Vascular ageing is the main cause of organ ageing

If all the blood vessels in the body were connected, they would have a total length of 176,000 kilometres, or 4.5 times around the Earth's equator. With such long blood vessels, they are constantly exposed to blood flow and over time, the endothelium is easily damaged and the blood vessels will age. As a result, a variety of health problems occur with ageing blood vessels. Many scientists agree: vascular ageing is the main cause of organ ageing.

The blood vessels of the body are divided into three parts: arteries, veins and capillaries. The arterial blood, which is red in colour, is considered to be the "lifeline" and transports various nutrients and oxygen to every part of the body. Of the various types of blood vessels, arterial ageing has a major impact on the body. In fact, during the ageing process, the number of microvessels in the organs also declines, resulting in a reduction in the supply of oxygen and blood to the organs. The function of the capillaries is therefore crucial to the ageing of the body.

As we age, the smallest blood vessels in the body become damaged, wither or even die, resulting in reduced blood flow and impaired oxidation of organs and tissues, leading to the development of a range of diseases (e.g. cardiovascular disease, neurological disorders, muscle loss, impaired wound healing, etc.).

Increased longevity of mice following improved capillary function

A study published in the journal Science in July 2021 confirmed this: when capillary density was increased and oxygen supply to the organs of experimental mice increased, the maximum lifespan increased by 48.6 percent in males and 39 percent in females, and the incidence of various The incidence of various ageing-related diseases was also reduced.

NMN may promote improved capillary function

So how do you promote capillary growth and increase capillary density?In 2018, a team of researchers led by David Sinclair, a professor at Harvard Medical School, published findings in the journal Cell: 18-month-old aged mice orally administered NMN for 2 months restored capillary numbers and density to the level of young mice.

In a series of experiments, the team found that blood flow decreases when endothelial cells begin to lose a key protein known as SIRT1. Supplementation with NMN increases NAD+, stimulates SIRT1 and restores endothelial cell growth. This results in an increase in capillary number and density and reverses vascular ageing.

Dr. Sinclair says the same mechanism can also stimulate angiogenesis in the brain, where "hypoxia and waste buildup" (the result of capillary loss) "trigger a vicious cycle of disease and disability" such as Parkinson's and Alzheimer's. . This may be why the use of NMN proved to be effective in early studies of such neurological diseases.

NMN reverses the expression profile of miRNAs in aging vessels

Scientists such as Kiss Tamas from the Department of Geriatrics at the University of Oklahoma Health Sciences Center have uncovered the exact mechanism by which NMN improves angiogenesis and prevents vascular dementia: activation of Sirtuins protein activity → reduction of mitochondrial ROS → improved neurovascular coupling (NVC) response → significant protection of cerebral blood vessels.

Later, they found a new basis for the vascular protection of NMN: NMN reverses the level of microRNA (miRNA) in the ageing blood vessels of mice, thereby rejuvenating epigenetics and resisting atherosclerosis. Their findings are published in the Journal of Gerontology.

miRNAs are also one of the biomarkers of ageing and have a role in regulating the lifespan of model organisms. As we age, miRNAs in the vasculature become dysfunctional and play an important pathogenic role in cellular mechanisms that target key signaling pathways, inflammation and protein homeostasis, thereby compromising the structural and functional integrity of the vascular system.

NMN supplementation fights vascular ageing

A study in Aging Cell found that NMN supplementation improved vascular dysfunction in aged mice, the first study to confirm that NMN supplementation can combat vascular ageing.

To confirm this conclusion. The researchers selected 3-month-old mice and 24-month-old mice (equivalent to humans around 60 years old) in three separate groups to carry out the experiment.

RESULTS: Aortic nitrotyrosine abundance was increased and superoxide content was increased in aged mice compared to juvenile mice. However, the superoxide content in the aorta of aged mice was significantly lower, approaching juvenile levels. However, aortic nitrotyrosine abundance was significantly reduced in aged mice after NMN supplementation.

NMN supplementation reversed age-related levels of arterial oxidative stress, resulting in improved endothelial function of the vasculature.

The results demonstrated that the arterial vascular condition of NMN-treated aged mice was similar to that of younger mice, whereas untreated aged mice differed significantly from these two groups.

NMN supplementation restores vascular stiffness

In addition to testing for superoxide levels, as we age - there is a gradual increase in the accumulation of collagen in the blood vessels, which is used to support their structure, but there is a gradual loss of elastin, which gives them their elasticity.

This tends to lead to stiffening of the blood vessels and increases the risk of cardiovascular disease

Experimental observation: after NMN supplementation, the collagen content of aged mice decreased to the level of young mice; whereas the elastin content was significantly enhanced. The stiffness of blood vessels in aged mice also returned to normal, showing similar levels to those of young mice.

The research paper in Senescent Cells also shows that NMN supplementation increases vascular elastin content, improves vascular endothelial function in aged mice, reduces vascular stiffness and rejuvenates ageing blood vessels.

To conclude: NMN does improve the ageing blood vessels.