In "The Age of Adeline," Blake Lively's character remains 29 years old forever. A review of the film in “Variety” called the tale of perpetual youthfulness little more than a "sensitively directed slab of romantic hokum."

Fortunately, scientific minds have looked at the difference between chronological age and the age your body really is, and today there's solid evidence that you can change your calendar age for good or for bad.

Genes account for about 20 percent of aging; the rest depends on your health behaviors and your environment.

Recently, a team of researchers decided to look at 1,000 people ages 26, 32, and 38 to assess their pace of aging.

Scientists measured immune and metabolic functions; the health of tiny blood vessels in the back of the eye (a window to the brain); cardiorespiratory fitness; and the length of their telomeres, which are protective caps at the ends of chromosomes that reflect a person's age.

They found that though some folks were younger and many were spot on, while some 38-year-old study participants had the body and brain of a 60-year-old!

The researchers concluded that disabilities associated with older age (memory and mobility problems, heart disease, etc.) start developing in your 20s and 30s.

So, starting in your 20s, get your cholesterol and blood pressure checked regularly; eat five to nine servings of produce daily along with 100 percent whole grains and lean proteins; and stay active (10,000 steps or equivalent daily, where one minute of aerobics equals 100 steps).