We all want good heart health, a high functioning immune system, strong bones, glowing skin, and the list goes on. Consuming a well-balanced diet that’s rich in essential nutrients plays an important role in aging optimally. But with busy schedules, potential financial barriers, and competing health demands, for some, if not many of us, this may feel like a tall order at times (1). So, our ears "perk up" at the sound of seemingly “easy” solutions to our health concerns or strategies that require low effort while still helping us achieve our health goals. The use of dietary supplements is one such strategy. These supplements line the physical and virtual shelves of our grocery stores, health food stores, and pharmacies; and have been successfully marketed as a key part of our health and wellness journeys (2).
Despite often overinflated promises doled out via advertising, evidence to support the use of dietary supplements for the prevention and treatment of various conditions or the promotion of overall health is not always so cut and dry (2-16). Sometimes it’s encouraging, but often within specific contexts such as in the case of vitamin D and diabetes or respiratory tract infections, and other times it’s lacking and calls for more research, such as in the case of cancer or dementia prevention. Results vary based on the population, type of supplement, and outcome being studied (3-16).
Cardiovascular (heart or blood vessel) diseases contribute to a significant proportion of global deaths. In 2019 alone, cardiovascular diseases were responsible for almost 18 million lives lost. Digging deeper into the data, we see that over 15 million of these deaths were directly related to heart attack and stroke (17). Currently, there is no consensus around the use of specific vitamin and mineral supplements for the prevention or treatment of cardiovascular diseases, yet use amongst the public remains high. A recent systematic review took on the task of reviewing the evidence on the role of supplements in lowering the risk for heart attack, stroke, or death due to cardiovascular diseases (2).
So, should the results raise our heart rate; in a good way?
What the research tells us
The findings may make people looking to protect their heart health pause before placing a supplement bottle in their shopping cart.
Overall, it was found that commonly used supplements—such as vitamins D and C, calcium, and multivitamins—do not appear to reduce the risk for total cardiovascular disease, heart attack, or stroke, compared to no supplement use. What’s more, there was also no reduction in death from cardiovascular disease, heart attack, stroke, or any cause. The evidence ranged from very low to high certainty depending on the outcome, meaning that future research could change the results for some outcomes but likely not others. For instance, the finding that vitamin D did not reduce the risk of death by any cause was the only one based on high-quality evidence, allowing us to be very confident in this particular result. The following vitamins and minerals may also have no effect on cardiovascular outcomes: antioxidants, beta-carotene, iron, magnesium, selenium, vitamin A, vitamin B3 (niacin), vitamin B6, vitamin E, and zinc. However, it should be noted that the consumption of antioxidants and niacin (with a statin) may increase the risk of death from any-cause.
There were some positive results worth noting, however. Specifically, the use of folic acid may reduce the risk for total cardiovascular disease and stroke, while B-complex vitamins (in which folic acid was also a component) may reduce the risk for stroke. With that said, these results need to be considered carefully and with additional information. Although the individual studies included within the review took place in countries all over the world, the positive results were driven by one large study from China. Unlike in North America, where foods are fortified with folic acid, China does not routinely do the same. This means that we cannot be sure that the benefits seen in the study from China would translate to other countries that supplement food with folic acid.
Where does this leave us? Ultimately, back to where we started the conversation, stressing the importance of consuming a healthy and balanced diet that allows you to get all of your needed vitamins and minerals without the use of supplements. A diet rich in plant-based sources is likely to help most people (unless they have specific underlying conditions that require the use of supplements) achieve this (2). Refer to Canada’s food guide for guidance on healthy eating and/or consult with your health care team. If you do choose to incorporate supplements into your diet, make sure it is a joint decision with your health care team, as not all supplements are safe for all people.