By Brittany Lubeck, RD 

Published on September 29, 2023

 Medically reviewed by Beth Thomas, PharmD

Worldwide, more than 50 million people have dementia, a disease that affects cognition. Cognition includes memory, thoughts, and the ability to perform daily functions.¹ With these staggering numbers, many people are looking to dietary supplements with the hope of preventing dementia and boosting overall brain health.

Research suggests, however, that many people are unaware of the safety or effectiveness of supplements for brain health.² Moreover, while certain supplements are marketed to treat poor brain health, evidence to support these claims is lacking.

This article will discuss various supplements for brain health, including which ones may work and which ones may not. It will also cover whether supplements are necessary or if lifestyle changes are enough to make a difference in the health of your brain.

Getty Images / Saipg

A Word of Caution

Supplement brands cannot (and should not) claim that their supplements serve as a treatment for specific health conditions or diseases like dementia or Alzheimer’s disease (AD).³

Supplements are not meant to prevent, cure, or treat diseases, especially on their own. There is a vast amount of evidence on the importance of an overall healthy diet and lifestyle for disease prevention. Conversely, there is an overwhelming lack of evidence supporting the use of any dietary supplement as a sole treatment or prevention measure for any health condition.

Whenever possible, choose a supplement tested by a trusted third party, such as U.S. Pharmacopeia (USP), ConsumerLab, or NSF. However, even if supplements are third-party tested, they are not necessarily safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications

Nutrients for Brain Health

Diet and nutrition have a major impact on the health of your brain. Your long-term eating patterns are a vital part of not only your overall health but also your brain health.

Research on brain health has revealed that certain foods and nutrients may be better for your brain than others. Still, eating brain-healthy foods here and there may not be enough. Your overall diet is much more important.

Not getting enough of certain nutrients through your diet may even lead to cognitive decline in some cases. There is evidence that low levels of vitamin B12 may lead to cognitive impairment or even dementia.⁴ Additionally, some studies have suggested that iron deficiency may be linked to problems with cognition.⁵

Various nutrients, such as those with antioxidant, anti-inflammatory, and probiotic properties, are mentioned in numerous studies on brain health. The Mediterranean diet, which focuses on fruits, vegetables, and olive oil, has also been found to be beneficial for brain health.⁶

While there is strong research on nutrition for brain health, the same can't be said for research on supplements for brain health.

Some nutrients regularly mentioned in the literature on brain health are also common ingredients in supplements for brain health. These include omega-3 fatty acids, vitamin B12 and other B vitamins, choline, vitamin E, and other micronutrients. However, the evidence that these and other nutrients improve brain health when in supplement form is weak.

Omega-3 Fatty Acids

Omega-3 fatty acids (omega-3s) are a class of polyunsaturated fatty acids. Consuming omega-3s through food and dietary supplements is the only way to increase levels in the body. Certain types of omega-3s are thought to be vital to brain health.⁷

Docosahexaenoic acid (DHA) is a long-chain omega-3 that has been extensively researched for its role in brain health. DHA is found in high concentrations in the brain, making it essential to brain health and development. Researchers have also found that DHA levels tend to be low in people with AD compared to people who are cognitively healthy.⁷

Some research has focused on omega-3 supplements specifically.

One systematic review of studies covered the effects of various dietary supplements on cognition in healthy young adults, including military personnel. Researchers found that omega-3 supplements showed little to no improvement in cognitive performance among the studies included in the review.

Just one study on an omega-3 supplement containing DHA and another omega-3 called eicosapentaenoic acid (EPA) showed positive results (although these results have contradicted other findings).⁸

However, there is some evidence that omega-3 supplements may improve cognition in older adults or those with dementia or AD. Studies have shown that adults over the age of 70 who used EPA and DHA supplements experienced improved aspects of cognition, such as executive functioning, working memory, and brain signaling. Supplementation was also correlated with increases in omega-3s circulating in the blood.⁹

The Bottom Line

Omega-3s from the diet are essential to brain health, but more research is needed to determine if supplements are the best choice for increasing your intake of these important nutrients.

Vitamin B12

Vitamin B12 is another nutrient that is essential for brain health throughout the lifespan. From the beginning, vitamin B12 plays a role in the development and function of the central nervous system (CNS), which makes up the brain and spinal cord. Vitamin B12 is thought to be key to the prevention of dementia and other cognitive diseases.¹⁰

Research shows that low levels of vitamin B12 may lead to cognitive decline, depression, and idiopathic fatigue. When vitamin B12 is low, an amino acid called homocysteine may rise and cause damage to nerves in the brain or spinal cord.¹¹

However, studies looking at vitamin B12 supplementation as a treatment for cognitive decline have produced mixed results. While B12 supplementation has shown positive effects for people with advanced neurological disorders, it has not shown the same effects in those without such disorders.¹¹

Other research has shown a potential link between low levels of vitamin B12 and the development of AD or dementia. Low vitamin B12 in people with dementia has also been associated with poorer performance on the Mini Mental State Exam (MMSE), a test of mental performance, compared to those with adequate levels of vitamin B12. Thus, researchers have concluded that low levels of vitamin B12 might be associated with the development of dementia, but this theory is not completely proven.¹²

Multivitamin Supplements

There is some evidence that a basic multivitamin supplement may boost cognition.

