Causes of acne

Acne develops as a result of blockages in follicles. Hyperkeratinization and formation of a plug of keratin and sebum (a microcomedo) is the earliest change. Enlargement of sebaceous glands and an increase in sebum production occur with increased androgen (DHEA-S) production at adrenarche. The microcomedo may enlarge to form an open comedone (blackhead) or closed comedone (whitehead). Whiteheads are the direct result of skin pores becoming clogged with sebum, a naturally occurring oil, and dead skin cells. In these conditions the naturally occurring largely commensal bacteria Propionibacterium acnes can cause inflammation, leading to inflammatory lesions (papules, infected pustules, or nodules) in the dermis around the microcomedo or comedone, which results in redness and may result in scarring or hyperpigmentation.

Primary causes

The root causes of why some people get acne and some do not are not fully known.^{[citation needed]} It is known to be partly hereditary. Several factors are known to be linked to acne:

• Family/Genetic history. The tendency to develop acne runs in families. For example, school-age boys with acne often have other members in their family with acne as well. A family history of acne is associated with an earlier occurrence of acne and an increased number of retentional acne lesions.^[11]
• Hormonal activity, such as menstrual cycles and puberty. During puberty, an increase in male sex hormones called androgens cause the follicular glands to get larger and make more sebum.^[12]
• Inflammation, skin irritation or scratching of any sort will activate inflammation. Anti-inflammatories are known to improve acne.^{[citation needed]}
• Stress, through increased output of hormones from the adrenal (stress) glands.^{[citation needed]} While the connection between acne and stress has been debated, scientific research indicates that "increased acne severity" is "significantly associated with increased stress levels."^[13] The National Institutes of Health list stress as a factor that "can cause an acne flare."^[14] A study of adolescents in Singapore "observed a statistically significant positive correlation […] between stress levels and severity of acne."^[15]
• Hyperactive sebaceous glands, secondary to the three hormone sources above.
• Accumulation of dead skin cells that block or cover pores.^{[citation needed]}
• Bacteria in the pores. Propionibacterium acnes (P. acnes) is the anaerobic bacterium that causes acne. In-vitro resistance of P. acnes to commonly used antibiotics has been increasing.^[16]
• Use of anabolic steroids.^[17]
• Any medication containing lithium, barbiturates or androgens.^{[citation needed]}
• Exposure to certain chemical compounds. Chloracne is particularly linked to toxic exposure to dioxins, namely Chlorinated dioxins.^{[citation needed]}
• Exposure to halogens. Halogen acne is linked to exposure to halogens (e.g. iodides, chlorides, bromides, fluorides).^{[citation needed]}
• Chronic use of amphetamines or other similar drugs.^[18]

Several hormones have been linked to acne: the androgens testosterone, dihydrotestosterone (DHT) and dehydroepiandrosterone sulfate (DHEAS), as well as insulin-like growth factor 1 (IGF-I). In addition, acne-prone skin has been shown to be insulin resistant.^{[citation needed]}

Development of acne vulgaris in later years is uncommon, although this is the age group for Rosacea which may have similar appearances. True acne vulgaris in adult women may be a feature of an underlying condition such as pregnancy and disorders such as polycystic ovary syndrome or the rare Cushing's syndrome. Menopause-associated acne occurs as production of the natural anti-acne ovarian hormone estradiol fails at menopause. The lack of estradiol also causes thinning hair, hot flashes, thin skin, wrinkles, vaginal dryness, and predisposes to osteopenia and osteoporosis as well as triggering acne (known as acne climacterica in this situation)

Diet

Chocolate

The popular belief that consumption of chocolate can cause acne is not supported by scientific studies.^[19][20] As discussed below, various studies point not to chocolate, but to the high glycemic nature of certain foods containing simple carbohydrates as a cause of acne. Chocolate itself has a low glycemic index.^[21]

Milk

Recently, three epidemiological studies from the same group of scientists found an association between acne and consumption of partially skimmed milk, instant breakfast drink, sherbet, cottage cheese, and cream cheese.^[22][23][24] The researchers hypothesize that the association may be caused by hormones (such as several sex hormones and bovine insulin-like growth factor 1 (IGF-1)) or even iodine^[25] present in cow milk.

