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Worried About Your Risk of Dementia? Get Your Vitamin B9 Levels Checked

Dementia may actually cause low folate levels, not the other way around.

When you think about the signs of dementia, what comes to mind? Your first thoughts are most likely memory loss, difficulty concentrating, or the struggle to find the right word in a conversation. While these are important signs of cognitive decline, new research suggests there’s another test that doctors should add to their list: a folate (vitamin B9) blood test. In a study published earlier this year in the BMJ journal Evidence Based Mental Health, researchers found that low folate (vitamin B9) levels are linked to a greater risk of dementia and death. They also found that early dementia may actually cause low B9 levels — rather than low B9 causing dementia.

The Study Set-Up and Findings

The research team noted that previous studies have already confirmed the link between a folate deficiency and dementia. However, few studies have offered strong evidence that a folate deficiency causes dementia. So, the researchers set out to determine whether low folate levels cause dementia, or whether dementia causes low folate levels. They used data from the electronic health records of 27,188 Israeli citizens aged 60 to 75. None of the participants had a dementia diagnosis at the start of the study.

Over the course of four years (2013 to 2017), the researchers noted the number of participants who had or developed a folate deficiency. They also noted the number of people who developed dementia and/or died (from any cause) in those four years. Here’s what they found: People with a folate deficiency were 1.68 times more likely to develop dementia and 2.98 times more likely to die.

Finding Out Whether Low Folate Causes Dementia

As the researchers suspected, the evidence that a folate deficiency causes dementia was not as strong. Authors found that getting enough folate was only moderately linked to low dementia risk, and only mildly linked to mortality.

In other words, meeting your folate requirements won’t necessarily prevent you from getting dementia. It won’t necessarily delay death either, because so many other factors contribute to life expectancy. As a result, the study authors concluded that a folate deficiency may actually be a consequence of dementia, rather than its cause.

Why Dementia May Cause a Folate Deficiency

It’s not yet clear why dementia would cause a vitamin deficiency, and the authors stress that their results are not definitive. Rather, the research simply shows how important it is to not jump to conclusions; low folate levels don’t necessarily cause dementia. Still, the authors agreed that vitamin B9 testing is important for people who suspect their cognitive health is declining.

Study Limitations

While the research is eye-opening, it has its limitations. The study was observational, which means the authors could not control the participants’ diets or lifestyles, both of which could influence dementia risk. For example, people who don’t consume enough folate and have a high dementia risk may also be people who don’t exercise or eat healthy foods.

In addition, the researchers only used data from participants who were chosen by their doctors to get folate tests. This might seem minor, but it makes a big difference. It means the participants were already suspected to have an issue with their folate levels. As a result, the number of participants who were folate deficient in this study may have been skewed. Now, the researchers say that the numbers were similar to folate deficiency in the greater population. Still, they agree that this makes it difficult to apply their findings to all people over 60.

Recommended Folate Amount

While the study didn’t prove that folate prevents dementia, getting enough of this vitamin each day is definitely important for your overall health. Folate helps the body create healthy red blood cells and DNA. The National Institutes of Health (NIH) recommend that adult women get 400 micrograms (mcg) daily. The safe daily limit is about 1,000 mcg, but it’s extremely rare to reach a toxic level. (If you go over 1,000 mcg in a day, you should be okay.) Looking for folate-rich foods to add to your diet? Try these:

  • Nutritional yeast, 1 tablespoon (457 mcg, 114% DV)
  • Beef liver, 3 ounces (215 mcg, 54% daily value, or DV)
  • Spinach, boiled, ½ cup (131 mcg, 33% DV)
  • Black-eyed peas, boiled, ½ cup (105 mcg, 26% DV)
  • Rice, white, medium-grain, cooked, ½ cup (90 mcg, 22% DV)
  • Asparagus, boiled, 4 spears (89 mcg, 22% DV)
  • Brussels sprouts, frozen, boiled, ½ cup (78 mcg, 20% DV)
  • Spaghetti, cooked, enriched, ½ cup (74 mcg, 19% DV)
  • Lettuce, romaine, shredded, 1 cup (64 mcg, 16% DV)
  • Avocado, raw, sliced, ½ cup (59 mcg, 15% DV)

The easiest way to reach your daily requirements is with a tablespoon of nutritional yeast, which tastes similar to cheese. Bonus: It’s packed with other B vitamins, including thiamin (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), and cobalamin (B12). Sprinkle it on your sautéed vegetables, use it as a healthy topping on plain popcorn, or mix it into a bowl of mac and cheese (you won’t even know it’s there). A brand we love: Bob’s Red Mill Nutritional Yeast.

Speak with your doctor before increasing your folate intake, especially if you are taking anticonvulsants (for seizures), barbiturates (central nervous system depressant), methotrexate (treats cancer), or pyrimethamine (antimalarial).

Bottom Line

While this study doesn’t prove that low folate causes dementia or vice versa, it does highlight the importance of getting enough folate every day, especially if you are over 60. The researchers also suggest that doctors start checking patients’ folate levels regularly, particularly if they suspect cognitive decline. So, at your next annual check-up, ask your doctor about your vitamin B9 levels. If they’re low, it’s time to make a more conscious effort to increase your intake.

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