GAINESVILLE, Fla. — University of Florida health researchers are saying that feast-or-famine diets can extend life, but if fasting is supplemented with antioxidants benefits from fasting can be negated.
The research appears in the journal Rejuvenation Research.
The research shows fasting in mice extended their lifespan and improved age-related diseases.
In human studies of 24 participants, measurements were taken of changes in weight, blood pressure, heart rate, glucose levels, cholesterol, markers of inflammation and genes involved in protective cell responses over 10 weeks during intermittent fasting.
To test antioxidant supplements, the participants repeated the diet but also included vitamin C and vitamin E.
Results included a slight increase in SIRT 3, which promotes longevity and that is involved in protective cell responses.
Researchers say proteins such as SIRT3 are activated by oxidative stress, which is triggered when there are more free radicals produced in the body than the body can neutralize with antioxidants.
Small levels of free radicals can be beneficial: When the body undergoes stress — which happens during fasting — small levels of oxidative stress can trigger protective pathways.
The researchers found that the intermittent fasting decreased insulin levels in the participants, which means the diet could have an anti-diabetic effect as well.
At the end of the three weeks, the researchers tested the same health parameters. They found that the beneficial sirtuin proteins such as SIRT 3 and another, SIRT1, tended to increase as a result of the diet.
However, when antioxidants were supplemented on top of the diet, some of these increases disappeared.
This is in line with some research that indicates flooding the system with supplemental antioxidants may counteract the effects of fasting or exercise.
Dr. Jillian Finker, ND, CNS at Finker Wellness, Inc. in New York says this study is valid because supplements have some of the same properties that are found in food. Therefore, it wouldn’t be the same as fasting if you are taking-in supplements.
“I always have patients stop their supplements if they are going to be fasting,” Finker says.