Carbohydrates

The long-held belief that there is no link between diets high in refined sugars and processed foods, and acne, has recently been challenged.^[26] The previous belief was based on earlier studies (some using chocolate and Coca Cola) that were methodologically flawed.^[26][27][28] The recent low glycemic-load hypothesis postulates that rapidly digested carbohydrate foods (such as soft drinks, sweets, white bread) produce an overload in blood glucose (hyperglycemia) that stimulates the secretion of insulin, which in turn triggers the release of IGF-1.^[26] IGF-1 has direct effects on the pilosebaceous unit (and insulin at high concentrations can also bind to the IGF-1 receptor)^[29] and has been shown to stimulate hyperkeratosis and epidermal hyperplasia.^[30] These events facilitate acne formation. Sugar consumption might also influence the activity of androgens via a decrease in sex hormone-binding globulin concentration.^[31][32]

In support of this hypothesis, a randomized controlled trial of a low glycemic-load diet improved acne and reduced weight, androgen activity and levels of insulin-like growth factor binding protein-1.^[33] High IGF-1 levels and mild insulin resistance (which causes higher levels of insulin) had previously been observed in patients with acne.^[34][35][36] High levels of insulin and acne are also both features of polycystic ovarian syndrome.^[26]

According to this hypothesis, the absence of acne in some non-Westernized societies could be explained by the low glycemic index of these cultures' diets.^[37] It is possible that genetic reasons account for there being no acne in these populations, although similar populations (such as South American Indians or Pacific Islanders) do develop acne.^[38][39] Note also that the populations studied consumed no milk or other dairy products.^[40]

Further research is necessary to establish whether a reduced consumption of high-glycemic foods, or treatment that results in increased insulin sensitivity (like metformin) can significantly alleviate acne, though consumption of high-glycemic foods should in any case be kept to a minimum, for general health reasons.^[41] Avoidance of "junk food" with its high fat and sugar content is also recommended.^[42]

Vitamins A and E

Studies have shown that newly diagnosed acne patients tend to have lower levels of vitamin A circulating in their bloodstream than those who are acne free.^[43] In addition people with severe acne also tend to have lower blood levels of vitamin E.^[44]

Hygiene

Acne is not caused by dirt. This misconception probably comes from the fact that blackheads look like dirt stuck in the openings of pores. The black color is not dirt but simply oxidised keratin. In fact, the blockages of keratin that cause acne occur deep within the narrow follicle channel, where it is impossible to wash them away. These plugs are formed by the failure of the cells lining the duct to separate and flow to the surface in the sebum created there by the body. Built-up oil of the skin can block the passages of these pores, so standard washing of the face could wash off old oil and help unblock the pores.

Treatments

Available treatments

There are many products available for the treatment of acne, many of which are without any scientifically proven effects. Generally speaking, successful treatments show little improvement within the first two weeks, instead taking a period of approximately three months to improve and start flattening out.^{[citation needed]} Many treatments that promise big improvements within two weeks are likely to be largely disappointing.^{[citation needed]} However, short bursts of cortisone can give very quick results, and other treatments can rapidly improve some active spots, but usually not all active spots.^{[citation needed]}

Modes of improvement are not necessarily fully understood but in general treatments are believed to work in at least 4 different ways (with many of the best treatments providing multiple simultaneous effects):

• normalising shedding into the pore to prevent blockage
• killing Propionibacterium acnes
• anti-inflammatory effects
• hormonal manipulation

A combination of treatments can greatly reduce the amount and severity of acne in many cases. Those treatments that are most effective tend to have greater potential for side effects and need a greater degree of monitoring, so a step-wise approach is often taken. Many people consult with doctors when deciding which treatments to use, especially when considering using any treatments in combination. There are a number of treatments that have been proven effective

Topical bactericidals

Widely available OTC bactericidal products containing benzoyl peroxide may be used in mild to moderate acne. The gel or cream containing benzoyl peroxide is rubbed, twice daily, into the pores over the affected region. Bar soaps or washes may also be used and vary from 2 to 10% in strength. In addition to its therapeutic effect as a keratolytic (a chemical that dissolves the keratin plugging the pores) benzoyl peroxide also prevents new lesions by killing P. acnes. In one study, roughly 70% of participants using a 10% benzoyl peroxide solution experienced a reduction in acne lesions after six weeks.^[45] Unlike antibiotics, benzoyl peroxide has the advantage of being a strong oxidizer and thus does not appear to generate bacterial resistance. However, it routinely causes dryness, local irritation and redness. A sensible regimen may include the daily use of low-concentration (2.5%) benzoyl peroxide preparations, combined with suitable non-comedogenic moisturisers to help avoid overdrying the skin.

Care must be taken when using benzoyl peroxide, as it can very easily bleach any fabric or hair it comes in contact with.

Other antibacterials that have been used include triclosan, or chlorhexidine gluconate. Though these treatments are often less effective, they also have fewer side-effects.

Prescription-strength benzoyl peroxide preparations do not necessarily differ with regard to the maximum concentration of the active ingredient (10%), but the drug is made available dissolved in a vehicle that more deeply penetrates the pores of the skin.

Topical antibiotics

Externally applied antibiotics such as erythromycin, clindamycin, azelaic acid or tetracycline kill the bacteria that are harbored in the blocked follicles. While topical use of antibiotics is equally as effective as oral use, this method avoids possible side effects including upset stomach and drug interactions (e.g. it will not affect use of the oral contraceptive pill), but may prove awkward to apply over larger areas than just the face alone.

