with Alzheimer's had low levels. Alzheimer's also predates the use of DDT.

The researchers believe the chemical is increasing the chance of Alzheimer's and may be involved in the development of amyloid plaques in the brain, a hallmark of the disease, which contribute to the death of brain cells.

to linger: to stay longer than expected or needed. Click here for more information.

Prof Allan Levey, the director of the Alzheimer's Disease Research Centre at Emory, said: "This is one of the first studies identifying a strong environmental risk factor for Alzheimer's disease.

"The magnitude of the effect is strikingly large, it is comparable in size to the most common genetic risk factor for late-onset Alzheimer's."

Fellow researcher Dr Jason Richardson added: "We are still being exposed to these chemicals in the United States, both because we get food products from other countries and because DDE persists in the environment for a long time," .

Dr Simon Ridley, the head of research at the charity Alzheimer's Research UK, said: "It's important to note that this research relates to DDT, a pesticide that has not been used in the UK since the 1980s.

"While this small study suggests a possible connection between DDT exposure and Alzheimer's, we don't know whether other factors may account for these results.

"Much more research would be needed to confirm whether this particular pesticide may contribute to the disease."

1. Strikingly: surprinsingly.
2. onset: start to develop
3. chemicals: chemical products.
4. charity: a charity is an organization that wants to do positive things for other people. 
5. relates to: is connected to
6. suggests: says, but not directly
7. whether: if