Reliable study of more than 1,200 Japanese adults with high blood pressure found that people who slept for less than 7.5 hours each night were more likely to suffer a heart attack or stroke or die of cardiac arrest over a 4-year period. Man women who slept less than 7.5 hours per night experienced a 68% higher risk of heart attacks, cardiac arrest or strokes.

“Short sleepers” — people who fail to have a blood-pressure dip that normally occurs overnight were at even higher risk.

Waiting for latest study to appear in PubMed.gov

Other studies …

Eguchi K, Ishikawa J, Hoshide S, Pickering TG, Schwartz JE, Shimada K, Kario K. Night Time Blood Pressure Variability Is a Strong Predictor for Cardiovascular Events in Patients With Type 2 Diabetes.  Am J Hypertens. 2008 Oct 2.

Scientists studied 35 men and 36 women aged between 18 and 45. Some were exposed to radiation that exactly mimicked mobile phone radiation; others were placed in precisely the same conditions, but without radiation exposure.

The research showed that using the handsets before bed caused people to take longer to reach deeper stages of sleep and and in shorter intervals. Exposure to 884 MHz wireless disrupted sleep periods that involve the body’s ability to repair damage suffered during the day.

The sleep disturbance can lead to mood and personality changes, ADHD-like symptoms, depression, lack of concentration and poor academic performance, grouchiness, difficulty concentrating, and hyperactivity and behavior problems in children.

About half of the people in the study believed themselves to be “electrosensitive”, with claims of symptoms such as headaches and impaired cognitive function from mobile phone use, but they proved unable to tell if they had been exposed to the radiation in the test.

Published by the Massachusetts Institute of Technology’s Progress in Electromagnetics Research Symposium and funded by the Mobile Manufacturers Forum, representing the main handset companies.

Pubmed abstract not found.

See also …

Hillert L, Akerstedt T, Lowden A, Wiholm C, Kuster N, Ebert S, Boutry C, Moffat SD, Berg M, Arnetz BB. The effects of 884 MHz GSM wireless communication signals on headache and other symptoms: An experimental provocation study. Bioelectromagnetics. 2007 Nov 28

Sex – claims for the physiological benefits of sexual activity.

As research confirms time and time again, good sex in a healthy, stable, monogamous relationship can only better our physical, mental, emotional and spiritual well being.

Body composition, weight loss and weight control. Each person can burn  200 calories or more during 30 minutes of sex. The sexual act conditions strength, flexibility, muscle tone, and cardiovascular conditioning. The action that involves rhythmic pelvic tilting is especially good for the core muscles (the abdominal muscles and spinal muscles). Flexibility is also improved as positions are held. Some isometric and weight resistance action is also performed during sexual activity.

Prolonged sexual activity also has cardiovascular benefits.

Sex has been shown to offer migraine and menstrual cramp relief, as well as alleviate chronic back pain thanks to the endorphins and corticosteroids released during sexual arousal and orgasm.

Sex helps the way we respond to stress, increasing levels of oxytocin and stimulating feelings of warmth and relaxation. The quality of the sexual response also helps people monitor their physical and mental stress and physiological status.

Sex has also been associated with improved immunity.

Sex helps self-esteem and intimacy, especially when sex is consistent and involves mutual pleasure. Sex causes a surge in oxytocin at orgasm and  stimulates feelings of affection, intimacy, and closeness.

Sex releases endorphins during arousal and climax that can relieve depression and anxiety, and increase vibrancy. Sex improves overall attitude toward life and relationships. One study even concluded that components of semen which are absorbed through the vagina and enter the bloodstream may antagonize depressive symptoms.

Sex can be beneficial, spiritually, and lead to a better quality of life and a stronger spiritual relationship with your partner.

Sex, including masturbation, helps sleep and fights off insomnia.

Sex keeps you looking and feeling younger and, according to some research, may lead to shiny hair, a glowing complexion and bright eyes, mostly due to the increase secretion of the hormone DHEA (dehydroepiandrostone).

Research shows that there is a significant relationship between frequency of orgasm and risk of death, especially with men. Men who orgasm two times a week have a 50 percent lower chance of mortality than those who climax one time per month.

Decreased risk of breast cancer. One study of women who had never given birth found that an increased frequency of sexual intercourse was correlated with a decrease in the incidence of breast cancer.

Reproductive system health benefits: Sex may decrease a man’s risk of prostate cancer, and a woman’s risk of endometriosis. Sexual activity can also improve fertility in women by regulating menstrual patterns.

See also the introduction to this topic.

References:
Brody S.  Blood pressure reactivity to stress is better for people who recently had penile-vaginal intercourse than for people who had other or no sexual activity.
Biol Psychol. 2006 Feb;71(2):214-22. Epub 2005 Jun 14

Charnetski CJ, Brennan FX.  Sexual frequency and salivary immunoglobulin A (IgA).
Psychol Rep. 2004 Jun;94(3 Pt 1):839-44.