Oral antibiotics

Oral antibiotics used to treat acne include erythromycin or one of the tetracycline antibiotics (tetracycline, the better absorbed oxytetracycline, or one of the once daily doxycycline, minocycline, or lymecycline). Trimethoprim is also sometimes used (off-label use in UK). However, reducing the P. acnes bacteria will not, in itself, do anything to reduce the oil secretion and abnormal cell behaviour that is the initial cause of the blocked follicles. Additionally the antibiotics are becoming less and less useful as resistant P. acnes are becoming more common. Acne may return soon after the end of treatment—days later in the case of topical applications, and weeks later in the case of oral antibiotics. Furthermore, side effects of tetracycline antibiotics can include yellowing of the teeth and an imbalance of gut flora, so are only recommended after topical products have been ruled out.

It has been found that sub-antimicrobial doses of antibiotics such as minocycline also improve acne. It is believed that minocycline's anti-inflammatory effect also prevents acne.

Hormonal treatments

In females, acne can be improved with hormonal treatments. The common combined oestrogen/progestogen methods of hormonal contraception have some effect, but the antiandrogen, Cyproterone, in combination with an oestrogen (Diane 35) is particularly effective at reducing androgenic hormone levels. Diane-35 is not available in the USA, but a newer oral contraceptive containing the progestin drospirenone is now available with fewer side effects than Diane 35 / Dianette. Both can be used where blood tests show abnormally high levels of androgens, but are effective even when this is not the case. Along with this, treatment with low dose spironolactone can have anti-androgenetic properties, especially in patients with polycystic ovarian syndrome.

If a pimple is large and/or does not seem to be affected by other treatments, a dermatologist may administer an injection of cortisone directly into it, which will usually reduce redness and inflammation almost immediately. This has the effect of flattening the pimple, thereby making it easier to cover up with makeup, and can also aid in the healing process. Side effects are minimal, but may include a temporary whitening of the skin around the injection point; and occasionally a small depression forms, which may persist, although often fills eventually. This method also carries a much smaller risk of scarring than surgical removal.

Topical retinoids

A group of medications for normalizing the follicle cell lifecycle are topical retinoids such as tretinoin (brand name Retin-A), adapalene (brand name Differin), and tazarotene (brand name Tazorac). Like isotretinoin, they are related to vitamin A, but they are administered as topicals and generally have much milder side effects. They can, however, cause significant irritation of the skin. The retinoids appear to influence the cell creation and death lifecycle of cells in the follicle lining. This helps prevent the hyperkeratinization of these cells that can create a blockage. Retinol, a form of vitamin A, has similar but milder effects and is used in many over-the-counter moisturizers and other topical products. Effective topical retinoids have been in use over 30 years but are available only on prescription so are not as widely used as the other topical treatments. Topical retinoids often cause an initial flare up of acne and facial flushing.

Oral retinoids

Main article: isotretinoin

A daily oral intake of vitamin A derivative isotretinoin (marketed as Accutane, Amnesteem, Sotret, Claravis, Clarus) over a period of 4–6 months can cause long-term resolution or reduction of acne. It is believed that isotretinoin works primarily by reducing the secretion of oils from the glands, however some studies suggest that it affects other acne-related factors as well. Isotretinoin has been shown to be very effective in treating severe acne and can either improve or clear well over 80% of patients. The drug has a much longer effect than anti-bacterial treatments and will often cure acne for good. The treatment requires close medical supervision by a dermatologist because the drug has many known side effects (many of which can be severe). About 25% of patients may relapse after one treatment. In those cases, a second treatment for another 4–6 months may be indicated to obtain desired results. It is often recommended that one lets a few months pass between the two treatments, because the condition can actually improve somewhat in the time after stopping the treatment and waiting a few months also gives the body a chance to recover. Occasionally a third or even a fourth course is used, but the benefits are often less substantial. The most common side effects are dry skin and occasional nosebleeds (secondary to dry nasal mucosa). Oral retinoids also often cause an initial flare up of acne within a month or so, which can be severe. There are reports that the drug has damaged the liver of patients. For this reason, it is recommended that patients have blood samples taken and examined before and during treatment. In some cases, treatment is terminated or reduced due to elevated liver enzymes in the blood, which might be related to liver damage. Others claim that the reports of permanent damage to the liver are unsubstantiated, and routine testing is considered unnecessary by some dermatologists. Blood triglycerides also need to be monitored. However, routine testing are part of the official guidelines for the use of the drug in many countries. Some press reports suggest that isotretinoin may cause depression but as of September 2005 there is no agreement in the medical literature as to the risk. The drug also causes birth defects if women become pregnant while taking it or take it while pregnant. For this reason, female patients are required to use two separate forms of birth control or vow abstinence while on the drug. Because of this, the drug is supposed to be given to females as a last resort after milder treatments have proven insufficient. Restrictive rules (see iPledge program) for use were put into force in the USA beginning in March 2006 to prevent misuse, causing occasioned widespread editorial comment.^[46]

