An investigation pioneered by experts from the University Hospital Zurich suggests that combining high-dose vitamin D, omega-3s, and exercise may be an effective cancer prevention strategy, finding that they reduced cancer risk by 61%.
The DO-HEALTH trial is the first to analyse the combined effects of these simple and affordable public health interventions as methods for cancer prevention. The study results illuminated that high-dose vitamin D, omega-3s, and a basic home strength exercise program (SHEP) have significant beneficial outcomes for healthy adults aged 70 and older, decreasing their cancer risk by 61%.
The research, which is published in Frontiers in Aging, could enhance the lives of millions worldwide, as cancer is a major age-related disease in Europe and the US and is the second leading cause of mortality in older adults, with cancer risk increasing with age. Although cancer prevention recommendations such as not smoking and sun protection are widely publicised, public health efforts to mitigate cancer risk are limited.
Dr Heike Bischoff-Ferrari of the University Hospital Zurich commented: “Preventive efforts in middle-aged and older adults today are largely limited to screening and vaccination efforts.”
Supplements and exercise
Previous research has illustrated that vitamin D can slow cancer cell growth, omega-3 potentially inhibits normal cells from developing into cancer cells, and exercise can enhance immune function and decrease inflammation, boosting cancer prevention. However, robust clinical studies are sparse on whether these strategies alone or in combination effectively reduce cancer risk.
To address this research gap, the team examined the effects of daily high-dose vitamin D3 (one form of vitamin D supplements), daily supplemental omega-3s, and a simple home exercise programme individually and in combination in a cohort of older adults.
The DO-HEALTH trial
The DO-HEALTH trial included 2,157 participants from Switzerland, France, Germany, Austria, and Portugal and was conducted over three years.
Bischoff-Ferrari explained: “In DO-HEALTH, our aim was to test promising combined interventions for cancer prevention, taking advantage of potentially small additive benefits from several public health strategies. In fact, novel cancer treatments aim to block multiple pathways for cancer development by combining several agents. We translated this concept into cancer prevention.”
The participants were randomly assigned to eight groups: group one received 2,000 IU per day of Vitamin D3 (equivalent to > 200% of the amount of current recommendations for older adults, which is 800 IU per day), 1g per day of omega-3s, and three times per week SHEP; group two vitamin D3 and omega-3s; group three vitamin D3 and SHEP; group four omega-3s and SHEP; group five vitamin D3 alone; group six omega-3s alone; group seven SHEP alone; and the last group received a placebo. Subsequently, the participants received phone call checks ups every three months and had their health and function examined at baseline, year one, year two, and year three.
Cancer prevention performance
The research revealed that all three treatments effectively helped to reduce cancer risk. Individually, vitamin D3, omega-3s, and SHEP had small benefits; however, when combined, the impacts were statistically significant, displaying an overall reduction in cancer risk of 61%.
Bischoff-Ferrari concluded: “This is the first randomised controlled trial to show that the combination of daily vitamin D3, supplemental marine omega-3s, and a simple home exercise programme may effectively prevent invasive cancer among generally healthy and active adults aged 70 and older.
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.”