Genetic factors play an important role, so acne occurs earlier and is more severe if there is acne in a family history.
1) Hormones, like androgens, oestrogen, insulin are strongly connected with acne and sebaceous secretion.
2) Milk consumption is linked to acne because milk is an insulinotropic nutrient which would increase serum insulin level.
A study dated 1949 reported an association between frequent milk consumption and acne severity.
Skimmed milk intake causes a break-out and/or worsening of acne.
It also contains other hormone pecursors which are implicated in comedogenesis.
Yoghurt consumption was not correlated with acne occurrence and is consistent with the findings of a number of studies.
Lactoferrin-enriched fermented milk decreases acne severity owing to the anti-inflammatory effects of lactoferrin and its ability to suppress microbial growth.
An intake of polyunsaturated fatty acids (omega-6 and omega-3) modulates the skin’s inflammatory response. Omega-3 fatty acids may decrease acne.
3) Chocolate is rich in biologically active compounds (caffeine, theobromine and serotonin), which increases secretion of insulin and its peripheral resistance.
Chocolate has an effect on the processes involved in the development of acne lesions. Certain individuals eating chocolate may present with the development or worsening of acne lesions.
4) Some cosmetics can contain comedogenic agents. They are blocking follicular structures and inducing comedonal disease on the cheeks of females. Remember it name: isopropyl myristate.
However, because the majority of cosmetic products are noncomedogenic, cosmetics are an uncommon cause.
5) Stress is a major factor in acne growth, involved both as a trigger factor and exacerbating factor. Stress induces neuroendocrine changes that are involved in the appearance of acne lesions.
6) Smoking is a major factor in non-inflammatory type post-adolescent female acne. Smoking is strongly linked to acne, with the severity of acne following a linear correlation with the number of cigarettes smoked. The prevalence of acne in smokers is higher compared with non-smokers. Smoking is associated with impairment of wound healing mainly by vasoconstriction. It has a lot of adverse effects on the skin, it impress not only microcirculation, but also on collagen, and elastin synthesis.That is why it is associated with development of wrinkles, atrophy, grey appearance or red complexion.
Smoking increases of sebum production induced by the nicotine and the reduced level of vitamin E in the sebum. Additionally, some compounds found in cigarette smoke, including nicotine, have a hyperkeratinising effect (lots of dead cells on the top skin layer).