The interaction of food and genes.
If the idea that food can drive biological processes by interacting with the genome sounds amazing, you need look no further than a beehive to find a perfect, tried-and-true example of how this happens. Worker bees work nonstop, are sterile, and live only a few weeks. The queen bee, sitting deep in the hive, has a life span of years and such powerful fertility that she gives birth to an entire colony.
And yet, worker and queen bees are genetically identical organisms. They become two different life forms due to the food they eat. The queen bee feasts Royal jelly; worker bees feed on nectar and pollen. Both foods provide energy, but royal jelly has an extra feature: its nutrients can unlock genetic instructions to create the anatomy and physiology of a queen bee.
So how does food translate into biological instructions? Remember it Food is made up of macronutrients.. These include carbohydrates, or sugars, proteins, and fats. Food also contains micronutrients such as vitamins and minerals. These compounds and their degradation products can trigger genetic switches residing in the genome.
Like the switches that control the intensity of the light in your house, genetic switches determine how much of a certain gene product is produced. Royal jelly, for example, contains compounds that activate genetic controllers to form the queen’s organs and maintain her reproductive capacity. In humans and mice, 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 protect the genome from oxidative damage; it also promotes the function of cellular pathways that can repair the genome if it becomes damaged.
Depending on the type of nutritional information, the activated genetic controls and the cell that receives them, the messages in food can influence wellness, disease risk and even life expectancy. 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 extend through generations. Studies show that in humans and animals, grandparents diet influences the activity of genetic switches and the risk of disease and mortality of grandchildren.
Cause and effect
An interesting aspect of thinking of 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’ve eaten, down to a molecular level, then what the food we eat “ate” could also affect our genome. For example, compared to milk from grass-fed cows, milk from grain-fed cattle has 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.
Similarly, a human mother’s diet changes the levels of fatty acids and vitamins such as B-6, B-12, and folate found in breast milk. This could alter the type of nutritional messages that reach the baby’s own genetic switches, although whether or not this has an effect on the child’s development is unknown at this time.
And, perhaps unbeknownst to us, we too are part of this food chain. The food we eat plays not only with the genetic switches in our cells, but also with those of the microorganisms that live in our intestines, skin and mucous membranes. A striking example: In mice, the breakdown of short-chain fatty acids by intestinal bacteria alters serotonin levelsa brain chemical messenger that regulates mood, anxiety, and depression, among other processes.
Food additives and packaging.
Added ingredients in foods can also alter the flow of genetic information within cells. breads and cereals are enriched with folic acid to prevent birth defects caused by deficiencies of this nutrient. But some scientists suppose that high levels of folate in the absence of other natural micronutrients such as vitamin B-12 could contribute to the increased incidence of colon cancer in Western countries, possibly by affecting the genetic pathways that control growth.
This could also be true with chemicals found in food packaging. Bisphenol A, or BPA, a compound found in plastic, turn genetic dials in mammals that are critical for development, growth and fertility. For example, some researchers suspect that, in both human and animal modelsBPA influences the age of sexual differentiation and decreases fertility by making genetic switches more likely to be activated.
All of these examples point to the possibility that genetic information in food may arise not only from its molecular makeup – amino acids, vitamins and the like – but also from a country’s agricultural, environmental and economic policies, or lack thereof. .
Scientists have only recently begun to unravel these genetic messages from foods and their role in health and disease. 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 so far have been done only in animal models, and much remains to be resolved about what food-gene interactions mean for humans.
What is clear, however, is that unraveling the mysteries of nutrigenomics is likely to empower present and future societies and generations.
Monica Dus is an assistant professor of molecular, cell, and developmental biology at the University of Michigan.
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