By now it’s common knowledge that our diets have a substantial impact on our overall health. To be more precise, the nutrients, protein, sugar, and fat contained in the food we eat contribute to the biochemical cycles that determine cellular function. Poor nutrition is frequently cited as an important factor in the rise of chronic diseases because of the disrupting influence of some chemicals on these cellular cycles.
Unfortunately, when we look for advice regarding healthy eating and how to improve our diets, we’re faced with an overwhelming amount of contradictory guidelines and fads like eating raw food, consuming as much meat as possible or avoiding it completely, eating five small meals per day or trying intermittent fasting and so on.
Consumers are becoming increasingly concerned with the relationship between what they eat and their health, so they start reading nutritional labels or avoiding certain additives. Nevertheless, there’s still a lot of confusion, which is why you often feel like you need advanced knowledge in the field of chemistry just to pick the right things from the supermarket.
Why Is It so Difficult to Put Forward Consistent Dietary Recommendations?
When it comes to chronic disease, governmental agencies and medical associations do provide patients with dietary recommendations to help them mitigate their symptoms and avoid complications. For example, people suffering from heart disease are advised to reduce their consumption of salt and saturated fat, which should help decrease their blood pressure. Likewise, people with diabetes are told to be cautious with the amount of sugar in their food as to compensate for the effects of metabolic imbalances in their insulin secretion.
Part of the problem with investigating the scientific connection between dietary habits and health outcomes is that study participants will often give inaccurate reports with respect to what type of food they ate and the amount. Health effects that come specifically from certain foods are also hard to detect and track as many other variables could influence the data.
Most studies will establish a correlation between a particular diet and health effects, and these are called observational studies. To determine causal links, you’d need to abide by the gold standard of scientific research that requires randomized controlled trials in which a group of participants will adopt certain dietary modifications while the control group will not. If the results can be accurately interpreted as to suggest a causal relationship between specific dietary habits and health benefits or negative effects, chemistry can serve to identify the molecular components that account for these effects.
Case Study: The Mediterranean Diet
The Seven Countries study from 1958 observed 16 groups of participants from seven different countries and found that those living in Greece, Crete, and southern Italy showed a lower frequency of heart disease and tended to live longer than the participants from other countries.
This diet is now commonly referred to as the “Mediterranean” diet and consists of vegetables, fruit, whole grains, small amounts of meat and dairy, olive oil, nuts, beans, and red wine in moderation.
The observations of the Seven Country study were followed by an examination of data resulting from clinical studies which did, indeed, show that this diet reduces some of the risk factors of heart disease and concluded that, in order to show what effects the “Mediterranean” diet will have on different populations, more research and evidence is needed.
Here, we go back to why gaining some basic knowledge of chemistry can help you improve your eating habits. At this point, chemists started analyzing every component of the diet. They measured the fiber content of the whole grains and beans as well as the fat content of nuts, evaluated the percentage of carbohydrates, and classified the polyphenols found in red wine and olive oil. Polyphenols are natural compounds of plant foods that can act as antioxidants and reduce the negative impact free radicals have on cellular health as well as decrease inflammation and improve gut health.
Whole grains are cereals that belong to the grass family Gramineae and include rice, wild rice, wheat, corn, barley, oats, rye, millet, and sorghum. Quinoa, buckwheat, and amaranth are considered pseudocereals and belong to a different plant family. There is strong scientific evidence suggesting a correlation between the consumption of whole grains and lower blood pressure.
A single grain consists of three components: the fiber-rich bran outer layer, the starchy endosperm, and the germ, which is a small inner reservoir of nutrients. When the grain is refined, the outer layers of bran, as well as the gran, are removed. Many of the commercial whole grain products we see in supermarkets now actually add back these two components in proportions equal to those in the natural seed. Still, these reconstituted food items appear to cause the same sudden rise in blood glucose as the ones made from refined flour. This would suggest that the structure of the grain is vital to maintaining its health benefits.
There’s also scientific research to suggest that the nature of polyphenols found in whole grains accounts for the lower risk of developing colon cancer. Unlike the soluble phenols contained in fruit and vegetables that seep through the small intestine and never make it to the colon, the ones in whole grain are attached to insoluble components of the plant and travel to the colon.
Pulses are edible seeds that grow in a pod such as beans, lentils and peas. Because of the composition and crystallinity of starchy carbohydrates contained in pulses, they take 45% more time to digest. Note that the digestive problems some people report when eating beans are a result of oligosaccharides such as verbacose and raffinose and not from the slowly digestible starches.
Pulses are, in fact, excellent sources of vitamins and minerals. For example, two servings of some pulses like beans can provide you with the entire recommended amount of folic acid, while black beans and red kidney beans have high amounts of anti-inflammatory polyphenols. The lectin found in kidney beans is even used in antiretroviral therapy (ART) for patients infected with HIV.
Randomized controlled trials have linked the consumption of pulses to lower blood pressure and improved outcomes regarding metabolic syndrome and type 2 diabetes.