Davey Smith G, Frankel S, Yarnell J.  Sex and death: are they related? Findings from the Caerphilly Cohort Study. BMJ. 1997 Dec 20-27;315(7123):1641-4.

Gallup GG Jr, Burch RL, Platek SM.  Does semen have antidepressant properties?
Arch Sex Behav. 2002 Jun;31(3):289-93.

Sleep is the state of natural rest observed throughout the animal kingdom — all mammals and birds, and in many reptiles, amphibians, and fish. In humans, other mammals, and many other animals that have been studied, such as fish, birds, ants, and fruit-flies,  regular sleep is necessary for survival. The capability of arousal from sleep is a protective mechanism that is also necessary for health and survival.

UNDER CONSTRUCTION …

Sleep is generally characterized by a reduction in voluntary body movement, decreased to little reaction to external stimuli, loss of consciousness, reduction in audio receptivity, an increased rate of anabolism (the synthesis of cell structures), and a decreased rate of catabolism (the breakdown of cell structures).

In mammals, the measurement of eye movement during sleep is used to divide sleep into two categories or phases: rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. Each category has a distinct set of associated physiological, neurological and psychological features.

Sleep occurs in cycles of REM and NREM phases. In humans, this cycle is approximately 90 to 120 minutes. Each phase may have a distinct physiological function. Drugs such as alcohol and sleeping pills can suppress certain stages of sleep (see Sleep deprivation). This can result in a sleep that exhibits loss of consciousness but does not fulfill its physiological functions.

In the REM phase, the brain is active and the body inactive, and this is when most dreaming occurs. REM sleep is characterized by an electroencephalography (EEG) that has low voltage and mixed frequency — similar in appearance to the wakeful EEG. During REM sleep there is loss of skeletal muscle tone, and an active sympathetic nervous system. Also during REM sleep our muscles are paralyzed so that we don’t act out our dreams.

In the NREM sleep phase, the body is active and the brain is inactive, and there is relatively little dreaming. Non-REM encompasses four stages; stages 1 and 2 are considered ‘light sleep’, and 3 and 4 ‘deep sleep’. They are differentiated silence, or “drowsy sleep”. Associated with the onset of sleep during N1 may be sudden twitches and hypnic jerks. These are normal, as is an increased instance of flatulence[citation needed]. Other people may also experience hypnagogic hallucinations during this stage, which can be more troublesome to the subject. During N1 the subject loses some muscle tone, and conscious awareness of the external environment.

Stage N2, is characterized by “sleep spindles” (12 to 16 Hz) and “K-complexes.” During this stage the electromyography (EMG) lowers, and conscious awareness of the external environment disappears. This occupies 45 to 55% of total sleep.

In Stage N3, the delta waves, also called delta rhythms (0.5 to 4 Hz) make up less than 50% of the total wave-patterns. This is considered part of the slow-wave sleep (SWS) and functions primarily as a transition into stage N4. Overall it occupies 3 to 8% of total sleep time. This is the stage in which night terrors, bed wetting, sleepwalking, and sleep-talking occur.

In Stage N4, delta-waves make up more than 50% of the wave-patterns. Stages N3 and N4 are the deepest forms of sleep; N4 is effectively a deeper version of N3, in which the deep-sleep characteristic, such as delta-waves, are more pronounced.[1]

UNDER CONSTRUCTION …

An altered gene, named “after hours” or Afh, is a variant of a gene called Fbxl3, which had not been known to have any relationship to control of the body clock that keeps our metabolism, digestion and sleep patterns in tune with the rising and setting of the sun.

Instead of following the typical 24 hour pattern, a discovery showed that some mice had body clocks that stretched to up to a 27 hour day. Closer study of the DNA from the mice revealed that those on a 27-hour-cycle had the after hours or Afh version of the Fbxl3 gene — a large family of genes that controls the breakdown of specific proteins within body cells. Specifically, the mutation, a Cys358Ser substitution in Fbxl3, an F-box protein with leucine-rich repeats, results in long free-running rhythms of about 27 hours.

The internal body clocks of mice with the after hours gene run on a longer cycle than mice that have a normal copy of the gene with the 24 hour schedule. The body clock consists of interlocked cycles of proteins that wax and wane in cells. A key protein in the loop called CRY had a delayed rate of degradation.

Also noted, the circannual body calendar is reset every summer, when increased light inhibits the production of melatonin — important in the relationship to mood.