A multivitamin supplement contains various micronutrients (vitamins and minerals) your body needs daily. While a multivitamin should never replace a well-balanced diet, it may help "fill in the gaps" if your diet lacks certain vitamins and/or minerals.¹³

While a multivitamin is recommended for certain populations (such as those who are pregnant), it may not be necessary for everyone. A healthcare provider can help you decide if you should take a multivitamin.¹³

New research shows that multivitamin supplement use may benefit older adults with memory issues.

In a recent clinical trial, over 3,000 older adults were randomized to take a placebo or multivitamin daily for three years. Those who took the daily multivitamin were found to have improved immediate recall memory. These improvements were sustained over the entire three-year trial period.¹⁴

As this is a newer area of research, more studies may be warranted to better determine if daily multivitamin use can improve cognition in older adults or other populations.

Nootropics for Brain Health

Nootropics (or "smart drugs") are natural or synthetic supplements meant to support brain health and cognition. They contain substances that may be made in a lab or derived from plants. The majority of nootropics are natural herbs, however.¹⁵

Like other herbal remedies, nootropics are considered a fairly safe supplement option. Very few have been found to cause serious side effects, but little is known about the safety of using nootropics long-term.¹⁵

Examples of nootropics include:¹⁵

• Deanol (DMAE)

• Meclofenoxate

• Nicergoline

• Pyritinol

• Vinpocetine

• Naftidrofuryl

• Dihydroergotoxine

• Lecithin

• Ginseng (Panax ginseng)

• Ginkgo (Ginkgo biloba)

• Asiatic pennywort (Centella asiatica)

• Ashwagandha (Withania somnifera)

• Water hyssop (Bacopa monnieri)

• Guarana (Paullinia cupana)

• Rhodiola (Rhodiola rosea)

• Schisandra (Schisandra chinensis)

• Maca root (Lepidum meyenii)

There are numerous nootropics on the market, some with better research support than others. Some of the compelling research behind certain nootropics is outlined below.

Ginseng

Panax ginseng is an herb commonly used in traditional Chinese medicine and other types of alternative medicine. It is said to have properties that reduce the risk of neurodegenerative diseases or decline.¹⁶

When it comes to brain health, researchers from one review found that Panax ginseng may have the most positive effects on depression. Compounds found in Panax ginseng are thought to cause antidepressant effects by interacting with certain cell signaling pathways.¹⁶

While much of the research on Panax ginseng for brain health has been performed in a laboratory setting, some human trials have been conducted.

In one large human trial, researchers compared long-term Panax ginseng users to nonusers. Compared to those who didn't use the herb, study participants who used Panax ginseng for long periods had higher cognition test scores later in life. However, these effects were only seen with long-term use (more than five years) of Panax ginseng.¹⁷

Ginkgo

The leaves from the Ginkgo biloba plant have been used to make herbal remedies for centuries. These leaves are used for many purposes in alternative medicine, including brain health.

A review of large-scale clinical trials on Ginkgo biloba found conflicting results regarding the herb's efficacy for cognitive functions.

According to the review, Ginkgo biloba extract is most commonly used for cognitive decline, poor memory, and decreased alertness. While many studies included in the review found no positive effects of Ginkgo biloba, several studies showed a potential role of the herb in treating cognition in patients with mild dementia. Ginkgo biloba was most effective when used for at least 24 weeks and at a dose of 240 milligrams (mg) per day.¹⁸

More research is needed to determine if Ginkgo biloba supplements work for brain health.

Ashwagandha

Due to its perceived neuroprotective properties, ashwagandha (Withania somnifera) has been recommended as an herbal treatment for cognitive decline.

A clinical trial from 2021 looked at how ashwagandha use would affect healthy, stressed adults. After randomization, participants took either a placebo or an ashwagandha supplement for 90 days. Taking 300 mg of ashwagandha root extract in a sustained-release capsule form per day was found to be safe and also led to improvements in memory, focus, sleep quality, stress, and overall psychological well-being.¹⁹

Scientists believe that ashwagandha reduces oxidative stress in the central nervous system and, thus, may be beneficial for diseases such as Parkinson's disease, Huntington's disease, and Alzheimer's disease. Some clinical trials have supported its use for brain health, but there isn't a clear consensus on how effective ashwagandha is.²⁰

Caffeine

In some studies, healthy caffeine consumption has been linked to better cognitive performance.

