Alpha-carotene, a lesser-known relative of the more recognized beta-carotene, has shown potential in promoting longevity and elucidating the health benefits of consuming fruits and vegetables. A study conducted by researchers at the CDC analyzed data from over 15,000 adults participating in a national nutrition survey and found that those with elevated blood levels of alpha-carotene had a 39% lower likelihood of dying from any cause over nearly 14 years.
Carotenoids, a diverse group encompassing more than 600 compounds—including alpha-carotene, beta-carotene, lutein, and lycopene—are the vibrant red, orange, and yellow pigments that color many fruits and vegetables. Alpha-carotene, alongside beta-carotene and beta-cryptoxanthin, is classified as a provitamin A carotenoid since the body converts these compounds into vitamin A. While alpha-carotene is chemically similar to beta-carotene, it appears to be more effective in inhibiting specific cancer cells. Previous trials examining the role of beta-carotene in preventing cancer and heart disease have yielded disappointing results, but these new findings may ignite interest in additional research surrounding alpha-carotene.
Dr. Chaoyang Li, MD, PhD, from the CDC’s Division of Behavioral Surveillance, and colleagues explored the relationship between blood levels of alpha-carotene and mortality rates using data from the Third National Health and Nutrition Examination Survey (NHANES) Follow-up Study. Among the 15,318 adults in their analysis, 3,810 died during an average follow-up period of 13.9 years.
Dr. Li and his team observed a consistent decline in overall mortality risk associated with higher blood levels of alpha-carotene compared to individuals with lower levels. This correlation remained significant for deaths resulting from cardiovascular disease, cancer, and various other causes, even after accounting for other lifestyle and health risk factors.
In alignment with previous research, Dr. Li’s team reported in the Archives of Internal Medicine that their findings indicated a particularly strong link between serum alpha-carotene levels and mortality risk from specific conditions, including cancers of the aerodigestive tract, diabetes, and chronic lower respiratory disease. (Cancers affecting the aerodigestive tract comprise those of the lip, oral cavity, pharynx, larynx, esophagus, stomach, colon, rectum, liver, and pancreas.)
These findings lend further credence to past research suggesting that a diet rich in fruits and vegetables is beneficial for health. The researchers noted that if these results are validated in future studies, it could spur clinical research focused on the health advantages of serum alpha-carotene.
It is important to note that this observational study was not designed to establish direct cause-and-effect relationships. Clinical trials, which often address confounding variables, frequently do not align with positive outcomes observed in population studies—similar to previous findings regarding beta-carotene. Nonetheless, both types of studies hold value, and scientists consider the overarching evidence. Until more definitive research is conducted, the established health benefits of consuming fruits and vegetables, including those rich in alpha-carotene, serve as a compelling reason to incorporate a variety of colorful produce into our diets.
Alpha-carotene is predominantly found in yellow-orange vegetables and certain green produce. According to the USDA, the top foods rich in alpha-carotene include:
- Pumpkin
- Carrots and carrot juice
- Winter squash
- Plantains
- Vegetable juice cocktail
- Tangerines
- Collard greens
- Snap beans
- Tomatoes
- Cornmeal and corn
- Peas
- Raspberries
- Sweet potatoes
- Bell peppers
- Mangos
These findings underscore the importance of diet in promoting health and longevity. As we continue to explore the benefits of nutrients like alpha-carotene, it remains essential to embrace a colorful variety of fruits and vegetables in our daily meals.
Archives of Internal Medicine, online before print; abstract available at dx.doi.org/10.1001/archinternmed.2010.440
