Environmental contaminants increase risk of dementia 

sperm, brain tumours, Common drugs, diabetes, chronic wounds, magnetism, intestinal tumours, molecular scissors, disease, genetic, immune cells, drug development, Diabetes, Antibiotic, hydrogen generation, chronic obstructive pulmonary disease, malaria, photosynthesis, kidney failure, Brain tumours, mental health, blood cancer, cancer, dementia, cancer treatment, antibiotic resistance, blood vessel leakage, quantum simulations, atrial fibrillation, batteries, goiter treatment, terahertz radiation, organic materials , Guild of European Research Intensive Universities, gene copies, social anxiety, blue light screens, ‘Our hope is that these findings will make it possible to discover a way to selectively inhibit the TGF-beta signals that stimulate tumour development without knocking out the signals that inhibit tumour development, and that this can eventually be used in the fight against cancer,’ says Eleftheria Vasilaki, postdoctoral researcher at Ludwig Institute for Cancer Research at Uppsala University and lead author of the study. TGF-beta regulates cell growth and specialisation, in particular during foetal development. In the context of tumour development, TGF-beta has a complicated role. Initially, it inhibits tumour formation because it inhibits cell division and stimulates cell death. At a late stage of tumour development, however, TGF-beta stimulates proliferation and metastasis of tumour cells and thereby accelerates tumour formation. TGF-beta’s signalling mechanisms and role in tumour development have been studied at the Ludwig Institute for Cancer Research at Uppsala University for the past 30 years. Recent discoveries at the Institute, now published in the current study in Science Signaling, explain part of the mechanism by which TGF-beta switches from suppressing to enhancing tumour development. Uppsala researchers, in collaboration with a Japanese research team, discovered that TGF-beta along with the oncoprotein Ras, which is often activated in tumours, affects members of the p53 family. The p53 protein plays a key role in regulating tumour development and is often altered – mutated – in tumours. TGF-beta and Ras suppress the effect of mutated p53, thereby enhancing the effect of another member of the p53 family, namely delta-Np63, which in turn stimulates tumour development and metastasis.

Individuals subjected to chronic low-dose exposure to organochlorine pesticides show an increased risk of obtaining a future diagnosis of cognitive impairment.

Organochlorine pesticides (OCPs) are a group of environmental contaminants that were banned in developed countries 20-30 years ago. But since they accumulate through the food chain and remain for a very long time in the human body, especially adipose tissue, high levels can still be found in a majority of the population of Sweden, as well as in most other industrial countries. The most commonly known of these compounds is the pesticide DDT.

The research group at Uppsala University has previously shown associations between environmental contaminants and diabetes, atherosclerosis and stroke (links below, if needed). Using the same large data set they have now shown that the OCPs are related to future cognitive impairment.

The so-called PIVUS study (Prospective Investigation of Uppsala Seniors) comprises around 1,000 70-year-olds in Uppsala who have been studied over a longer period of time. The researchers measured three different OCPs in plasma from the individuals and investigated who received a diagnosis of cognitive impairment over the coming 10-year period.

The results show that individuals with high levels of three OCPs (p,p’-DDE (a metabolite of DDT), transnona-chlordane and hexachlorobenzene) had about 3 times higher future risk of cognitive impairment than elders with low levels of OCP. These results are independent of factors such as sex, smoking, diabetes, exercise habits, alcohol intake, weight change and high blood pressure.

‘Even though OCPs are well-known neurotoxins, our findings are surprising because current exposure levels of these chemicals are very low. However, our study subjects were the first generation with almost life-time exposure to these chemicals. Thus, we found evidence that low-dose, but chronic, exposure of OCPs can be harmful to the human brain’, says Lars Lind, Professor of Medicine at Uppsala University.

The study was conducted together with Professor Duk-Hee Lee, Kyungpook National University, Daegu, Korea, Professor Bert van Bavel and Samira Salihovic, PhD, Örebro University, Professor David Jacobs, University of Minnesota, Minneapolis, and Monica Lind, Associate Professor in Environmental Medicine at the Department of Occupational and Environmental Medicine, Uppsala University Hospital.

The study is part of the so-called PIVUS study at Uppsala University.

The study has been funded by Formas and the Swedish Research Council.

Reference: Lee D-H et al. Association between background exposure to organochlorine pesticides and the risk of cognitive impairment: a prospective study that accounts for weight change. Env Int (in press) doi:10.1016/j.envint.2016.02.001