Cures for cardiovascular disease, cancer, diabetes, and obesity have eluded scientists for decades, but research in nutritional genomics suggests that halting the progression of these diseases may be as simple as a dietary intervention.
Thousands of years ago, Greek physician Hippocrates concluded that good health was inextricably linked to the types of food humans consumed: “Let food be thy medicine and medicine be thy food.” Yet in a modern world that rewards innovation, promotes health, and provides access to a variety of cuisines, the food that is becoming the most prevalent around the globe does little to improve and maintain human health. Diets high in saturated fats and added sugars, low in fiber, high in refined grains and animal products, and low in plant foods are increasingly being consumed by humankind. Such poor dietary habits are contributing factors to many noncommunicable chronic diseases—in particular, cardiovascular disease, certain cancers, obesity, and type 2 diabetes. As a consequence, noncommunicable chronic diseases are the leading causes of death in the world. Sixty-three percent of the deaths that occurred around the globe in 2008 were attributed to noncommunicable chronic diseases—most of which are preventable (WHO, 2011).
Cultures that have resisted the lure of unhealthy dietary habits, however, rarely experience the symptoms of noncommunicable diseases. Such societies eat diets rich in vegetables, fruits, and whole grains and have low or no incidence of disease and disability. Indubitably, the most nutritious foods on the planet are plant foods, and research studies have long indicated an inverse relationship between a high consumption of plant foods and chronic diseases. But recent discoveries in nutritional genomics are unveiling the specifics of why such diets are effective at warding off disease. Plant foods contain hundreds of bioactive compounds—vitamins, antioxidants, and other phytochemicals—that, when consumed, catalyze a variety of changes within the body. More specifically, the bioactive compounds in plant foods interact with cells, enzymes, hormones, and DNA, playing a role in controlling gene expression and cell changes that lead to chronic disease. In essence, the genetic makeup of humans is not static; it is dynamic, and nutrients from foods can sway gene expression in a positive direction.
Past scientific studies alluded to this by highlighting the effects of various plant compounds on specific ailments. For example, some studies have concluded that lycopene, a compound present in tomatoes, appears to lower the risk of prostate, lung, and bladder cancers while other studies have concluded that foods rich in anthocyanins, such as blueberries and strawberries, significantly reduce mortality from cardiovascular disease (Wallace, 2011). But why is the interaction between the bioactive compounds in plant foods and the genes embedded within human cells so advantageous and what do they do?
Oxygen Radicals Stress Out DNA
Many chronic diseases have been at least partially attributed to chronic inflammation and damage caused by oxygen radicals, also known as reactive oxygen species. A byproduct of the body’s natural metabolic process, reactive oxygen species are small, unstable molecules that can cause deleterious changes to complex cellular molecules such as proteins and DNA, the building blocks of cells. Oxygen radicals are missing an electron, so they attack healthy cells to pilfer electrons, initiating a chain reaction that impairs cells. Environmental factors such as cigarette smoke, alcohol, ultraviolet rays from the sun, and a poor diet also cause the formation of reactive oxygen species in the human body.