You are what you eat. To the chagrin of unhealthy dieters everywhere, science is proving this to truer than ever. The role diet plays in health is apparent by the amount of heart disease and obesity in this country, but the power food holds to both negatively and positively affect health delves deeper.

"Nutrition is underrated and under appreciated for the power is has to protect our health," said Denise Cedar, a registered dietitian at Salem Hospital's Diabetes and Nutrition Education Center.

Genetics also plays a large role in determining what diseases people are at risk for. It's why doctors and insurance companies always want to know a patient's family history and why disease can more greatly affect members of one race over another.

It's the synergy of these fields of study (along with related fields such as proteomics and bioinformatics) that has allowed for a breakthrough in understanding how genes are regulated by naturally occurring components of food and how this influences the balance between health and sickness.

In a word, nutrigenomics.

While other aspects of one's lifestyle and environment can create discrepancies between people of different ethnicities and socio-economic backgrounds, nutrigenomics is making headway in what could be a revolutionary way of managing health and practicing disease prevention through diet in coming years.

"I think we'll see incredible changes in nutrition," Cedars said. "It's really exciting. Now, I'll prick your finger, take a drop of blood and know what your blood sugars are, but in the future I think we'll have a meter and see what a patient's genetic risks are."

Some scientists already have a means of measuring gene expression.

"Scientists can now take a blood sample to measure the levels of genes being expressed," Colby Caldwell, Doctor of Pharmaceutical Sciences and Director of Chemistry at Ecelctic Institute, said.

Gene expression simply means that genes can essentially be turned on and off.

"In terms of genes, people think you're doomed or blessed," Cedar said. "This is a common misconception as one's health is heavily influenced by lifestyle."

Many people carry the genes of a disease but never actually suffer from the condition.

"Diabetes is a perfect example," Cedar said. "Genes put them at risk, but not everyone who has the gene has the disease."

This is where lifestyle choices, primarily food, comes into the picture.

According the the NCMHD Center of Excellence for Nutritional Genomics at U.C. Davis "Some diet-regulated genes are likely to play a role in the onset, incidence, progression, and/or severity of chronic diseases. Dietary intervention based on knowledge of nutritional requirement, nutritional status, and genotype (i.e., personalized nutrition) can be used to prevent, mitigate or cure chronic disease."

The antithesis of this lies in the negative affects of certain chemicals on gene expression.

"Toxins can work in the opposite way as abnormal gene expression can lead to cancer and a lot of chronic diseases," Caldwell said.

According to the Centers for Disease Control, genomics plays a role in nine of the ten leading causes of death in the United States, namely cancer and heart disease.

The science of nutrigenomics is, however, still in its infancy.

"We don't have enough data because the science is young, so it's not yet affecting practice," Cedars said.

For the most people it's too early to prescribe a specialized diet.

"We have to go by population studies and for the majority of people, the Mediterranean diet is healthiest until there's more research and practical application," Cedars said.

Caldwell's Eclectic Institute located in Sandy, Ore. is a research company founded by nautropathic physicians who create organic supplements out of botanicals and foods.

They now sell a nutrigenomic berry powder that customers can mix into water or juice.

"Berries contain these compounds - polyphenols - that operate at a more fundamental level turning genes on and off," Caldwell said. "This helps normalize gene expression."

The end product is freeze dried whole berries that are finely ground.

"It's a whole, raw food," Caldwell said.

Other professionals express the need for more unbiased research in the field.

"We need pure research rather than, 'How can I make a product?' Cedars said. "Food is complex. Looking at nutrigenomics, you're taking in phytonutrients, one food can have 60. You have to look at complete food and not just study one chemical and see the results."

Specialized diets may be the wave of the future in preventative health care, but taking those other lifestyle factors into consideration (i.e. smoking, environment) is what is known as phenotype.

"This is what you observe; how the genes we have are influenced by the environment," Cedar said. "We need a balance."