Ring out the old, ring in the new. But when it comes to carotenoids and cancer, it seems like what’s old is new again.
As you know, when I worked at the National Cancer Institute (NCI) back in the mid-1980s, experts there had a single-minded, misguided idea that synthetic beta-carotene pills could prevent cancer. They embarked on multi-million dollar studies to investigate beta-carotene pills as a cancer preventive agent.
But they put the cart before the horse.
They conducted this misguided research before they knew which carotenoids were actually present in cancer-preventive foods…before they knew how humans metabolized carotenoids to achieve various blood levels…and before they knew about all the different carotenoids actually present in foods and human blood and tissues!
So in the mid-1980s, when I conducted my research with the USDA, I exposed the NCI’s beta-carotene theory as a big bust. But my political bosses at the NCI prevented me from publishing the research.
Partially as a result, I left the NCI to work as an Associate Medical Director at Walter Reed Army Medical Center, where they had no petty political bias against science.
I finally published my results about beta-carotene in the Journal of the National Cancer Institute, which thankfully has an outside, independent editorial board. Walter Reed Medical Center awarded me the “Brinton Young Research Investigator Award” that year for my work.
The best cancer protection comes straight from the supermarket
In essence, my research found that many active carotenoids in foods provide powerful protection against cancer. But the synthetic beta-carotene pills the NCI tested don’t protect against cancer. Worse yet, they might even contribute to it.
Insiders at the NCI quickly got over their bias once my results were published by the outside editors in their own journal. And they quickly claimed credit for ongoing work on carotenoids. Some made comfortable careers out of it. How quickly they forget — from one research-funding cycle to the next!
Of course, I also found a huge difference between taking synthetic beta-carotene pills manufactured by big pharma and carotenoids naturally present in the whole food matrix.
As you may recall, two other carotenoids — lycopene and lutein — came up on the radar screen in my research with the USDA because the cancer-protective foods we analyzed had high levels of them. Also, the participants in our controlled food consumption studies at the USDA had high levels of these nutrients in their blood.
Nobody in health research had heard about these carotenoids before. And these discoveries of lutein and lycopene spawned entire new dietary supplement industries. (Though those industries don’t typically use the same degree of scientific rigor I brought to my research.)
In the days before these nutrients became available as dietary supplements, I remember giving an interview to the National Institutes of Health radio network about my findings. The interviewer expressed dismay because the now-worse-than-worthless beta-carotene supplements were already available, but the new lutein and lycopene supplements were not yet available.
I said not to worry — since you could find them in the produce section at your local grocer. And if you didn’t know how to find them, you could ask your mother, or grandmother, as the case may be!
It seems my original research continues to spread to this day all the way to China — whence it must have taken that proverbial “slow boat.”
“New” research proves what I’ve known for decades
A new Chinese study at Sun Yat-Sen University and Guangzhou Medical University looked at 521 women ages 25 to 70 years diagnosed with breast cancer over three month’s time, compared to 521 age-matched control women who did not have breast cancer. Specifically, they looked at levels of the pro-vitamin A carotenoids together, as well as lycopene and lutein/zeaxanthin in the participants’ blood.
Overall, they found a “significant inverse relationship” between the levels of these nutrients in the blood and breast cancer risk. In other words, the higher the levels of these nutrients in the blood, the lower the breast cancer risk. And on the flip side – the lower the nutrient levels, the higher the breast cancer risk.
After all this time, the researchers say their study is the first to examine these different types of carotenoids circulating in the blood with respect to breast cancer risk.
Why did it take so long?
We’ve known since the 1980s carotenoids could potentially protect against DNA damage by neutralizing “free-radical” oxygen species and activating the anti-oxidant response. In addition, we know a few carotenoids like alpha-carotene and beta-cryptoxanthin are safely converted to retinol or vitamin A by the liver, which is involved in cellular differentiation. Clearly, one would expect these activities could confer anti-cancer benefits. It would also help explain why certain foods high in these nutrients seem to protect against cancer. (Albeit these foods also contain high levels of B vitamins, vitamin C, and other biologically active phytochemicals.)
In any case, I’m glad the research happened. Better late than never.
Breast cancer remains the most common cancer in women worldwide. It’s the second most common cancer overall after lung cancer. Nearly 1.7 million cases were diagnosed worldwide in 2012, representing about 12 percent of all new cancer cases, and 25 percent of all cancers in women. The researchers reported the rate of breast cancer in China is still lower than in western countries but is rapidly rising.
To learn what you can do to protect yourself against a breast cancer diagnosis, please see the lead story in the January 2016 issue of my Insiders’ Cures newsletter. If you’re not yet a subscriber, now is the perfect time to start the New Year right.
- “Specific serum carotenoids are inversely associated with breast cancer risk among Chinese women,” British Journal of Nutrition January 2016; 115 (1): 129-137