Sofia I. H. Godinho, Elizabeth S. Maywood, Linda Shaw, Valter Tucci, Alun R. Barnard, Luca Busino, Michele Pagano, Rachel Kendall, Mohamed M. Quwailid, M. Rosario Romero, John O’Neill, Johanna E. Chesham, Debra Brooker, Zuzanna Lalanne, Michael H. Hastings, and Patrick M. Nolan. The After-Hours Mutant Mouse Reveals a Role for Fbxl3 in Determining Mammalian Circadian Period. Published online 26 April 2007 [DOI: 10.1126/science.1141138] (in Science Express Reports).

Science

Men can take action to protect their sexual desires and abilities throughout life, especially by tending to physiological and emotional health. 

Jim Pfaus, a professor of psychology and neuroscience at Concordia University in Montreal who studies the biology of libido offers this advice. With some regular sex drive maintenance, sexual desire and performance can be lifelong. Frequent, stimulating sex keeps the brain wanting and expecting more sex later in life. Regular, cardio style or aerobic exercise also helps sex drive. Increased blood flow is physiological helpful to the physiology of arousal. The beneficial effect of exercise toward sexual performance is long lasting, not just immediate.

According to David Rowland, sex expert and professor of psychology at Valparaiso University, there’s no biological reason why an older man can’t continue with a strong libido.

Julian Davidson of Stanford University conducted research that concluded that sex drive can overcome decreased testosterone, the male hormone that promotes sex drive. He reported that about one-third of men with extremely low testosterone levels (often due to testicular disease) still had frequent, satisfying sex. He concluded that the men with persistent sex drive had a drive that did not require hormonal assistance.

It is also important to prevent obesity because male fat cells secrete estrogen, which can decrease sex drive. Obesity might mean more to love, but it can cause interference with body mechanics in sexual performance.

Maintain good circulation by avoiding smoking and avoiding excess drinking

Some types of stress can increase sexual drive, but other types of stress, especially prolonged stress, can decrease sexual drive. Relaxation and meditation procedures and physical exercise can help return sex drive.

It is also important to prevent chronic resentment, especially over a power struggle, or chronic routine can destroy sex drive in a relationship.

Sources:
Rowland DL, Greenleaf WJ,  Dorfman LJ,  Davidson JM. Aging and sexual function in men. Arch Sex Behav. 1993 Dec;22(6):545-57.

Davidson JM, Chen JJ, Crapo L, Gray GD, Greenleaf WJ, Catania JA.  Hormonal changes and sexual function in aging men. J Clin Endocrinol Metab. 1983 Jul;57(1):71-7.

No doubt a powerful and controversial subject, sex has many different meanings, results, benefits and risks.

STARTING WITH THE BENEFITS …
Sex as Exercise
Sexual activity can burn 150 calories in a half-hour, so you could view it as a form of exercise. All the same benefits of spending time in the gym, including cardio exercise and improved circulation, lower cholesterol, elevated good cholesterol, flexibility, isometric and dynamic muscular exercise, and the release of feel-good endorphins.

Sex as an Immune Booster
Dr. Carl Charnetski, professor of psychology at Wilkes University in Wilkes-Barre, Pa studied 112 college students, who reported the frequency of their sexual encounters and were divided into four categories: none, infrequent (less than once a week), frequent (one to two times per week), and very frequent (three or more times per week).  Individuals in the frequent group showed significantly higher levels of IgA than the other three groups.

Sex as a Mood Booster
People who have regular sex know that they handle stress better, feel relaxed and sleep better. A study by Stuart Brody of the University of Paisley in Scotland found that penile-vaginal intercourse, but not other sexual activity was associated with better psychological and physiological function. People who had penile-vaginal intercourse had lower baseline BP and lower BP reactivity to stress of public speaking and verbal arithmetic compared to people who had sexual activity without penile-vaginal intercourse or people who had no sexual activity.

Sex and Longevity
Research by Smith and others at the University of Bristol studied 918 men aged 45-59 in the town of Caerphilly, South Wales and five adjacent villages. All deaths and deaths from coronary heart disease were compared to orgasmic frequency. Mortality risk was 50% lower in the group with high orgasmic frequency compared to the group with low orgasmic frequency. Deaths were most marked for coronary artery disease-related deaths.

————————————-
References:
Brody S.  Blood pressure reactivity to stress is better for people who recently had penile-vaginal intercourse than for people who had other or no sexual activity.
Biol Psychol. 2006 Feb;71(2):214-22. Epub 2005 Jun 14

Charnetski CJ, Brennan FX.  Sexual frequency and salivary immunoglobulin A (IgA).
Psychol Rep. 2004 Jun;94(3 Pt 1):839-44.

Davey Smith G, Frankel S, Yarnell J.  Sex and death: are they related? Findings from the Caerphilly Cohort Study. BMJ. 1997 Dec 20-27;315(7123):1641-4.

Gallup GG Jr, Burch RL, Platek SM.  Does semen have antidepressant properties?
Arch Sex Behav. 2002 Jun;31(3):289-93.