Breast cancer risk is significantly decreased by eating more foods with carotenoids according to several studies.
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| Carotenoids are found in tomatoes, carrots and other foods. |
Eating carotenoids reduces breast cancer risk
A 2018 study from Harvard University tested 32,826 women for levels of carotenoid levels in their blood. Of these, 18,743 were tested again 12 years later. The women were then followed for the next ten years. The women were followed for over 20 years for incidence of breast cancer.
The researchers found that those women with less carotenoids in their blood had a higher incidence of breast cancer. Higher levels of alpha-carotene, beta-carotene, lycopene and total carotenoids had up to 28 percent lower incidence of breast cancer according to the research.
Previous research confirms results
In a 2014 study, scientists also found that women who eat more carotenoids have a significantly reduced risk of breast cancer.
The study, published in the British Journal of Nutrition, followed 561 women who had been diagnosed with breast cancer along with 561 healthy women who were matched for age and where they lived.
Each of the women were interviewed directly the researchers and given a food frequency questionnaire.
The researchers used a quartile system – meaning they compared those whose consumption of carotenoids were in the highest 25 percent with those who were in the lowest 25 percent of carotenoid consumption.
The researchers found the highest quartile of beta-carotene dietary consumption had a 46 percent reduced incidence of breast cancer. Those who consumed the highest quarter of alpha-carotene in their diets had a 39 percent reduced risk of breast cancer. And those who consumed higher amounts of beta-cryptoxanthin within their diets had a 62 percent reduced risk of breast cancer. Furthermore, those who consumed more luteins and zeaxanthins resulted in 51 percent reduction in breast cancer risk.
This result confirms another study done several years ago, after a study of 122 women with breast cancer along with 632 healthy women. This study found that greater lycopene consumption reduced breast cancer risk by 74 percent, beta-carotene reduced risk by 62 percent and greater beta-cryptoxanthin reduced breast cancer risk by 57 percent.
This study also found that total carotenoid consumption reduced breast cancer risk by 63 percent.
In a 2015 study, researchers from the American Cancer Society also tested a large population of women. This study found that higher alpha-carotene levels reduced the incidence of breast cancer by between 40 and 43 percent. Among women who also ate higher levels of fruits and vegetables, the higher alpha-carotene levels reduced breast cancer incidence by 50 percent.
Yes, breast cancer rates were double for those women who ate less carotenoids along with fruits and vegetables in general. This supports other diet and breast cancer research.
Lutein like a chemotherapy drug
In another 2018 study, doctors at the Paul L. Foster School of Medicine at Texas Tech University studied several carotenoids against human breast cancer cells. The researchers tested beta-carotene, lutein and astaxanthin. The researchers found that lutein in particular inhibited the growth of breast cancer cells similar to chemotherapy drugs. These chemotherapy drugs include taxanes, paclitaxel and docetaxel.
That means that the carotenoid lutein works like these chemotherapy drugs.
Foods high in carotenoids
Carotenoids are the color pigments in vegetables and some fruits.
Sources of beta-carotene include:
- Carrots
- Pumpkins
- Sweet potatoes
- Collard greens
Sources of alpha-carotene include:
- Pumpkin
- Squash
- Green beans
- Leafy greens
Sources of beta-cryptoxanthin include:
- Peppers (hot or sweet)
- Squash
- Persimmons
- Apples
- Pumpkins
- Carrots
- Tangerines
- Oranges
- Papayas
Some sources of lutein and zeaxanthins:
- Romaine
- Broccoli
- Corn
- Spinach
- Kale
- Yellow carrots
- Chard
- Turnip greens
- Peas
- Goji berries
Greater protection among pre-menopausal women
While the protective capacity of these foods was across the board in terms of the above percentages, the researchers noted that even greater protection was provided by these foods to those women who were pre-menopausal.
This of course means it is better not to wait too long to start changing the diet.
Also, those women who were exposed to secondhand smoke also had a greater amount of protection from breast cancer from the above carotinoid foods. Alcohol consumption also increases breast cancer risk according to other research.
What is the mechanism?
One of the main reasons for this reduction is the fact that these carotenoids are significant free radical neutralizers. They bind to free radicals before they can seriously damage our tissues, and thus prevent that damage.
Furthermore, these free radical scavengers each collect different types of free radicals – namely some of those involved in lipid peroxidation.
Significant research has established that free radicals play a critical role in tumor creation and production, along with cardiovascular disease.
It should be noted that men also get breast cancer.
REFERENCES:
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Ramírez-Expósito MJ, Sánchez-López E, Cueto-Ureña C, Dueñas B, Carrera-González P, Navarro-Cecilia J, Mayas MD, Arias de Saavedra JM, Sánchez-Agesta R, Martínez-Martos JM. Circulating oxidative stress parameters in pre- and post-menopausal healthy women and in women suffering from breast cancer treated or not with neoadjuvant chemotherapy. Exp Gerontol. 2014 Jul 11. pii: S0531-5565(14)00211-3. doi: 10.1016/j.exger.2014.07.006.
Gong X, Smith JR, Swanson HM, Rubin LP. Carotenoid Lutein Selectively Inhibits Breast Cancer Cell Growth and Potentiates the Effect of Chemotherapeutic Agents through ROS-Mediated Mechanisms. Molecules. 2018;23(4):905. Published 2018 Apr 14. doi:10.3390/molecules23040905