I have been skeptical of supplements for a long time – not because I have some predisposition against them. My skepticism results from the relative lack of any robust evidence that supplements have any positive effect on human health other than in unique situations of chronic diseases or malnutrition. In fact, most of the high-quality evidence about supplements show that it does not work. And a recently published review shows that using supplements for cardiovascular diseases are expensive and useless.
Since many readers fail to read what I wrote above, let me repeat myself for clarity. Supplements are not completely useless – of course, they are important for those who have chronic diseases or conditions may require supplements of some or many micronutrients. Someone who has had bariatric surgery or other types of serious gastrointestinal surgery may not be able to consume enough vitamins and minerals from food, and they will require multivitamins.
Also, some individuals may be malnourished, which doesn’t mean just not eating enough, but not eating some foods that have specific nutrients. For example, avoiding certain foods that contain vitamin C could put you at risk for a disease called scurvy, which can be deadly. There are several other diseases that result from missing key nutrients. However, in the modern developed world, these diseases are extremely rare because of the varied diet we have – and the availability of supplements to treat those diseases.
However, several points have got to be made. Just because vitamin C can treat scurvy doesn’t mean that more vitamin C makes your immune system suddenly powerful enough to destroy the common cold or flu or cure cancer. Vitamin D, although there are many cases of deficiency in many countries, is not a miracle supplement. It cannot cure or prevent cancer. It does not impart superpower abilities to your immune system.
The whole supplement industry has an overreliance on logical fallacies (like appeal to popular belief or appeal antiquity) or anecdotes (which aren’t data) to convince customers to buy their nonsense. They do this because they are not required to undergo gold-standard clinical trials to convince the FDA to approve their claims. Real pharmaceuticals, on the other hand, take 10-20 years of research and clinical trials before they are approved for use.
Big Supplement (yeah, it’s a huge industry, over US$100 billion annually, worldwide) also pushes the trope that if a little helps, a lot is better. This is not good science. The millions of years of human evolution (following up a billion years of immune system evolution) has led to a rather powerful immune system that is exceedingly complex and has always been able to do its job without the addition of supplements (unless early Homo sapiens had access to a GNC someplace).
But let’s take a look at supplements for cardiovascular diseases (stroke, heart attacks, and other cardiovascular conditions) – a new review shows us, once again, that there’s nothing there.
Supplements for cardiovascular diseases – a systematic review
In a systematic review and meta-analysis, considered the pinnacle of quality biomedical research, published in Circulation: Cardiovascular Quality and Outcomes, a high ranked peer-reviewed journal, Kim et al. examined 18 prospective cohort studies and randomized controlled trials, 11 in the USA, 4 Europe, and 3 Japan. The meta-analysis included over 2 million participants and an average of 11.6 years of follow-up per participant. This is a powerful analysis of the effects of supplements for cardiovascular diseases.
So what are the key results? The relative risk ratios (see Note 1) with multivitamin and mineral supplements for cardiovascular disease were:
- 1.00 (numbers close to 1.0 mean no effect) for cardiovascular disease mortality.
- 1.02 for coronary heart disease mortality.
- 0.95 for stroke mortality.
- 0.98 for stroke incidence.
These results showed no statistically significant effects of supplements for cardiovascular diseases. And they provide fairly powerful evidence that using these supplements for cardiovascular health is not recommended.
In an accompanying editorial in Circulation: Cardiovascular Quality and Outcomes, the editors wrote:
The findings by Kim et al may not ultimately be surprising in 2018. Preventing or treating disease with vitamin supplements was relatively simple when foods were limited, frank vitamin deficiency was possible, and common diseases had a clear cause, such as vitamin C deficiency for scurvy or thiamine deficiency for beriberi. Now that diets are more varied, supplemented, and fortified, diseases of frank vitamin deficiency are rare, and the most commonly occurring diseases have a multifactorial cause. It may be unlikely for a supplement ingested once a day to confer a health benefit, and the study by Kim et al provides no reason to take one.
Summary – supplements for cardiovascular diseases
Like I wrote recently about omega-3 fish oils, the effects of multivitamin and mineral. supplements for cardiovascular diseases is negligible. The claims made about these supplements is just pure woo – there’s nothing there.
Even though it will anger the pseudoscience supplement pushing crowd, but if you want to prevent cardiovascular disease, your best choice is statins. A robust systematic review showed that statins reduced the risk of cardiovascular diseases, including mortality. In other words, real science supports the use of evidence-based medicine and rejects the use of woo-based supplements.
Vitamin and mineral deficiency is extraordinarily rare in the modern world. And excess micronutrients don’t make your more healthy – excess vitamins just filtered out of your blood by your kidneys and ultimately excreted in your urine. And for some vitamins, excessive amounts can actually be dangerous.
Again, outside of needs for chronic diseases or malnutrition, supplements don’t do anything magical. They really are a waste of money, but that’s how medical woo works – spend money for no effect.
If you’re worried about your cardiovascular health, see a real physician and get a real diagnosis followed by real science-based treatments. Don’t use supplements for cardiovascular diseases – they don’t do anything useful.
- A risk ratio measures the relative risk of a particular outcome between an experimental group and a control group. A number greater than 1.0 implies that the experimental group has a higher risk of an outcome compared to the control. A number less than 1.0 implies the experimental group has a lower risk than the control. Any number that is statistically equivalent to 1.0 means there’s no difference between the groups. Thus, an RR = 0.98 means that the omega-3 supplement group shows no difference in risk of all-cause mortality than the control group.
- Haslam A, Prasad V. Multivitamins Do Not Reduce Cardiovascular Disease and Mortality and Should Not Be Taken for This Purpose: How Do We Know That? Circ Cardiovasc Qual Outcomes. 2018 Jul;11(7):e004886. doi: 10.1161/CIRCOUTCOMES.118.004886. PubMed PMID: 29991647.
- Kim J, Choi J, Kwon SY, McEvoy JW, Blaha MJ, Blumenthal RS, Guallar E, Zhao D, Michos ED. Association of Multivitamin and Mineral Supplementation and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis. Circ Cardiovasc Qual Outcomes. 2018 Jul;11(7):e004224. doi: 10.1161/CIRCOUTCOMES.117.004224. PubMed PMID: 29991644.
- Navarese EP, Robinson JG, Kowalewski M, Kolodziejczak M, Andreotti F, Bliden K, Tantry U, Kubica J, Raggi P, Gurbel PA. Association between baseline LDL-C level and total and cardiovascular mortality after LDL-C lowering – a systematic review and meta analysis. JAMA2018; 319(15):1566-1579. .