Phototherapy

'Blue' and red light

Light exposure has long been used as a short term treatment for acne. Recently, visible light has been successfully employed to treat mild to moderate acne (phototherapy or deep penetrating light therapy) - in particular intense violet light (405-420 nm) generated by purpose-built fluorescent lighting, dichroic bulbs, LEDs or lasers. Used twice weekly, this has been shown to reduce the number of acne lesions by about 64%^[47] and is even more effective when applied daily. The mechanism appears to be that a porphyrin (Coproporphyrin III) produced within P. acnes generates free radicals when irradiated by 420 nm and shorter wavelengths of light.^[48] Particularly when applied over several days, these free radicals ultimately kill the bacteria.^[49] Since porphyrins are not otherwise present in skin, and no UV light is employed, it appears to be safe, and has been licensed by the U.S. FDA.^[50][51]

The treatment apparently works even better if used with a mixture of the violet light and red visible light (660 nanometer) resulting in a 76% reduction of lesions after three months of daily treatment for 80% of the patients;^[52] and overall clearance was similar or better than benzoyl peroxide. Unlike most of the other treatments few if any negative side effects are typically experienced, and the development of bacterial resistance to the treatment seems very unlikely. After treatment, clearance can be longer lived than is typical with topical or oral antibiotic treatments; several months is not uncommon. The equipment or treatment, however, is relatively new and reasonably expensive to buy initially, although the total cost of ownership can be similar to many other treatment methods (such as the total cost of benzoyl peroxide, moisturizer, washes) over a couple of years of use.

Photodynamic therapy

In addition, basic science and clinical work by dermatologists Yoram Harth and Alan Shalita and others has produced evidence that intense blue/violet light (405-425 nanometer) can decrease the number of inflammatory acne lesion by 60-70% in four weeks of therapy, particularly when the P. acnes is pretreated with delta-aminolevulinic acid (ALA), which increases the production of porphyrins. However this photodynamic therapy is controversial and apparently not published in a peer reviewed journal. A phase II trial, while it showed improvement occurred, failed to show improved response compared to the blue/violet light alone.^[53]

Laser treatment

Laser surgery has been in use for some time to reduce the scars left behind by acne, but research has been done on lasers for prevention of acne formation itself. The laser is used to produce one of the following effects:

• to burn away the follicle sac from which the hair grows
• to burn away the sebaceous gland which produces the oil
• to induce formation of oxygen in the bacteria, killing them

Since lasers and intense pulsed light sources cause thermal damage to the skin, there are concerns that laser or intense pulsed light treatments for acne will induce hyperpigmented macules (spots) or cause long-term dryness of the skin.

In the United States, the FDA has approved several companies, such as Candela Corp., to use a cosmetic laser for the treatment of acne. However, efficacy studies have used very small sample sizes (fewer than 100 subjects) for periods of six months or less, and have shown contradictory results.^[54] Also, laser treatment being relatively new, protocols remain subject to experimentation and revision,^[55] and treatment can be quite expensive. Also, some Smoothbeam laser devices had to be recalled due to coolant failure, which resulted in painful burn injuries to patients.^[56]

Less widely used treatments

• Aloe vera: there are treatments for acne mentioned in Ayurveda using herbs such as Aloe vera, Neem, Haldi (Turmeric) and Papaya. There is limited evidence from medical studies on these products.^[57] Products from Rubia cordifolia, Curcuma longa (commonly known as Turmeric), Hemidesmus indicus (known as ananthamoola or anantmula), and Azadirachta indica (Neem) have been shown to have anti-inflammatory effects, but not aloe vera.^[58]
• Azelaic acid (brand names Azelex, Finevin and Skinoren) is suitable for mild, comedonal acne.^[59]
• Calendula used in suspension is used as an anti-inflammatory agent.^[60]
• Cortisone injection into spots, also cortisone pills are sometimes used.
• Heat: local heating may be used to kill the bacteria in a developing pimple and so speed healing.^[61]
• Naproxen or ibuprofen^[62] are used for some moderate acne for their anti-inflammatory effect.
• Nicotinamide, (Vitamin B3) used topically in the form of a gel, has been shown in a 1995 study to be of comparable efficacy to topical clindamycin topical antibiotic used for comparison.^[63] Topical nicotinamide is available both on prescription and over-the-counter. The property of topical nicotinamide's benefit in treating acne seems to be its anti-inflammatory nature. It is also purported to result in increased synthesis of collagen, keratin, involucrin and flaggrin and may also according to a cosmetic company be useful for reducing skin hyperpigmentation (acne scars), increased skin moisture and reducing fine wrinkles.^[64]
• Tea tree oil (melaleuca oil) dissolved in a carrier (5% strength) has been used with some success, where it is comparable to benzoyl peroxide but without excessive drying, kills P. acnes, and has been shown to be an effective anti-inflammatory in skin infections.^[57][65][66]
• Rofecoxib was shown to improve premenstrual acne vulgaris in a placebo controlled study.^[67]
• Zinc: Orally administered zinc gluconate has been shown to be effective in the treatment of inflammatory acne, although less so than tetracyclines.^[68][69]
• Comedo extraction
• Pantothenic acid, (high dosage Vitamin B5)^[70]
• Detoxification is a common method used by alternative medicine practitioners for the treatment of acne, although there have been no studies to prove its success. Detoxification is the process of cleansing the body of toxins purportedly caused by the environment, pharmaceutical drugs, food, and cosmetics.

