Combining high doses of vitamin D with omega-3s and exercise reduces the risk of developing cancer in older adults by 61 per cent, according to a new study.
The research, detailed in Frontiers in Aging, is the first to test the cumulative effect of the three preventative measures on the risk people over the age of 70 face from developing the invasive disease. Although an individual’s risk of cancer increases over time, there are few strategies that focus on mitigation beyond quitting smoking and using sunscreen.
According to researchers, clinical studies have largely neglected to explore the effectiveness of these measures alone, or in tandem, despite evidence from mechanistic studies that they play a role in the progression of the disease (vitamin D slows the growth of cancerous cells; omega-3 may inhibit cells from turning cancerous; and exercise boosts immune function).
We can go further in preventing cancer
“Preventive efforts in middle-aged and older adults today are largely limited to screening and vaccination efforts,” said Heike Bischoff-Ferrari, one of the authors of the study and a professor at University Hospital Zurich.
To remedy this, researchers conducted a three-year experiment that subjected 2,157 participants from five European countries — Switzerland, France, Germany, Austria, and Portugal — to varying combinations of the three interventions. “Our aim was to test promising combined interventions for cancer prevention taking advantage of potentially small additive benefits from several public health strategies,” Bischoff-Ferrari said. “In fact, novel cancer treatments aim to block multiple pathways for cancer development by combining several agents. We translated this concept into cancer prevention.”
Participants were randomly divided into eight groups: Group 1 was given 2,000 IU per day of Vitamin D3 (more than double the recommended dose for older adults), 1 gram per day of omega-3s and instructions to complete a simple home exercise program (SHEP) three times per week; Group 2 was given vitamin D3 and omega-3s; Group 3, vitamin D3 and SHEP; Group 4, omega-3s and SHEP; Group 5, vitamin D3 alone, Group 6, omega-3s alone, Group 7, SHEP alone; and Group 8, a placebo.
Subjects were contacted by researchers once every three months and underwent standard health examinations at baseline and after the first, second and third year of the study.
The results revealed that while all three interventions carried small benefits, they combined to become statistically significant and decrease an individual’s overall risk of developing invasive cancer by 61 per cent.
“This is the first randomized controlled trial to show that the combination daily vitamin D3, supplemental marine omega-3s and a simple home exercise program may be effective in the prevention of invasive cancer among generally healthy and active adults aged 70 and older,” Bischoff-Ferrari said. “Our results, although based on multiple comparisons and requiring replication, may prove to be beneficial for reducing the burden of cancer.
“Future studies should verify the benefit of combined treatments in the prevention of cancer, also extending to longer follow-ups beyond the three-year duration assessed in this trial.”
Cancer remains the leading cause of death in Canada, with around 40 per cent of the population expected to be diagnosed with the disease at some point in their lives and around 25 per cent expected to die from it, according to the Public Health Agency of Canada. It is estimated that just under 330,000 Canadians were diagnosed with cancer in 2021 and around 85,000 succumbed to the disease. The current five-year net survival rate for all cancers combined is 64 per cent, meaning 64 per cent of Canadians will still be alive five years after diagnosis.
Dave Yasvinski is a writer with Healthing.ca