The Effectiveness of an Intervention of Fresh Strawberries on Menstrual Pain and Menstrual Distress

Dysmenorrhea is a prevalent problem among women of childbearing age; previous studies carried out among young university students have identified that it affects 74% of them. Dysmenorrhea can also be accompanied by the well-known menstrual distress, which has been estimated to affect between 75 and 94% of women. The symptoms included in menstrual distress are diverse, including irritability, nausea, vomiting, abdominal pain, general weakness or fatigue, among others. Dysmenorrhea and distress have a significant impact on the lives of women who suffer from it, affecting their social life, quality of life and academic and work performance.

The methods that women use to relieve dysmenorrhea are usually pharmacological, with NSAIDs (Non Steroidal Anti-Inflammatory Drugs) and hormonal contraceptives, but these are not free of adverse effects, so more and more studies are investigating non-pharmacological methods to relieve pain. Menstrual distress is also being included as an object of study.

A healthy lifestyle has been shown to be beneficial in relieving primary dysmenorrhoea. In particular, exercise and eating at least 2 pieces of fruit per day have been identified as protective habits.

Most of the studies that evaluate food intake in women with dysmenorrhea are observational and the few clinical trials that exist are with small samples. Strawberries are rich in flavonoids and phenolic acids, giving them anti-inflammatory and antioxidant properties. Studies carried out with strawberries have shown their benefits against chronic inflammatory and cardiovascular diseases. For these reasons, it is necessary a clinical trial to evaluate the benefits of strawberry in relieving dysmenorrhea and menstrual distress.

Carrying out a clinical trial with strawberries is a challenge. Firstly, there is no consensus on the optimal dose that should be ingested to influence health biomarkers. On the other hand, the use of fresh strawberries involves a significant cost, in addition to the fact that it is a seasonal fruit, which is why the most of trials with strawberries are carried out with freeze-dried strawberry powder.

The aim of this study is to analyze the benefits of strawberry consumption in relieving menstrual pain using the VAS (Visual Analogue Scale) scale and menstrual distress using the MEDI-Q scale, previously validated in Spanish in a previous phase of the study in female university students. The results obtained will be compared between the intervention group belonging to the intake of strawberry (specifically the "Fortuna" variety) and with a control group that will continue with their usual diet during the same period of time. They will be evaluated previously, one month and two months after receiving the intervention. The project has been approved by the Andalusian Ethics and Research Committee.

For the design of the clinical trial, previous studies on food intake and dysmenorrhea, as well as studies on the health benefits of strawberries, have been taken into account.

The "Fortuna" strawberry variety will be provided by the association Fres Huelva and must be eaten daily for a month. Participants will be provided with a menstrual diary in order to avoid forgetfulness bias. Participants who are part of the intervention group will be invited to participate in focus groups in order to know about their experiences during the trial.

Our hypothesis is that women who regularly consume strawberries in their diet will improve their pain intensity and levels of menstrual distress, as well as other symptoms associated with dysmenorrhea.

Inclusion criteria

• Nulliparous women
• Suffer menstrual pain at least 1 time in the last 6 months or 3 times in the last year
• Without a history of diagnosed gynecological pathology
• Not taking hormonal contraception
• Being enrolled at the University of Huelva for the academic year 2023/2024

Exclusion criteria

• Those who do not meet the inclusion criteria
• Being in the process of mobility during the months of study
• Have had an abortion
• Suffer from a problem that requires limiting the consumption of fruit or strawberries in their diet
• Suffer from a chronic disease that causes pain