Cold brew coffee is a popular beverage made by steeping coarse coffee grounds in cold or room-temperature water for an extended period, typically 12 to 24 hours. This process yields a concentrated liquid characterized by a smooth, low-acid flavor profile. A primary concern with any coffee preparation method is its potential impact on cholesterol levels, particularly low-density lipoprotein (LDL) and total cholesterol. The way coffee is prepared determines whether certain natural compounds are present in the final cup, influencing this health outcome.
Coffee Oils: Cafestol and Kahweol
Coffee beans naturally contain oily compounds known as cafestol and kahweol, which are responsible for coffee’s cholesterol-raising effect. These molecules interfere with the body’s normal cholesterol regulation. The mechanism involves the liver, the central organ for maintaining cholesterol balance.
Cafestol and kahweol disrupt metabolic pathways by suppressing the activity of key liver enzymes, such as cholesterol 7α-hydroxylase (CYP7A1). This enzyme is responsible for converting cholesterol into bile acids, a major route for the body to eliminate excess cholesterol. By inhibiting this conversion, these coffee oils reduce the rate at which cholesterol is cleared from the body.
This interference leads to a build-up of cholesterol, resulting in elevated levels circulating in the bloodstream. Studies show that cafestol strongly raises both total cholesterol and LDL cholesterol, often referred to as “bad cholesterol.” The presence of these compounds in the final brew depends entirely on the preparation method, not the water temperature used.
How Cold Brew Preparation Affects Oil Content
The primary factor determining the level of cholesterol-raising oils is whether the final brew is separated from the grounds using a highly porous filter. Traditional cold brewing is an immersion method where the grounds sit directly in the water for many hours. When brewing is complete, the liquid is often strained through a metal mesh or a reusable cloth filter.
This method of separation is not as effective as paper filtration at trapping the microscopic oil droplets containing cafestol and kahweol. Unlike paper, metal or cloth filters allow a significant portion of these oily compounds to pass through and remain suspended in the finished cold brew. This results in an unfiltered beverage rich in cholesterol-raising substances.
A standard paper filter used in drip coffee preparation can remove between 80% and 90% of the cafestol and kahweol from the brew. Other unfiltered methods, such as French press or boiled coffee, also contain high levels of these oils due to the lack of effective paper filtration. Therefore, the lack of filtration in the common cold brew process, rather than the cold temperature, links it to these coffee oils. Some commercial products and home recipes incorporate paper filtration during the final straining, which significantly reduces the oil content.
Clinical Impact on Cholesterol and Consumption Guidance
Consumption of unfiltered coffee, including cold brew prepared without a paper filter, has a measurable clinical impact on blood lipid levels. The increase in cholesterol is dose-dependent; the more unfiltered cold brew consumed daily, the greater the potential elevation of total and LDL cholesterol. Studies on similar unfiltered brews have shown that daily consumption can significantly increase total cholesterol, with elevations averaging around 18.5 mg/dL in some cases.
This effect is pronounced with heavy consumption, often defined as five or more cups per day, but even moderate intake of unfiltered coffee can cause a noticeable rise over time. For individuals already dealing with elevated cholesterol or those with a history of cardiovascular disease, this consistent daily intake poses a greater health concern.
The increase in cholesterol levels caused by cafestol and kahweol is generally reversible upon switching to a filtered method. If cold brew is a regular part of your diet, a simple adjustment can mitigate the risk. Consumers can easily switch to a paper-filtered cold brew, use a paper filter when straining their home brew, or opt for standard filtered drip coffee. For anyone with pre-existing high cholesterol, it is prudent to discuss daily cold brew consumption with a healthcare provider.