Why is nutrition so hard to study?

Is dairy good or bad for health? Is cholesterol evil? Does red meat kill or cure? Is the ketogenic diet a godsend or a health hazard? Can the vegan, vegetarian, pescatarian, or raw food diet extend disease-free life?

Nutrition is wrapped in multiple confusions. Why is it so hard to determine whether a food is good or bad for health?

In medical science, proving any theory is difficult. The science of nutrition is no different, but it also has some unique challenges. In this feature, we outline just some of these stumbling blocks.

Despite the many issues that nutrition scientists face, understanding which foods benefit or harm health is essential work.

Also, the public is growing increasingly interested in finding ways to boost health through diet. Obesity and diabetes are now highly prevalent, and both have nutritional risk factors. This has sharpened general interest further.

All areas of scientific research face the following issues to a greater or lesser degree, but because nutrition is so high on people’s agenda, the problems appear magnified.

A changing world

Although the water is muddy and difficult to traverse, there have been substantial victories in the field of nutrition research. For instance, scientists have determined that vitamin C prevents scurvy, that beriberi develops due to a thiamine deficiency, and that vitamin D deficiency causes rickets.

In all of these cases, there is a link between a particular compound and a specific condition. However, the picture is rarely so clear-cut. This is especially true when investigating conditions wherein multiple factors are at play, such as obesity, osteoporosis, diabetes, or heart disease.

Also, nutrition-related conditions have changed over time: The most common threats to health used to be deficiencies, whereas in Western countries today, overeating tends to be the primary concern.

Understanding the role of food in health and disease is essential and deserves attention. In this feature, we discuss some of the reasons that nutrition research seems to be so indecisive, difficult, and downright confusing.

The ‘perfect’ nutritional study

In an ideal world, to understand the health impact of a given food — goji berries, for instance — an experiment would go something like this:

Scientists recruit 10,000 participants (both males and females, from a range of nationalities and ethnicities) and house them in a laboratory for 10 years. The scientists feed each person the exact same diet for the duration of their stay, with one difference: Half of the participants consume goji berries surreptitiously — perhaps blended into a mixed fruit smoothie.

Alcohol and tobacco are banned for the duration of the study.

The participants must also exercise for the same amount of time each day; if some people exercised more, they might become healthier, regardless of their goji berry intake. This would skew the data.

 Source: Medical News Today