A nutritionist who specializes in the treatment and prevention of cancer has warned that supplement fanatics could be putting themselves at risk of the disease.
Nichole Andrews, 38, a Washington-based registered dietitian and nutritionist specializing in oncology, shared a video on social media explaining why vitamins can be toxic.
She told her 316,000 Instagram followers that high doses of some vitamins can turn into harmful molecules called free radicals, which can trigger the cascade of cell damage that leads to cancer.
Those who survive cancer are particularly vulnerable because of their high genetic risk of secondary tumors, she added.
“Unfortunately, cancer survivors are preyed upon by many people selling supplements.
“They’re trying to get you to take all these different supplements to say this is the way to detox and reduce cancer.”
‘You can get a very high dose of a micronutrient with just one pill, while with food you will never reach that toxic level’ she added.
‘Do not take supplements unless you have an actual deficiency that your doctor will show you and prove with laboratory results.
‘Supplements do not reduce the risk of cancer, they can increase the risk to a very high level.’
Several studies echo her concerns and discourage taking vitamins in excessive amounts.
One 2023 study published in The Journal of Clinical Investigation, suggested that antioxidants such as vitamins C and E may actually help tumors grow.
These two nutrients play a crucial role: Vitamin C is important for wound healing and healthy skin, blood vessels, bones and cartilage; and vitamin E for eye health and immunity.
Vitamin C is found in foods such as broccoli, citrus fruits and vitamin E is found in nuts and seeds.
While these vitamins do not pose a problem when consumed in the amounts found in food, consuming more vitamins than your body needs by taking supplements can help cancer thrive.
One study suggested that antioxidants like vitamins C and E can actually help tumors grow
Researchers at the Karolinska Institute, a medical university in Sweden, injected mice with lung cancer cells before giving them increasingly higher doses of vitamins C and E in their drinking water.
They then performed regular ultrasound scans to monitor the formation of blood vessels that help the cancer cells form a solid tumor.
The results showed that the vitamins boosted a protein in the body that helped increase blood flow to tumors, allowing them to grow.
Another 2015 judgement Experts from the University of Colorado found that those who took extra vitamins and minerals were more likely to develop health problems.
One particular vitamin beta-carotene – a supplement advertised as an immune system boost – was found to increase the risk of developing lung cancer and heart disease by as much as 20 percent.
But that’s only when people took more than the recommended dose of 7 mg per day.
The substance gives yellow and orange fruits and vegetables their color and is converted into vitamin A in the body.
However, in high doses the vitamin can be dangerous and increase the risk of lung cancer in people who smoke or have been heavily exposed to asbestos at work, the NHS said.
Nicotinamide riboside (NR), a form of vitamin B3, is advertised as having anti-aging effects and may lower high cholesterol and high blood pressure.
But a University of Missouri-Columbia study on mice found that NR increased the risk of breast cancer and caused the disease to spread to the brain, which is fatal.
The supplement is converted by the body into nicotinamide adenine dinucleotide (NAD+), an enzyme essential for providing energy to cells. But cancer cells can also feed on this energy.
To test this theory, researchers gave genetically engineered mice with cancer 400 times the standard recommended daily dose of 250 mg of NR.
The researchers monitored their cancer cells, T cells (a type of ‘fighter’ white blood cell) and healthy tissue.
NR increased the spread of cancer cells to the brain in nine of 11 mice, compared to only three of 12 mice in the control group that did not receive the supplement.
When they applied the technique to breast cancer cells, they found that the risk of developing the cancer also increased.
In 2019, one of Britain’s top pharmacists and former government adviser unleashed a scathing attack on supplements, declaring them ‘untested and unproven’.
Dr. Paul Clayton, a clinical pharmacologist, told MailOnline: ‘Of all the vitamins, the multivitamins, omega 3s, vitamin C tablets and the like, there is no evidence to support this one.
‘The one thing they all have in common is that they don’t work and there is no evidence to support them. If you test any of these things, they do nothing.
“These products are sold by companies that don’t really know what they’re selling, and are bought by customers who don’t really know what they’re buying.
‘But that doesn’t really matter with nutritional supplements, because they don’t actually do anything – just for the consumer’s wallet.’