You are what you eat. That's the heart of a new science called nutrigenomics, which looks at how diet switches certain genes on or off. Just as the plant Audrey II in "Little Shop of Horrors" turned into an evil eating machine, your diet transforms your genes' attitude (and the attitude of your gut bacteria's genes, too).

Certain foods turn them nasty, and that fuels inflammation, immune dysregulation, dementia, diabetes, stroke, cancer and other lifestyle-related disorders. The good news? Genes switch on and off pretty easily. One study found that six days on an improved diet changes gene expression from risky to beneficial.

So which foods should you eat and which should you avoid?

• Eat foods rich in all B vitamins: dark leafy greens, nuts, legumes, skinless chicken, fish, asparagus, 100 percent whole grains, and fruit; ask your doc about taking a folic acid and/or a vitamin B-12 supplement daily (we take both). One study showed that if your diet is rich in these nutrients, you can turn off genes activated by environmental pollutants like BPA (a hormone disrupter in plastics, receipts and linings of cans) that are linked to miscarriages, childhood obesity and, perhaps, breast cancer.
• Long-chain polyunsaturated fatty acids in canola oil, salmon and ocean trout turn off inflammatory genes in fat cells and increase production of anti-inflammatory cytokines.
• Too many carbs turn on risky genes: Max is 30 percent of your daily calories, and they should be 100 percent whole grains, nothing processed.
• Eliminate saturated fat. It prods your gut bacteria to turn on inflammatory genes.