{"id":60148,"date":"2025-10-04T00:38:07","date_gmt":"2025-10-04T00:38:07","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/60148\/"},"modified":"2025-10-04T00:38:07","modified_gmt":"2025-10-04T00:38:07","slug":"how-are-pesticides-and-parkinsons-disease-linked-one-doctors-research-spans-25-years","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/60148\/","title":{"rendered":"How are pesticides and Parkinson\u2019s disease linked? One doctor\u2019s research spans 25 years"},"content":{"rendered":"

While\u00a0Dr. Beate Ritz<\/a> was undergoing training in psychiatry in Germany, her 62-year-old department chair developed Parkinson\u2019s disease. It progressed rapidly.<\/p>\n

\u201cWhen I naively asked what causes Parkinson\u2019s,\u201d Ritz, a distinguished professor of epidemiology in the\u00a0UCLA Fielding School of Public Health<\/a>\u00a0and a professor in the department of neurology at the\u00a0David Geffen School of Medicine at UCLA<\/a>, recalled, \u201ceverybody said, \u2018We don\u2019t know.\u2019\u201d<\/p>\n

That question began more than 25 years of research into the neurodegenerative disorder for Ritz.<\/p>\n

She would eventually narrow her focus to one of California\u2019s hubs of agriculture: the Central Valley.<\/p>\n

Her\u00a0Parkinson\u2019s Environment Genes<\/a>\u00a0(PEG) research has shown associations between environmental exposures \u2013 both pesticides and air pollution \u2014 and increased risk for developing Parkinson\u2019s disease, an important step toward determining its causes.<\/p>\n

Ritz\u2019s work is increasingly critical as Parkinson\u2019s \u2014 for which there is no cure and only symptomatic treatment \u2014 is the fastest-growing neurological disease worldwide.<\/p>\n

Pesticides exposure<\/p>\n

Examining the environment as a possible cause for Parkinson\u2019s began in the late 1980s, with \u201cfrozen addicts.\u201d<\/p>\n

After injecting a synthetic heroin, these individuals were found to have severely limited movement and speech. The drug was contaminated with a chemical similar to paraquat dichloride \u2014 a commonly used herbicide.<\/p>\n

Ritz employed a unique resource \u2014 California\u2019s\u00a0Pesticide Use Reports<\/a>\u00a0\u2014 that allowed her to precisely gauge the pesticides being sprayed on acres of fruits and vegetables in the Central Valley.<\/p>\n

The compounds would then find their way into people through inhalation or ingestion (contained in dust or well water).<\/p>\n

That exposure to paraquat was associated with an increased risk for Parkinson\u2019s disease, Ritz\u2019s studies found.<\/p>\n

Since then, several animal models have shown paraquat causing disease symptoms. \u201cWe are now basically convinced that paraquat can cause Parkinson\u2019s,\u201d Ritz said.<\/p>\n

Additional analyses of hundreds of pesticides found that more than 10 were directly toxic to the neurons that produce and release the neurotransmitter dopamine. Her team is now analyzing which combinations of pesticides are particularly toxic.<\/p>\n

Air pollution<\/p>\n

Ritz\u2019s latest studies have expanded to the role of air pollution.<\/p>\n

As with pesticides, there are associations between increased disease risk and exposures to traffic-related pollutant markers such as carbon monoxide and the fine particulate matter found in dust.<\/p>\n

Air pollution contains metals and is known to increase inflammation, both implicated in the immune dysfunction that partially drives Parkinson\u2019s disease.<\/p>\n

Another connection concerns the nose. A majority of those who develop Parkinson\u2019s disease lose their sense of smell prior to diagnosis.<\/p>\n

Ritz theorizes that an effect of pollution is that nanoparticles cross the nasal epithelium. They make their way to the olfactory bulb, then into the brain and may therefore contribute to the development of Parkinson\u2019s.<\/p>\n

But she cautions that understanding air pollution\u2019s effects on neurodegenerative diseases can be challenging.<\/p>\n

That\u2019s especially true when considering the varied influences of pollution sources, co-exposures, comorbidities and personal vulnerabilities.<\/p>\n

Patient registry<\/p>\n

When Ritz embarked on research into Parkinson\u2019s disease, there was no way to measure its incidence or prevalence in California.<\/p>\n

So she lobbied for a patient registry, joined by advocacy groups and colleagues in neurology such as\u00a0Dr. Jeff M. Bronstein<\/a>. The state passed a law in 2004 \u2014 finally funded in 2017 \u2014 that providers must report every patient with Parkinson\u2019s.<\/p>\n

For the three counties in the Central Valley, nearly 1,000 registered people with the diagnosis have enrolled in UCLA studies. A similar number \u2014 neighbors and community members without the disease \u2014 have volunteered to act as control subjects.<\/p>\n

The registry has made the science possible and given the community a sense of agency, especially as \u201cthey feel they are suffering quietly and alone,\u201d according to Ritz.<\/p>\n

To inform the community of their contributions to progress, her team sends annual Christmas cards explaining their findings and summarizing what\u2019s new in the field of Parkinson\u2019s disease and patient care.<\/p>\n

Policy changes<\/p>\n

As Ritz and her team study the links between pesticide exposure and Parkinson\u2019s disease, the hope is to progress from merely associating the two to establishing causation.<\/p>\n

Ritz believes that delving deeper into cellular mechanisms will help in that effort, so \u201cwe actually see fingerprints of exposures on the human body.\u201d<\/p>\n

Whether causation can also lead to changes in policy \u2014 including reducing pesticide use around communities \u2014 is another question.<\/p>\n

Regulating insecticides is a cost-effective measure to reduce the burden of Parkinson\u2019s disease, Ritz found in an\u00a0analysis<\/a>. But there are likely only two ways that industry will act, she pointed out.<\/p>\n

One is an outright ban, a long process of convincing the Environmental Protection Agency, Ritz said.<\/p>\n

California is much more open than the rest of the U.S. to pesticide regulation and to integrated options for pest management. But the state must also balance the sometimes-contradictory interests of the agriculture industry and community health.<\/p>\n

Another route is legal action. Ritz is an expert witness in several lawsuits that allege paraquat exposure contributed to Parkinson\u2019s disease.<\/p>\n

Paraquat has been sprayed since the 1960s. Its use has even increased, as weeds become resistant to other herbicides.<\/p>\n

More than 70 other countries have already banned it because of dangers to human health. However, legal and policy issues surrounding its use continue to be debated in the U.S. to this day.<\/p>\n","protected":false},"excerpt":{"rendered":"While\u00a0Dr. Beate Ritz was undergoing training in psychiatry in Germany, her 62-year-old department chair developed Parkinson\u2019s disease. It…\n","protected":false},"author":2,"featured_media":60149,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[41756,103,61,60,33479,89,41755],"class_list":{"0":"post-60148","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-health","8":"tag-evolving-research","9":"tag-health","10":"tag-ie","11":"tag-ireland","12":"tag-parkinsons","13":"tag-research","14":"tag-ucla-health"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/60148","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=60148"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/60148\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/60149"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=60148"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=60148"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=60148"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}