TM may help fight depression

Transcendental meditation, a stress-busting technique, may help reduce symptoms of depression, according to two new studies.

The studies will be presented at the 31st Annual Meeting of the Society of Behavioural Medicine in Seattle, Washington on April 9.

The studies, conducted at Charles Drew University in Los Angeles and University of Hawaii in Kohala included African Americans and Native Hawaiians, 55 years and older, who were at risk for cardiovascular disease. Participants were randomly allocated to the transcendental meditation programme or health education control group, and assessed with a standard test for depression-the Centre for Epidemiological Studies-Depression (CES-D) inventory over 9-12 months.

“Clinically meaningful reductions in depressive symptoms were associated with practice of the transcendental meditation programme,” said Sanford Nidich, lead author and senior researcher at the Institute for Natural Medicine and Prevention at Maharishi University of Management. “The findings of these studies have important implications for improving mental health and reducing the risk of cardiovascular morbidity and mortality,” said Dr Nidich.

Sunscreen nanoparticles toxic if accidentally eaten

Nanoparticles of zinc oxide present in sunscreens could prove toxic if consumed accidentally, according to a study.

Particles smaller than 100 nanometers are slightly more toxic to colon cells than conventional zinc oxide.

Solid zinc oxide was more toxic than equivalent amounts of soluble zinc, and direct particle to cell contact was required to cause cell death.

Philip Moos and colleagues note that there is ongoing concern about the potential toxicity of nanoparticles of various materials, which may have different physical and chemical properties than larger particles.

Nanoparticles are used in foods, cosmetics and other consumer products. Some sunscreens contain nanoparticles of zinc oxide.

“Unintended exposure to nano-sized zinc oxide from children accidentally eating sunscreen products is a typical public concern, motivating the study of the effects of nanomaterials in the colon,” noted the scientists.

The experiments with cell cultures of colon cells compared the effects of zinc oxide nanoparticles to zinc oxide sold as a conventional powder.

They found that the nanoparticles were twice as toxic to the cells as the larger particles.

Blame CO2 in blood for ‘near-death experiences’

Excess carbon dioxide in the blood could be the cause behind near-death experiences such as seeing “a bright light at the end of a tunnel”, according to a new study.

Near death experiences (NDEs) are reported to include sensations such as life flashing before the eyes, feelings of peace and joy, and apparent encounters with mystical entities.

To reach the conclusion, boffins investigated the unexplained events in 52 cardiac arrest patients. Zalika Klemenc-Ketis worked with a team of researchers from the University of Maribor, Slovenia, to examine patients who reported NDEs.

She said, “Several theories explaini1ng the mechanisms of NDEs exist. We found that in those patients who experienced the phenomenon, blood carbon dioxide levels were significantly higher than in those who did not”.

According to Zalika, “Our study adds new and important information to the field of NDE phenomena”.