First a little history. The first nutritional study, per Microsoft Bing, was conducted in 1747 by Dr. James Lind. He was a physician in the British Navy. Years earlier in 1740, Great Britain was in war with Spain, named the War of Jenkins’ Ear. Leading a squadron of eight ships, Commodore George Anson set out on a mission to capture the possessions of the Spanish Empire in the Pacific Ocean. His journey led him from England across the Atlantic Ocean to rounding the southern tip of South America then north to Mexico. His journey continued home by crossing the Pacific Ocean to China and then rounding the southern tip of Africa and on to Portsmouth, England. He had circumnavigated the globe. This voyage attracted much attention from the European people because 1400 out of the 1900 men died. They believed that the cause of these deaths was from scurvy. Scurvy is a disease resulting from a deficiency of vitamin C. Unfortunately, it wasn’t until the 1900s that vitamins were discovered.
Dr. Lind was the first to use a systematic study experiment in 1747. By the use of control groups, he could conduct these clinically controlled experiments to arrive at a conclusion. I won’t leave you hanging. He determined that the use of citrus fruits would cure sailors of scurvy.
Since then, studies have been used for a wide range of different things.
In the last five years, there have been approximately 2,000 nutrition-related clinical studies. A few topics are listed below:
- Differences in the response of different people to certain foods.
- How diets can affect varies from person to person
- The impact of a controlled healthy diet on diabetes.
- The influence of certain diets on reproductive health
- How proper nutrition promotes health.
Studies have gotten messy and are no longer that simple. Just in the field of nutritional science, scientists and doctors are trying to determine the causes of chronic diseases such as heart disease, diabetes, stroke, obesity, and cancer. This has led to a multitude of contradictory studies, each containing its own limitations and flaws. Couple this with the vast information on the internet, just adds to everyone’s confusion.
Here are some of the reasons why it is so difficult to conduct and study nutrition. For the most part, researchers will use randomized control trials. The way the trial is conducted is by taking a group of people, test subjects, and dividing them into two groups. The first group will get the treatment and the other group will get a placebo. A placebo is essentially a fake treatment. Say you were testing the effects of vitamin C. One group would get a vitamin C pill and the other group would get a sugar pill. Researchers believed that because the test groups were randomly assigned and the only difference between the two groups was the treatment, therefore the treatment was the cause or cure depending on what you were studying.
As far as nutritional studies, you can begin to see the problem here. Not only is it too difficult to track peoples’ diets, but to ensure that they stick to the diets that they have been assigned. These studies normally involve many people and last for a measurable amount of time, such as six months to a couple of years. Unfortunately, unless you are going to keep them confined, there is no way to guarantee what they eat.
Another way to conduct these trials, researchers use observational studies. This is where researchers track a very large number of people over many years. These people are already eating a certain way. The researchers will periodically check in on the subjects, evaluating them and seeing who gets any chronic disease, such as heart disease or cancer. Once again you can see how less precise this is because the trials aren’t conducted in a controlled setting. Many other factors can affect the outcome. You might have people that you’re tracking that are more health-conscious, better or less educated, or even have differences in income which affect what food they buy and eat.
Many of these observational studies use food surveys. Since the researchers can’t constantly monitor the test subjects and record everything they eat, they give them surveys about what they ate over the last year. Now I don’t know about you, but do you remember what you had to eat last week? Let alone, yesterday or two days ago? Do you remember if you had any snacks between meals? Did you consume any cookies, crackers, or potato chips, and how many? Self-reporting of what you eat is very imprecise and very flawed. This is because, for the most part, people can lie about what they eat. Think about the last time you went to the dentist, and you were asked that common question “When was the last time you flossed?” I am not going to say I haven’t lied about that one.
One of the other common problems with nutritional studies is that there are so many different people out there. Since test subjects weren’t born yesterday, their eating habits and healthy choices like smoking or physical activity are different. No two people are alike. So, testing two different people, you might get two very different results.
It is also very important to note that these studies since they involve so many people and time frames, are very costly. If a certain industry is funding a study, do you not think that the results will be more targeted towards a favorable outcome and any negative outcome might be discarded. It has been reported that the majority of the industry-funded studies were favorable to the industry conducting the study.
What do we believe? With all the conflicting information out there, it makes it impossible to know the truth.
I found this very interesting and informative.