When it comes to food, most people think of calories, energy, and nutrients. However, recent research suggests that food also “communicates” with our genome, i.e. with the genetic blueprint that controls the functioning of our body down to the cellular level.

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This communication between food and genes can impact our health, physiology, and longevity. The idea that food delivers important messages to an animal's genome is at the heart of an area known as nutrigenomics. This discipline is still in its infancy and many questions remain unresolved. However, researchers have already learned a great deal about how dietary components influence the genome.

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Scientists' efforts to decipher this transfer of information could one day lead to healthier and happier lives for all of us. But by then, nutrigenomics has revealed at least one important fact: Our relationship with food is far more intimate than we imagined.

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The interplay of food and genes

The idea that food can control biological processes by interacting with the genome sounds amazing, but a beehive is a perfect example of how this happens. Worker bees work continuously, are sterile and live only a few weeks. The queen bee, who sits deep in the hive, lives for years and is so fertile that she gives birth to an entire bee colony.

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Yet workers and queen bees are genetically identical organisms. They become two different forms of life because they feed on food. The queen bee feeds on royal jelly, the worker bees on nectar and pollen. Both foods provide energy, but royal jelly has an additional property: its nutrients can decipher the genetic instructions for the anatomy and physiology of a queen bee.

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So how is food translated into biological instructions? As a reminder, food is made up of macronutrients — these include carbohydrates, protein, and fat, and it also contains micronutrients such as vitamins and minerals. These compounds and their breakdown products can trigger genetic switches that are located in the genome.

The field of nutrigenomics is trying to decipher how different types of food transmit different — and important — messages to our cells.

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Like a light switch that controls the intensity of a light, genetic switches determine how much of a particular gene product is produced. Royal jelly, for example, contains compounds that activate genetic controls to form the queen bee's organs and maintain her reproductive capacity. In humans and mice, by-products of the amino acid methionine, which are abundant in meat and fish, are known to influence genetic switches that are important for cell growth and division. And vitamin C helps maintain health by protecting the genome from oxidative damage; it also promotes the function of the cellular pathways that can repair the genome when it is damaged.

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Depending on the type of nutrient information, the activated genetic control system and the cell that receives it, the messages in food can influence well-being, the risk of disease and even the lifespan. However, it is important to mention that most of these studies so far have been done on animal models, such as bees.

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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 and the risk of disease and mortality among grandchildren.

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Cause and effect

An interesting aspect of looking at food as a type of biological information is that it gives new meaning to the idea of a food chain. In fact, if our bodies are influenced by what we have eaten — down to the molecular level — then what we have “eaten” could also influence our genome. For example, milk from grain-fed cows contains different amounts and types of fatty acids and vitamins C and A compared to milk from grass-fed cows. So when we drink these different types of milk, our cells also receive different nutritional messages.

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Similarly, a human mother's diet alters the levels of fatty acids and vitamins, such as B-6, B-12, and folate, found in her breast milk. This could change the type of nutrient messages that reach the baby's genetic switches, although it is currently unknown whether this has an impact on the child's development.

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Food information derived from animals — such as cow's milk — is transmitted to humans who drink the milk.

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And, perhaps without us knowing it, we too are part of this food chain. The food we eat not only manipulates the genetic switches in our cells, but also those of the microorganisms that live in our intestines, skin, and mucous membranes. An impressive example: In mice, the breakdown of short-chain fatty acids by intestinal bacteria changes the content of serotonin, a messenger substance in the brain that regulates mood, anxiety and depression, among other things.

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Food additives and packaging

Food additives can also alter the flow of genetic information in cells. Bread and cereal products are fortified with folic acid to prevent birth defects due to deficiencies in this nutrient. However, some scientists hypothesize that high folate levels in the absence of other naturally occurring micronutrients, such as vitamin B-12, could contribute to the higher incidence of colorectal cancer in western countries.

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The same could also apply to chemicals in food packaging. Bisphenol A, or BPA, a compound found in plastics, switches genetic switches in mammals that are crucial for development, growth, and fertility. For example, some researchers suspect that BPA influences the age of sexual differentiation in both humans and animal models and reduces fertility by increasing the likelihood of genetic switches being activated.

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All of these examples suggest that the genetic information in foods could come not only from their molecular composition — amino acids, vitamins, and the like — but also from a country's agricultural, environmental, and economic policies, or the lack of such policies.

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Researchers have only recently begun to decipher these genetic messages of foods and their role in health and disease. It is still not known exactly how nutrients act on genetic switches, what rules they use to communicate and how the eating habits of previous generations influence their offspring. Many of these studies have so far only been carried out on animal models, and much remains to be clarified as to what the interactions between food and genes mean for humans.

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It is clear, however, that unlocking the secrets of nutrigenomics is likely to benefit both current and future societies and generations.