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Women with the highest concentrations of several plant-derived carotenoids in their blood were substantially less likely to develop lethal breast cancer over three decades of follow-up, with the strongest association reaching a 48% reduction in risk.
By yourNEWS Media Newsroom.
Women with higher circulating levels of carotenoids — naturally occurring pigments concentrated in many fruits and vegetables — were markedly less likely to develop lethal breast cancer during a study that followed thousands of participants for as long as 30 years.
The analysis involved 6,099 women participating in the Nurses’ Health Study who were cancer-free when their blood samples were collected. Researchers later examined those stored samples for several carotenoids as well as retinol, the pre-formed form of vitamin A commonly obtained from animal-derived foods.
During approximately three decades of follow-up, 2,583 of the women were diagnosed with invasive breast cancer. Among those cases, 190 women either experienced a recurrence or died from the disease.
The strongest overall relationship emerged when researchers considered several carotenoids together.
Women with the highest combined concentrations of alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene and lutein/zeaxanthin had a 48% lower risk of lethal breast cancer compared with women whose circulating levels were lowest.
Beta-carotene stood out individually as well. Women with the highest blood concentrations had a 41% lower likelihood of developing lethal breast cancer than those in the lowest group.
Beta-cryptoxanthin was also associated with reduced risk, although the relationship was less pronounced.
The protective association appeared particularly strong among postmenopausal women, women who had ever smoked and participants with lower body mass.
Retinol Did Not Show the Same Association
One of the study’s notable findings involved what researchers did not see.
Retinol showed no protective association with lethal breast cancer.
That distinction is important because carotenoids and retinol are both connected to vitamin A biology, but they come from different sources and behave differently in the body.
Carotenoids are found predominantly in plant foods, while retinol is the pre-formed vitamin A found in animal-derived foods.
The absence of a similar association for retinol suggests that the observed relationship may involve the carotenoid compounds themselves rather than simply higher levels of vitamin A.
The findings nevertheless do not establish that carotenoids directly prevent breast cancer or breast cancer death. The research was observational, meaning it identified relationships between blood nutrient levels and later outcomes rather than proving that increasing carotenoid consumption would produce the same reduction in risk.
Why the Findings Do Not Translate Directly Into a Supplement Recommendation
The researchers cautioned against interpreting the results as evidence that women should take high-dose carotenoid supplements.
The blood concentrations measured in the participants reflected their diets, metabolism and other biological factors rather than participation in a trial in which women were assigned carotenoid pills.
That distinction matters because concentrated supplements do not necessarily produce the same effects as obtaining nutrients through food.
Previous clinical trials involving high-dose synthetic beta-carotene, for example, found increased rather than decreased lung cancer risk among smokers.
The contrast illustrates why an association between naturally occurring blood carotenoid levels and better health outcomes cannot automatically be reproduced by taking isolated nutrients in large doses.
Whole foods provide carotenoids alongside fiber, vitamins, minerals and numerous other plant compounds that are consumed and metabolized together.
Carotenoids Have Been Linked to Other Long-Term Health Benefits
The breast cancer findings add to a larger body of research examining carotenoids and chronic disease.
Lutein and zeaxanthin, which are abundant in leafy green vegetables, are particularly concentrated in tissues of the eye and have been studied for their potential role in preventing or slowing age-related macular degeneration.
Another analysis using U.S. national health survey data collected between 2003 and 2018 found associations between higher carotenoid intake and lower overall mortality among women.
Women consuming the most beta-carotene had a 28% lower all-cause mortality rate, while those with the highest intake of lutein and zeaxanthin had a 33% lower rate.
That research, published in BMC Public Health, likewise could not establish that carotenoids themselves caused the reduction. Dietary patterns associated with higher carotenoid intake may differ in numerous other ways from diets containing fewer fruits and vegetables.
Together, however, the findings strengthen interest in carotenoid-rich foods as part of dietary patterns associated with healthier aging.
Building Carotenoids Into Everyday Meals
Carotenoids are widely available in ordinary foods and do not require complicated dietary calculations.
Carrots, sweet potatoes, winter squash, tomatoes, kale, spinach, red bell peppers, apricots and watermelon are among the foods that provide substantial amounts of different carotenoid compounds.
Eating a variety of colors is useful because individual pigments are concentrated in different foods. Orange vegetables are commonly rich in alpha- and beta-carotene, tomatoes are a major source of lycopene, and dark leafy greens contain high levels of lutein and zeaxanthin.
How those foods are prepared can also influence absorption.
Carotenoids are fat-soluble, meaning they are generally absorbed more efficiently when eaten with some dietary fat. Pairing vegetables with foods such as avocado or olive oil can therefore increase the amount available to the body.
Chopping and cooking some carotenoid-rich vegetables can also break down plant structures and make the compounds easier to absorb.
The new findings do not establish colorful produce as a treatment or guarantee against breast cancer. They do, however, add unusually long-term evidence to the association between higher circulating carotenoid levels and favorable health outcomes.
Among more than 6,000 women followed for up to three decades, the clearest signal was seen in those with the highest combined carotenoid levels: a 48% lower risk of lethal breast cancer compared with women at the lowest end of the range.
For researchers, the next question is whether carotenoids themselves are responsible for part of that difference or whether they primarily serve as biological markers of broader dietary and lifestyle patterns.
For consumers, the safest implication remains considerably simpler than taking concentrated supplements: regularly eating a varied selection of carotenoid-rich fruits and vegetables provides these compounds in the form in which they naturally occur.
Source: Natural News
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