How can nutrition impact aging?
Aging is a gradual process that happens throughout the lives of humans. Causing a decline in the physical and mental functioning of humans, aging leads to several health issues, and although the overall life expectancy has increased in the past few years, it does not mean people experience a better quality of life in their later years as compared with other generations. Aging is associated with many alterations in gene expression which are observed in the heart, brain and skeletal body; this increases the exposure of humans to developing age-related diseases.
Cellular, molecular, functional and physiological features affect aging and result in chronic diseases. Aging is often associated with telomere shortening, stem cell exhaustion, epigenetic alterations, genomic instability and dysregulated nutrient sensing at the molecular level. All these factors impact the cellular level leading to mitochondrial dysfunction and cellular senescence as well as weakening the functional and physiological levels. Additionally, there are a few more risk factors associated with aging such as dietary and lifestyle patterns, the alteration of which can help to promote healthy aging.
The World Health Organization has defined the term ‘healthy aging’ as the process of developing and maintaining functional ability to promote wellbeing at older ages. Previous research has highlighted nutrition to be one of the key factors that influence healthy aging, and nutrients are essential for the development of immune responses, the synthesis of new molecules, and cell differentiation.
A recent systematic review published in Nutrients aimed to address the gaps that remain concerning what foods and diets can improve healthy aging, as well as how they can modulate biomarkers and prevent age-related diseases.
The review included a total of 36 studies, most of which were conducted in Europe, 9 in North America, 6 in Asia, and 1 in Australia. Most of the studies took place in academic medical centers. A few of these studies included participants with or at risk of developing type-2 diabetes (T2D), type-1 diabetes (T1D), cardiovascular disease (CVD) and mild cognitive impairment (MCI).
The ketogenic diet (KD) was reported to improve CVD biomarkers in T2D patients and decrease inflammation as well as prevent brain aging. The Mediterranean diet (MedDiet) was observed to play an important role in the regulation of the relationship between cognition and genetic risk factors. A high-quality diet in combination with the intake of a variety of vegetables was reported to reduce the risk of cognitive decline, and in addition, the intake of green tea catechins daily was observed to improve working memory in adults.
An anti-inflammatory diet showed a reduction in the rate of telomere shortening through the improvement of telomerase activity in people with a high risk of CVD. On the contrary, diets rich in ultra-processed foods (UPFs) and processed meat were observed to be associated with a higher risk of having shorter telomeres. UPF was also reported to be associated with an increased risk of ischemic heart disease (IHD), CVD and all-cause mortality.
The studies also indicated MedDiets to have positive impacts on blood glucose, triglycerides, and insulin levels. Additionally, the ketogenic Mediterranean diet was reported to promote reductions in body mass index, weight, percentage of fat mass, blood glucose, triglycerides, LDL-C and total cholesterol, while it increased HDL-C. Another modified version of MedDiet was also observed to improve these factors in elderly people.
A healthy Nordic diet was reported to decrease non-high-density lipoprotein cholesterol, apolipoprotein B (ApoB)/ apolipoprotein A1 (ApoA1) ratio, low-density lipoprotein cholesterol (LDL-C)/HDL-C ratio, and interleukin-1 receptor antagonist (IL-1 Ra), thereby improving the lipid profile. A restricted-calorie diet (RCD) was also observed to improve lipid profile, reduce a few CVD risk factors, as well as promote high levels of HDL-C/LDL-C ratio and HDL-C in overweight adults.
Consumption of fruits was observed to improve many cardiometabolic risk factors as well as improve the negative effects of a high-fat high energy (HFHE) diet. MedDiet has also been reported to decrease hepatic steatosis risk and atherothrombosis biomarkers. Supplementation of MedDiet with coenzyme Q10 was observed to promote higher excretion of urinary metabolites in older individuals. It was also observed to play a role in the positive modulation of the inflammatory response as well as protect the DNA from oxidative damage. Additionally, a MedDiet supplemented with virgin olive oil was observed to increase serum osteocalcin, thereby being beneficial to the bones.
Maintaining good health is crucial to both healthspan and lifespan, but with numerous research studies available and myriad different diets and health trends jostling for attention, it can be challenging to know what works and what doesn’t – and why. Scientific research has shown that certain diets, such as the Mediterranean and ketogenic diets, as well as those rich in fruits and vegetables, offer numerous health benefits that can help reduce the risk of age-related conditions.
In fact, these diets have been observed to be particularly effective in reducing the risk of several conditions, including cardiovascular disease, diabetes, hepatic steatosis, and ischemic heart disease. Additionally, they can even help prevent DNA damage and slow down telomere shortening, which has been linked to aging. It is often said that longevity and good health start with diet and exercise, and that advice still rings true.