ISLAMABAD, OCT 11 (ONLINE): Previous research shows that what we eat and following certain diets can have a positive impact on the aging process and how long we live.
\nA new study has found via a mouse model that while eating fewer calories may help extend life span, those that lived the longest lost the least amount of weight while on a calorie-restricting diet.
\nResearchers also report that certain genetic factors may play a larger role than diet when it comes to longevity.
\nPrevious research shows that what we eat can have an impact on the aging processTrusted Source and how long we live.<\/p>\n
Different diets such as the Mediterranean diet, intermittent fastingTrusted Source, and caloric restrictionTrusted Source have been shown to help extend longevity.<\/p>\n
Now, researchers from The Jackson Laboratory in Bar Harbor, ME, and Calico Life Sciences in South San Francisco, CA, have found via a mouse model that while eating fewer calories may help extend life span, those that lived the longest lost the least amount of weight while on a calorie-restricting diet.<\/p>\n
In the new study, recently published in the journal Nature, scientists also report that certain genetic factors, such as genetically-encoded resilienceTrusted Source, may play a larger role in extending life span than diet.<\/p>\n
Examining caloric restriction and intermittent fasting
\nFor this study, researchers used 960 genetically diverse female mice that were assigned to five different diets:<\/p>\n
calories limited to 60% or 80% of baseline calories each day
\nfasting for one or two consecutive days each week with no caloric restrictions
\neating any amount of food whenever it wanted
\n\u201cWe wanted to know if lifespan-extending interventions like caloric restriction or intermittent fasting could be beneficial for everyone or only for some people. This is hard to do with people, so we turned to a genetically diverse mouse model,\u201d Gary Churchill, PhD, Karl Gunnar Johansson Chair and professor at The Jackson Laboratory and senior author of this study, explained to Medical News Today.<\/p>\n
\u201cCaloric restriction is known to extend life span in rodents since its discovery in rats in the 1930s, however it is still not fully understood how this works,\u201d added Andrea Di Francesco, PhD, principal scientist at Calico Life Sciences LLC and lead author on this study. \u201cRecent studies have shown that the timing of feeding is important in addition to reduced caloric intake.\u201d<\/p>\n
\u201cAdditionally, recent studies have suggested that in mice, some individuals (genotypes) may have reduced life span on caloric restriction. We were interested in determining how universal life span extension on caloric restriction is and if the benefits depended on the strength of caloric restriction (20% vs 40%),\u201d Di Francesco told MNT.<\/p>\n
Longer life span in calorie-restricted mice
\nAt the study\u2019s conclusion, scientists found that while mice who could eat whenever and whatever lived an average of 25 months, those on intermittent fasting diets extended their lifespans for an average of 28 months.<\/p>\n
The mice on caloric restriction achieved the longest lifespans \u2014 mice eating 80% of their baseline calories lived an average of 30 months, and those eating 60% stayed alive an average of 34 months.<\/p>\n
\u201cWe were surprised that the extreme (40%) caloric restriction extended life span to such a great extent with no indication that it shortened life span of any mice. We assumed that in a genetically diverse population \u2014 a unique feature of our study \u2014 some animals would have reduced life span on 40% caloric restriction or on a two-day intermittent fasting routine,\u201d Churchill said.<\/p>\n
Losing weight may not extend longevity
\nResearchers also discovered that genetic factors \u2014 such as genetically encoded resilience \u2014 played a larger role in longevity than diet in the mouse model.<\/p>\n
\u201cIn mouse studies where we can control the environment, we see a strong genetic contribution. The genetics gives us a \u2018ruler\u2019 to evaluate how impactful the diets are \u2014 despite the dramatic life span extension e.g. on 40% caloric restriction, there is still a lot of individual variability (genetic and random). In other words, diets are not magic bullets \u2014 they increase average life span but do not guarantee long life for an individual. There are other factors that contribute at least as much to life span,\u201d Di Francesco explained.<\/p>\n
Scientists reported mice that naturally kept the same body weight, body fat percentage, and immune cell health during periods of reduced food intake and stress, as well as mice that did not lose body fat later in life, lived the longest.<\/p>\n
\u201cIt has been proposed that caloric restriction works to extend life span by reducing obesity and prediabetes traits in mice. Improving metabolic health is important for humans in modern societies, and so it seems reasonable to think that life span extension in mice might be due to reducing obesity and its negative health effects,\u201d Churchill said.<\/p>\n
\u201cThis seems to not be the case \u2014 life span extension was greater in mice that retained higher body weight. Weight loss is \u2018good\u2019 from a human perspective, but weight loss does not cause life span extension \u2014 they are distinct outcomes of caloric restriction,\u201d he added.<\/p>\n
Research translation to humans needed
\nAfter reviewing this research, Mir Ali, MD, a board certified general surgeon, bariatric surgeon, and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA, told MNT what was interesting about the study is it showed lower calories or eating less increased life span, but not necessarily losing weight, which he found to be counterintuitive.<\/p>\n
\u201cYou would think that if you eat less, you would lose weight and therefore extend your life span, but it was more about restricting the calories and losing weight in mice, at least \u2014 I don\u2019t know how well that translates to humans. Animal studies are a great place to start, but obviously animals are a lot different than humans. And we need to see that the research done in animals translates to humans as well,\u201d Ali continued.<\/p>\n
MNT also spoke with Monique Richard, MS, RDN, LDN, a registered dietitian nutritionist and owner of Nutrition-In-Sight, about this study.<\/p>\n
\u201cI was not surprised by the results of the study because of what we are learning regarding cell turnover and optimal function related to lower-calorie diets, fasting, and other manipulations of distribution and quantity of intake,\u201d Richard said.<\/p>\n
Tips for improving aging and longevity
\nDuring this study, researchers found that genetics and genetically encoded resilience might be unmodifiable factors in longevity. What can readers do to improve the aging process and maybe even increase their life span, whether through diet or other options?<\/p>\n
\u201cYour genetics plays a big role, obviously, but you want to avoid things that are going to counteract genetics (such as) obesity (and) eating unhealthy,\u201d Ali explained. \u201cEven if you have good genes, but you don\u2019t do the right things, you can counteract that, so you obviously want to continue to eat healthy and maintain a normal weight to maximize your genetic potential.\u201d<\/p>\n
\u201cThe body is in a constant state of self-regulation, always trying to find a balance of being \u2018just right\u2019 \u2014 humming on all cylinders,\u201d Richard detailed. \u201cWhen the body has adequate nutrients to support all its cellular functions, for all the systems to work in specific amounts, at regular times, in appropriate intervals, it is like a machine functioning at its peak, or in the \u2018zone,\u2019 likely increasing its ability to function longer, hence likelihood of connection to increased life span.\u201d<\/p>\n
\u201cTips to possibly optimize diet in order to increase lifespan would be to prioritize understanding what this may mean specifically for you and your needs by meeting with a registered dietitian nutritionist (RDN. It is important to understand what the baseline of energy and distribution your individual body would need to be, especially related to preventing unnecessary or dangerous restriction, an imbalance of nutrient distribution or disordered eating patterns and behavior. There is no \u2018magic formula\u2019 to be calculated that works for everyone.\u201d
\n\u2014 Monique Richard, MS, RDN, LDN<\/p>\n","protected":false},"excerpt":{"rendered":"
ISLAMABAD, OCT 11 (ONLINE): Previous research shows that what we eat and following certain diets can have a positive impact on the aging process and how long we live. A new study has found via a mouse model that while eating fewer calories may help […]<\/p>\n
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