It has long been known that postmenopausal women are at a higher risk of developing breast cancer. But now, new research suggests that adopting a diet rich in tomatoes may reduce this risk. This is according to a study published in the Journal of Clinical Endocrinology and Metabolism.
According to the National Cancer Institute, women in the US have a 12.4% risk of developing breast cancer at some point in their lives. This risk increases with age, with women over the age of 50 having a 1 in 42 chance of developing the disease.
According to the study researchers, led by Adana Llanos of Rutgers University, postmenopausal women increase their risk of breast cancer further as their body mass index (BMI) climbs. But this latest study suggests that this risk may be reduced simply by adopting a different diet.
To reach their findings, the investigators analyzed 70 postmenopausal women for a period of 20 weeks.
For the first 10 weeks, the women were required to follow a tomato-rich diet. This involved consuming a minimum of 25 mg of lycopene each day. Lycopene is an antioxidant found in tomatoes and other fruits and vegetables.
For the remaining 10 weeks, the women followed a soy-rich diet. This required them to consume at least 40 g of soy protein daily.
All women were asked to refrain from eating any soy or tomato products 2 weeks prior to each diet.
Tomato-rich diet increases adiponectin levels
Postmenopausal women showed a 9% increase in levels of adiponectin - a fat and blood sugar regulating hormone - after following a tomato-rich diet for 10 weeks, lowering their risk of breast cancer.
Results of the study revealed that when the women followed the tomato-rich diet, they showed a 9% increase in their levels of adiponectin. This is a hormone that plays a part in the regulation of fat and blood sugar levels.
The researchers note that this effect was more prominent for women who had a lower BMI.
Llanos says the advantages of eating a high amount of tomatoes and tomato-based products are clearly evident in their findings, even if consumption is only for a short period.
"Eating fruits and vegetables, which are rich in essential nutrients, vitamins, minerals and phytochemicals such as lycopene, conveys significant benefits.
Based on this data, we believe regular consumption of at least the daily recommended servings of fruits and vegetables would promote breast cancer prevention in an at-risk population."
Llanos points out that their findings also emphasize the importance of obesity prevention, since a tomato-rich diet had a bigger impact on adiponectin levels for women who maintained a healthy body weight.
Tomatoes have also been linked to other health benefits. Last year, Medical News Today reported on a study suggesting that eating lots of tomatoes may reduce the risk of stroke, while other research has suggested that eating a combination of soy and tomato foods may help prevent prostate cancer.