Lifestyle changes to diet, sleep, and exercise—paired with interventions like relaxation exercises and supplements—could reverse the aging process, according to recent research.

Six women between the ages of 46 and 65 underwent an eight-week program that included alterations to diet, sleep, and exercise. They were also given relaxation guidance, women’s probiotic and phytonutrient supplements, and nutritional coaching.

Blood tests showed a reduction in biological age of up to 11 years in five of the six women, with the average participant experiencing a 4.6-year decrease, according to the study, published last year in the journal Aging.

Participants had an average chronological age of 58 years at the beginning of the study, and all but one had a younger biological age. Because of this, it’s unlikely that the reduction in biological age most participants experienced during the study was due to disease improvement. Instead, the improvement “might be attributed to underlying age mechanisms,” the authors—from Washington, Virginia, and Illinois universities—wrote.

Biological vs. chronological age

Just what is the difference in biological and chronological age? Simply put, chronological age is how long you’ve been alive, while biological age is “how old your cells are,” according to Northwestern Medicine.

Biological age is also referred to as the epigenetic age. The epigenome “consists of chemical compounds that modify, or mark, the genome in a way that tells it what to do, where to do it, and when to do it,” according to the U.S. National Institutes of Health. Those changes—influenced by environmental factors like stress, diet, drugs, and pollution—can be passed down from cell to cell as they divide, and from generation to generation.

They’re also reversible, as this study seemingly demonstrates.

Lifestyle changes that appeared to reverse aging

As part of the study, participants were asked to consume the following foods daily:

2 cups dark, leafy greens
2 cups cruciferous vegetables
3 cups colorful vegetables
¼ cup pumpkin seeds
¼ cup sunflower seeds
1 to 2 beets
Liver or liver supplement (three 3-ounce servings per week)
1 serving of egg (5–10 per week)

They were also asked to eat two servings daily of methylation adaptogens—foods that support DNA methylation, a process that controls gene expression. Examples of one serving of such foods include:

½ cup berries, preferably wild
2 medium garlic cloves
2 cups green tea, brewed 10 minutes
3 cups oolong tea, brewed 10 minutes
½ tsp rosemary
½ tsp turmeric

Participants were also asked to make the following daily lifestyle adaptations:

Take 2 probiotic capsules
Take 2 servings of “greens powder”
Drink 8 cups of water per day
Exercise for at least 30 minutes
Practice breathing exercises twice
Sleep at least 7 hours
Fast 12 hours after their last meal of the day

None of the women completed all tasks all days, and that’s okay, researchers wrote. Improvements in biological age were seen among women who adhered to the program an average of 82% of the time. The relatively high level of adherence among patients was likely due in large part to the nutritional coaching provided, they added.

The effect of stress on biological age

A seventh participant—a male—withdrew from the study due to a family emergency. Prior to the study, he had a chronological age of 71 and a biological age of 57.6. He had his biological age tested again at eight weeks, despite having withdrawn from the study, and it had increased to 61.6 years. Prior research has documented “sudden acceleration in biological age due to diverse stressful events,” though that aging is reversed when the stressor resolves, the authors noted.

For some, however, stress isn’t transient, and displays a more permanent effect on aging. Those with longstanding mental health conditions like depression, anxiety, and bipolar disorder are routinely biologically older than their chronological age, according to recent research presented at the European Congress of Psychiatry in Paris.