New research on Parkinson's, prostate cancer, brain benefits of having pets

Hidden brain benefits come with pet ownership

Owning a pet, like a dog or cat, especially for five years or longer, may be linked to slower cognitive decline in older adults, according to a new study. In fact, having a dog for more than 10 years may have important brain benefits.

“Prior studies have suggested that the human-animal bond may have health benefits like decreasing blood pressure and stress,” said study author Dr. Tiffany Braley with the University of Michigan Medical Center in Ann Arbor. “Our results suggest pet ownership may also be protective against cognitive decline.”

The study included 1,369 older adults (average age of 65) who had normal cognitive skills at the start of the study. A total of 53% owned pets, and 32% were long-term pet owners, defined as those who owned pets for five years or more.

Researchers used data from the Health and Retirement Study, a large study of Medicare beneficiaries. In that study, people were given multiple cognitive tests. Researchers used those cognitive tests to develop a composite cognitive score for each person, ranging from zero to 27. The composite score included common tests of subtraction, numeric counting and word recall. Researchers used participants’ composite cognitive scores and estimated the associations between years of pet ownership and cognitive function.

Over six years, cognitive scores decreased at a slower rate in pet owners. This difference was strongest among long-term pet owners. Taking into account other factors known to affect cognitive function, the study showed that long-term pet owners, on average, had a cognitive composite score that was 1.2 points higher at six years compared to non-pet owners.

“As stress can negatively affect cognitive function, the potential stress-buffering effects of pet ownership could provide a plausible reason for our findings,” said Dr. Braley. “A companion animal can also increase physical activity, which could benefit cognitive health. That said, more research is needed to confirm our results and identify underlying mechanisms for this association.”

Sniffing out Parkinson’s disease

Scientists have been trying to build devices that could diagnose Parkinson’s disease (PD) through odor compounds on the skin. Now, researchers have developed a portable, artificially intelligent olfactory system, or “e-nose,” that has the potential to diagnose the disease in a doctor’s office.

Parkinson’s disease causes motor symptoms, such as tremors, rigidity and trouble walking, as well as non-motor symptoms, including depression and dementia. Although there’s no cure, early diagnosis and treatment can improve one’s quality of life, relieve symptoms and prolong survival.

Currently, the disease isn’t identified until patients develop motor symptoms, and by that time they’ve already experienced irreversible neuron loss. Recently, scientists discovered that individuals with Parkinson’s disease secrete increased sebum (an oily substance produced by the skin’s sebaceous glands). Individuals with Parkinson’s disease also have increased production of yeast, enzymes and hormones, which combine to produce certain odors.

Chinese researchers developed a fast, easy to use, portable and inexpensive system to diagnose Parkinson’s disease through smell, making it suitable for point-of-care testing. The researchers developed an e-nose and machine learning algorithms. The team collected sebum samples from 31 Parkinson’s patients and 32 healthy individuals by swabbing their upper backs with gauze. They analyzed volatile organic compounds emanating from the gauze with the e-nose, finding three odor compounds (octanal, hexyl acetate and perillic aldehyde) that were significantly different between the two groups.

Ultrasound scan can help diagnose prostate cancer

An ultrasound scan can be used to detect cases of prostate cancer, according to a new study by researchers at Imperial College London, University College London and Imperial College Healthcare NHS Trust. The team found that a new type of ultrasound scan can diagnose most prostate cancer cases with good accuracy.

In a clinical trial involving 370 men, the ultrasound scans missed only 4.3% more clinically important prostate cancer cases (cancer that should be treated rather than monitored) compared to magnetic resonance imaging (MRI) scans currently used to detect prostate cancer.

MRI scans are expensive and time-consuming. The team believes that an ultrasound scan could be used as a first test in a community healthcare setting. The researchers also hope it may be safely used in combination with MRI scans to maximize cancer detection.

The study, which was published in Lancet Oncology, points out that prostate cancer develops slowly and symptoms such as blood in the urine do not appear until the disease has developed. It usually affects men over 50 and often men with a family history of the disease.

“MRI scans are one of the tests we use to diagnose prostate cancer. Although effective, these scans are expensive, take up to 40 minutes to perform and are not easily available to all. Also, there are some patients who are unable to have MRI scans such as those with hip replacements or claustrophobia fears,” said lead study investigator Dr. Hashim Ahmed, who is the chair of Urology at Imperial College London, England.

Prostate cancer is the most common non-skin cancer in America and 1 in 8 men will be diagnosed with prostate cancer in his lifetime in the United States. Although only about 1 in 451 men under age 50 will be diagnosed, the rate shoots up to 1 in 55 for ages 50 to 59. It continues to climb, with 1 in 20 for ages 60 to 69, and 1 in 12 for men 70 and older, according to the Prostate Cancer Foundation.

John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at

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John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute.

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