Combined Vitamin D, Omega-3 Supplementation, and Exercise Reduce Cancer Risk in Older Adults: Evidence from the DO-HEALTH Trial

Cancer risk increases significantly with age, making preventive strategies particularly important for older adults. While single interventions such as vitamin supplementation or physical activity have shown mixed results in cancer prevention, growing evidence suggests that combined lifestyle and nutritional approaches may offer greater protective benefits. A landmark example of this strategy is the DO-HEALTH study, a large randomized, double-blind, placebo-controlled clinical trial led by Dr. Heike A. Bischoff-Ferrari of the University of Zurich and published on April 25, 2022, in Frontiers in Aging.

The DO-HEALTH trial investigated whether a combination of vitamin D3 supplementation, omega-3 fatty acid intake, and a structured home-based exercise program could reduce the risk of invasive cancer in healthy older adults. The study enrolled 2,157 participants aged 70 years and older from five European countries, making it one of the most comprehensive lifestyle intervention trials conducted in this age group. Participants were randomly assigned to receive vitamin D3 (2,000 IU per day), omega-3 fatty acids (1 g per day), a simple strength and balance exercise program, combinations of these interventions, or a placebo.

After three years of follow-up, the results revealed a striking reduction in cancer risk among participants who received all three interventions simultaneously. The combined-intervention group experienced a 61% reduction in invasive cancer incidence compared with the placebo group. Notably, only four cases of invasive cancer were reported in the group receiving vitamin D, omega-3 fatty acids, and exercise, whereas twelve cancer cases occurred in the placebo group. These findings highlight the potential of synergistic interventions to produce clinically meaningful outcomes that exceed the effects of any single component alone.

The study also reported a number needed to treat (NNT) of 35, meaning that for every 35 older adults following this combined regimen for three years, one case of invasive cancer was prevented. This is considered a highly favorable outcome in preventive medicine, especially given the low cost, accessibility, and safety profile of the interventions involved. Importantly, when vitamin D, omega-3 supplementation, or exercise were analyzed individually, none showed a statistically significant reduction in cancer risk on their own. This reinforces the conclusion that the observed benefit arose from the combined approach rather than any single intervention.

Biologically, the findings are supported by existing evidence. Vitamin D plays a role in cell differentiation, immune regulation, and inhibition of tumor growth. Omega-3 fatty acids are known for their anti-inflammatory properties and potential to influence cancer-related signaling pathways. Meanwhile, regular strength and balance exercise improves metabolic health, immune function, and systemic inflammation. When combined, these interventions may create a biological environment less favorable for cancer initiation and progression.

In conclusion, the DO-HEALTH trial provides strong clinical evidence that a combined strategy of vitamin D3 supplementation, omega-3 fatty acid intake, and regular exercise can substantially reduce invasive cancer risk in older adults. Rather than relying on a single preventive measure, this study underscores the power of integrated lifestyle and nutritional interventions in promoting healthy aging and cancer prevention.

Reference:
Bischoff-Ferrari, H. A., Vellas, B., Rizzoli, R., et al. (2022). Effect of vitamin D, omega-3 fatty acids, and exercise on invasive cancer risk among healthy older adults: The DO-HEALTH randomized clinical trial. Frontiers in Aging.