Does Choline Increase Blood Pressure? Unpacking the Research

January 8, 2026 •

4 min read

Some human studies have found no link between normal dietary choline intake and blood pressure, while others suggest it may actually lower it. This complexity raises a common question for health-conscious individuals: does choline increase blood pressure, or is the relationship more nuanced?

Quick Summary

The relationship between choline and blood pressure is complex; while normal dietary amounts are not associated with hypertension, excessive intake can lead to a potentially harmful drop in blood pressure. TMAO, a metabolite of choline, is linked to an increased cardiovascular risk, but not necessarily hypertension directly.

Key Points

Normal Intake is Not a Risk: Consuming recommended amounts of choline, primarily from dietary sources, is not linked to increased blood pressure or hypertension.
High Doses Can Cause Hypotension: Excessive intake, typically from supplements far exceeding the 3,500 mg daily upper limit, can cause a drop in blood pressure (hypotension).
TMAO is the Potential Issue: High levels of TMAO, a metabolite of choline, are associated with cardiovascular risk, but its direct link to causing high blood pressure is still debated and likely complex.
Beneficial Effects at Normal Levels: Adequate choline intake may have a protective effect on cardiovascular health by supporting vagal nerve function and reducing inflammation.
Food is Safer Than Supplements: Getting choline from a balanced diet rich in eggs, meat, and vegetables is the best way to meet your needs without risking the side effects of excessive supplementation.

The Dual Nature of Choline's Impact on Blood Pressure

Choline is an essential nutrient vital for various bodily functions, including cell membrane formation, brain development, and fat metabolism. The idea that a nutrient so fundamental to health could negatively impact blood pressure seems counterintuitive, yet research shows a complex, and sometimes contradictory, relationship. At standard dietary levels, there is little to no evidence to suggest that choline increases blood pressure; in fact, some studies in both humans and animal models point to a neutral or even beneficial effect. However, at the extreme high end of intake—typically from large doses of supplementation—the risk profile changes significantly.

Choline's Protective Role and Acetylcholine

One of choline's key functions is as a precursor to acetylcholine, a neurotransmitter that plays a role in regulating the heart rate and blood vessel dilation. This mechanism is one reason researchers have explored choline's potential in managing hypertension. A study on spontaneously hypertensive rats found that choline treatment attenuated the development of high blood pressure and improved cardiovascular function. This was attributed to choline's effect on improving vagal nerve activity and reducing inflammatory responses. While these animal studies show promise, it is important to remember that such results do not always translate directly to humans. Additionally, research involving the direct administration of the enzyme choline acetyltransferase (ChAT) in hypertensive mice also demonstrated a dose-dependent decrease in blood pressure via nitric oxide-dependent vasodilation.

The Controversial TMAO Connection

A significant aspect of the choline-cardiovascular health conversation revolves around trimethylamine N-oxide (TMAO), a metabolite produced when gut bacteria process choline from certain foods. Elevated levels of TMAO in the blood have been associated with an increased risk of cardiovascular disease, including atherosclerosis, which is a major contributor to high blood pressure. This has led to speculation that high choline intake, via TMAO production, could indirectly increase blood pressure. However, recent Mendelian Randomization (MR) studies, which analyze genetic data to determine causal links, have suggested that while TMAO may be causally linked to blood pressure, the direct link between dietary choline intake and blood pressure is less clear and appears to be inconsistent across studies. It's a key distinction: the risk might be more related to the TMAO produced, rather than the choline itself, and TMAO's effect is more complex than a simple pressure increase.

Excessive Intake and Low Blood Pressure

In a direct contradiction to the idea that choline would cause a rise in blood pressure, health authorities like the Harvard T.H. Chan School of Public Health warn that very high intakes of choline can actually lead to low blood pressure, or hypotension. This effect, often accompanied by other side effects such as a fishy body odor, excessive sweating, and diarrhea, occurs when consumption far exceeds the recommended levels, typically via high-dose supplements. The Tolerable Upper Intake Level (UL) for adults is 3,500 mg per day. It is highly unlikely for someone to reach this level from food alone.