Acne

Acne vulgaris (commonly called acne) is a common skin condition, caused by changes in the pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland via androgen stimulation. It is characterized by noninflammatory follicular papules or comedones and by inflammatory papules, pustules, and nodules in its more severe forms. Acne vulgaris affects the areas of skin with the densest population of sebaceous follicles; these areas include the face, the upper part of the chest, and the back. Severe acne is inflammatory, but acne can also manifest in noninflammatory forms.^[1] Acne lesions are commonly referred to as pimples, blemishes, spots, zits, or acne.

Acne is most common during adolescence, affecting more than 85% of teenagers, and frequently continues into adulthood. The cause in adolescence is generally an increase in male sex hormones, which people of both genders accrue during puberty.^[2] For most people, acne diminishes over time and tends to disappear—or at the very least decrease—after one reaches one's early twenties. There is, however, no way to predict how long it will take to disappear entirely, and some individuals will carry this condition well into their thirties, forties and beyond.^[3]

The face and upper neck are the most commonly affected, but the chest, back and shoulders may have acne as well. The upper arms can also have acne, but lesions found there are often keratosis pilaris, not acne. Typical acne lesions are comedones, inflammatory papules, pustules and nodules. Some of the large nodules were previously called "cysts" and the term nodulocystic has been used to describe severe cases of inflammatory acne.^[4]

Aside from scarring, its main effects are psychological, such as reduced self-esteem^[5] and, according to at least one study, depression or suicide.^[6] Acne usually appears during adolescence, when people already tend to be most socially insecure. Early and aggressive treatment is therefore advocated by some to lessen the overall impact to individuals.

Terminology

The term acne comes from a corruption of the Greek άκμή (acne in the sense of a skin eruption) in the writings of Aëtius Amidenus. Used by itself, the term "acne" refers to the presence of pustules and papules.^[7] The most common form of acne is known as "acne vulgaris", meaning "common acne". Many teenagers get this type of acne. Use of the term "acne vulgaris" implies the presence of comedones.^[8]

The term "acne rosacea" is a synonym for rosacea, however some individuals may have almost no acne comedones associated with their rosacea and prefer therefore the term rosacea.^[9] Chloracne is associated with chlorine toxicity.

Weight loss

Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue. It can occur unintentionally due to an underlying disease or can arise from a conscious effort to improve a perceived overweight or obese state.

Unintentional weight loss

Poor management of type 1 diabetes mellitus, also known as insulin-dependent diabetes mellitus (IDDM), leads to an excessive amount of glucose and an insufficient amount of insulin in the bloodstream. This triggers the release of triglycerides from adipose (fat) tissue and catabolism (breakdown) of amino acids in muscle tissue. This results in a loss of both fat and lean mass, leading to a significant reduction in total body weight. Note that untreated type 1 diabetes mellitus will usually not produce weight loss, as these patients get acutely ill before they would have had time to lose weight.

Myriad additional scientific considerations are applicable to weight loss: physiological and exercise sciences, nutrition science, behavioral sciences, and other sciences.

One area involves the science of bioenergetics including biochemical and physiological energy production and utilization systems, that is frequently evidence of diabetes, and ketone bodies, acetone particles occurring in body fluids and tissues involved in acidosis, also known as ketosis, somewhat common in severe diabetes.

In addition to weight loss due to a reduction in fat and lean mass, illnesses such as diabetes, certain medications, lack of fluid intake and other factors can trigger fluid loss. And fluid loss in addition to a reduction in fat and lean mass exacerbates the risk for cachexia.

Infections such as HIV may alter metabolism, leading to weight loss.^[1]

Hormonal disruptions, such as an overactive thyroid (hyperthyroidism), may also exhibit as weight loss.^[2]

Recent research has shown fidgeting to result in significant weight loss.

Intentional weight loss

Intentional weight loss refers to the loss of total body mass in an effort to improve fitness, health, and/or appearance.

Therapeutic weightloss, in individuals who are overweight or obese, can decrease the likelihood of developing diseases such as diabetes,^[4] heart disease, high blood pressure, stroke, osteoarthritis,^[5] and certain types of cancer.

Attention to diet in particular can be extremely beneficial in reducing the impact of diabetes and other health risks of an expanding waist.

