The Role for Vitamins and Dietary Supplements, Part Two
by Paul E. Lemanski, MD, MS, FACP
Editor’s Note: This is the 51st in a series on optimal diet and lifestyle to help prevent and treat disease. Any planned change in diet, exercise or treatment should be discussed with and approved by your personal physician before implementation. The help of a registered dietitian in the implementation of dietary changes is strongly recommended.
Medicines are a mainstay of American life and the healthcare system not only because they are perceived to work by the individual taking them, but also because their benefit may be shown by the objective assessment of scientific study. Clinical research trials have shown that some of the medicines of Western science may reduce the risk of heart attacks, strokes and cardiovascular death while others may reduce certain types of cancer.
In the first 50 installments of The Non-Medicated Life, informed diet and lifestyle have been shown to accomplish naturally for the majority of individuals, many, if not most of the benefits of medications in the treatment of chronic medical conditions. While the use of diet and lifestyle has a lower side effect profile and lower cost than medications the approach is less convenient and requires more effort. The dual issues of convenience and effort have led some to propose the use of vitamins and natural supplements as an alternative route to the non-medicated life. Unfortunately, from the perspectives of efficacy and safety vitamins and supplements have a decidedly limited role. Part One (September 2012) addressed vitamins, and Part Two now addresses supplements.
Natural supplements for purposes of this discussion may be categorized into two main groups, minerals and purified extracts from animals or plants. Minerals include calcium, magnesium, selenium and zinc. Purified extracts from animals include fish oil; purified extracts from medicinal plants include a large array of herbals, ground portions of parts of plants including seeds, cold pressed oils, and dried and ground flowers (which may be used in solution in the form of teas). I will address the efficacy and safety of both main groups along with several examples.
There is currently no evidence of a health benefit to be obtained through the use of mineral supplementation outside the reversal of a deficiency state. Calcium has routinely been prescribed for postmenopausal women for the maintenance of strong bones and as part of the treatment of osteopenia and osteoporosis, although by itself there is no evidence that it can correct such conditions. Heretofore calcium supplementation has not been shown to produce an increase risk unless an individual had preexistent high blood calcium.
Nevertheless, in an 11-year observational study of 24,000 participants as part of the European Prospective Investigation into Cancer and Nutrition study, risk was identified. Regular users of calcium supplements had an 86-percent increased risk of heart attack, compared with those who did not take supplements. Moreover, in those individuals with a moderately high intake of calcium from food sources, there was an associated 30-percent reduction in heart attack risk. It may be that consuming calcium in foods results in a slower release into the system and in this way reduces risk. Alternatively, consuming calcium as a supplement may be associated with individuals who eat other higher risk foods rather than getting their calcium from a more plant based diet.
Selenium, which is an antioxidant mineral, had been touted as a possible means to decrease oxidation of low-density lipoprotein (LDL) cholesterol, and thereby reduce cardiovascular risk. In the HDL-Atherosclerosis Treatment Study (HATS) Trial, however, selenium was part of an antioxidant cocktail that did not decrease risk, but actually decreased the benefit of other cholesterol lowering medications. In the Selenium and Vitamin E Cancer Prevention Trial looking at prostate cancer risk, selenium, which had been hoped to decrease such risk was shown to have no beneficial effect. As noted in Part One, vitamin E actually increased risk.
Fish oil has been shown to have a beneficial effect on blood cholesterol and heart arrhythmia. Indeed, several randomized controlled trials suggest a benefit. The GISSI-Prevenzione Trial, a randomized prospective placebo controlled study, looked at the effect of supplementing individuals with fish oil after a heart attack. Compared to those receiving placebo, those receiving one-gram of fish oil showed a decreased risk of death and cardiovascular death. More recently a meta-analysis of 20 studies and 68,000 patients published in Journal of the American Medical Association, suggests that omega-3 fats supplementation was not associated with lower risk of all-cause mortality, cardiac death, sudden death, heart attack or stroke. While the meta-analysis does raise concern, the structure of the study is less robust than a randomized, prospective placebo controlled study and therefore cannot establish a true lack of benefit. More study is needed.
Studies of botanicals and herbal products, unfortunately, do not show benefit. However, the larger concern with herbal products is their safety rather than their efficacy. First is the concern about interaction with prescription medications. It has been established that St. John’s wort, and ginkgo biloba may interact with blood thinners such as warfarin. Unfortunately, the warning of such an interaction may not consistently be present on a bottle of a given herbal product. A safe policy in using herbals and botanicals is to check for a possible interaction with a licensed pharmacist.
Of greater concern is that herbal products are not regulated and therefore not checked for purity by the Food and Drug Administration (FDA). Herbals, which may have been produced in another country, may contain heavy metals and other contaminants. While it would be best to only consume herbals that have been third-party tested for purity and freedom from contamination, such testing is not routinely done and adds to cost. At a minimum, one should check fda.org to determine if the herbal or botanical in question has been subject to an FDA warning or alert.
In conclusion, with the possible exception of omega-3 fish oil, there is to-date little scientific evidence that dietary supplements or herbal products have a health benefit. Studies are ongoing and are the appropriate way to determine efficacy. Safety is the greater concern and consumers should demand documentation of purity, and research possible interactions with prescription medications, as well as FDA warnings or alerts. A discussion with your personal physician may be of benefit to determine potential risks and benefits and such agents should not be used to prevent disease in an otherwise healthy individual.
The evidence would suggest that preventing disease and achieving the non-medicated life is best accomplished with a healthy diet and lifestyle rather than supplementation. In this way, one may best avoid the proverbial bottle of pills to address the majority of our health problems.
Paul E. Lemanski, MD, MS, FACP is a board certified internist with a master’s degree in human nutrition. He is director of the Center for Preventive Medicine of Paul E Lemanski MD PLLC. Paul is an assistant clinical professor of medicine at Albany Medical College and a fellow of the American College of Physicians.
**Originally published in Adirondack Life Magazine