Can a supplement lower a heart disease marker without raising bad cholesterol?

Taking a supplement called betaine can lower a substance in your blood called homocysteine, which is linked to a higher chance of getting Alzheimer’s—so this supplement might help protect your brain.

Taking betaine supplements may raise levels of betaine and some related compounds in your blood, slightly increase your 'bad' cholesterol, and lower a harmful substance called homocysteine — but it’s not clear if this is good or bad for your health.

Taking up to 4 grams of betaine a day might help lower a harmful blood chemical called homocysteine without making your cholesterol or fats go up—but taking more than that could raise your cholesterol and fats.

Taking betaine supplements doesn't seem to make a noticeable difference in your blood fats, sugar, inflammation, liver health, or blood pressure — at least not in most adults.