What’s your ZU-B?

You may literally have to add it to your to-do list, but scheduling a good night’s sleep could be one of the smartest health priorities you set. It’s not just daytime drowsiness you risk when shortchanging yourself on your seven to eight hours. Possible health consequences of getting too little or poor sleep can involve the cardiovascular, endocrine, immune and nervous systems. In addition to letting life get in the way of good sleep, between 50 and 70 million Americans suffer from a chronic sleep disorder—insomnia or sleep apnea, say—that affects daily functioning and impinges on health. Consider the research:

1) Less may mean more. For people who sleep under seven hours a night, the fewer zzzz’s they get, the more obese they tend to be, according to a 2006 Institute of Medicine (IOM) report. This may relate to the discovery that insufficient sleep appears to tip hunger hormones out of whack. Leptin, which suppresses appetite, is lowered; ghrelin, which stimulates appetite, gets a boost.

2) You’re more apt to make bad food choices. A study published in the October 15, 2008 issue of the Journal of Clinical Sleep Medicine found that people with obstructive sleep apnea or other severely disordered breathing while asleep ate a diet higher in cholesterol, protein, total fat, and total saturated fat. Women were especially affected.

3) Diabetes and impaired glucose tolerance, its precursor, may become more likely. A 2005 study published in the Archives of Internal Medicine found that people getting five or fewer hours of sleep each night were 2.5 times more likely to be diabetic, while those with six hours or fewer were 1.7 times more likely.

4) The ticker is put at risk. A 2003 study found that heart attacks were 45 percent more likely in women who slept for five or fewer hours per night than in those who got more.

5) Blood pressure may increase. Obstructive sleep apnea, for example, has been associated with chronically elevated daytime blood pressure, and the more severe the disorder, the more significant the hypertension, suggests the 2006 IOM report. Obesity plays a role in both disorders, so losing weight can ease associated health risks.

6) Auto accidents rise. As stated in a 2007 report in the New England Journal of Medicine, nearly 20 percent of serious car crash injuries involve a sleepy driver—and that’s independent of alcohol use.

7) Balance is off. Older folks who have trouble getting to sleep, who wake up at night, or are drowsy during the day could be 2 to 4.5 times more likely to sustain a fall, found a 2007 study in the Journal of Gerontology.

You may be more prone to depression. Adults who chronically operate on fumes report more mental distress, depression, and alcohol use. Adolescents suffer, too: One survey of high school students found similarly high rates of these issues. Middle schoolers, too, report more symptoms of depression and lower self-esteem.

9) Kids may suffer more behavior problems. Research from an April issue of the Archives of Pediatric and Adolescent Medicine found that children who are plagued by insomnia, short duration of sleeping, or disordered breathing with obesity, for example, are more likely to have behavioral issues like attention deficit hyperactivity disorder.

10) Death’s doorstep may be nearer. According to three large studies published in the journals Sleep and the Archives of General Psychiatry, people over age 30 who slept five hours or less per night had approximately a 15 percent greater risk of dying—regardless of the cause—over the periods studied, which ranged from six to 14 years.

Antioxidant-rich extracts from green tea may reduce the effects of oxidative stress caused by breathing problems while people are sleeping, according to US researchers.

As such, people with this disorder are said to be at risk of oxidative stress and exhibit changes in their brain tissue in areas involved in learning and memory.

Supplements of green tea extracts may counter the cognitive deficits that may occur, suggests a new study with rats, published in American Journal of Respiratory and Critical Care Medicine.

If the results of the study can be repeated in humans, green tea and its extracts may offer a potential interventional strategy for people with the disorder, reported to be in the region of 12 million or so people in the US, according to the National Institutes of Health.

“OSA has been increasingly recognized as a serious and frequent health condition with potential long-term morbidities that include learning and psychological disabilities,” wrote lead researcher David Gozal from the University of Louisville.

Study details

Human OSA was modelled in rats by intermittently depriving the animals of oxygen during 12-hour “night” cycles for 14 days - intermittent hypoxia (IH). The researchers divided the 106 male rats into two groups, with one group assigned to receive drinking water containing green tea polyphenols.

The University of Louisville researchers, in collaboration with scientists from Soroka University Medical Center, then tested the animals for markers of inflammation and oxidative stress, in addition to using a water maze to test their performance in spatial learning and memory tasks.

They report that rats that received the green tea polyphenol (GTP)-supplemented water performed significantly better in a water maze than the rats that drank plain water.

Moreover, levels of malondialdehyde (MDA), a reactive carbonyl compound and a well-established marker of oxidative stress, were 40 per cent lower in the GTP-supplemented animals, added the researchers.

“GTP-[supplemented] rats exposed to IH displayed significantly greater spatial bias for the previous hidden platform position, indicating that GTPs are capable of attenuating IH-induced spatial learning deficits,” wrote Gozal.

“Because oxidative processes underlie neurocognitive deficits associated with IH, the potential therapeutic role of GTP in sleep-disordered breathing deserves further exploration,” he added.

Antioxidant activity

The benefits of the green tea extracts were attributed to the antioxidant properties of green tea polyphenols. “Recent studies have demonstrated the neuroprotective activity of GTP in animal models of neurodegenerative conditions such as Parkinson’s and Alzheimer’s disease,” wrote Gozal.

Green tea is said to contain over four times the concentration of antioxidant catechins than black tea (green tea leaves that have been oxidized by fermentation), about 70 mg catechins per 100 mL compared to 15 mg per 100 mL for black tea.

The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.

Source: American Journal of Respiratory and Critical Care Medicine
Volume 177, Pages 1135-1141, doi:10.1164/rccm.200701-110OC
“Green Tea Catechin Polyphenols Attenuate Behavioral and Oxidative Responses to Intermittent Hypoxia”
Authors: I.C. Burckhardt, D. Gozal, E. Dayyat, Y. Cheng, R.C. Li, A.D. Goldbart, B.W. Row