One of my greatest fears as I get older is to have a family member patiently tell me that we've already had the same conversation earlier in the day but for me to have no recollection of it - and for my brain to not function correctly. Cognitive decline is a very real concern as we age, and it's an area of study that has been ongoing for decades.
Thinking about cognitive decline and performance highlights both how brilliant and complex the mind is and also how fragile it is. We are our brains; in a very real way, our bodies exist for the sole purpose of supporting our minds. We want to do everything we can to support this incredibly valuable asset.
In this article, I'll show you an extremely popular supplement you're probably already taking, as well as the great evidence showing that it improves brain performance and helps protect against cognitive decline. I'll also show you why this supplement is controversial and discuss a recent study that has been going viral. Finally, I'll help you learn what to watch out for when choosing this supplement for yourself. If you'd like to watch a video on this subject, you can also view it here.
Table of Contents
The Source of the Claims: the COSMOS Studies
First, let's start with the obvious first question: how do we know this supplement improves brain performance? Extraordinary claims require extraordinary evidence, after all.
In this case, our evidence comes from a massive study called the COSMOS study. This study was accompanied by three ancillary studies called COSMOS-Mind, COSMOS-Web, and COSMIS-Clinic. Data from these three studies was also combined into a meta-analysis that involved over 5,000 people.
All three of these studies were randomized, placebo-controlled studies. This means that one group took the supplement while the other took a placebo medication. These studies were also double-blind, which means that the people in the studies – and the scientists conducting them – didn't know whether any given patient was receiving the real supplement or the placebo. This way, any source of bias, intentional or otherwise, is minimized.
This is the "gold standard" for industry studies, as the best way to conduct a trial to minimize the chances of bias influencing the results of the study. That's an important detail to keep in mind as we discuss the details of the studies, their results, and the controversy that has come up.
Two of the three studies (COSMOS-Mind and COSMOS-Clinic) looked at Global Cognition, and involved a total of 2,731 participants. The results had a P value of 0.0009, which means the results are highly statistically significant.
The third study, COSMOS-Web, measured episodic memory. It, too, showed significant results, and the combined 5,000 individual results of all three studies reached a P value of 0.0007, indicating a true benefit for the supplement.
Another really important point is that the overall effect was not heterogeneous across the studies. This means that all of the studies show the same result, meaning that the effects are reproducible.
Measuring the Impact
A study that shows results is good, but the second most important question is this: how big is the effect? What I mean is, how much benefit will this supplement provide for brain performance and long-term cognitive health?
It can be difficult to measure these kinds of attributes – the brain is very complex, after all – but the studies placed the impact as the equivalent of two years less cognitive aging in the supplement group compared to the control group.
"Regarding the clinical importance of our meta-analysis findings: the magnitude of the effect of MVM supplementation compared with placebo on global cognition score was equivalent on average to the difference observed between participants 2 y apart in age (that is, 2 y less cognitive aging)." - COSMOS
Given that the study only ran for 2-3 years, this is a pretty significant benefit. However, this is also where the controversies start to crop up. Let's talk about the first source of controversy, which stems from an older study.
The First Controversy
It's time to draw back the curtain and reveal the supplement: I'm talking today about a multivitamin and multimineral supplement.
The controversy comes from the fact that this is not a new supplement. In fact, there was a previous study performed prior to the COSMOS studies, which was also a long-term look at cognition. It was also a randomized, double-blind, placebo-controlled trial, just like the COSMOS studies. It involved nearly 6,000 male physicians.
In contrast to the COSMOS studies, the Physician's Trial found "no difference in mean cognitive change over time between the multivitamin and placebo groups or in the mean level of cognition."
So, we have a long-term study that ran from 1997 to 2011, which showed no impact, and another more recent study that showed a defined positive impact. What's going on? Why does the Physician's study show no benefits, but the COSMOS studies do?
As it turns out, there are three major differences between the studies, and the third one is likely the most important.
The first difference is that the Physician's study only included male participants, while the COSMOS studies included both males and females.
The second difference is that the Physician's study didn't start cognitive testing until, on average, two and a half years after the study started. This is important because it means that any benefits achieved in the first two and a half years of supplementation would be missed.
The third and possibly most important difference is that not all multivitamin and multimineral supplements are the same. The supplement taken in the Physician's study was Centrum Silver, while the supplement formula for the COSMOS studies was a different blend and included two important nutrients: lutein and lycopene. Keep those in mind for later.
The Viral Study
Up above, I mentioned that a new study has gone viral and brought controversy with it, so let's talk about that study. First, though, a bit of background.
We have had numerous studies in the past showing that multivitamin supplements do not reduce the risk of illnesses like cancer and cardiovascular disease, and do not reduce death rates. For example, a study from 2011 involving over 182,000 participants showed no effect. A similar study in 2022 found the same thing, with insufficient evidence for the use of multivitamins in the prevention of cancer and cardiovascular disease. The COSMOS study, too, found no impact on cancer, cardiovascular disease, or death rates.
