Three new studies show that restricting calories, even in non-obese people:
• reduces inflammation (Aging, July 2016)
• helps to prevent cancers (Cancer Research, July 14, 2016)
• increases autophagy (PLoS Genetics, July 14, 2016)
What is Autophagy?
Autophagy or cellular recycling extends the lives of many different species. Autophagy means "self-eating." When a cell dies, the body has a quick way to break down the dead cell’s parts (protein-making, power-generating and transport systems) into small molecules that can be reassembled to be used for making new cell parts and supply the energy to power these processes. That means that the body can use old cells to supply its needs and not depend entirely on food for new energy and new building blocks. "By removing this junk in old cells, autophagy serves as the garbage disposal and recycling system to keep bodies healthy and helps to delay aging and prevent cancers" (Nature, Nov 2015;527(7576):105-9). Poorly-functioning autophagy can cause aging, cancers, neurodegenerative diseases, muscular disorders, diabetes and weight gain. Much of the current research on prolonging lives and preventing diseases is aimed at analyzing and improving the autophagy process. More at Autophagy: Self-Eating
How Restricting Calories Improves Autophagy
A strain of C. Elegans worms called "eat-2" is genetically predisposed to eat less and as a result, they live much longer than the normal worms. These low-calorie-consuming worms have a more efficient autophagy function that maintains the inner linings of their intestines. With aging, the inner linings of the worms' intestines break down to become a "leaky gut" that allows increased amounts of food products to get into the bloodstream. However, the intestines of long-lived "eat-2" worms remain intact with aging and do not develop a leaky gut syndrome. Researchers showed that blocking autophagy in their intestines significantly shortened these long-lived worms' life spans and made them far less active (PloS Genetics, July 14, 2016). The researchers showed that restricting the amount of food makes the intestines more efficient, preventing them from absorbing harmful molecules, while giving excess food causes the intestines to absorb increased amounts of harmful molecules. The authors state that preventing autophagy causes a leaky gut and that a non-leaky intestine is an important factor for long life. Furthermore, overfeeding the worms not only shortened their lives, it also made them far less active than normal. They believe that the same process occurs in humans.
Moderately Reducing Calories in Non-Obese People Reduces inflammation
A study from Tufts shows that normal-weight people who reduce calories by 25 percent over two years lose all their measured markers of inflammation (Aging, July 2016) and keep up their normal immunities as evidenced by their ability to produce antibodies in response to vaccines. At 12 months of reduced-calorie intake, they had significant reduction in weight and body fat. At 24 months, they also had a large reduction in the inflammatory markers, C-reactive protein and TNF alpha.
We have known for more than 20 years that inflammation predicts increased risk for diabetes and heart attacks (J Clin Endocrinol Metab, Mar 2001;86(3):1154-9). A study published this month shows that even moderate weight gain increases all of the markers of inflammation (International Journal of Cardiology, July 15, 2016;215:318-24). The markers of inflammation measured in this study were:
• interleukin 6 (IL-6)
• high sensitivity C reactive protein (hs-CRP)
• total cholesterol
• systolic blood pressure
• diastolic blood pressure
Many previous studies show that weight reduction reduces inflammation, a primary force in developing cancers and heart attacks. Inflammation punches holes in inner linings of arteries to start plaques that can cause heart attacks, and can damage DNA to block apoptosis that can lead to cancer.
Losing Weight Helps to Prevent Cancers
Overweight or obese women who lost weight through diet or a combination of diet and exercise significantly lowered levels of angiogenesis proteins that help certain tumors grow (Cancer Research, July 14, 2016). Excess weight has been linked to increased risk for cancers of the colon and rectum, breast (after menopause), endometrium, kidney, esophagus, pancreas, thyroid, gall bladder, prostate, ovary and liver.
• Being even a little bit overweight fills fat cells and increases risk for diabetes, heart attacks and certain cancers.
• Excess calories shorten your life, while restricting calories with adequate nutrition appears to prolong life.
• I believe that Intermittent Fasting is the most effective way to reduce overall calorie intake without suffering deprivation or serious side effects.