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Progesterone Therapy News, Issue #002 - dangers of HRT
July 22, 2010

July 22nd 2010
Issue #003


In the previous newsletter I mentioned checking all labels for toxins, including endocrine disruptors. This is such an important topic, I'm making it the subject of this newsletter and the next one.

Probably the most insidious are those found in sunscreens. After all, aren't we protecting ourselves from skin cancer? No, far from protecting us, many of the compounds used are themselves carcinogens. More important, many are 'gender bending' chemicals, or oestrogen mimics.

In 2001 the Institute of Pharmacology and Toxicology at the University of Zurich, Switzerland, tested six UVA and UVB screens commonly used in sunscreens, lipsticks and other cosmetics, for estrogenicity. Five UVB screens increased cell proliferation in lab tests, making cancer cells grow more rapidly...

  • benzophenone-3 (oxybenzone)
  • homosalate
  • 4-methyl-benzylidene camphor (4-MBC)
  • octyl-methoxycinnamate (octinoxate)
  • octyl-dimethyl-PABA
  • butyl-methoxydibenzoylmethane (avobenzone)

The sixth, avobenzone, showed no activity during the study, but further research has found this breaks down into harmful chemicals, particularly if used with octinoxate. They concluded their study with... "Our findings indicate that UV screens should be tested for endocrine activity, in view of possible long-term effects in humans and wildlife."

One of the most common screening chemicals, 4-MBC, had a particularly strong effect. When applied transdermally to rat skin at concentrations allowed in sunscreens, it doubled the rate of uterine growth well before puberty. How many parents cover their young daughters in sunscreen?

Richard Sharpe from the Medical Research Council's Reproductive Biology Unit in Edinburgh, says... "It's not good news that we are lathering ourselves with creams with hormonal activity."

Their advice is to use sunscreens containing zinc oxide as the screening agent.

Apart from the above list there are many more toxic screening agents used in sunscreens, but the carriers, preservatives and non actives should be avoided too, a few of them are...

  • PEG (polyethylene glycol), polysorbates, ethoxylated alcohol (emulsifier which can contain
  • dioxane)
  • Propylene glycol (solvent, humectant, anti-freeze)
  • Sodium lauryl sulphate (surfactant)
  • Parabens (preservatives)
  • BHT and BHA (anti-oxidants)
  • Mineral oil (paraffin, often labelled paraffinum liquidum)
For a full explanation on the above and how vital the sun and vitamin D are, please see the sunumbra website.

As 'Our Stolen Future' says... "The cycle starts with an insulin injection, sunscreen slathered onto an arm, or a bottle of old pills dumped in the toilet... chemicals trickle back into rivers and underground aquifers that feed our taps. We may reach the afterlife, but our drugs are reincarnated."

To your good health,

Wray Whyte
Progesterone Therapy

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