‘In countries like Mexico the iron intake can be adequate but the problem is absorption. The type of iron makes a difference too.’ Photo Caroline Attwood / Unsplash After puberty, depression is almost twice as common in girls as in boys. Arli Zarate Ortiz studied the relationship between nutrition and depression in teenage girls in Mexico. ‘It is an understudied group in health studies: we think of adolescents as healthy people.‘
With the onset of puberty, twice as many girls as boys suffer from depression. The onset of menstruation (menarche) coincides with the onset of depressive symptoms, says Arli Zarate Ortiz, researcher at Human Nutrition and Health. Besides biology and social factors, nutrition may play an important role. Poor nutrition can cause not just overweight and obesity, but also to an iron deficiency.
Iron
Iron deficiency might be associated with depression, Zarate Ortiz found. Her questionnaires among more than 400 Mexican teenage girls showed that more than half of them scored as (very) likely depressed. Blood analyses in the same group showed that girls with iron deficiency were more likely to be depressed.
She also found that more Mexican girls (13 per cent) than boys (7 per cent) suffered from anaemia, which may be explained by blood loss during menstruation. In addition, girls who start menstruating early are more likely to be obese. The inflammation induced by obesity can also lead to iron deficiency.
Western diet
Obesity is normally accompanied by a low degree of inflammation that affects the absorption of iron. ‘In countries such as Mexico, the iron intake may be sufficient, but absorption is the problem.’ The type of iron makes a difference too. Animal products contain heme iron, which is more readily absorbed than iron from plant-based products. Zarate Ortiz analysed the dietary patterns of 7380 Mexican teenagers. Teenagers on a western diet were more likely to be overweight or obese and anaemic. A plant-based diet also increased the risk of obesity. ‘This is specific to Mexico: we eat a lot of vegetables and fruit, but we fry the vegetables and eat fruit with sugar.’
Taboo
If you have a nutrient deficiency in Mexico, you can go to your doctor for supplements, but people rarely do so. ‘People are not aware of the symptoms of iron deficiency. With a symptom like fatigue, you are more likely to think you’ve been working too hard than to go to the doctor.’ Zarate Ortiz hopes that her thesis will start a conversation about adolescent health, as well as sexual and mental health. ‘I wish there were no taboo. Since the pandemic, more people talk about mental health problems. That is badly needed. Suicide is the second leading cause of death among adolescents in Mexico, but no one does anything about it.’
