Ageing – biological perspective – 2

Measurement of biological age

When somebody asks your age? what will be your answer? Maybe will your reveal your chronological age. But the fact here is that the chronological age reveals only a little bit about the current position of the body. A person aged between 50 and 60 may run a marathon but another person of same age may find it difficult to climb the stairs. To find out the actual state of body we must measure biological age.

There are different types of methods to calculate our Biological age :

Epigenetic clock

It measures Epigenetic component DNA methylation that changes patterns with age.

Telomere length

As we discussed in the previous article Telomere is found at the end of chromosomes and it reduces the length after cell division. Its length determines biological age.

Body fluids

With the help of body fluids, we can find out the biological age. Our body fluids contain certain metabolic markers like glucose, insulin, inflammatory chemicals like chemokines, hormone levels and other markers of the immune system. These markers help us to determine the Biological clock of the body.

Physiological Test

Normal physiotherapy, organ function such as Lung capacity, Heart function and Liver function etc., may help us assess ageing.

Cognitive test

These tests will determine how an individual will think, process information, problem-solving ability and mental functioning. This test will give insight into our age.

Why do women survive more than men?

Scientifically speaking, women have two X chromosomes as a “genetic component”. If they have a mutation in any one of the X chromosomes they will be “remunerated” by the DNA duplication process. But for men have one X chromosome and one Y chromosome. A key factor in ageing is that the X chromosome contains gene segments that have an immune component. If these genes are defective in men it can’t be remunerated.

Socially speaking women have good life expectancy because they will not drink alcohol, use less tobacco and focus on healthier diet when compared to men. Suicide is also more common in men only due to a stressed lifestyle.

Can ageing be slowed down?

Dietary restrictions

Some animals as well as humans require exercise and calorie restriction that has the main influence on ageing. Research suggests that “reducing food intake leads to healthier and longer life expectancy”. It doesn’t mean the quantity we eat rather than what we eat. One interesting finding says that fruit fly fed with high protein has a low life span. Restriction of certain amino acids has a positive impact on health. So people should stick with a “balanced diet” rather than a protein-rich or fat-rich diet.

Gut microflora

As known earlier in “supercentenarians” the bacteria usually present in “our gut have a role in digestion and also it has a greater influence on the health and ageing”.  Peculiar research in killifish states that young gut bacteria present in intestines of older individuals which are injected artificially has more life expectancy compared to intestines having more pathogens and old gut bacteria.

Exercise

Physical exercise will lead us to a healthy and fit body, when calories are burned in our body. Definitely free radicals that come from fats like saturated fatty acids and unwanted carbs should be burned out. By doing exercise we can maintain a good physique and shows you are still young at 50.

Drugs will stop the ageing process??

“There is no drug or pill or treatment that has been proven to extend the lifespan of a human being”. However, some compounds are showing some promising results in trials.

Rapamycin

Much research has been done on drugs that help in reducing ageing but rapamycin is known as an “immunosuppressive” drug after kidney transplant. It is a metabolite found in soil that stops the growth of fungi. It has a positive effect on old age and increases life expectancy. It Still needs elaborate research.

Metformin

Metformin is popularly used for diabetic patients. It stops the formation of glucose in the liver. Studies show that mice fed with metformin lived longer and considered as the safest drug without side effects. It Still needs elaborate research.

Blue zones

Blue zones are regions where people live “long lives” and “healthier lives” than average. This term is used in social science. These zones are limited and analogous geographical areas share the same lifestyle and environment.

Blue zones in our world are

Okinawa – Japan
Sardinia –Italy
Icaria – Greece
Nicoy peninsula – Costa Rica

What are the secrets of blue zones for long life?

1. plant-based diet
2. Regular physical exercise
3. Social bonding
4. Moderate calorie intake
5. low tobacco and alcohol consumption

When does ageing start?

Many scientists suggest that “after humans reach sexual maturity” onset of ageing starts because after that our body will be out of “evolutionary pressure to reproduce. Some signs such as wrinkles of the skin and poor physical performance may start around the age of 20 and also based on environmental conditions and genetic predisposition it varies. Some researchers are suggesting that ageing starts “before birth itself”, cellular damage can occur in parental germ cells or during conception.

Why do we age?

Two main theories answer this question

Mutation accumulation theory

The force of natural selection works until reproduction and after that, there will be no pressure for species to fit in evoluntary pressure. Eventually cellular damage and decline of body function occur.

Antagonistic pleiotrophy

It states that natural selection favours gene variants and has positive impacts in an early stage that may have deleterious effects later.

Can our genes determine how old we are?

Yes, genes will be influenced by “genetic prediposition”  it will play a 10-15% role. The way we live basedon our lifestyle and “external factors in the environment” also determine the age.

R. Sankara Narayanan

Expertise inZebrafish biology and shrimp farming(Vannamei).
Well trained in Zebrafish larval rearing and embryos toxicology.
Having 1.5 years of experience at providing Technical support for farmers.
Focus area on Bio-floc, Nursery, high density and extensive cultures.
Passionate in Science communication( Blogging and Teaching)