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A new study examining two large cohort datasets found that higher levels of vitamin B are associated with a lower risk of stroke.Certain B vitamins were considered protective only up to a threshold. Experts say it’s still best to get your B vitamins from foods like spinach, avocado, whole grains, and poultry.
Stroke is the most common cause of disability in the U.S., making it something that you want to avoid. But while eating a healthy diet, exercising regularly, and avoiding smoking can help lower your risk, new research suggests there’s one other, less obvious thing you might consider: Upping your vitamin B intake.
There are a lot of different things that can cause a stroke, making it hard to say for sure that eating more B vitamins alone will make your risk disappear. But the findings, which were published in the American Journal of Preventive Cardiology, suggest that factoring in these nutrients as part of your risk-reduction strategy can’t hurt. Here’s why.
Meet the experts: Simin Liu, MD, study co-author and director of the Center for Global Cardiometabolic Health & Nutrition at the University of California, Irvine; Cheng-Han Chen, MD, interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, California; and Sonya Angelone, PhD, RDN, a nutritionist and registered dietitian based in San Francisco.
What are B vitamins?
Before we dive into the study’s findings, it’s important to point out that there are many B vitamins, collectively known as the B complex. Here’s a brief breakdown:
B1 (thiamin)B2 (riboflavin)B3 (niacin)B5 (pantothenic acid)B6 (pyridoxine)B7 (biotin)B9 (this can be as folate, the naturally occurring form of B9, or folic acid, the synthetic form)B12 (cobalamin)
This study found that a few B vitamins in particular—vitamin B1 (thiamin), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B6 (pyridoxine), and folate (the naturally occurring form of vitamin B9)—play a role in stroke risk.
What did the study find?
For the study, researchers analyzed data on nutrition intake and blood biomarkers of B vitamins from two large national cohort studies—the Women’s Health Initiative and All of Us Research Program. Overall, the analysis included about 222,000 men and women, who were tracked over time.
Over a period of two decades, about 6,800 participants in the Women’s Health Initiative had a stroke. Those with the highest intake levels of B1 (thiamin), B2 (riboflavin), B3 (niacin), B6 (pyridoxine), and B9 (folate) had up to a 20 percent lower risk of stroke compared to people with the lowest intake of these vitamins.
In the All of Us cohort, about 5,200 people had strokes over six years of follow-up. The researchers also found higher intakes of certain B vitamins linked to a lower risk of stroke. Those with the highest levels of B6 (pyridoxine) had a lower risk of stroke than those with the lowest intakes of the vitamin. Higher B9 (folate) levels were also associated with a lower risk of stroke.
Why are higher vitamin B levels linked to a lower stroke risk?
There are likely a few things going on here. Higher vitamin B levels might lower the risk of stroke by lowering levels of homocysteine in the blood, explains Cheng-Han Chen, MD, interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, California. Homocysteine is a molecule that increases stroke risk by promoting blood clots and damaging artery walls.
But lower homocysteine levels made up about 11 percent of the link between folate and reduced stroke risk, points out Simin Liu, MD, study co-author and director of the Center for Global Cardiometabolic Health & Nutrition at the University of California, Irvine. “This shows it’s an important piece of the puzzle, but definitely not the whole story,” he says.
Inflammation may be a factor, too. “Chronic inflammation is a driver of atherosclerosis and plaque build-up, which leads to a stroke if this occurs in the brain,” explains Sonya Angelone, PhD, RDN, a nutritionist and registered dietitian based in San Francisco, California. Several B vitamins help regulate inflammation and are also crucial for energy production that impacts blood vessels and vascular health, she adds.
Every B vitamin’s impact was slightly different.
Liu points out that the data showed “the more, the better” for folate, with a lower stroke risk observed up to at least 2,000 dietary folate equivalents per day.
“However, for thiamin, riboflavin, niacin, and pyridoxine, the pattern was reverse J-shaped,” he says. In lay terms, “this means that while higher intake is generally better, there does seem to be a threshold.”
As for what the “sweet spot” is for the non-folate B vitamins, Angelone says it would likely differ from person to person, as each individual’s absorption and metabolism differ. “The best advice is to avoid deficiencies and excesses,” she notes.
Is it better to get your vitamin B from food or supplements?
The study found perks from taking in B vitamins from food and supplements. But Liu says there isn’t much clinical trial data on supplementing with B vitamins such as thiamin or riboflavin. “Because of this, our findings shouldn’t be seen as a green light to start a high-dose regimen of additional B vitamins,” he explains.
Angelone says it’s still best to get your B vitamins (and all vitamins, if you can) from food so you can reap the benefits of added nutrients like fiber. That said, if someone has a family history of early cardiovascular disease, pregnancy loss, excess or deficient blood levels, high homocysteine, or other complications that may benefit from supplemental vitamin B, it might be a good idea to discuss that with a healthcare provider.
She recommends the following foods to load up on your B vitamins:
· B1 (Thiamin): whole grains, legumes, pork, and sunflower seeds
· B2 (Riboflavin): dairy products, eggs, lean meats, and almonds
· B3 (Niacin): whole grains, poultry, tuna, salmon, and peanuts
· B6 (Pyridoxine): poultry, fish, potatoes, garbanzo beans, and bananas
· B9 (Folate): dark green leafy vegetables, legumes, asparagus, avocado, edamame, and citrus fruits
Getting more B vitamins could be as easy as making healthier swaps, like making a filling spinach-and-quinoa dish for lunch, or ordering edamame as an appetizer with dinner. And for all its detractors, avocado toast on whole-grain bread is actually a pretty healthy, vitamin B-rich breakfast choice.
Ultimately, Liu says it’s important to be mindful of your vitamin B intake. “Even in the United States, where foods are already widely fortified with folic acid, maintaining higher long-term levels of vitamins B1, B2, B3, B6, and folate does seem to be important in terms of lowering stroke risk,” he says.
Korin Miller is a freelance writer specializing in general wellness, sexual health and relationships, and lifestyle trends, with work appearing in Men’s Health, Women’s Health, Self, Glamour, and more. She has a master’s degree from American University, lives by the beach, and hopes to own a teacup pig and taco truck one day.
Carina Hsieh, MPH, is the deputy features editor of Women’s Health. She has more than a decade’s worth of experience working in media and has covered everything from beauty, fashion, travel, lifestyle, pets, to health.
She began her career as an intern in the fashion closet at Cosmopolitan where she worked her way up to Senior Sex & Relationships Editor. While covering women’s health there, she discovered her passion for health service journalism and took a break to get her Masters in Public Health. Post-grad school, she worked as a freelance writer and as The Daily Beast’s first Beauty, Health, and Wellness Reporter.
Carina is an alum of the Fashion Institute of Technology and the Yale School of Public Health. She and her French Bulldog, Bao Bao, split their time between Brooklyn and Connecticut. She enjoys reformer Pilates, (slow) running, and smelling the fancy toiletries in boutique fitness class locker rooms.