Dietary Choline vs. Supplemental Choline

It is important to distinguish between getting choline from food sources and taking high-dose supplements. Whole foods provide choline alongside a complex array of other nutrients, and typically do not lead to excessive intake. Conversely, concentrated supplements can easily push intake levels into the range where adverse effects, including hypotension, may occur. The body’s response to choline is therefore dose-dependent.

Here is a comparison of choline intake from dietary sources versus high-dose supplementation:


Feature	Normal Dietary Choline Intake	Excessive Supplemental Choline Intake
Source	Whole foods like eggs, liver, fish, and certain vegetables.	High-concentration powders, pills, or liquids.
Blood Pressure Impact	Generally neutral or potentially beneficial for cardiovascular function.	High risk of causing hypotension (low blood pressure).
Associated Metabolite	Generates TMAO, but impact is moderated by gut microbiome composition.	Can lead to high TMAO levels, associated with increased cardiovascular disease risk.
Side Effects	Typically none, supporting overall health.	Can cause fishy body odor, excessive sweating, and diarrhea.
Daily Limit	Unlikely to exceed the Tolerable Upper Intake Level (UL) of 3,500 mg.	Easily exceeds the UL, increasing risk of toxicity.

What are the best food sources of choline?

To ensure adequate intake without the risk of toxicity, focusing on food sources is the safest approach. The richest sources include animal products, though plant-based options exist. A typical large egg contains about 147 mg of choline, while a 3-ounce serving of beef liver can provide over 350 mg. Other good sources are:

Beef and poultry
Fish, such as cod and salmon
Dairy products like milk and yogurt
Plant-based foods such as soybeans, quinoa, potatoes, and cruciferous vegetables like broccoli and Brussels sprouts

Conclusion

Addressing the question, "Does choline increase blood pressure?" requires a nuanced answer. The available evidence suggests that consuming choline within recommended dietary allowances, primarily from food, does not increase blood pressure. For many, sufficient intake may even contribute to cardiovascular health by supporting proper nerve and vessel function. Conversely, extremely high, and unnecessary, supplemental intake can lead to adverse effects, including dangerously low blood pressure. The association between choline's metabolite, TMAO, and increased cardiovascular risk adds a layer of complexity, but does not indicate that choline itself is a direct cause of hypertension. Always consult a healthcare provider before beginning any high-dose supplement regimen. A balanced diet rich in choline-containing foods is the best strategy for reaping its benefits safely.

For more information on the role of choline in human health, visit the NIH Office of Dietary Supplements website.

Frequently Asked Questions

No, a normal intake of choline from supplements or food is not known to raise blood pressure. In fact, excessive doses above 3,500 mg per day are more likely to cause a drop in blood pressure (hypotension).

The Tolerable Upper Intake Level (UL) for adults aged 19 and older is 3,500 mg per day. Exceeding this amount can lead to side effects like low blood pressure and liver toxicity.

Some studies have linked high levels of the choline metabolite TMAO with increased cardiovascular risk. However, the causal link between dietary choline, TMAO, and hypertension is complex and still under investigation. A balanced diet is generally not a concern.

Excellent food sources of choline include egg yolks, beef liver, salmon, soybeans, and cruciferous vegetables like broccoli. A varied, healthy diet should provide adequate amounts.

A choline deficiency can lead to negative health effects, most notably nonalcoholic fatty liver disease and muscle damage, as choline is crucial for fat metabolism and liver function.

Some animal studies suggest that choline may have a protective effect against the development of high blood pressure by improving vagal activity and reducing inflammation. In humans, a link is not consistently proven, but normal intake is generally considered beneficial for overall cardiovascular function.

Yes, excessive choline intake, often from high-dose supplements, can cause a fishy body odor, excessive sweating, vomiting, diarrhea, and low blood pressure (hypotension).