A study published in the British Medical Journal reports that the intake of fruits and vegetables rich in α carotene during adolescence reduces breast cancer risk later in life
A recent study published in the British Medical Journal has suggested that there is an association between the consumption of fruits and vegetables in adolescent females and overall reduced risk of invasive breast cancer, with stronger results for estrogen and progesterone receptor negative tumors. There was a significant association between fruits and vegetables rich in α carotene, a bioactive component found in yellow and orange vegetables, in the prevention of pre-menopausal breast cancer.
This was a prospective cohort study that pooled 90 476 participants from the Nurse’s Health Study II, who had previously completed food frequency questionnaires in 1991 and later completed questionnaires regarding their adolescent diets in 1998. During the 22 years of follow up, 1347 cases of invasive breast cancer were recorded in women for whom adolescent dietary information was available. What was found was that higher total fruit and vegetable intake during adolescence was associated with a lower risk of breast cancer. These results did not include fruit juice intake. Additionally, the results were adjusted for adolescent fiber intake, as this has proven risk reduction of breast cancer. The inverse association with adolescent vegetable intake appeared to show a dose dependent response, with reduced risk for up to 2.7 servings in a day. For vegetables, the association with reduced risk was not dependent on the hormonal subtype of cancer, while for fruit consumption there was only a stronger association for estrogen and progesterone receptor negative breast cancers.
While previous studies have not shown a link between fruit and vegetable consumption and breast cancer risk, it is purported that because these previous studies typically assessed mid-life and older cohorts, the period during adolescence when breast tissue is most susceptible to carcinogenic initiation was missed. After adolescence, in early adulthood, the intake of fruits and vegetables high in α carotenoids were associated with lower risk. There were significant differences between individual fruits and vegetables, with the consumption of apples, bananas, and grapes showing the most promise for risk reduction when consumed during adolescence, and oranges and kale during early adulthood.
Overall, the consumption of more than three servings of fruit a day during adolescence had the greatest protective benefit for developing breast cancer. These findings are keeping with healthy eating recommendations for cancer prevention, and can also reduce the risk of cardiovascular disease and diabetes. Several bioactive components including α carotene could be responsible for the reduction in risk, in addition to the fiber found in fruits and vegetables.
Written By: Sarah Kassenaar, BSc (Hons)