Weight loss occurs when an individual is in a state of negative energy balance. When the body is consuming more energy (i.e. in work and heat) than it is gaining (i.e. from food or other nutritional supplements), it will use stored reserves from fat or muscle, gradually leading to weight loss.^{[citation needed]}

It is not uncommon for some people who are currently at their ideal body weight to seek additional weight loss in order to improve athletic performance, and/or meet required weight classification for participation in a sport. However, others may be driven by achieving a more attractive body image. Consequently, being underweight is associated with health risks such as difficulty fighting off infection, osteoporosis, decreased muscle strength, trouble regulating body temperature and even increased risk of death.

Therapeutic weight loss techniques

See also: Obesity#Management and Bariatrics

The least intrusive weight loss methods, and those most often recommended by physicians, are adjustments to eating patterns and increased physical activity, generally in the form of exercise. Physicians will usually recommend that their overweight patients combine a reduction of processed^[7] and caloric content of the diet with an increase in physical activity.^[8]

Other methods of losing weight include use of drugs and supplements that decrease appetite, block fat absorption, or reduce stomach volume. Green tea and hoodia gordonii are often advertised as weight loss supplements. Medicines with herbs such as Fucus vesiculosus are popular.^[9] Weight Loss Coaching is rapidly growing in popularity in the United States, with the number of available coaches nearly doubling since 2000. Finally, surgery (i.e. bariatric surgery) may be used in more severe cases to artificially reduce the size of the stomach, thus limiting the intake of food energy.

Crash dieting

A crash diet refers to willful nutritional restriction (except water) for more than 12 hours. The desired result is to have the body burn fat for energy with the goal of losing a significant amount of weight in a short time. However, the body reacts by preserving fat stores and burning lean muscle tissue, such that this is a poor strategy for intentional weight loss.^{[citation needed]}

Crash dieting is not the same as intermittent fasting, in which the individual periodically abstains from food (e.g., every other day)

Weight loss industry

There is a substantial market for products which promise to make weight loss easier, quicker, cheaper, more reliable, or less painful. These include books, CDs, cremes, lotions, pills, rings and earrings, body wraps, body belts and other materials, not to mention fitness centers, personal coaches, weight loss groups, and food products and supplements. US residents in 1992 spent an estimated $30 billion a year on all types of diet programs and products, including diet foods and drinks.^[10]

Between $33 billion and $55 billion is spent annually on weight loss products and services, including medical procedures and pharmaceuticals, with weight loss centers garnering between 6 percent and 12 percent of total annual expenditure. About 70 percent of Americans' dieting attempts are of a self-help nature. Although often short-lived, these diet fads are a positive trend for this sector as Americans ultimately turn to professionals to help them meet their weight loss goals

Safe Sex Tips

Safe sex (also called safer sex or protected sex) is the practice of sexual activity in a manner that reduces the risk of infection with sexually transmitted diseases (STDs). Conversely, unsafe sex is the practice of sexual intercourse or other sexual contact without regard for prevention of STDs.

Safe sex practices became more prominent in the late 1980s as a result of the AIDS epidemic. Promoting safe sex is now a principal aim of sex education. From the viewpoint of society, safe sex can be regarded as a harm reduction strategy. The goal of safer sex is risk reduction through education.

The risk reduction of safe sex is not absolute: the reduced risk to the receptive partner of acquiring HIV from HIV seropositive partners not wearing condoms to compared to when they wear them is estimated to be about a four- to five-fold.^[1]

In contrast to protected sex is unprotected sex, which can refer to:

• The practice of sex without protection from pregnancy
• The practice of sex without protection from STDs

Although safe sex practices can be used as a form of family planning, the term refers to efforts made to prevent infection as well as conception. Many effective forms of contraception do not offer protection against STDs.

Terminology

Recently, and mostly within Canada and the United States, the use of the term safer sex rather than safe sex has gained greater use by health workers, with the realization the grounds that risk of transmission of sexually transmitted infections in various sexual activities is a continuum rather than a simple dichotomy between risky and safe. However, in most other countries, including the United Kingdom and Australia, the term safe sex is still mainly used by sex educators.

Focus on HIV/AIDS

Much attention has focused on controlling HIV, the virus that causes AIDS, through the use of condoms. However, as many STDs can be transmitted through other activities, some sex educators recommend that barrier protection be used for all sexual activities which have the potential for disease transmission, such as manual penetration of the anal or vaginal cavities, or oral stimulation of the genitals.

Safe sex precautions

Sex by yourself

Known as autoeroticism, solitary sexual activity is relatively safe. Masturbation, the simple act of stimulating one's own genitalia, is safe so long as contact is not made with other people's discharged bodily fluids. However, some practices, such as self-bondage and autoerotic asphyxia, are made considerably more dangerous by the absence of people who can intervene if something goes wrong.

Modern technology does permit some activities, such as "phone sex" and "cybersex", that allow for partners to engage in sexual activity without being in the same room, eliminating the risks involved with exchanging bodily fluids.

