A small study (56 men and women, 38-55 years old) found that taking supplements for 6 months had no effect on a number of cardiovascular risk factors:
Multiple Dietary Supplements Do Not Affect Metabolic And Cardio-Vascular Health, Aging, September 2013
Both the supplement group and the control group took a daily multivitamin/mineral. But the supplement group also took the following supplements each day (“the most self-prescribed dietary supplements in middle-aged men and women eating a Western diet”):
100 mg resveratrol ($72 for 180 days)
800 mg green tea extract ($115)
800 mg black tea extract ($240)
800 mg white tea extract ($141)
250 mg pomegranate extract ($156)
650 mg quercetin ($180)
500 mg acetyl-l-carnitine ($68)
600 mg lipoic acid ($318)
900 mg curcumin ($117)
1 g sesamin ($62)
1.7 g cinnamon bark extract ($230)
1.0 g fish oil ($70)
Those costs in parentheses: I went online and priced each supplement at the given strength. I chose brands randomly but looked for no other ingredients and an easily scalable potency. Total cost for 6 months (not counting the vitamin/mineral supplement): $1769.
After 6 months, there was no effect on:
Endothelial (blood vessel) function
Body fat (measured by DEXA)
Plasma lipids (triglycerides, total cholesterol, LDL, HDL)
Insulin resistance (HOMA-IR)
Advanced glycation end-product (AGE) concentrations
Biomarkers of inflammation and oxidative stress
Conclusion: “In summary, supplementation with a combination of popular dietary supplements has no cardiovascular or metabolic effects in non-obese relatively healthy individuals.”
“Since completing the randomized trial, all but one of the participants in the SUP group continued for another 6 months on the supplementation regimen. Even with this longer, 12 month period of supplementation, no changes in any outcome were observed.”
Even the authors were surprised at the lack of effect:
“Because all the supplements that we used have been reported to have powerful anti-inflammatory and anti-oxidant effects, it is interesting that no biological change in endothelial function was observed.
One possible explanation for the lack of beneficial metabolic effects of these over-the counter dietary supplements could be the low phytochemical bioavailability or inadequate supplement potency of the phytochemicals contained in some of these compounds which are available without prescription . Nonetheless, the fact remains that millions of individuals in USA and Europe are consuming these supplements, sometimes instead of a healthy diet and conventional medical treatment, which might contain hazard trace amounts of pesticides and heavy metals, including lead, arsenic, mercury, and cadmium [1,33]”
The good news was that there was no negative effect, at least on the markers tested, except for gastrointestinal distress from taking so many supplements. The bad news was that these supplements didn’t do anything, but, as you can see, cost about $1769 for a 6-month supply!
These are the kinds of controlled, efficacy studies supplement makers don’t want to perform, don’t perform, and don’t have to perform. (From FDA: “Unlike drug products that must be proven safe and effective for their intended use before marketing, there are no provisions in the law for FDA to “approve” dietary supplements for safety or effectiveness before they reach the consumer.”) Supplement makers enjoy helping to separate consumers from their disposable income without much justification other than cell culture or animal studies and a few testimonials (which could be placebo effect, which is why you conduct studies, to rule out placebo effect).