In a growing aging population, increasing life expectancy is becoming a secondary concern to mitigating age-related disease and the associated repercussions. Improving health outcomes for rising older population is necessary to decrease the socio-economic burden of age-related disease, while promoting overall population health. Although the human lifespan has greatly expanded over the past century, good health and its maintenance remain topics of importance. Recently, dietary solutions to quelling the aging process have surged in popularity, with intermittent fasting, calorie restriction, and other diet plans spearheading the movement.
Although they have the potential to increase lifespan and delay age-related disease, low-calorie diets and long periods of time without sustenance are not suitable for everyone – especially older individuals. While low carbohydrate and calorie restrictive diets are similar – both reduce serum insulin levels, increase ketone production, and target the same signaling pathways – the former may prove a safe and more efficacious option. Further research is needed to compare the benefits of both diets and their effects on inflammation, cachexia, and aging. However, the current understanding of aging as the main contributor to metabolic decline and diseases such as CVD, type 2 diabetes, and stroke, underscores the importance of slowing down age-related metabolic changes to decrease health risk factors and increase longevity.
Recent research is suggestive of the benefits of carbohydrate restriction, which may be more efficacious at preserving muscle mass, decreasing inflammatory markers, and increasing longevity in older individuals at risk of cachexia. A scientific study led by Dr. Saad Sami Ai Sogair examines how a diet low in carbohydrates yet adequate in fats and proteins can help reverse aging processes and metabolic changes. Published in the Journal of the American Academy of Aesthetic Medicine, his findings reveal that a low carbohydrate diet has the potential to decrease inflammatory markers, enhance insulin sensitivity, and trigger mitochondrial biogenesis, among many other beneficial mechanisms that support the aging body.
Effects of a Low Carbohydrate Diet on Metabolic Changes
Aging is associated with increased pro-inflammatory cytokine production which often leads to chronic inflammation and subsequent insulin resistance. Diets that are high in fat content and low in carbohydrates have been shown to decrease inflammation by inhibiting inflammatory mediators; they can suppress the expression of inflammatory cytokines by restricting NLRP3 inflammasome activity. Reduced inflammation has a positive correlation with extended longevity as well as a decreased risk for cardiometabolic disease.
The development of insulin resistance is associated with increases in pro-inflammatory cytokines and chronic inflammation. High glucose diets have been linked to reduced lifespans in animal and human studies, revealing decreases in sirtuin expression. Improvements in glucose metabolism and insulin sensitivity have been observed in previous studies with low carbohydrate diets leading to better weight and glycemic control.
Body Composition Changes
Increased fat accumulation can occur between the ages of 30 and 70, as subcutaneous fat levels decrease and visceral fat increases due to insulin resistance. Visceral fat in the abdominal region is a significant risk factor for cardiovascular disease, diabetes, and other cardiometabolic conditions. Following a carbohydrate restrictive diet may encourage weight loss, while maintaining muscle mass in those at risk of sarcopenia, as well as increase anabolic hormones while controlling appetite.
With age, there is a progressive loss of mitochondrial function, including in the skeletal muscle cells. Decreases in mitochondrial oxidative capacity and ATP synthesis can contribute to insulin resistance and are a significant risk factor for the development of age-related diseases. A diet that is low in carbohydrates and adequate in fat and proteins may improve mitochondrial function, decreasing oxidative stress, and stimulating ATP production through increased uncoupling protein activity.
Age-related declines in hormone production may lead to increased risk for cardiovascular disease, cognitive decline, and stroke. Studies have found that a low carbohydrate diet may prompt improvements in serum factors, decreasing metabolic mediators, such as insulin, leptin, glucose, and triglycerides. Additionally, such diets can promote weight loss despite not focusing on caloric intake. As such, following a low carbohydrate diet has the potential to mitigate the effects of declining hormonal levels and slow down metabolic changes related to aging.
As Dr. Sogair reveals in his research, the outcomes of various studies demonstrate the promising potential of a low carbohydrate diet – rather than just a decreased caloric intake – to improve metabolic changes associated with aging, increasing longevity while delaying the aging process. Further research in the field will aim to identify the metabolic pathways involved in carbohydrate restriction and subsequent metabolic changes to provide more clinical evidence for the low carbohydrate diet. In the meantime, the risk-to-benefit ratio needs to be assessed for middle-aged individuals following a calorie restrictive diet as new research indicates a carbohydrate restrictive diet may assist them to better adapt to age-related disease and metabolic changes.