Diet Helps Shed Pounds, Release Toxins, and Reduce Oxidative Stress
Research by Skidmore College exercise scientist Paul Arciero, DPE, has found that a balanced, protein-pacing, low-calorie diet that includes intermittent fasting not only achieves long-term weight loss but also helps release toxins in the form of polychlorinated biphenyls (PCBs) from the body's fat stores, in addition to enhancing heart health and reducing oxidative stress.
Arciero's findings add to a growing body of evidence on the benefits of a "protein-pacing" caloric restriction (P-CR) diet, which reduces calories and features four to six meals per day, each of which includes 20 to 25 g protein. Participants in Arciero's study also engaged in intermittent fasting.
His research results are discussed in "Serum Polychlorinated Biphenyls Increase and Oxidative Stress Decreases with a Protein-Pacing Caloric Restriction Diet in Obese Men and Women," which is published in the International Journal of Environmental Research and Public Health.
A professor of health and exercise sciences at Skidmore, Arciero also is director of the college's Human Nutrition and Metabolism Laboratory. Skidmore students, health services staff, and other colleagues assisted with the P-CR diet research.
The International Journal of Environmental Research and Public Health article is the third publication in recent months to report on Arciero's findings on the impact of a P-CR diet. Previous articles in the July 30, 2016, edition of Nutrients and the August 29, 2016, edition of Frontiers in Physiology highlighted improvements in body composition and vascular health, respectively.
In each case, Arciero first compared the results of the P-CR diet between obese men and women following a 12-week weight loss diet and subsequently compared the P-CR diet with those achieved by the heart-healthy diet over a 52-week period. The 12-week P-CR diet was equally effective at reducing body weight (>24 lbs, 10%), oxidative stress (25%), and arterial stiffness (12%) and increasing toxin release (25%) in women and men. Following the 52-week phase, P-CR demonstrated improvements over the traditional heart-healthy diet in maintaining weight loss, reducing artery stiffness, and releasing toxins.
"The heart-healthy diet has proven health benefits," Arciero says, "but it's important to continue to research and identify additional dietary strategies that may help improve individual and public health."
A Toxin-Fighting Response
His findings on toxins can help allay concerns that weight loss—which releases toxins into the blood—could have a negative effect on dieters' health.
Environmental pollutants and other toxins are stored in fatty tissue. During weight loss, fat breaks down and toxins are discharged into the bloodstream. Scientists have expressed concern that the released toxins could increase dieters' oxidative stress and their risk of developing serious conditions, including hormone (endocrine) disruption (reproductive and fertility problems), heart disease, cancer, Alzheimer's disease, and Parkinson's disease.
Arciero's research findings—that a P-CR diet doesn't increase disease markers and, in fact, can aid detoxification and reduce oxidative stress—help reduce those fears. Furthermore, the findings suggest that those who aren't overweight or obese also could benefit from a P-CR diet.
"Although weight loss typically leads to improved health, we know that in those who are overweight and obese—and, therefore, storing excessive toxins—there's the potential for the release of toxins to impact the body in negative ways," Arciero explains. "We wanted to capture the release of those toxins and the body's response.
"What we found was that the body compensated by increasing antioxidants. In response to this flood of PCBs, the body was coming to its own defense, scavenging and squelching the toxins. We had a healthy weight loss intervention," Arciero adds.
The objective of the first 12-week phase was to assess the ability of a P-CR diet to achieve successful weight loss (defined as 10% of starting body weight) and this was achieved, with a mean weight loss of more than 25 lbs.
During this phase, women consumed 1,200 kcal per day and men consumed 1,500 kcal. Of those, 30% came from lean protein, 45% from unrefined carbohydrates, and 25% from healthful fat. One day a week, participants followed an intermittent fast/cleanse consisting of 300 to 450 kcal from antioxidant-rich plant sources.
The second phase (52 weeks) of the research compared the results of the P-CR diet with a more traditional heart-healthy diet. All dieters consumed roughly the same number of calories: approximately 1,900 for both groups. P-CR dieters fasted/cleansed either once every two weeks or once per month. Those on the heart-healthy diet followed the guidelines of the National Cholesterol Education Program, consuming 35% of calories as fat and 50% to 60% as carbohydrates. Heart-healthy dieters also ate 20 to 30 g per day of fiber and consumed fewer than 200 mg per day of dietary cholesterol.
At the end of the 12-month period, the results for the two groups deviated significantly, with the P-CR diet outperforming the heart-healthy diet for both maintaining weight loss, reduced blood vessel stiffness, and eliminating toxins.
Research participants who remained on the P-CR diet regained about 1.5 lbs of the weight they'd lost and continued to eliminate toxins. Those on the heart-healthy diet, however, regained 12 lbs. Most of it was fat—and that fat likely may have (re)stored toxins.
"We have scientific evidence that it's the quality of your diet that matters," Arciero says. "Through diet alone, we can favorably impact the detoxification process, decrease oxidative stress levels, reduce blood vessel stiffness, and enhance weight loss. That's an important public health message."
— Source: Skidmore College