2016-04-11

masturbation the #healthy #sin

partial transcript of Masturbation Myths | Teesha Morgan | TEDxStanleyPark
with some supporting research.

4.10..11: health/masturbation/the healthy sin:

. a sex therapist says those who visit most
are women are afraid to masturbate
and then complain about not getting an orgasm;
whereas the men often do masturbate
to the exclusion of other outlets.
. if a man masturbates quickly,
there may be problems with lasting longer during couple sex;
. men who are aroused by unusual porn
may have arousal problems during couple sex.
. to enhance couple sex,
make your masturbation more like your couple sex.

. women who do use devices such as vibrators
are not less prone to get orgasm from a penis;
in fact, women who masturbate in any way,
are more prone to orgasm from a penis.
. some women insert dildos into their vagina,
but most women use clitoral hood stimulation.
. you only see the clitoris tip as a button,
but the clitoris is 9-12cm long; 6cm wide.

. those in dating relationships are more likely to masturbate
than those who are single.
men masturbate more than women
homosexual men more than other men;
but african americans less than other races;
5% of men and 11% of women never masturbate.
. as would be expected,
younger masturbate more than older;
highly educated more than less educated;
and non-religious more than christians
(in fact, roman catholics consider it sinful);
[they apparently adopted this from Judaists].

. masturbation is healthy
enhancing sleep and immune function;
women who masturbated during their period
can reduce the risk of menstrual cramps.
. pre-adolescent and even infantile masturbation
is normal (not "hypersexual").

. masturbation doesn't reduce fertility;
[daily ejaculation obviously might reduce
the numbers of sperm per ejaculation;
but, sperm often survive 2-3 days
in the woman's fertile cervical fluid;
so, the woman can accumulate 3 day's worth of ejaculations;
and therefore fertile sex can be done daily
without concern for sperm count per ejaculation.
. conversely, stale sperm reduces fertility
so ejaculate at least once per week.
[Dr. Renee Hanton] ]

[also consider it to be prostate exercise:
. even small levels of masturbation in a man's 50s
could offer protection from prostate cancer.
[Dimitropoulou BJU Int. 2009]

. the Health Professionals Follow-up Study
(February 1, 1992, through January 31, 2000)
of 29,342 US men aged 46 to 81 years,
who provided information on history of ejaculation frequency
on a self-administered questionnaire in 1992
and responded to follow-up questionnaires every 2 years to 2000.
Ejaculation frequency was assessed by asking participants
to report the average number of ejaculations they had
per month during the ages of 20 to 29 years,
40 to 49 years, and during the past year (1991).
Most categories of ejaculation frequency were
unrelated to risk of prostate cancer.
However, high ejaculation frequency was related to
decreased risk of total prostate cancer.

The multivariate relative risks for men reporting
21 or more ejaculations per month
compared with men reporting 4 to 7 ejaculations per month
at ages 20 to 29 years were
0.89 (95% confidence interval [CI], 0.73-1.10);
ages 40 to 49 years,
0.68 (95% CI, 0.53-0.86);
previous year,
0.49 (95% CI, 0.27-0.88);
and averaged across a lifetime,
0.67 (95% CI, 0.51-0.89).
. perhaps a reduced ejaculatory output in otherwise normal men
is an etiologic risk factor for prostate cancer.
That proposition is based on the theory that
infrequent ejaculation increases the risk of prostate cancer
because of retained carcinogenic secretions in the prostatic acini.
[Prostate 1983]
A further hypothesis implicates repression of sexuality
as a risk factor for prostate cancer
and is derived from reports of greater sexual drive
coupled with deprived sexual activity
[Cancer Treat Reports 1977]
and greater interest in more sexual intercourse
[J Chronic Dis.1971]
than experienced among prostate cancer cases compared with controls.

We only evaluated ejaculation frequency during adulthood,
but not during adolescence.
The peripubertal period may be of etiologic significance
with respect to prostate carcinogenesis
because prostate epithelial cell differentiation
occurs at this critical period.22
If ejaculation frequency during puberty was
most important for prostate carcinogenesis,
measuring adult ejaculation frequency would fail to capture
the relevant period of exposure.
However, our findings suggest that
ejaculation frequency during mid and late adulthood
rather than in early adulthood
are etiologically relevant periods for influencing prostate tumors.
Because the inverse relation was observed for
organ-confined cases but not advanced cases,
sexual activity may be hypothesized only to affect
slow-growing, early stage prostate cancers.
Our results are generalizable to
white US men aged 46 years or older.

Previous investigations on reported
ejaculation frequencies or sexual intercourse
and prostate cancer are limited to studies of
retrospective design and results are mixed.
Nine studies observed a statistically significant1,23- 27
or nonsignificant28- 30 positive association;
3 studies27,31,32 reported no association;
7 studies found a statistically significant4,5,10,33
or nonsignificant34- 36 inverse relationship;
and 1 study37 found a U-shaped relationship.

Nine4,24,25,27,30- 32,35,36 of the aforementioned studies
found little or no variation in prostate cancer risk
according to sexual activity during different ages.
However, 1 study35 observed a nonsignificant inverse association
between sexual activity before the age of 30 years and prostate cancer,
and no relationship with sexual activity in later life.
In contrast, 2 other studies38,39 reported a positive association
between frequency of sexual intercourse before ages 50 to 60 years
and prostate cancer
and an inverse relationship for frequency of sexual intercourse
after age 60 years.
A recent meta-analysis9 of these studies1,4,5,23- 39
reported RRs for sexual activity at 3 times per week of
1.14 (95% CI, 0.98-1.31) during the third decade of life,
1.24 (95% CI, 1.05-1.46) during the fifth decade, and
0.68 (95% CI, 0.51-0.91) during the seventh decade.
That meta-analysis9 noted the somewhat inconsistent association
between frequency of sexual activity
and risk of prostate cancer in previous studies.

Several features distinguish our analysis from
previous reports on sexual activity and prostate cancer.
First, the prospective study design precluded
bias attributable to differential recall of sexual activity
by men with and without prostate cancer.
Second, we focused on ejaculation frequency
rather than on frequency of sexual intercourse,
which enhanced exposure variability
and allowed us to explore the physiological effects of sexual function per se.
Third, our analysis included nearly 50% more cases
than the number of cases included in any of the previous studies
reporting on sexual activity and prostate cancer.
Fourth, our study had data on PSA tests,
which allowed us to address the possibility of detection bias.
Finally, because we controlled for a wide range of
medical, lifestyle, and dietary factors,
potential confounding by these factors was likely minimized.
[JAMA. 2004] ]