Caffeine is found in various foods and drinks, with coffee being the most popular option. While a moderate dose of caffeine (100 to 300 mg) has been shown to enhance alertness, a high dose (400 mg or more) may cause side effects like anxiety and trouble sleeping.²¹

According to one review, researchers agree that caffeine consumption improves basic cognitive functions (like attention and reaction time). However, there is less of a consensus among researchers on the effects of caffeine on "higher" cognitive functions (like decision-making and problem-solving).²¹

A 2021 review noted opposing results among several clinical trials on caffeine's effects on brain health. While there was not enough scientific evidence to support caffeine as an attention booster, there was evidence that caffeine improves both short-term and long-term memory in adults.²²

Hopefully, research will continue in this area so that the role of caffeine as a nootropic will become clearer.

Supplements That Don't Boost Brain Health

Regarding dietary supplements, you can't always believe everything you hear. This might be especially true for supplements marketed to boost brain health.

Many supplements that claim to boost brain health haven't been researched enough to support their use in everyone.

Nevertheless, some researchers believe there simply isn't enough clear evidence to support using any dietary supplement for brain health. This goes for people who are healthy as well as those with dementia or other neurodegenerative diseases.²³

For at least a few dietary supplements, there isn't strong evidence that supports their use in brain health. These include:

• Prevagen is an over-the-counter (OTC) supplement that contains apoaequorin, a protein found in jellyfish. There is only one clinical trial that supports the use of Prevagen for brain health. According to one review, this clinical trial had several limitations calling its validity into question.²⁴

• Vitamin E is an important nutrient that acts as an antioxidant. It has been researched for its potential role in brain health, but results have been conflicting, and there is yet to be a consensus on its use in AD and other diseases. According to one review, there haven't been enough reliable studies showing a positive effect of vitamin E, which may be due to the poor bioavailability of the nutrient.²⁵

• Vitamin D deficiency has been linked to an increased risk of developing AD. However, there is no evidence that supplementing with vitamin D improves cognition or outcomes in those with AD. There is also no solid evidence that vitamin D supplementation prevents AD.²⁶

In general, more research is needed on the use of dietary supplements for brain health. As previously mentioned, many researchers have a hard time recommending supplements to improve your brain's health.

Should I Take a Brain Health Supplement?

Besides the fact that brain health supplements may not do the work as intended, they also may come with safety concerns.

Recall that dietary supplements are not tested for safety or effectiveness like prescription medications are. This means that some brain health supplements may contain ingredients that either aren't listed on the nutrition label or are included in the supplement in amounts different than what is listed. When choosing a supplement, look for third-party tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.

To put this into perspective, a review of 12 supplements for brain health found just one to be third-party tested and actually contain what was listed on the nutrition label.²³

For the most part, side effects are rare but possible when taking dietary supplements. You are especially likely to experience side effects if you take too much of a supplement, so be sure to only use supplements as directed.²⁷

Some people may need to avoid using brain health supplements altogether. Unless told otherwise by a healthcare provider, children and people who are pregnant or nursing may need to avoid many brain health supplements. Many supplements (including those for brain health) have not been thoroughly tested in these populations.²⁸

Additionally, although many supplements may be generally safe, little is known about how herbs or nutrients often found in brain health supplements interact with medications you may take.²⁷ Be sure to discuss any supplements you plan to take with a healthcare provider. They can help you determine if the supplement may interact with any medications or other supplements you use.

Remember, dietary supplements alone cannot treat or prevent diseases. Talk with a healthcare provider for guidance on whether a brain health supplement is right for you.

Other Ways to Keep Your Brain Healthy

There are a number of other ways to keep your brain healthy that don't involve dietary supplements.

The Alzheimer's Association recommends several lifestyle changes and choices to help you maintain your brain health and lower your risk of AD and other neurodegenerative diseases. These include:²⁹

• Engaging in regular physical activity

• Eating a well-balanced diet that includes plenty of fruits and vegetables

• Reading books or taking classes online or at your local community college

• Quitting smoking

• Taking care of your heart health

• Wearing a helmet when riding a bike and a seatbelt when riding in a car

• Getting enough sleep

• Taking care of your mental health

• Staying socially active

• Challenging your brain with puzzles, games, or anything else that engages your mind

In general, dietary supplements are unnecessary for any aspect of health, including brain health. Talk with a healthcare provider to learn more about how to take care of your brain.

Summary

Certain supplements may help improve your brain health and reduce the risk of neurodegenerative diseases like dementia and Alzheimer's disease. However, the evidence behind the safety and efficacy of many supplements for brain health is weak or conflicting.

Fortunately, there are many ways to improve the health of your brain that don't require dietary supplements. A healthcare provider can help you determine the best steps to improve your brain health.