If you are wondering whether to purchase canned tuna that is packed in oil or in water, and if your purchase decision is based on it being a emergency survival food prep, you many consider the following facts.
The primary difference is that tuna packed in oil has about four times as much fat content (4 grams versus 1 gram packed in water in a typical 5 ounce can), and therefore contains more calories. Some tuna is packed in vegetable oil while others are packed in olive oil. Olive oil may be slightly better for you than the vegetable oil, however no doubt that the canners are not using the ‘good’ oil.
In a typical 5 ounce can of tuna,
Packed in water…
150 calories, 7% fat, 93% protein
Packed in oil…
250 calories, 40% fat, 60% protein
Although I can’t find manufacturer data to support it, tuna in oil probably has a lower freezing point, which may matter to those in very cold climates or outdoor winter situations.
Remember that not everyone may enjoy the taste/texture of eating tuna packed in oil versus that of water. Store what you eat and eat what you store…
Overall, it seems that from a survival preparedness standpoint, tuna packed in oil may be the better choice due to its higher calorie content. From a health standpoint, the choice may be ‘water’.
Also, be aware of the dangers of mercury in tuna. The general advice that I’ve read is to not consume more than one or two cans per week.