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Your wish is its command

Researchers have demonstrated that individuals who cannot voluntarily move the upper and lower parts of their body can, after extensive training, operate wheelchairs with their minds, even in a natural, cluttered environment.

In the small study, three persons who were unable to use their arms and legs due to spinal injuries were able to move their wheelchair using only their thoughts, which were translated into mechanical commands.

“We show that mutual learning of both the user and the brain-machine interface algorithm are both important for users to successfully operate such wheelchairs,” said José del R. Millán, a researcher at the University of Texas at Austin.

Each of the participants underwent training sessions three times per week for two to five months. The participants wore a skullcap that detected their brain activities through electroencephalography (EEG), which would be converted to mechanical commands for the wheelchairs via a brain-machine interface (BMI) device.

The participants were asked to control the direction of the wheelchair by thinking about moving their body parts. Specifically, they needed to think about moving both hands to turn left and both feet to turn right.

“We see from the EEG results that the subject has consolidated a skill of modulating different parts of their brains to generate a pattern for ‘go left’ and a different pattern for ‘go right,’” Millán said.

By the end of the training, all participants were able to move their wheelchairs across a cluttered hospital room, to varying degrees of success. They were asked to navigate around obstacles, such as a room divider and hospital beds, which were set up to simulate the real-world environment.

—John Schieszer

Diet may help lower hip fracture risk

Increasing intake of protein and drinking regular cups of tea or coffee may be a good way for women to reduce their risk of suffering a hip fracture, according to new research.

Food scientists have found that for women, a 25 gram a day increase in protein was associated with, on average, a 14% reduction in their risk of hip fracture. In a surprise twist, they also discovered that every additional cup of tea or coffee they drank was linked with a 4% reduction in risk.

Writing in the journal Clinical Nutrition, the researchers noted that the protective benefits were greater for women who were underweight, with a 25 gram/day increase in protein reducing their risk by 45%.

The protein could come in any form: meat, dairy or eggs, and for people on a plant-based diet, from beans, nuts or legumes. Four eggs would provide around 25 grams of protein as would a 4-ounce steak or piece of salmon.

The observational study reviewed records from more than 26,000 middle-aged women for whom they were able to identify associations between factors in diet and hip fractures, which were identified through hospital records.

Women who are underweight may be more likely to have reduced bone mineral density and muscle mass. Increasing intakes of several foods and nutrients, especially protein, may help reduce hip fracture risk more in underweight women than in healthy or overweight women by helping to establish or restore bone and muscle health. However, the researchers caution that these findings require further confirmation.

Tea and coffee both contain biologically active compounds called polyphenols and phytoestrogens, which may help to maintain bone health.

The data used in the study came from the UK Women’s Cohort Study, which recruited participants between 1995 and 1998. At the time they entered the study, the women ranged between 35 and 69 years of age. Of the 26,318 women involved in the study, 822 cases of hip fracture were identified (3.1% of the participants).

—John Schieszer

Avocados linked to heart health

The creamy, pale green flesh of an avocado is full of nutrients closely tied to heart health. Now, a long-term study finds that eating at least two servings per week is linked to a lower risk of cardiovascular disease.

Study co-author Dr. Frank Hu, the Frederick J. Stare Professor of Nutrition and Epidemiology at the Harvard T.H. Chan School of Public Health (HSPH), puts this finding in perspective: “This study adds to the evidence to support the benefits of healthy fat sources like avocados to help prevent cardiovascular disease,” he said.

A key take-home message is to substitute avocados for less-healthy foods such as butter, cheese and processed meats.

The study included more than 110,000 people involved in two long-running Harvard studies: the Nurses’ Health Study and the Health Professionals Follow-up Study. Most of the participants were white; they ranged in age from 30 to 75, and were free of heart disease and cancer when the study began.

Researchers assessed the participants’ diets via questionnaires given at the start of the study and then every four years. One question asked how much and how often people ate avocado. A serving was considered a half an avocado or one-half cup, cubed.

During the 30-year follow-up, researchers documented 9,185 heart attacks and 5,290 strokes among the participants. Compared with people who never or rarely ate avocados, those who ate at least two servings each week had a 16% lower risk of cardiovascular disease and a 21% lower risk of experiencing a heart attack or related problem due to coronary artery disease.

Research shows that replacing foods high in saturated fat (such as butter, cheese and meat) with those rich in unsaturated fats (such as avocados, nuts and seeds) helps lower blood levels of harmful LDL cholesterol, a key culprit in coronary artery disease.

One serving of avocado also provides up to 20% of the daily recommended dietary intake of fiber, a nutrient that’s often lacking in the typical American diet. Fiber-rich diets may lower heart disease risk as much as 30%, probably because fiber helps lower not only cholesterol, but also blood pressure and body weight.

—Harvard Heart Letter

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