A daily multivitamin can help your memory, but only if you’re in this age group

Research checks query newly published studies and how they are reported in the media. The analysis is undertaken by one or more academics not involved in the study and reviewed by another to ensure it is accurate.

Don’t we all want to do what we can to reduce the impact of age-related decline on our memory?

A new study suggests that a daily multivitamin and mineral supplement is an easy and inexpensive way to help older adults slow the decline in some aspects of memory function.

The new study, which comes from a long-running clinical trial, shows there may be little benefit to taking a daily multivitamin and mineral supplement for one type of cognitive task (immediate word recall) among well-functioning older whites. At least in the short term.

But that doesn’t mean we should all rush out and buy multivitamins. The study findings do not apply to the entire population or to all types of memory function. Nor does the study show long-term benefits.

How was the study conducted?

The global COSMOS study is a well-designed double-blind randomized control study. This means that participants were randomly assigned to receive the intervention (a daily multivitamin and mineral supplement) or a placebo (dummy tablet), but neither the participants nor the researchers knew which they were taking.

This type of study is considered the gold standard and allows researchers to compare various results.

Participants (3,562) were older than 64 for women and 59 for men, with no history of heart attack, invasive cancer, stroke, or serious illness. They couldn’t use multivitamins or minerals (or cocoa extract, which they also tested) during the trial.

Participants completed a battery of online cognitive tests at the start of the study (known as a baseline), then annually for three years, of which only three are reported in this paper:

• ModRey, measuring immediate recall. Participants were shown “a list of 20 words, one at a time, for three seconds each,” and then had to type the list from memory
• ModBent, object recognition measurement. Participants were given 20 suggestions with one shape and then had to select the correct match from a pair of similar suggestions. Next, they were asked to take turns with 40 shapes and had to indicate whether or not each was included in the original 20
• Flanker, measuring “executive control”. Participants had to select a colored block that corresponded to an arrow in an arrow matrix, which could have the same (or different) color as the surrounding arrows and the same (or different) direction as the prompt block.

What did the researchers find?

Of all the tests performed by the researchers, only the immediate booster (ModRey) at one year showed a significant effect, meaning the result is unlikely to be just the result of chance.

At two and three years, the effect was no longer significant (meaning it could have been due to chance).

However, they added an “overall estimate” by averaging the results from all three years to arrive at another significant effect.

All effect sizes listed are very small. The largest effect is for immediate recall of participants at one year, which was 0.07, a value generally considered very small without justification.

It is also notable that both the multivitamin and placebo groups had higher immediate word recall scores at one year (compared to baseline), although the increase in the multivitamin group was significantly greater.

In the researchers’ previous study, increased word recall scores were described as a “typical learning (practice) effect.” This means that they attributed the highest scores at one year to familiarization with the test.

For some reason, this “learning effect” was not discussed herein, where the treatment group showed a significantly greater increase than those given the placebo.

What are the limitations of the study?

The team used adequate statistical analysis. However, it did not fit demographic characteristics such as age, gender, race, and education level.

The authors describe well the main limitation of their study: it is not very generalizable, as it used “mostly white participants” who must have been very computer savvy, and it could be argued that it would be quite cognitively well-functioning.

Another limitation not mentioned is the advanced age of their sample, meaning that long-term outcomes for young people cannot be evaluated.

Additionally, the baseline diet score for their sample was bad. Researchers say participants’ dietary scores “were consistent with U.S. population averages,” but the cited study found “overall dietary quality [was] poor.”

And they didn’t measure dietary changes over the three years, which could affect the results.

How should we interpret the results?

The sample’s poor food quality begs the question: Could a better diet be the simple solution, rather than multivitamin and mineral supplements?

Even for the effect they observed, which micronutrient from the supplement was the contributing factor?

Researchers speculate on vitamins B12 and D. But you can find cognitive function research for any arbitrarily chosen ingredient, including selenium, which can be toxic at high levels.

So should I take a multivitamin?

Health authorities advise daily use of multivitamins isn’t necessary, as you can get all the nutrients you need by eating a wide variety of healthy foods. However, supplementation may be appropriate to address any specific nutritional deficiencies in an individual.

Using a good-quality multivitamin at the recommended dose shouldn’t cause any harm, but at best, this study shows that well-functioning older whites might show some additional benefit in one type of cognitive activity from using a supplement. multivitamin.

The case for most of the rest of the population and the long-term benefit for young people cannot be argued.

Blind peer review

Clare Collins writes:

I agree with the reviewer’s assessment, which is a comprehensive critique of the study. The key finding was a small effect size of daily intake of a multivitamin and mineral (or “multinutrient”) supplement on memory recall at one year (but not at subsequent time points) and is equivalent to an effect of training where you get better at taking a test the more times you do it.

It is also worth noting that the study authors received backing and funding from commercial companies to undertake the study.

While the study authors say they don’t believe the quality of the baseline diet affected the results, they didn’t comprehensively evaluate it. They used a brief diet quality assessment score at baseline only. Participants may have changed their eating habits during the study, which could therefore impact the results.

Given that all participants reported low diet quality scores, an important question is whether providing participants with the knowledge, skills, and resources to eat healthier would have a greater impact on cognition than would taking supplements.

Jacques Raubenheimer, Senior Research Fellow, Biostatistics, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.