U. WASHINGTON (US) — Eating peppers may reduce the risk of Parkinson’s disease, a new study suggests.
Peppers are in the same botanical family as tobacco, and research has shown that dietary sources of nicotine may prove protective.
Nearly one million people in the United States are living with Parkinson’s disease, a neurodegenerative disorder that results from the loss of dopamine-producing brain cells. In early stages, Parkinson’s is characterized by difficulties in controlling movement.
Initial symptoms include hand tremors, limb rigidity, and problems walking. As the disease progresses, cognitive problems may develop and advance into dementia.
“Eating peppers twice or more per week was consistently associated with at least 30 percent reduced risk of developing Parkinson’s disease,” says Susan Searles Nielsen, a research scientist in the Department of Environmental and Occupational Health Sciences at the University of Washington.
The investigation of dietary sources of nicotine stems from the puzzling epidemiologic findings that repeatedly show that people who have regularly used tobacco have about half the risk of developing Parkinson’s disease, Searles Nielsen says.
In 2012, she published a study that suggested that second-hand smoke also might reduce risk of the disease.
“It’s possible that people predisposed to Parkinson’s disease simply don’t respond well to tobacco smoke and therefore avoid it. However, if tobacco is actually protective, and if the reason is nicotine as some experimental studies suggest,” Searles Nielsen says, “then our hypothesis was that other plants in the Solanaceae family that contain nicotine might also be protective.”
For the study, published in the Annals of Neurology, researchers interviewed 490 Parkinson’s patients diagnosed between 1992-2008. The control study subjects were 644 unrelated, neurologically normal people.
While the study investigated the association between Parkinson’s and the subjects’ dietary consumption of a variety of vegetables, including nicotine-containing peppers, tomatoes, and potatoes in the Solanaceae family, peppers showed the greatest protection.
The decreased risk of disease grew stronger with increasing pepper consumption and occurred mainly in people with little or no prior use of tobacco, which contains much more nicotine than the foods studied.
Searles Nielsen cautions that further studies are needed to confirm these findings and explore whether a similar but less toxic chemical shared by peppers and tobacco might be equally or more protective than nicotine.
Funding for the study was provided by the National Institute of Environmental Health Sciences.
Source: University of Washington