Tuesday, 3 March 2015

Why the 5:2 diet works

Why the 5:2 diet works: Study shows 'feast and famine' DOES help you live longer - as long as you stay away from superfoods

  • Fasting is thought to prevent diseases including cancer and diabetes 
  • Starving body allows it to respond better to stress that might otherwise damage it, according to a study on 24 volunteers over 10 weeks
  • It causes a small increase to SIRT 3, a gene that promotes longevity 
  • When antioxidants were added, some of the benefits disappeared
  • These can be found in high doses in superfoods such as chokeberries
The 5:2 diet claims to not only help people lose weight, but also guard against diseases including cancer, diabetes and Alzheimer's.
Created by scientist Michael Mosley, it involves women reducing their calorie intake to 500 for two days a week, and men to 600 calories. The rest of the time, they can eat normally.
Now a new study argues that the health benefits of 5:2 also exist when someone sticks to a 'feast and famine' diet, eating far more than they would one day and fasting another.

The 5:2 diet claims to not only help people lose weight, but also guard against diseases including cancer, diabetes and Alzheimer's. Created by scientist Michael Mosley, it involves women reducing their calorie intake to 500 for two days a week, and men to 600 calories. The rest of the time, they can eat normally

WHAT IS INTERMITTENT FASTING AND HOW CAN IT IMPROVE HEALTH?

Intermittent fasting is an umbrella term for various diets that cycle between a period of fasting and eating normally. 
Perhaps the most famous is the 5:2 diet which involves women reducing their calorie intake to 500 for two days a week, and men to 600 calories. The rest of the time, they can eat normally.
Previous animal studies suggest that intermittent fasting can guard against  diseases including cancer, diabetes and Alzheimer's.
Scientists believe it provides these benefits by allowing the body to respond better to stress that might otherwise damage it.
For instance, fasting could reduce inflammation, or improve the removal of damaged molecules, as well as starve tumors, according to previous research.
But the health benefits of the diet only appear if people don't increase their intake of antioxidants, which can be found in high doses in superfoods such as chokeberries, as well as vitamin C and vitamin E supplements.
During a three-week period, 24 participants alternated one day of eating 25 per cent of their daily caloric intake with one day of eating 175 per cent of their daily caloric intake.
The study by the University of Florida measured the participants' changes in weight, blood pressure, heart rate and glucose levels over 10 weeks.
They also looked at cholesterol, markers of inflammation and genes involved in protective cell responses.
'We found that intermittent fasting caused a slight increase to SIRT 3, a well-known gene that promotes longevity and is involved in protective cell responses,' said Michael Guo, a co-author at Harvard Medical School.
The SIRT3 gene encodes a protein also called SIRT3.
The protein SIRT3 belongs to a class of proteins called sirtuins which, if increased in mice, can extend their lifespans.
Researchers think proteins such as SIRT3 are activated by oxidative stress, which is triggered when there are more free radicals produced in the body than it can neutralise with antioxidants. 
However, 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, Guo said.
'The hypothesis is that if the body is intermittently exposed to low levels of oxidative stress, it can build a better response to it,' Wegman said.
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.