Key Points:
- A combination of 2000 IU of vitamin D3, 1 gram of omega-3s, and home exercise is associated with reduced risk of cancer.
Growing older accompanies impending cancer, a disease of aging second only to cardiovascular disease in leading to the most deaths in the United States. While diet and exercise are well-known preventative measures for cardiovascular disease, a new study suggests that such measures could also potentially reduce the risk of cancer.
In the journal Frontiers of Aging, Bischoff-Ferrari and colleagues from the University of Zurich in Switzerland report that combining vitamin D, omega-3 fatty acids, and home exercise may reduce cancer risk in older adults. These findings suggest that these highly accessible interventions can potentially be utilized to delay or prevent age-related cancer.
“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,” explained Bischoff-Ferrari. “In fact, novel cancer treatments aim to block multiple pathways for cancer development by combining several agents. We translated this concept into cancer prevention.
Vitamin D, Omega-3s, and Exercise Reduce Risk of Cancer
Bischoff-Ferrari and colleagues analyzed data from the DO-HEALTH trial (NCT0174563), made up of 2,157 participants 70 years and older from five European countries (Switzerland, Germany, Austria, France, and Portugal). They found that participants treated with a combination of vitamin D, omega-3 fatty acids, and exercise for three years had a lower risk of cancer compared to participants who were not treated with any of the three interventions. Individually, these interventions did not significantly reduce cancer risk, demonstrating the need for a combination therapy. Indeed, there was also a significant reduction in cancer risk when combining omega-3s and exercise.
Combining Therapies to Prevent Cancer
Two studies involving less than 100 participants have shown that the combination of vitamin D and omega-3s can reduce inflammation in cancer patients. Bischoff-Ferrari and colleagues’ study, with over 2000 participants is the first large-scale study to experiment with combination therapies for cancer.
“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 commented.
Since the results of these studies are promising, it may be beneficial to implement combo therapies in future studies.
Protocol Details
2000 IU of Vitamin D3
Several studies suggest that while vitamin D alone does not reduce the risk of cancer, it could reduce the risk of death from cancer. The dose associated with reducing risk of death from cancer is 2000 IU, the same as in this study. However, some participants who were treated with 2000 IU of vitamin D3 were already supplementing with 800 IU (the recommended dose for older adults), increasing the total dose to 2800 IU. This falls within range of the recommended upper limit for adults (4000 IU). Additionally, there are two forms of vitamin D supplements, vitamin D2 and D3. The superior form, the form used in this study, is generally thought to be vitamin D3 as it raises vitamin D levels higher and for a longer duration. Vitamin D3 is widely available and inexpensive, making it a highly accessible supplement.
1000 mg of Omega-3s (500 mg EPA & 500 mg DHA)
Overall, studies show that omega-3s alone are not associated with reduced risk for cancer. However, omega-3s could help with other age-related conditions like rheumatoid arthritis and macular degeneration. Fish and shellfish are rich in omega-3s and vitamin D, which may reduce the risk of stroke, heart disease, and cognitive decline. Animal studies have shown that omega-3s improve memory. Therefore, a diet containing fish or shellfish supplemented with omega-3s could be beneficial in preventing multiple age-related diseases.
The American Heart Association recommends all adults eat fish at least twice a week. Patients with coronary heart disease should take 1 gram of combined EPA and DHA a day, as these are the most beneficial fatty acids found in fish oil. Since this dosage is similar to the dosage of EPA and DHA used in this study, it could have preventative effects for both heart disease and cancer. The cost of omega-3 fatty acid supplements may vary depending on the EPA and DHA conent, but is generally more expensivie than vitamin D3.
Resistance Exercise
Exercise may reduce cancer risk by decreasing inflammation and improving immune function. Studies consistently support that higher physical activity reduces the risk of cancer. However, clinical trials that test this effect are lacking. Bischoff-Ferrari and colleagues show that dietary changes (increasing vitamin D and omega-3 intake) combined with exercise reduces the risk of cancer, adding to the tower of evidence showing that diet and exercise improve healthspan — living longer without disease.
The exercise program used in this study consisted of strength exercises for thirty minutes, three times a week, and included sit-to-stands, one-leg stance, pullbacks against elastic resistance, external shoulder rotation against elastic resistance, and steps. The control exercise group performed mostly mobility exercises, demonstrating the importance of resistance/strength training. For adults aged 65 and older, the CDC recommends at least two days of activity to strengthen muscles, which could prevent age-related muscle decline. They also recommend 150 minutes a week of moderate-intensity activity or 75 minutes of vigorous-intensity activity, such as hiking or jogging. Additionally, activities that improve balance, such as standing on one foot, should be performed about three days a week.
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