One of the reasons that I keep reading about medical subjects so much is that new information can change the way we look at things. This, in turn, can lead us to give different advice, sometimes nearly opposite to what we have been taught before.
For example, health experts have been telling us for many years that to decrease the risk of heart attacks and cancer, it would be wise to cut back on red meat, and especially processed red meat, like bacon.
However, five recent systematic reviews have suggested that the unhealthful effects of regular meat consumption are in question and might be insignificant.
While the scientists did not address the environmental aspects of meat production and the potential benefits of a non-meat diet, they did change the way some of us might feel about our choice to be carnivores.
Some of the previous conclusions were based on case-control studies, where researchers started with an endpoint (for example, people who already have cancer). For each person with a disease, they find a match or control subject (someone without the disease). Then, they would look at the history of those people and try to determine if any patterns of exposure (like eating meat) differed in those with cancer compared to those who did not have cancer.
Researchers tried to control for confounding factors, the unmeasured variables that might lead to one person getting cancer while another stayed healthy. But they could never factor in all the possibilities.
Such observational studies cannot tell you enough to make definitive recommendations. But if many of the best quality observational studies found a large effect on a disease in the data, they were thought to be probably pointing to something real.
A few years ago, this sort of thinking about the available studies, including animal and case-control studies resulted in the World Health Organizations International Agency for Research on Cancer announcing that people should cut back on processed meats if they wanted to avoid certain types of cancer. The American Heart Association and the U.S. governments dietary guidelines panel have also been pointing us toward a plant-rich diet for years.
The new meat studies attempted to rely on higher quality evidence to draw their conclusions. Even then, the results are not perfect, and will no doubt produce much debate over the coming years.
That nutrition science is updating old findings with new evidence does not mean the science has been completely wrong. Science a long and sometimes circuitous process involving continuing re-analysis in the effort to get to the truth.
If anything, despite the confusion the recent meat studies produce, they remind us that the science is getting better and that it okay to question conventional wisdom as new information becomes available.
These re-evaluations are not evidence that science is doomed. We should not doubt every scientific finding that is out there, especially when the conclusion is not the result of a single study, but the result of a lot of good studies.
I spend a lot of time trying to recognize when evidence is strong or weak and who sponsored the studies involved. Since not all published findings are equal, it is always important to maintain a critical eye. This is especially true when we are dealing with large shifts in the conclusions, like the idea that the amount of red meat we consume is not really a significant factor in our health.
In my opinion, it is reasonable to recommend moderation in all things, including our diet. Perhaps, a plant-rich diet could contain some red meat without quite as much guilt for some of us who want to be healthy but love consuming meat.
Read more:
Use moderation in all things, including diet | Columnists - KPCnews.com
