With many people indiscriminately popping vitamins and dietary supplements — commonly regarded as safeguards for our health — as part of their daily routines, a new study conducted by researchers at Sweden’s prestigious Karolinska Institutet has now made a startling discovery.
The study found that excessive consumption of vitamins and dietary supplements may unintentionally stimulate tumour growth and the development of cancer.
Research challenges common belief
The research, recently published in the Journal of Clinical Investigation, has led to various discussions, prompting renowned liver specialist Dr Cyriac Abby Philips to take to social media platform X — via his handle @TheLiverDoc — to educate the public on the implications of this alarming revelation.
“Hello there. I do not want to scare you but here is something terrifyingly cool that you should know about. But first, we all know that vitamins, minerals, and antioxidants are all important for our health, right? And we get exactly what is required, in the right amounts from our daily diet,” reads his tweet.
Hello there. I do not want to scare you, but here is something terrifyingly cool that you should know about.
But first, we all know that vitamins, minerals and anti-oxidants are all important for our health right? And we get exactly that what is required, in the right amounts… pic.twitter.com/8QoqhNRTxG
— TheLiverDoc (@theliverdr) September 2, 2023
However, the research challenges the widespread belief that daily multivitamin supplements are a panacea for disease prevention and overall well-being.
“Which supplements are you on now? I’ll tell you the common ones — Vitamin C (everyone takes extra), zinc, and Vitamin B complex!” Dr Philips points out and adds, “But hear me out. There is a fantastically terrifying paper published in the Journal of Clinical Investigation (oh it is a kickass journal, by the way).”
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So, what did the study find?
In simple terms, the study revealed that taking excessive vitamins or dietary supplements could potentially feed tumours and promote their growth.
The researchers at the Karolinska Institutet found that common antioxidants, including vitamins A, C, selenium, and zinc, can stimulate the growth of blood vessels within cancerous tumours when consumed in excess.
The formation of new blood vessels is a major step in development of cancers. Citing the example of lung tumours, the study’s authors proposed that this discovery may have broader implications for all types of cancers and their metastatic potential.
“We found that antioxidants activate a mechanism that causes cancerous tumours to form new blood vessels, which is surprising, since it was previously thought that antioxidants have a protective effect,” said lead researcher Martin Bergö, Professor at the Department of Biosciences and Nutrition and Vice-President of the Karolinska Institutet in Sweden.
“The new blood vessels nourish the tumours and can help them grow and spread,” he added.
The research team discovered that antioxidants are effective at reducing the level of free oxygen radicals. However, when excessive amounts of antioxidants are introduced, this reduction in free radicals triggers the activation of a protein called BACH1. Consequently, BACH1 initiates the process of angiogenesis (formation of new blood vessels).
Ting Wang, a doctoral student in Professor Bergö’s group at the Karolinska Institutet, commented on the implications of their findings, “Numerous clinical trials have assessed the effectiveness of angiogenesis inhibitors, but the outcomes have fallen short of expectations. Our study provides a pathway to more potent strategies for inhibiting angiogenesis in tumours. For instance, patients whose tumours exhibit elevated BACH1 levels may derive greater benefits from anti-angiogenesis therapy, compared to those with lower BACH1 levels.”
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Experts simplify it
Explaining it in simpler language, Dr Philips writes in his tweet, “THERE IS NO NEED TO FEAR ANTIOXIDANTS IN NORMAL FOOD — excessive intake of antioxidants/vitamins in the form of supplements in apparently healthy individuals is the problem.”
Importantly, the study distinguishes between natural levels of antioxidants found in food and excessive supplementation.
Armed with a clearer understanding of how vitamins, dietary supplements, and antioxidants can potentially promote the progression of tumours, medical professionals and individuals alike are urged to exercise caution when considering supplementation.
“Now that we have a really scary but cool explanation of how the use of vitamins/dietary supplements and antioxidants can promote the development of, or progression of tumours, we can go back to this really cool, large observational study that already showed that long-term use of multivitamin supplements can lead to the development of different types of cancers,” Dr Philips concludes his tweet.
Commenting on Dr Philips’s educative tweet, a public health doctor Dr Bhaskar Rajkumar tweeted, “On this one, totally with you.. When I tell my patients you don’t need any supplements.. they roll their eyeballs. Mild deficiencies exist in most.. if no evident clinical signs may not need supplemental pills. All Drs from GM to Surgeons to Derma prescribe them left-Rt-Center.” [sic]
On this one totally with you..
When I tell my patients you don’t need any supplements.. they roll their eyeballs
Mild deficiencies exist in most.. if no evident clinical signs may not need supplemental pills
All Drs from GM to Surgeons to Derma prescribe them left-Rt-Center
— Dr Bhaskar Rajakumar (ಡಾ. ಭಾಸ್ಕರ್ ರಾಜಕುಮಾರ್)🇮🇳 (@DrBhaskarRaj) September 2, 2023
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Explaining how cancer cells work, Dr Rajeev Jayadevan, gastroenterologist and Member, Public Health Advisory Panel, Kerala State IMA, says, “Cancers are basically cells that have a rogue character, disobeying the laws of the human body. They replicate uncontrollably, stealing the body’s nutrients in the process. An important part of how cancers grow and spread is by the formation of new vessels. This allows them to tap nutrient resources from nearby normal tissues, eventually leading to the weakening of the body.”
He adds, “There are genes in the body that respond to low oxygen levels. For instance, within tumours, where oxygen levels are low, genes get activated and the cells turn on various adaptations, one of which is to form new blood vessels.”
Regarding the study, he says, “The researchers have found that consuming excess antioxidants such as Vitamin C increases the ability of cancers to form new blood vessels, thus potentially increasing the speed of growth and spread. As to how this translates into clinical practice will need further observation. There is a general belief that antioxidants are beneficial because they mop up circulating free radicals and reduce oxidative stress. However, according to the new research, this appears to have a downside as well, which is in fact, not surprising.”
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‘Large-scale human study is needed’
Speaking to South First, Dr Nitin Yashas, renowned medical oncologist at Manipal Hospital in Sarjapur and Jayanagar in Bengaluru, explains angiogenesis as one of the hallmarks of cancer that help the cancer propagate and spread to other organs.
“This study is a pure lab-based study studied on lung cancer cell lines and on how certain antioxidants, such as NAC and Vitamin C, increase angiogenesis through certain pathways and molecules,” he explains.
However, the doctor says that before jumping to conclusions, it is always important for a large-scale human study to be conducted to understand whether this lab finding is translating into clinical implications.
“Certain interventional randomised studies and meta-analyses done over the years have also shown that supplementation with antioxidants, like beta carotenes, was associated with an increased risk of lung cancer, particularly amongst smokers and those exposed to asbestos. Hence, it is always important to discuss with one’s treating oncologist before consuming any supplements,” Dr Yashas adds.