People usually think of food as synonymous with calories, energy, and nourishment. However, the latest evidence suggests that food also “talks” to our genome, which is the genetic blueprint that directs how the body works down to the cellular level.
This communication between food and genes can affect your health, physiology and longevity. The idea that food delivers important messages to an animal’s genome is central to a field known as nutrigenomics. This is a discipline that is still in its infancy and many questions remain shrouded in mystery. Yet we researchers have already learned a great deal about how food components affect the genome.
I am a molecular biologist who studies the interactions between food, genes and the brain with the aim of better understanding how food messages affect our biology. Efforts by scientists to decipher this transmission of information could one day translate into healthier, happier lives for all of us. But so far, nutrigenomics has unveiled at least one important fact: our relationship with food is far more intimate than we ever imagined.
The Interaction of Food and Genes
If the idea that food can drive biological processes by interacting with the genome sounds amazing, you only have to search a hive to find a proven, perfect example of how it happens. Worker bees work non-stop, are sterile and only live a few weeks. The queen bee, sitting at the bottom of the hive, has a lifespan that lasts for years and a fecundity so powerful that she gives birth to an entire colony.
And yet, workers and queens are genetically identical organisms. They become two different life forms because of the food they eat. The queen bee feasts on royal jelly; worker bees feed on nectar and pollen. Both foods provide energy, but royal jelly has an added feature: its nutrients can unlock the genetic instructions to create the anatomy and physiology of a queen bee.
So how is food translated into biological instructions? Remember that food is made up of macronutrients. These include carbohydrates – or sugars – proteins and fats. Foods also contain micronutrients such as vitamins and minerals. These compounds and their breakdown products can trigger genetic switches that reside in the genome.
Like light switches that control the intensity of the light in your home, genetic switches determine how much of a certain genetic product is produced. Royal jelly, for example, contains compounds that activate genetic controllers to form the queen’s organs and maintain her ability to reproduce. In humans and mice, the byproducts of the amino acid methionine, which are abundant in meat and fish, are known to influence genetic dials that are important for cell growth and division. And vitamin C plays a role in keeping us healthy by protecting the genome from oxidative damage; it also promotes the function of cellular pathways that can repair the genome if damaged.
Depending on the type of nutritional information, the genetic controls activated and the cell that receives them, the messages contained in food can influence well-being, the risk of disease and even lifespan. But it’s important to note that to date, most of these studies have been conducted in animal models, such as bees.
Interestingly, the ability of nutrients to alter the flow of genetic information can span generations. Studies show that in humans and animals, the diet of grandparents influences the activity of genetic switches as well as the risk of disease and mortality in grandchildren.
cause and effect
An interesting aspect of thinking about food as a type of biological information is that it gives new meaning to the idea of a food chain. Indeed, if our body is influenced by what we ate – down to the molecular level – then what the food we ate “ate” could also affect our genome. For example, compared to milk from grass-fed cows, milk from grain-fed cows contains different amounts and types of fatty acids and vitamins C and A. So when humans drink these different types of milk, their cells also receive different nutritional messages.
Likewise, a human mother’s diet alters the levels of fatty acids as well as vitamins such as B-6, B-12, and folate that are found in her breast milk. This could alter the type of nutritional messages reaching the baby’s own genetic switches, although whether or not this has an effect on the child’s development is, at this time, unknown.
And, perhaps unbeknownst to us, we too are part of this food chain. The food we eat not only changes the genetic switches of our cells, but also those of the microorganisms living in our intestines, skin and mucous membranes. A striking example: in mice, the breakdown of short-chain fatty acids by gut bacteria alters levels of serotonin, a chemical messenger in the brain that regulates mood, anxiety and depression, among other processes.
Food additives and packaging
Adding ingredients to food can also alter the flow of genetic information inside cells. Breads and cereals are fortified with folate to prevent birth defects caused by deficiencies of this nutrient. But some scientists speculate that high levels of folate in the absence of other natural micronutrients such as vitamin B-12 could contribute to the higher incidence of colon cancer in Western countries, possibly in affecting the genetic pathways that control growth.
This could also be true for chemicals found in food packaging. Bisphenol A, or BPA, a compound found in plastic, activates genetic dials in mammals that are essential for development, growth and fertility. For example, some researchers suspect that, in humans and animal models, BPA influences the age of sexual differentiation and decreases fertility by making genetic switches more likely to activate.
All of these examples point to the possibility that the genetic information in food derives not only from its molecular composition – amino acids, vitamins, etc. – but also a country’s agricultural, environmental and economic policies, or the lack of them.
Scientists have only recently begun to decode these genetic dietary messages and their role in health and disease. We researchers still don’t know precisely how nutrients act on genetic switches, what their communication rules are, and how the diets of past generations influence their offspring. Many of these studies have so far only been done in animal models, and much remains to be determined about what food-gene interactions mean for humans.
What is clear, however, is that unraveling the mysteries of nutrigenomics has the potential to empower present and future societies and generations.
This article is republished from The Conversation under a Creative Commons license. Read the original article.