Citrus Flavonoids and Metabolic Disease
Several studies over the last decade or two have pointed to the value of citrus flavonoids in treating one of the most common and growing health concerns in North America – metabolic disease.
In addition to nutrients like vitamins and minerals, citrus fruits are rich in flavonoids. Flavonoids, as the term implies, are the compounds (polyphenolic compounds) in most fruits and vegetables that give them both color and flavor. Citrus fruits are rich in certain types of flavonoids, namely:
Why are flavonoids important? When cells become oxidized, it can result in a cascade of damage at the cellular level. Flavonoids have antioxidant properties, which means that they can help protect the body’s cells against oxidative damage.
Diet and disease
There is epidemiologic evidence that shows a correlation between the so-called Western diet – heavy on red meat and processed meats, packaged and processed foods, high-fat diary, eggs, refined grains, high sugar drinks, potatoes, and corn – and higher rates of cardiovascular diseases, diabetes, and elevated levels of fat in the blood. This high fat diet results in metabolic syndrome.
What is metabolic syndrome? It’s a cluster of conditions and diseases that can result in further problems.
• Hypertension (high blood pressure);
• Dyslipidemia (high and uncontrolled levels of fats in the blood);
• Insulin-resistant diabetes;
• Fat gain centered around the abdomen.
While there are drug therapies that are effective, they come with unwanted side effects. That’s why the potential of citrus flavonoids is so exciting.
The results are encouraging
Many recent studies point to the protective properties of citrus flavonoids.
• A 2006 study from the University of Palermo in Italy noted that there was an inverse relationship between the incidence of heart disease and the intake of flavonoids.
• A 2013 research study from the University of Western Ontario, in London, Canada, looked at the relationship between citrus flavonoids and the way the body metabolizes lipids or fats. Researchers studied the way the citrus flavonoids seem to actually regulate the metabolism of lipids and other factors that relate directly to metabolic disease, type 2 diabetes, and heart disease.
The paper noted that limited clinical studies already linked citrus flavonoids to several beneficial properties:
Just how that works is as yet unknown, although some clues are starting to emerge. “These recent studies suggest an important role of citrus flavonoids in the treatment of dyslipidemia, insulin resistance, hepatic steatosis, obesity and atherosclerosis,” researchers note.
• A 2014 study focused on naringin and naringenin, and their possible role in therapy for metabolic syndrome. The researchers noted citrus flavonoids have, “strong anti-inflammatory and antioxidant activities”.
Research using animal subjects has been promising, and they believe that eating citrus fruits may be more beneficial than taking naringin supplements.
More recent studies, including one from 2018, are looking at ways to use the parts of citrus that are typically discarded – including the peels – to extract flavonoids and other compounds such as citric acid, essential oils, and pectin.
The moral of the story? Citrus flavonoids are just one more reason to eat more lemons, oranges, grapefruits, and other citrus fruits.