The diet you eat affects your weight, the response you get to exercise training and how you look and feel, but the type of food choices you make may affect your health at another level – at the level of your genes. Genes are segments of DNA that code for proteins. They serve as a blueprint for how your body looks and performs. For example, genes determine your eye color, your height and your susceptibility to certain health problems, among other things.
You inherited the genes you were born with from your parents but that doesn’t mean the information they contain is set in stone. A relatively new field called epigenetics offers a peek into how genes can be turned on and turned off by your environment – and the foods you eat. Yes, the diet you eat and your lifestyle can influence how your genes are expressed.
The Diet You Eat Affects Future Generations Too
Here’s a compelling idea. The diet a person eats may affect future generations. Preliminary research in animals and humans shows the diet a person eats affects all cells including sperm and egg cells. Some of these changes may be passed to future generations through the sperm and egg. It’s already clear that a pregnant woman’s diet can influence the health of her offspring. Doctors stress the importance of moms-to-be getting enough folic acid in their diet.
Folic acid lowers a baby’s risk for birth defects called neural tube defects. These birth defects can have a devastating impact on a child’s brain and nervous system. Folic acid is important for “turning on” and “turning off” a variety of genes throughout the body. Genes are activated or deactivated by a process called methylation where a chemical group called a methyl group is added or removed from DNA. Some animal studies show offspring that don’t get enough folic acid during pregnancy can suffer from genetic changes that persist throughout life. The diet an animal is exposed to in the womb “primes” them for health problems later.
So compelling is the evidence that diet impacts the expression of genes that a whole new field called nutrigenomics is gaining momentum in the field of nutrition. Nutrigenomics looks at the effects diet has on gene expression and develops customized nutritional solutions based on a person’s genetics.
Nutrigenomics: What Diet Is Best for Your Genes?
Since each individual’s genes are different, the same dietary approach may not be “ideal” for everyone. Still, research suggests some nutritional approaches encourage healthy gene expression more than others.
Researchers at the Norwegian University of Science and Technology looked at different types of diets and the effect each had on gene expression in slightly overweight individuals. They discovered a diet consisting of 65% carbohydrates increased expression of genes linked with inflammation. Low-grade inflammation has been linked with an increased risk for age-related health problems like type 2 diabetes, heart disease and some forms of cancer.
As the researchers point out, these findings don’t necessarily mean you should adopt a low-carb diet, it just shows that diets high in carbs may turn on the expression of inflammatory genes in people who are overweight. It’s possible a higher carb diet would have a different effect on normal weight people who exercise. Plus, the type of carbs matters too. A high-carb diet of whole grains, fruits and vegetables would likely have a different impact than one that emphasizes processed, high-glycemic carbs. Ideally, each person would have their genes sequenced and a custom diet designed based on their genetics. Personalized nutrition may be the wave of the near future.
The researchers at the Norwegian University of Science and Technology believe, based on this research, that most people can benefit from a diet of roughly one-third carbohydrates, a third protein and one-third healthy fats. Sounds like a pretty balanced approach, doesn’t it?
Exercise: Another Epigenetic Influence
What we know about epigenetic shows diet AND lifestyle, including exercise, affects gene expression. A study carried out in Sweden showed exercise can change the way genes are expressed. When 23 previously sedentary but healthy men did aerobic exercise 2 to 3 times a week, their fitness sessions affected the expression of more than 7,000 genes including ones that impact the risk for obesity and type 2 diabetes. Other research shows exercise alters the expression of genes involved in breast cancer survival. This may partially explain why exercise lowers the risk of breast cancer and increases breast cancer survival.
Not surprisingly, resistance exercise turns on the expression of genes inside muscle cells that promote muscle growth and recovery. It also affects the genes involved in blood sugar regulation. These changes take place quickly in response to a workout, within in a few hours, and may account for why exercise lowers the risk for metabolic syndrome and type 2 diabetes. Exercise is one of the best things you can do for your metabolic health.
The Bottom Line?
To change the expression of genes on a long-term basis, be consistent with your diet and exercise plan. Changes in gene expression occur rapidly, on an hour-by-hour basis, in response to diet, exercise, and lifestyle. In a way, this is good news since it means genes change their expression quickly in response to lifestyle changes. You may not see changes in your weight or physique right away, but gene expression may change for the better in a matter of hours. It’s one more reason to make the right choices every day.
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