All of this brings us to a new study, a 2024 study called the Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts study, involving over 390,000 people. This study – you guessed it – shows no benefit from multivitamins on cancer, cardiovascular disease, or general death rates.
Why is this important, why has it gone viral, and why am I drawing attention to it? Well, I've seen news outlets and other medical channels use this study to say that multivitamin and multimineral supplements are useless. But, and this is key, the study didn't look into cognitive benefits like the COSMOS studies.
Neither I, nor the COSMOS study, suggests that anyone should take a multivitamin and multimineral supplement for the prevention of cancer, of heart disease, or for any other illness. I take it for the benefits to cognitive health over time.
I want to make it clear, though, that just because I take a supplement doesn't mean you should take the same thing. I pick my supplements to achieve specific goals. You should identify what your goals and health concerns are and talk to your doctor about supplements and other options you can take to achieve them. What works for me may not be what's best for you because we are all different people.
How to Pick a Multivitamin and Multimineral Supplement
One of the biggest issues with supplements, and a point I frequently discuss here and on my channel, is a warning about megadosing.
The human body needs vitamins and minerals to function properly. Some of those vitamins and minerals can be made from the nutrients we eat; others need to be consumed directly. All of them have a range of recommended daily intake; if you go below that range, you can suffer from a deficiency, and if you go above that range, there may be side effects. Not all nutrients have negative effects if you exceed the recommended daily intake, but many do.
Megadosing is simply the act of taking much more of a given supplement than your recommended daily intake would recommend. It's a useful strategy to address a deficiency or a medical problem, but if your diet is already balanced, it isn't necessary and can be harmful.
A supplement should be just that: a supplement to a healthy diet to help make up for a slightly low intake from our normal diets. It shouldn't be megadoses of everything in an attempt to guarantee high enough levels across the board.
The COSMOS study supplement is appropriately dosed as a supplement, and I was very close to choosing it, but there is a problem.
In the US Preventive Services Task Force recommendations from 2022, they concluded that supplementing beta-carotene (which the body processes into Vitamin A) is harmful enough to outweigh the benefits. They also recommended against supplementing Vitamin E.
The reason for this is another study which indicated that higher doses of Vitamin E and Vitamin A could increase mortality.
A healthy diet will already have enough of both Vitamin A and Vitamin E, so any supplement that includes them is almost always going to go over your recommended daily intake as long as your base diet is already healthy. I know I get enough of both, so I didn't want to take a supplement that contained them.
Personally, I also wanted a supplement that contains Vitamin K2, Magnesium Taurate, trimethylglycine (TMG), and Hyaluronic Acid for cognitive benefits, exercise benefits, and skin health. Since no supplement on the market contained exactly what I wanted without adding other things I didn't want, I designed MicroVitamin to suit my needs. Again: just because I take MicroVitamin doesn't mean you should as well. Read the ingredients list, understand your own goals, and determine for yourself if it's right for you.
Finally, remember above where I mentioned the primary difference between the Physician's study and the COSMOS studies was the inclusion of lutein and lycopene? Because of the COSMOS study, I plan to adjust the MicroVitamin formula to include these nutrients for their cognitive benefits.
MicroVitamin is a changing formula, one I customize to suit my needs and make available to others who want to pursue similar goals. It's important to me to follow the latest research, remove potentially harmful ingredients when evidence suggests they should be reduced, and include other ingredients when a study indicates they have benefits I want to achieve.
If all of that sounds like something you're interested in, you can follow along with this blog and subscribe to my YouTube channel for the latest updates, research, and analysis. Along the way, I'll help with science-based advice on how to improve the three core pillars of health: diet, exercise, and sleep. With the assistance of your own medical professionals, you can tailor these pillars to achieve your goals.
Sources:
- Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS: https://www.sciencedirect.com/science/article/abs/pii/S0002916523663427?via%3Dihub
- Long-Term Multivitamin Supplementation and Cognitive Function in Men: A Randomized Trial: https://www.acpjournals.org/doi/10.7326/0003-4819-159-12-201312170-00006
- Multivitamin Use and the Risk of Mortality and Cancer Incidence: The Multiethnic Cohort Study: https://academic.oup.com/aje/article/173/8/906/156839
- Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer, US Preventive Services Task Force Recommendation Statement: https://jamanetwork.com/journals/jama/fullarticle/2793446
- Multivitamins in the prevention of cancer and cardiovascular disease: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial: https://pubmed.ncbi.nlm.nih.gov/35294969/
- Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11208972/
- Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases: https://www.cochrane.org/CD007176/LIVER_antioxidant-supplements-for-prevention-of-mortality-in-healthy-participants-and-patients-with-various-diseases