Non-penetrative sex

A range of sex acts, sometimes called "outercourse", can be enjoyed by lovers with significantly reduced risks of infection and pregnancy. U.S. President Bill Clinton's surgeon general, Dr. Joycelyn Elders, tried to encourage the use of these practices among young people, but her position encountered opposition from a number of outlets, including the White House itself, and resulted in her being fired by President Clinton in December 1994

Limiting fluid exchange

Various devices are used to avoid contact with blood, vaginal fluid, and semen during sexual activity:

• Condoms cover the penis during sexual activity. They are most frequently made of latex, but can also be made out of polyurethane. Polyurethane is thought to be a safe material for use in condoms, since it is nonporous and viruses cannot pass through it. However, there is less research on its effectiveness than there is on latex.
• Female condoms are inserted into the vagina prior to intercourse. They may also be used for anal sex, although they are less effective.
• A dental dam (originally used in dentistry) is a sheet of latex used for protection when engaging in oral sex. It is typically used as a barrier between the mouth and the vulva during cunnilingus or between the mouth and the anus during anilingus.
• Medical gloves made out of latex, vinyl, nitrile, or polyurethane may be used as an makeshift dental dam during oral sex, or to protect the hands during mutual masturbation. Hands may have invisible cuts on them that may admit pathogens that are found in the semen or the vaginal fluids of STD infectees. Although the risk of infection in this manner is thought to be low^{[citation needed]}, gloves can be used as an extra precaution.
• Another way to avoid contact with blood and semen is penetration, but not by the penis, such as using (properly cleaned) dildos or other sex toys. If a sex toy is to be used in more than one orifice, a condom can be used over it and changed when the toy is moved. Fisting (penetration by the hand), has its own risks, but the risk of HIV transfer can be reduced by latex gloves or a condom. Pegging, female-to-male anal sex with a strap-on dildo, as promoted by sex educator Carol Queen does not involve fluid transfer.

If a latex barrier is being used, any lubrication must not be oil based, as this can break down the structure of the latex and undo the protection it gives.

Condoms (male or female) may be used along with other forms of contraception to protect against STDs and improve contraceptive effectiveness. For example, simultaneously using both the male condom and spermicide (applied separately, not pre-lubricated) is believed to reduce perfect-use pregnancy rates to those seen among implant users.^[5] However, two condoms should not be used simultaneously (male condom on top of male condom, or male condom inside female condom), since this increases the chance of condom failure

Other Precautions

Acknowledging that it is usually impossible to have entirely risk-free sex with another person, proponents of safe sex recommend that some of the following methods be used to minimize the risks of STD transmission and unwanted pregnancy.

• Circumcision is now backed by the World Health Organization as a preventative measure against HIV. African studies have found that circumcision can reduce the transmission rate of HIV by up to 60%^[8]. Some advocacy groups dispute these findings.^[9][10]
• Periodic STD testing has been used to reduce STD infections in Cuba and among pornographic film actors. Cuba implemented a program of mandatory testing and quarantine early in the AIDS epidemic. ^[11] In the US pornographic film industry in the US, many production companies will not hire actors without tests for Chlamydia, HIV and Gonorrhea that are no more than 30 days old-and tests for other STD's no more than 6 months old. AIM Medical foundation claims that program of testing has reduced the incidence of STD infection to 20% of that of the general population.
• Soap and water can reduce infectivity of HIV on devices, such as barrier contraceptives^[12]. Douching with soap and water should be avoided because it has not been studied and by disrupting the vaginal flora it might increase risk of infection.^[12]
• Monogamy or polyfidelity, practiced faithfully, is very safe (as far as STDs are concerned) when all partners are non-infected. However, many monogamous people have been infected with sexually transmitted diseases by partners who are sexually unfaithful, have used injection drugs, or were infected by previous sexual partners; the same risks apply to polyfidelitous people, who face slightly higher risks depending on how many people are in the polyfidelitous group.
• For those who are not monogamous, reducing the number of one's sexual partners, particularly anonymous sexual partners, may also reduce one's potential exposure to STDs. Similarly, one may restrict one's sexual contact to a community of trusted individuals - this is the approach taken by some pornographic actors and other non-monogamous people.
• Communication with one's sexual partner(s) makes for greater safety. Before initiating sexual activities, partners may discuss what activities they will and will not engage in, and what precautions they will take. This can reduce the chance of risky decisions being made "in the heat of passion".
• Refraining from the use of recreational drugs, including alcohol, before and during sexual activity can protect against associated risks such as lowered inhibitions, decreased immune response, impaired judgment, and loss of consciousness.
• If a person is sexually active with a number of partners, it is important that they get regular sexual health check-ups from a doctor. Anyone noticing unusual symptoms should get medical advice quickly as HIV is sometimes asymptomatic or symptoms will have a nonspecific nature and can even be misdiagnosed

