Is sous vide cooking healthy for you?

Sous vide (pronounced "soo veed") is a cooking technique that involves vacuum sealing food in a bag, and cooking it in a water bath at a precisely controlled temperature (Figure 1). The term is French for "under vacuum.”

The food (e.g., meat, fish, vegetables) is seasoned and placed in a vacuum-sealed bag or a zip-top bag with the air removed. A sous vide machine (i.e. heated water bath) heats water to the desired temperature and maintains it constantly. The typical temperature range is from 120°F to 185°F, which is high enough to kill any bacteria. The vacuum-sealed food is submerged in the water, cooking slowly and evenly at the set temperature. For some foods, such as steak, a final finishing step like searing, grilling, or broiling is used to enhance flavor and texture.

Sous vide cooking is favored by professional chefs and home cooks for its precision, convenience, and ability to produce high-quality results. From a cooking standpoint there are several advantages over conventional cooking methods. First, the water bath is controlled to within a fraction of a degree, ensuring even cooking and preventing overcooking. Second, the food cooks evenly from edge to edge, unlike traditional methods where the outside may cook faster than the inside. Third, the vacuum-sealing process locks in juices and flavors, making food tender and flavorful. Finally, different levels of doneness can be achieved reliably (e.g., medium-rare steak every time).

One downside is the requirement for special equipment which includes:

• An immersion circulator that heats and circulates water in the cooking container.
• A large pot or sous vide-specific container to hold the water.
• Vacuum-sealed bags and sealing device or resealable plastic bags suitable for cooking.

Altogether a mid-range set-up may cost $300-500 in total.

From a health perspective, sous vide cooking possesses several advantages that may make it healthier than some traditional cooking methods.

Because sous vide involves cooking food at lower, more precise temperatures in vacuum-sealed bags, it helps retain more nutrients (especially water-soluble nutrients like vitamin C and B vitamins) that are often lost in high-heat methods such as boiling or frying. Methods like boiling or grilling can lead to significant nutrient loss due to high temperatures or leaching into water or oils.

Sous vide often requires little to no added fat since the vacuum-sealing and low-temperature cooking maintain the food's moisture and flavor.  Many traditional methods, like frying or sautéing, involve added fats, which can increase calorie content.

Sous vide enhances natural flavors, reducing the need for salt or heavy seasoning. Regular cooking may rely more on salt to enhance flavor, particularly in methods like roasting or grilling.

Cooking at lower temperatures avoids the formation of potentially harmful compounds, such as heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which can occur when grilling or frying at high temperatures. High-heat methods can generate these compounds, which are linked to cancer risks when consumed in excess.

If done correctly, sous vide cooking ensures food reaches a precise temperature that eliminates harmful bacteria, making it safe to eat. High heat usually kills bacteria effectively, but uneven heating or undercooking can pose risks.

In summary, sous vide cooking can be considered healthier in terms of nutrient retention, reduced fat and salt usage, and avoiding/killing harmful compounds/bacteria. However, the overall healthiness of the dish still depends on the ingredients and how they're handled before and after cooking.

Figure 1. A sous vide cooking set-up with a temperature controlled water circulator and heater placed in a water bath that is heated to a desired cooking temperature. The food is vacuum sealed in bags and cooked in the water bath.