Illustration showing the position of telomeres at the end of our chromosomes. Image credit: Genome Research Limited·
Article in brief
Telomeres are caps of DNA at the ends of chromosomes that protect your cells from ageing.
· These caps naturally wear down over time until they get so short that they can no longer protect the cell. Short telomeres are linked to chronic and degenerative diseases like cancer and Alzheimer’s, and early death.
· Telomere length is viewed as a reliable marker for biological age (as opposed to your age by years)
· Telomeres naturally shorten over time, but you can protect and lengthen your telomeres with meditation, exercise, and a diet full of healthy fats and vegetables.
In this article I am going to look at the ageing process in relationship to Telomere shortening; discuss factors that both positively and negatively influence this process and look at how your lifestyle and diet can impact on this.
The rate at which telomeres shorten may determine the rate at which we age. Scientists view telomere length as a reliable marker of your biological age Telomeres naturally shorten over time, but certain habits, like smoking, excessive stress, not exercising, and a diet full of processed foods can accelerate the process due to a process of chronic inflammation. Patients with shorter telomeres than the average length for their age group have a higher risk for serious disease and possible earlier death. It is also known that shorter-than-average telomeres have been linked to heart disease, cancer, diabetes and osteoporosis.
TELOMERES are a significant factor in ageing, accounting for around 40% of the ageing process, so what are they?
Telomeres shorten as we get older causing ageing in our cells. Telomere shortening is the main cause of age-related break down of our cells. When telomeres get too short, our cells can no longer reproduce, which causes our tissues to degenerate and eventually die.
Short telomeres increase the likelihood of cells becoming senescent and producing molecules that lead to inflammation, which we know is a huge risk factor for every age-related disease
Telomeres are distinctive structures found at the ends of our chromosomes. They consist of the same short DNA sequence repeated over and over again. Telomeres are like caps at the ends of each of our chromosomes, made up of DNA.
They consist of the same sequence of base pairs repeated multiple times
In humans the telomere sequence is TTAGGG.
This sequence is usually repeated about 3,000 times and can reach up to 15,000 base pairs in length.
So what do our telomeres do exactly?
Telomeres carry out 3 main roles:-
1. Firstly they organise each of our 46 chromosomes in the nucleus of our cells
2. Secondly they protect the ends of our chromosomes by forming a cap, much like the plastic tip on shoelaces; see below. If the telomeres were not there, the chromosomes may become sticky and attach to other chromosomes.
3. Finally they permit the chromosome to be replicated properly during cell division every time our cell DNA replicates the chromosomes are shortened by about 25-200 bases per replication. However, because the ends are protected by telomeres, the only part of the chromosome that is lost, is the telomere, and the DNA is left undamaged. Without telomeres, important DNA would be lost every time a cell divides and would eventually lead to the loss of entire genes.
When the telomere becomes too short, the chromosome reaches a ‘critical length’ and can no longer be replicated. This ’critical length’ triggers the cell to die by a process called apoptosis also known as programmed cell death.
Why is telomere shortening important?
· Loss of tissue renewal capacity
· Failure of stem cells to divide in sufficient numbers
· Poor immune response
In addition we understand that shortened telomeres accelerate the onset of age-related diseases such as:-
· Cardiovascular Disease
· Metabolic Syndromes including Diabetes Type 2
· Certain Cancers
· Central Nervous System Diseases
· Arthritis & Osteoporosis
We also understand that factors which influence telomere length are a contributing factor to virtually all age-related diseases. Genetics play a role in determining telomere length but environmental factors, including lifestyle choices, are even more important
Ageing is a process that changes an optimally healthy, fit individual into a less healthy, less fit individual.
Why we age can be broken down into:-
1. Your genetic makeup
3. Environmental factors
Although telomeres typically shorten with ageing, shortening is not inevitable, and telomeres can also lengthen.
Folate, vitamin B12, nicotinamide, vitamin A and D, vitamin C and E, zinc, magnesium, omega-3 fatty acids, tea, and polyphenols are associated with longer telomere length via the up-regulation of telomerase activity and DNA methylation, or the decrease of oxidative stress
So you can actually lengthen your telomeres — and perhaps your life — by following sound health and lifestyle advice,
It is important to identify these positive influencers that might promote telomere stability over time. It is possible that blood levels of polyunsaturated fatty acids (PUFAs) may be one of the factors that can prevent telomere shortening over time. The omega-3 PUFAs can reduce inflammation and decrease oxidative stress described below, and thus could buffer telomeres from their deleterious effects.
Dietary intakes of both the n-3 and omega-6 (n-6) PUFAs influence inflammation. Arachidonic acid (AA) is an n-6 PUFA that may be derived from its precursor, linoleic acid, found in popular dietary oils such as corn and sunflower oils. These in turn increase proinflammatory cytokine production. In contrast, EPA, a long chain n-3 PUFA found in cold water fish oils, reduce the production of AA-derived eicosanoids . Thus, both higher plasma levels of n-3 PUFAs as well as lower plasma n-6:n-3 PUFA ratios restrain proinflammatory cytokine production.
It is therefore not surprising that both higher levels of n-3 PUFAs as well as lower n-6:n-3 PUFA ratios have been associated with lower proinflammatory cytokine production in epidemiological and observational studies
As further evidence, researchers have identified an inverse relationship between baseline marine omega-3 fatty acid blood levels and the rate of leukocyte telomere shortening, the emerging marker for biological age, giving clues into the mechanisms underlying the protective effects of increased oily fish intake for patients with CHD.
The results of the study suggested that omega-3 fatty acids may prolong life by another mechanism: slowing the rate of telomere shortening. As people age, telomeres become progressively shorter, and telomere length is considered to be a marker of ageing. The results of the study suggest that the fatty acids in fish oil may slow the aging process in heart patients. The mechanism of this effect has not been identified.
Concluding that a diet containing an increased level of Omega 3 is associated with prolonged survival in patients with coronary heart disease. These fatty acids have a number of beneficial effects, including reducing triglyceride levels and blood pressure, inhibiting platelet aggregation, and decreasing inflammation
Understanding the role that our genes, environment and life-style factors play in our health is key to creating a wellness management program at any age in our life.
However, the earlier we make changes towards a healthier diet and lifestyle, the more we can make a positive influence to our health and longevity as establishing a healthy life-style will maximize our telomeres as we age.
While having good genes is helpful, the rate of telomere attrition is progressively more heavily weighted to where and how we live than our genetic roots.
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