The following memo appeared in the newsletter of the West Meria Public Health Council.
“An innovative treatment has come to our attention that promises to significantly reduce absenteeism in our schools and workplaces. A study reports that in nearby East Meria, where fish consumption is very high, people visit the doctor only once or twice per year for the treatment of colds. This shows that eating a substantial amount of fish can clearly prevent colds. Furthermore, since colds are the reason most frequently given for absences from school and work, attendance levels will improve. Therefore, we recommend the daily use of a nutritional supplement derived from fish oil as a good way to prevent colds and lower absenteeism.”
Write a response in which you discuss what questions would need to be answered in order to decide whether the recommendation and the argument on which it is based are reasonable. Be sure to explain how the answers to these questions would help to evaluate the recommendation.
The author of the memo makes several assertions to support his recommendation that fish consumption be used to prevent colds. First, he notes that since colds are frequently cited as the reason for absenteeism, ‘attendance levels will improve.’ Second, he claims that fish consumption lowers cold rates by 40 percent. Third, and perhaps most significantly, he asserts that fish consumption prevents colds, thus improving attendance and decreasing absenteeism.
These assertions are reasonable, but the memo does not go far enough to demonstrate that they are valid. There are several questions that the memo should answer before concluding that fish consumption prevents colds and, therefore, that it improves attendance and absenteeism. For instance, the memo does not mention whether the fish consumed in the study area were of the same species as the fish consumed by the residents of the areas in which colds occur most frequently or whether the consumption of fish in the areas is sporadic or consistent.
One of the first questions that needs to be answered is whether or not the fish consumed by the residents of the areas in which colds occur most frequently are the same species as the fish consumed by the residents of the areas in which colds occur less frequently. Fish contain a number of beneficial nutrients, including omega-3 essential fatty acids. People living in areas with low fish consumption may consume a diet which is lacking in omega-3s, thereby making them more susceptible to colds. Furthermore, people who live in areas with low fish consumption may not consume fish on a regular basis. Thus, they may not receive the same health benefits from eating fish as those who live in areas with regular fish consumption.
Since the memo does not state whether the fish consumed by residents of cold-prone areas is the same or different than the fish consumed by residents of cold-free areas, it cannot determine whether fish consumption lowers cold rates in cold-prone areas. Furthermore, the memo does not state whether the fish consumption is low or sporadic in either area. If fish consumption is low in cold-prone areas, residents there may not benefit from eating fish. If consumption is sporadic, residents of cold-prone areas may benefit from eating fish, but those individuals who live in cold-free areas may not.
Another question that could be asked is whether fish consumption is consistent in cold-prone and cold-free areas. While it is understandable that residents of cold-prone areas would consume fish more often than residents of cold-free areas, the consistency of consumption in cold-prone areas cannot be ascertained from the memo. For example, residents of cold-free areas may have increased their consumption of fish, rather than decreased it, due to improved nutrition. Thus, fish consumption may be inconsistent in cold-prone areas.
Additionally, the memo does not state whether residents living in cold-prone areas eat the same type of fish as those who live in cold-free areas. Some fish, such as salmon, contain large amounts of omega-3 fatty acids, whereas others, such as lake trout, contain very little. Therefore, residents of cold-prone areas may be consuming fish that are rich in omega-3 fatty acids, but residents of cold-free areas may be consuming fish that are low in omega-3 fatty acids, negating any benefits that may accrue to residents of cold-prone areas.
Finally, the memo does not state whether the fish consumed in the areas studied are the same type of fish that residents of cold-free areas eat. Some fish, such as salmon, contain high amounts of omega-3 fatty acids, whereas others, such as lake trout, contain very little. Therefore, residents of cold-free areas may be eating fish that are rich in omega-3 fatty acids, but residents of cold-prone areas may be eating fish that are low in omega-3 fatty acids, negating any benefits that may accrue to residents of cold-free areas.
If the fish consumed in the areas studied are the same type as fish consumed by residents of cold-free areas, then the memo fails to explain why fish consumption lowers cold rates in cold-prone areas. If, on the other hand, the fish consumed in the areas studied are very different from the fish consumed by residents of cold-free areas, then the memo cannot conclude that fish consumption lowers cold rates in cold-prone areas.
The memo makes several other assertions, but these assertions are based on speculation rather than on evidence. Therefore, they are not reasonable.
The memo’s final conclusion that eating a significant amount of fish is an effective way to prevent colds and lower absenteeism is unsupported by any facts and is, therefore, not reasonable. If, however, the assumptions upon which the recommendation and the argument are based are valid, then the memo is a reasonable recommendation.
Although it is true that colds are frequently cited as the explanation for absences from school or work, the memo does not demonstrate that fish consumption lowers cold rates. The memo needs to answer several questions before it can draw valid conclusions.