Your Calorie Intake and Longevity
The relation between calorie intake and human longevity has been a subject of great scientific interest. Based on animal studies, the most proven approach to counteracting aging is calorie restriction. Aside from genetic manipulation, calorie restriction represents the only proven record for prolonging life in animals. And that's not its only benefit.
Tests conducted on laboratory animals have shown that calorie restriction can lower the risk of cancer, diabetes, and cardiovascular disease. It had also been shown to stave off age-related neurodegeneration.
In practice, calorie restriction means lowering normal calorie intake by about 40 to 60 percent. But you still maintain a healthy diet rich in vitamins, minerals, and antioxidants. A growing number of people are now living by this regimen. Many of them are scholars and researchers, passionate in their belief that the methodical restriction of their calorie intake can extend their lives.
Can calorie restriction promote longevity in humans?
It certainly seems so, but it's still too early to predict. And even if calorie restriction extends life, at what price does it come?
One notable side effect of chronic calorie restriction is the lowering of your body's temperature and metabolic rate. That side effect is essentially an energy-preservation mechanism, and it kicks in when your body's energy intake is chronically low. The consequences of that may include hormonal decline, with decreased thyroid activity and a decline in sex hormones. Metabolic declines of this type have been also associated with loss of muscle strength and libido. Again, it's still too early to predict, but even if calorie restriction enables people to live longer, it may come at the cost of some of the most important things that make life worth living.
Is there anything else that can be done to trigger your longevity genes, apart from chronically restricting your calorie intake? Apparently there is one dietary option: intermittent fasting.
Intermittent Fasting: How Meal Frequency Affects Your Longevity
Recent studies have indicated that lowering your meal frequency to one meal per day or every other day may actually provide you with the same benefits as calorie restriction without restricting your calories.
The initial studies were done on mice. The mice had to go through a special feeding cycle called intermittent fasting. That feeding cycle consisted of a fasting day followed by an overfeeding day in which the mice were allowed to consume twice their normal calorie intake. The results revealed astonishing longevity benefits. Mice on intermittent fasting have been shown to improve their insulin sensitivity, rejuvenate their brain cells, and substantially increase their life span. Most importantly, the studies' findings supported the hypothesis that humans and animals evolved to better survive when there's a large gap between meals (at times twenty-four or even forty-eight hours).
According to Dr. Mark Mattson, professor of neurosciences at Johns Hopkins University, humans adapted early on to intermittent fasting as an evolutionary favorite feeding cycle. Mattson, who conducted the initial studies on intermittent fasting, argues that primordial conditions of food scarcity and a hunter-gatherer lifestyle created the necessity to adapt to one meal per day or even every other day.
One of the greatest advantages of intermittent fasting is the rejuvenating impact on your brain and muscle. It literally forces your body to recycle and rejuvenate brain and muscle tissues.
Fasting increases the expression of brain-derived neurotrophic factor (BDNF) in your brain and muscle. This neurotrophic growth factor has been shown to catalyze conversion of brain stem cells and muscle satellite cells into new neurons and new muscle cells, respectively. BDNF has profound neuro-protective properties. It plays important roles in brain cognitive function and long-term memory and protects against dementia, Alzheimer's disease, Parkinson's disease, and brain aging.
The rejuvenating effect of fasting on your brain and muscle tissues is more profound than was initially thought.
In your muscle, fasting triggers the removal and recycling of broken proteins and damaged cells. This recycling process is done by the ubiquitin enzymes (cellular recycling enzymatic system), which detect and digest broken proteins and damaged cells. The nitrogen amino by-products are then recycled and used for synthesis of new proteins and generation of new cells.
Note that this tissue-rejuvenating process is triggered by the catabolic process of protein breakdown such as that due to injury, fasting, or exercise.
During the overfeeding phase, your body shifts from a catabolic recycling mode into an anabolic tissue-building mode. Overfeeding may yield additional benefits. When done properly, it boosts your thyroid and sex hormones along with your body's metabolic rate. And note that if you add a viable exercise protocol to this regimen, it may yield an even stronger impact on your body composition, tissue integrity, and biological age.
The notion that calorie restriction and intermittent fasting can increase life span has been controversial and arguable. Can our society accept the idea that hunger and “near starvation” is healthy?
We habitually like eating lots of foods all day long, and most of us will fail to restrict calorie intake or follow periodical fasting even if trying to. So here we are today desperate for something else – perhaps a pill that can extend life and requires no calorie restriction and no hustle.
But there is no such pill.
Longevity is inherent to your body and it’s essentially triggered by how you eat, exercise, and live. There is no pill in the world that will ever change that. No pill will ever substitute the effects of exercise, fasting, and good nutrition on your genes.
When your longevity genes are triggered, they activate mechanisms that improve your energy efficiency, recycle old damaged cells, destroy tumors, and regenerate tissues. Your body not only retains its youthful appearance, it also gets stronger and healthier. But you need to make a choice – adjust your diet and lifestyle to stay physically young or keep a “normal” routine and be ready to accept the consequences on your biological age.