According to a study that followed more than a million people over 30 years, epilepsy, high blood pressure and type 2 diabetes also increase the risk.
The research was conducted in the East End of London, where the most ethnically diverse population lives.
He found that tremors – a classic symptom of Parkinson’s disease – don’t lead to a diagnosis until on average 10 years after they start.
Study co-author Dr Alastair Noyce said: “It’s too long for patients to wait. If we are able to diagnose Parkinson’s disease earlier, we have a real opportunity to ‘intervene early and propose treatments that could improve the quality of life of patients.’
Worldwide, six million people have Parkinson’s disease, including 145,000 in the UK.
Classic symptoms include tremors, sluggishness, stiff muscles, and memory loss. The number of cases is expected to triple over the next two decades. There is no remedy.
Analysis of electronic primary care records between 1990 and 2018 showed that tremors and forgetfulness appeared up to a decade and five years respectively before diagnosis.
Hearing loss and epilepsy were also identified as early features – confirmed using additional data from the UK Biobank, a database of half a million volunteer health records. The new study was the first to look at ethnic minority groups in an underprivileged urban population. Previous research has largely focused on affluent white populations.
Almost half of east London residents are from black, South Asian or other ethnic groups, compared to 14% in the rest of the UK.
It also has some of the highest levels of deprivation, with eight out of 10 participants from low-income households.
Lead author Dr Cristina Simonet, Queen Mary University of London, said: “This is the first study to look at the pre-diagnosis phase of Parkinson’s disease in such a diverse population. To enable us to have the full picture of the disease, we need to ensure research is inclusive and represents all affected people.”
She said more research is needed to understand the link between Parkinson’s disease and the other conditions.
She added: “It is important that primary care practitioners are aware of these links and understand how early symptoms of Parkinson’s disease can appear, so that patients can get a timely diagnosis and doctors can act early to help manage the disease.” The results are in the journal Jama Neurology.