By James Beltran

Dr. Dwight German

Dr. Dwight German envisions a day when anyone age 60 or older can walk into a doctor’s office for a blood test that detects risk of developing Alzheimer’s disease.

The test would flag signs of potential trouble and prompt further examinations before the disease takes hold. In some cases, the solution could be as simple as drinking mineral oil.

The research of Dr. German, Professor of Psychiatry at UT Southwestern Medical Center, indicates that the science to make this happen already exists. A test he helped develop several years ago has been further substantiated to show that people with certain protein-level changes in the blood are more likely to develop Alzheimer’s.

It may be on the market within the next few years for patients seen by a primary care doctor.

“You’d like to have a test that’s going to tell you that maybe in 10 years you’re going to be in big trouble unless you do something today,” said Dr. German, who collaborated on developing the blood test with Dr. Sid O’Bryant, Interim Executive Director of the Institute for Aging & Alzheimer’s Disease Research at the University of North Texas Health Science Center.

Dr. German’s work on early detection could be vital as other scientists at UT Southwestern seek methods to slow or stop the spread of toxic proteins associated with Alzheimer’s, such as beta-amyloid and tau, which are blamed for destroying groups of neurons in the brain.

Some of Dr. German’s recent research has focused on DDT, a pesticide widely used in the 1940s that he found may be linked to Alzheimer’s. His group reported that a DDT metabolite exists in high levels in the blood of some Alzheimer’s patients, and the higher the pesticide levels, the lower the patients’ cognitive abilities.

Dr. German’s next step is to study whether the pesticide actually produced brain damage in patients who had Alzheimer’s. Based upon these findings, he said, doctors could better identify at-risk individuals before symptoms arise and prescribe mineral oil, which research shows reduces the DDT-related pesticide in the blood.

“It looks like this pesticide exposure may play a role in getting the disease,” said Dr. German.

The U.S. banned DDT in 1972 after scientists found it was an environmental hazard and could potentially harm people. Immigrants from countries that still use DDT have high levels of DDE in their blood, which is the metabolite of DDT, and it remains in the body for decades.

Using data from the National Health and Nutrition Examination Survey, Dr. German’s colleagues found that Mexican-Americans have three times higher levels of DDE in their blood than non-Hispanic whites. Mexican-Americans also develop Alzheimer’s disease at an earlier age than non-Hispanic whites.

Dr. German’s group plans to examine whether the higher blood levels of DDE are related to the earlier onset of disease in Mexican-Americans.