Puberty – Females
Puberty is a time of great transition for females. Puberty typically begins between age 8 – 13 in females, although age of onset is affected by race, ethnicity and environmental factors, such as food availability and nutrition status. Puberty begins with development of breast buds under the areola, known as thelarche, followed 1-1.5 years later by pubic hair appearance (known as pubarche), and finally onset of mensturation, known as menarche, around 2-2.5 hours following the thelarche.
Periods normally begin between the ages of 10-16, although they can begin at a younger age, due to genetic and environmental factors. Periods onset may also be delayed to a later age in individuals who have a family history of late-onset periods, are doing large amounts of exercise, experience stress, are underweight, or have an eating disorder or health condition affecting the ovaries.
Some key nutrients for menstruating women include:
The average blood loss experienced across a period is estimated to be between 3-5 tbsps of blood, and iron loss may occur at varying degrees depending on heaviness of the period blood flow. It is therefore imperative to ensure iron levels are maintained across a woman’s lifespan. Females with iron deficiency may manifest with symptoms such as pale skin, low energy, failure to thrive, reduced appetite and behavioural and emotional issues.
Females with iron deficiency may also have higher risk of developing depression and anxiety, because deficiency of iron causes altered levels of serotonin and dopamine. Serotonin and dopamine are two neurotransmitters involved in mood regulation. Furthermore, iron deficiency results in alteration to balances of the neurotransmitters glutamate and GABA, which have an excitatory and calming effect on the nervous system, respectively. Iron status should be monitored and supported through nutrition and, if required, supplementation throughout a woman’s menstrual life.
Consuming fats is essential for female hormone health. Oestrogen and progesterone, hormones involved in the female reproductive system, are synthesised from cholesterol. There has been a focus in the last few decades on cholesterol levels that are too high. However, it is equally important, but perhaps less discussed, to ensure that cholesterol levels do not become too low, as this can impact on female hormone balance. Female adolescents following low fat diets, or diagnosed with an eating disorder, are particularly at risk of experiencing hormonal imbalance, for this reason.
Women should ensure they are consuming monounsaturated fats, such as avocado and olive oil, and polyunsaturated fats, such as omega-3. Research has demonstrated that omega-3 is involved in modulating mood, memory and cognition. The role of omega-3 in supporting the gut-brain axis is also an important consideration. Omega-3 fats are essential for increasing and maintaining levels of beneficial bacteria in the gut microbiome. Some strains of beneficial gut bacteria are involved in the synthesis of neurotransmitters such as serotonin, dopamine and GABA, which are all involved in modulating mood. This provides one possible explanatory mechanism for why omega-3 may be supportive of mental well being during a woman’s cycle, as low serotonin and dopamine levels have been suggested to be associated with some symptoms of PMS and PMDD. Furthermore, in a recent study women with PMS who were administered omega-3 fatty acids were observed to experience fewer symptoms long term.
Omega-3 fats, in the forms of EPA and DHA, are found in oily fish such as salmon and mackerel, as well as in algae. They are also found in walnuts and flaxseeds, in the form of ALA. However, it should be noted that the body has to convert ALA into DHA and EPA, forms the brain can utilise more readily. This conversion process is not particularly efficient, but recent research has suggested that this conversion pathway can be enhanced by curcumin, which is found in turmeric. Although these findings hold promise for the potential role of curcumin, and possibly other polyphenols, in supporting ALA conversion, further research is required to explore these findings in humans.
An emerging area of research is the role of zinc in supporting women’s hormone health. A recent randomised double blinded control trial indicated that women with PMS who were administered zinc sulphate were observed to experience significant improvement to PMS symptom severity and improvement to quality of life. These findings were further supported in a 2020 study on female university students. An additional study demonstrated that zinc supplementation had a significant impact on reducing physical and psychological symptoms of PMS, as well as increasing levels of BDNF (brain derived neurotrophic factor), a key molecule in the brain involved in learning and memory, and reducing oxidative stress, a major trigger for inflammatory processes.