Why do my feet stink?

Foot odor affects more people than it seems. This is because our feet sweat more than other parts of the body, as they have about 250,000 sweat glands. Quickly becoming damp, they turn into breeding grounds for bacteria, including the Kytococcus sedentarius, which feeds on the salt present in our sweat.

When it comes to unpleasant odors, these microorganisms and sweat do not mix well. Indeed, it is they, not perspiration, that are the cause of smelly feet. These bacteria and various fungi accumulate between the toes and multiply by feeding on the dead cells and sebum present on and under the feet. It is when they decompose that they release an unpleasant odor. Indeed, this is the case with the bacteria Brevibacterium spp which feeds on the keratin of the scales on the feet, degrading the methionine, an amino acid, to form methane-thiol, the source of the bad odor.

Do you wear closed shoes or sneakers all day long? You might have athlete's foot, one of the other causes of excessive foot perspiration and thus, the development of these harmful bacteria. Wearing closed shoes and socks that do not allow good air circulation can trap moisture and promote bacterial proliferation. Closed shoes also create a dark and warm environment, ideal for bacterial growth.

Beyond abnormally sweaty feet, particularly between the toes, other symptoms of athlete's foot include intense itching and/or skin rashes that can lead to infections. The combination of sweat, bacteria, and infections inevitably results in unpleasant odors.

During changes or disruptions in women's hormonal cycles, the body undergoes numerous modifications. These changes alter perspiration, leading to an increase in bacteria and a change in body odor, which can be one of the causes of smelly feet. In addition to pregnancy, menstruation, or menopause, which influence women's sweating, puberty also affects the perspiration of adolescents.

Indeed, a study has shown that changes in estrogen levels influence the signaling pathways of norepinephrine (NE) and serotonin (5-HT), which are essential for the processing of thermoregulation, in the preoptic area of the hypothalamus. A hormonal change then modulated key neurotransmitters and the expression or function of their receptors, thereby altering the response patterns of thermoregulatory circuits and changing sweating thresholds.

The effects that stress can have on the mind, as well as the body, can often exceed our understanding. In this regard, stress, but also depression, anxiety, or overwork, are believed to be capable of activating a dual innervation pathway that could lead to an increase in perspiration. And with abnormal perspiration comes a favorable environment for the growth of certain bacteria. Uncontrollable foot odor is then an inevitable consequence.

Shoes and removable insoles are often made from synthetic materials. These non-breathable materials absorb foot odors along with sweat and other impurities. Therefore, if you do not regularly wash your shoes and allow them to dry in sunlight to kill bacteria, they can end up smelling as bad as your feet. Moreover, this unpleasant odor can be transferred to clean feet.

It's not enough to just take a bath and rinse your feet. It's crucial to wash them thoroughly and regularly with soap, scrubbing between the toes and brushing the nails. Indeed, this is where fungal infections develop and persist. And it's also what causes the unpleasant odor of feet.

After drying your feet, you can apply our 10-ingredient body moisturizing cream for deeply hydrated skin. It is suitable for all skin types, even sensitive skin.

Note: There are solutions to counteract the effect of bad foot odor.

DEECHER D. C. & al. Understanding the pathophysiology of vasomotor symptoms (hot flushes and night sweats) that occur in perimenopause, menopause, and postmenopause life stages. Archives of Women's Mental Health (2007).

HARKER M. Psychological Sweating: A Systematic Review Focused on Aetiology and Cutaneous Response. Skin Pharmacology and Physiology (2013).