For years people have searched for ways to prevent cancer, which occurs significantly more with age. A recent study conducted in 5 European countries offers hope that some simple steps could reduce the incidence of invasive cancer up to 61 % in older adults (over 70 years of age).
The 3 year long study tested individual and combinations of vitamin D3, marine omega-3, and a simple home strength exercise program and found that the combination of all 3 (vitamin D3 + marine omega-3 supplements + exercise) reduced the incidence of invasive cancer by 61 percent. In other words, it prevented cancer.
What they took: Persons in the double-blind (no one knew who was in what group) study were randomly assigned to one of 8 groups with the intervention alone or combined: daily supplements of 2000 IU of vitamin D3, and/or daily 1 g of marine omega-3s, and/or a simple home strength exercise program compared to a placebo/control group. NOTE: The marine omega-3s supplements used were algae-based (EPA + DHA ratio: 1:2), and not fish oil.
Even though there were over 2000 participants in the study, the numbers were too low to see if there were effects on certain types of cancers. Can only say there was a reduction in invasive cancers when all 3 interventions were combined. Looking at the study report, it is unclear how frequently and how many of the home-strengthening exercises were done each week.
Other studies: As the researchers note - other studies have had mixed results on vitamin D3 and omega-3 supplements, which are typically fish oil. A major review in 2020 of 27 studies using fish oil supplements (for a total of 113,557 participants) found little or no benefit regarding cancer or cancer death, and a 2021 review of 5 studies found increased risk of atrial fibrillation. So once again, we'll see... Three years (the length of this study) is a short time regarding cancer.
Bottom line: While vitamin D3 and fish oil supplements are being debated over their health effects, all studies find health benefits from exercise and eating a diet rich in fruits, vegetables, whole grains, seeds, nuts, some fish, and olive oil. Also, vitamin D3 is superior to vitamin D2, and that taking it daily is better than a mega-dose occasionally (e.g., once a month). Getting some sunlight (vitamin D) is also recommended.
A new study published in Frontiers in Aging found that a combination of high-dose vitamin D, omega-3s, and a simple home strength exercise program (SHEP) showed a cumulative reduction by 61% in cancer risk in healthy adults aged 70 or older.
Cancer is considered a major age-related disease in Europe and the US. It is the second leading cause of mortality in older adults and the chances of getting most cancers increases with age.
Mechanistic studies have shown that vitamin D inhibits the growth of cancer cells. Similarly, omega-3 may inhibit the transformation of normal cells into cancer cells, and exercise has been shown to improve immune function and decrease inflammation, which may help in the prevention of cancer.
Bischoff-Ferrari and her colleagues wanted to fill these knowledge gaps by testing the effect of daily high-dose vitamin D3 (one form of vitamin D supplements), daily supplemental omega-3s, and a simple home exercise program, alone and in combination, on the risk of invasive cancer among adults aged 70 or older.
To do so, the researchers conducted the DO-HEALTH trial: a three-year trial in five European countries (Switzerland, France, Germany, Austria, and Portugal) with 2,157 participants.
The participants were randomized into eight different groups to test the individual and combined benefit of the interventions: group one received 2,000 IU per day of Vitamin D3 (equivalent to > 200% 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.
The results show that all three treatments (vitamin D3, omega-3s, and SHEP) had cumulative benefits on the risk of invasive cancers. Each of the treatments had a small individual benefit but when all three treatments were combined, the benefits became statistically significant, and the researchers saw an overall reduction in cancer risk by 61%.