• Anna Solana, science journalist

    When smelling bad is not a matter of hygiene

    28 Aug When smelling bad is not a matter of hygiene



    EFE Salud

    An offensive body odour may not be the result of a lack of hygiene. Bromhidrosis is a disorder affecting both men and women and usually associated with secretions by the apocrine sweat glands located in the armpits, pubis, perineum and navel, behind the ears and in the folds under the breast. It is a chronic but treatable disorder.


    Persons affected by bromhidrosis do not perspire more; rather, their apocrine glands produce sweat containing ceramides that are different to those of the rest of the population. When broken down by the skin’s bacteria, a strong odour is the result. This odour, which is often described as pungent, musty or sour, cannot be dissumulated. The condition is believed to be genetic in origin, but may also be caused by a metabolic disorder such as diabetes, by thyroid or adrenal gland alterations or by certain drugs. In addition, certain foods, such as onions, garlic and spices, and also tobacco use and alcohol consumption, can aggravate the condition. Read More

  • Susana Andújar, chemist

    How Is the Efficacy of Cosmetics Measured?

    15 May How Is the Efficacy of Cosmetics Measured?

    Cosmetic products packaging and advertising can sometimes promise the moon. After watching certain TV commercials, you get the impression some creams will work wonders on your skin: wrinkles will disappear and the skin will become soft and silky, just like the model in the ad. But is it true? How do they check the real effects of cosmetics?


    Legislation on cosmetic products requires that proof be provided for each claim made. For this reason, before a new formula is launched on the market, the manufacturing company's R&D department performs different tests, depending on the product properties they want to focus on. The "claims" that appear on the label and in ads must be backed by scientific studies. These tests are done in vitro (in an artificial or natural laboratory environment), in vivo (on people, never on animals) or using both methods. Finally, the results are always checked by applying the product on volunteers. Read More

  • Fede Montagud, editor

    Who hasn’t got body odour?

    Our genes determine what our skin secretes in sweat and, consequently, how we smell. No two body odours are alike as we all have our own unique “cocktail” of bacteria that break down sweat to release volatile substances. But there are people who do not smell ... and they even use deodorant.


    Our body odour develops when skin bacteria degrade certain substances produced by the sweat glands: steroid hormones, fatty acids and sulphur compounds. Our genetic characteristics determine the amount and proportion of each such substance secreted and, consequently, differences in how we smell. However, in a recent UK study of 6 500 women it was found that 2% had virtually no smell because of their particular version of the ABCC11 gene. However, over 75% of these women used underarm deodorant – out of habit. Identifying this genetic trait could lead to odourless people both saving money and reducing their exposure to chemicals. Such studies also open the way for the future application of genetics to the field of personal hygiene.

  • Elisabet Salmerón, science journalist

    Fascinating alum crystal

    Alum crystal, used by ancient civilizations, has come back into fashion with the rise of natural cosmetics. It has many properties, including as a body deodorant. How does it benefit the skin? Is the aluminium it contains hazardous?


    Alum crystal is a naturally occurring sweet-tasting mineral that looks like translucent glass. It is usually composed of an aluminium sulfate and a sulfate from another metal. The most commercially exploited alum is the hydrated form of potassium aluminium sulfate (potassium alum), which comes from a volcanic igneous rock called aluminiferous trachyte; it can also be manufactured industrially, however. Read More