Wearable Winner

In this week's Rundown, activity trackers encourage more walking, moderate drinking leads to cognitive decline and electrified chopsticks pave the way for consuming less salt.

The Rundown

Wearable Winner. Skepticism about the effectiveness and accuracy of wearable activity trackers (WAT) has been widespread in exercise science research. But a new study from the University of South Australia has found that their overall impact is positive because they encourage us to walk up to 40 more minutes each day (or approximately 1800 more steps).

The researchers reviewed almost 400 studies involving 164,000 people using WATs to monitor their activity. Lead author Ty Ferguson notes that the overall results showed that wearable activity trackers are effective across all age groups for long periods of time.

“They encourage people to exercise on a regular basis, to make it part of their routine and to set goals to lose weight,” he says. Another reported benefit, he adds, is that WATs improved depression and anxiety through an increase in physical activity.

Four and Done. A new study set out to understand exactly how alcohol could contribute to cognitive decline and its findings suggest that as little as four standard alcoholic drinks per week can be linked to brain changes. It is the first research to directly correlate increased brain iron levels with moderate alcohol consumption.

The team analyzed data from more than 20,000 people enrolled in the UK Biobank. Self-reported alcohol consumption was correlated with brain iron levels, measured through MRI.

Anya Topiwala, an author of the study, notes that drinking more than seven units of alcohol weekly was associated with iron accumulation in the brain and higher brain iron was in turn linked to poorer cognitive performance. (One unit of alcohol is defined here as 10 milliliters of pure alcohol. A large glass of wine could be two to three units, for example. A regular can of beer can contain 1.5-2 units).

Exactly how alcohol consumption increases iron levels in the brain is a question for future studies, say the researchers, but their theory is that alcohol suppresses hepcidin production, the major hormone-regulating iron homeostasis. This suppression then increases intestinal absorption of dietary iron.

In addition, alcohol has been shown to reduce thiamine levels and alcohol-induced thiamine deficiency has been found to break down the permeability of the blood-brain barrier.

Salty Solution. According to the World Health Organization, an estimated 2.5 million deaths each year could be prevented globally if people reduced their salt consumption to the recommended daily intake of less than five grams. A group of Japanese researchers want to make that goal easier with a chopstick-like device that uses a weak electrical charge to stimulate how our tongues experience saltiness.

Earlier studies found that introducing a weak current to the tongue can affect the charged ions the make up sodium chloride to either reduce or enhance saltiness. This new paper is the first to explore how people on a low-sodium diet can use electric taste stimulation to reduce their salt consumption.

The scientists tested their electrified chopsticks on 31 people. Each person tasted and rated a low-sodium saltwater gel sample and a control sample that was 40% or more saltier. The results found that electric stimulation enhanced the saltiness of the low-sodium sample so that it was comparable to the control sample. Over 80% of the participants said they could handle the electric stimulation on a daily basis.

While the goal is to develop a commercial device for daily use by people wanting to reduce their salt intake, the scientists are also investigating how it might stimulate taste as part of a virtual reality experience.

Replay

This week’s vintage moment in fitness culture is brought to you by Shake Weight, which debuted in 2009. By 2010, it had $40 million in sales and its very own Saturday Night Live parody.