A new study showing that taking a multivitamin decreases cancer risk provides insight on how supplemental nutrition in conjunction with healthy lifestyle practices can prevent disease. The study is noteworthy because it was one of the first randomized trials to test multivitamin use in relation to cancer rates in a large population of doctors.
Called the Physicians’ Health Study II and published in the Journal of the American Medical Association, the trial compared the use of a multivitamin with a placebo taken daily for 11 years in men with an average age of 64 at the start of the study. Results showed that the group that took the multivitamin had a statistically significant 8 percent lower risk of developing cancer than the men in the placebo group.
The overall rate of getting cancer for the first time during the 11 year study was 17 per 1,000 person-years in the men who took the multivitamin and 18.3 per 1,000 person-years in the men who took the placebo. Multivitamin use was associated to the greatest degree with a lower risk of epithelial cancer. However it had no effect on the incidence of prostate cancer, which was the most common cancer diagnosed in the participants.
When researchers looked at the effect of taking the multivitamin on all cancers other than prostate, there was a 12 percent decrease in occurrence. Overall, death due to cancer was lower in the multivitamin group, but this difference was not statistically significant.
This study is noteworthy for the following reasons:
1) This was a well designed study
that tested multivitamin use compared to a placebo, rather than using self-reported questionnaires or “observations,” which many previous supplement studies have done. The study participants were physicians who were able to provide high-quality reporting of health information.
Being diligent about taking supplements is critical to their success. Many supplements will only convey a health benefit if taken daily for a long period of time. For instance, the research group suggests that the multivitamins may have made the difference in lowering cancer risk because the participants took their supplements regularly for 11 long years and didn’t skip doses.
2) The entire study population
(those receiving the multivitamin and those getting the placebo) had fairly healthy habits overall. Only three percent were current smokers and 56 percent had never smoked. Sixty one percent of the population exercised regularly and they ate more fruits and vegetables daily than the general population.
That the multivitamin proved beneficial is especially notable since the whole population was health-conscious, which could have muted the results due to confounding factors—but that was not the case.
Lifestyle habits are a major contributor to disease risk and this population had habits that laid the groundwork for long-term health. The addition of a multivitamin to these men’s diets appeared to make a difference in preventing cancer. An 8 to 12 percent lower risk of cancer is worth paying attention to.
3) Prostate cancer risk
was not lowered, which could indicate that additional nutrients are needed to decrease this cancer, which is the most common cancer besides skin cancer in men. For example, vitamin D deficiency significantly increases prostate cancer risk. According to the Prostate Cancer Foundation, men who live in the more Northern latitudes (north of Philadelphia, Columbus, Ohio, and Provo, Utah) have greater prostate cancer risk due to lower lifetime vitamin D levels.
In addition, other nutrients such as zinc and antioxidants that enhance the body’s internal detoxification system have been shown to decrease prostate cancer risk. The male prostate tissue requires ten times more zinc than other cells in the body to stay healthy. Adequate zinc level in the prostate protects the cells from damage, inflammation, and cancer development. Also, once the prostate cells are damaged and become cancerous, they lack the ability to accumulate zinc, leading to greater propagation of cancer cells that produce to tumors.
The multivitamin used in this study contained zinc, but based on the nutrition label, it is impossible to identify what form of zinc was included. The most common zinc found in dietary supplements is zinc sulphate because it is inexpensive. However, according to the University of Maryland medical reference database, zinc sulphate is the least easily absorbed and may upset the stomach. Other forms are more effectively absorbed and used by the body to prevent cancer.
It’s necessary to round out diet and multivitamin use with additional supplementation for optimal health and cancer prevention. Vitamin D, zinc, magnesium, extra B vitamins, and a probiotic can enhance the body’s production of glutathione (the powerhouse of the internal antioxidant system in the body), while decreasing prostate and site-specific cancer risk.
4) For perspective, multivitamins
cut the chance of developing cancer by 8 percent, but that is less effective than regular exercise, not smoking, or eating a good diet. Healthy lifestyle practices such as lifetime exercise can cut cancer risk by as much as 30 percent, whereas eating a diet that includes fruits and vegetables and avoids red and processed meats can decrease cancer risk by as much as 20 percent.
Simply eating a serving of nuts daily has been shown to lower cancer risk by as much as 15 percent. In a study of older men and women, eating a 1-ounce serving of nuts 5 times per week resulted in a 50 percent lower risk of heart disease than eating the same serving only once a week.
Alcohol or regularly drinking coffee or tea can also have a huge impact on health. Alcohol use increases risk of cancer and other diseases in a dose response relationship—the more you drink, the more likely you are to get cancer. In contrast, one study found that men who drank 5 or more cops of green tea daily were half as likely to be diagnosed with prostate cancer as those who drank less than a cup. Coffee is protective too—a huge study of over 67,000 women found that those who drank more than 4 cups a day had a 25 percent lower risk of estrogen-related cancer.
Disease prevention is best achieved with a healthy lifestyle that includes diet, physical activity, mental health, stress management, and other interrelated factors. A multivitamin is a smart way to avoid nutrient deficiencies that arise due to restrictive diets or poor soil.
5) The study discussion didn’t touch the issue of how a multivitamin
might aid in supporting healthy hormones that can decrease cancer risk. The topic of how adequate nutrient levels can aid in the elimination of toxins, which alter hormone levels was not addressed either.
But, it’s worth mentioning since the process by which the body eliminates everything including chemicals we breathe or ingest in food, excess hormones like estrogen, or alcohol requires adequate nutrients. If those nutrients aren’t present, detoxification will be slowed and waste products will accumulate in the body, causing inflammation, decreasing metabolism, and damaging cells—all processes that lead to disease over time.
There are three phases of detoxification: For the first phase you need adequate B vitamins that can bind to toxins. For the second phase you need adequate amino acids and antioxidants, which facilitate the removal of the bound toxin. For phase three you need a healthy gastrointestinal tract with sufficient fiber. Plus, along the way, your body must have certain nutrients to enable enzymatic reactions for the whole system to work, which is why it’s often called the anti-inflammatory or detoxification cascade.
A multivitamin in addition to a high-fiber, high-quality diet will support the cascade of actions that must occur for detoxification, and this may have been a contributing factor to lower cancer risk in the study. That those physicians were deliberate about taking their vitamins day after day may have given their bodies that extra pool of nutrients needed for cancer prevention.
For more information on the topic of multivitamins, read Why Should I Take a Multivitamin