Limitations

While the use of condoms can reduce HIV transmission, it does not do so completely. One study has suggested it might be around by a factor of 85% to 95% and questioned that effectiveness beyond 95% would be unlikely because of slippage, breakage, and incorrect use.^[15] It also noted "In practice, inconsistent use may reduce the overall effectiveness of condoms to as low as 60–70%".^{[15]p. 40.}

The risk of the receptive partner acquiring HIV from HIV seropositive partners not wearing condoms is 0.82% and from those wearing condoms is 0.18%, a four- to five-fold reduction.^[1] Where the partner's HIV status is unknown, "Estimated per-contact risk of protected receptive anal intercourse with HIV-positive and unknown serostatus partners, including episodes in which condoms failed, was two thirds the risk of unprotected receptive anal intercourse with the comparable set of partners.

Ineffective methods

Note that most methods of contraception other than the barrier methods mentioned above are not effective at preventing the spread of STDs. This includes the "rhythm method".

The spermicide Nonoxynol-9 has been claimed to reduce the likelihood of STD transmission. However a recent study by the World Health Organization ^[16] has shown that Nonoxynol-9 is an irritant and can produce tiny tears in mucous membranes, which may increase the risk of transmission by offering pathogens more easy points of entry into the system. Condoms with Nonoxynol-9 lubricant do not have enough spermicide to increase contraceptive effectiveness and are not to be promoted.

Coitus interruptus (or "pulling out"), in which the penis is removed from the vagina, anus, or mouth before ejaculation, is not safe sex and can result in STD transmission. This is because of the formation of pre-ejaculate, a fluid that oozes from the urethra before actual ejaculation. In opposition to conventional wisdom, some recent studies awaiting confirmation suggest that pre-ejaculate may not contain sperm^{[citation needed]}; it can, however, contain pathogens such as HIV.^[17][18]

If you keep ejaculate fluid out of any orifices this will do a great deal to help protect pregnancy and diseases. Especially important to note if you have cuts in your mouth. In addition, open sores on either partner can permit transmission, as can microscopic breaks in the skin which arise due to friction, or other irregularities in the skin of either partners genitalia or other body parts.

International Conference on Population and Development (ICPD), 1994

The International Conference on Population and Development (ICPD) was held in Cairo, Egypt, from 5 to 13 September 1994. Delegations from 179 States took part in negotiations to finalize a Programme of Action on population and development for the next 20 years. Some 20,000 delegates from various governments, UN agencies, NGOs, and the media gathered for a discussion of a variety of population issues, including immigration, infant mortality, birth control, family planning, and the education of women.

The ICPD Program of Action endorses a new strategy which emphasizes the numerous linkages between population and development and focuses on meeting the needs of individual women and men rather than on achieving demographic targets.^[4] The ICPD achieved consensus on four qualitative and quantitative goals for the international community, the final two of which have particular relevance for reproductive health:

• Reduction of maternal mortality: A reduction of maternal mortality rates and a narrowing of disparities in maternal mortality within countries and between geographical regions, socio-economic and ethnic groups.
• Access to reproductive and sexual health services including family planning: Family planning counseling, pre-natal care, safe delivery and post-natal care, prevention and appropriate treatment of infertility, prevention of abortion and the management of the consequences of abortion, treatment of reproductive tract infections, sexually transmitted diseases and other reproductive health conditions; and education, counseling, as appropriate, on human sexuality, reproductive health and responsible parenthood. Services regarding HIV/AIDS, breast cancer, infertility, delivery and abortion should be made available. Active discouragement of female genital mutilation (FGM).

Key to this new approach is empowering women and providing them with more choices through expanded access to education and health services and promoting skill development and employment. The Programme advocates making family planning universally available by 2015, or sooner, as part of a broadened approach to reproductive health and rights, provides estimates of the levels of national resources and international assistance that will be required, and calls on Governments to make these resources available.

Childbearing and health

Waiting until mother is at least 18 years old before trying to have children improves maternal and child health.^[3]

If an additional child is desired, it is considered healthier for mother, as well as for the succeeding child, to wait at least 2 years after previous birth before attempting to conceive (but not more than 5 years).^[3] After a miscarriage or abortion, it is healthier to wait at least 6 months.

Reproductive health

Within the framework of WHO's definition of health as a state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity, reproductive health, or sexual health/hygiene, addresses the reproductive processes, functions and system at all stages of life.^[1] Reproductive health, therefore, implies that people are able to have a responsible, satisfying and safer sex life and that they have the capability to reproduce and the freedom to decide if, when and how often to do so. Implicit in this are the right of men and women to be informed of and to have access to safe, effective, affordable and acceptable methods of fertility regulation of their choice, and the right of access to appropriate health care services that will enable women to go safely through pregnancy and childbirth and provide couples with the best chance of having a healthy infant.

According to the WHO, "Reproductive and sexual ill-health accounts for 20% of the global burden of ill-health for women, and 14% for men