Introduction
Process of growth starting from conception, continuing till the child grows into a fully mature being distinguishes him/her from an adult. Growth is characterized by net increase in size/mass of tissues and development signifies maturation organs and of functions. Growth and development are influenced by genetic, functional, environmental, nutritional, metabolic, social, emotional and cultural factors to a great extent. The process can be assessed by taking into account the increase in height and weight as an entity, when studied longitudinally. Pace of these changes taking place varies from person to person- in some individuals the developmental changes might appear earlier while among others same might take place at a slow rate.
One aspect of growing children that gets noticeable by all of us at school is the fact that in the same class of children some look very young while some look maturer then the others ,with one group in-between. This observation makes one wonder if there is some other way to assess biological maturation. Even in adulthood, people of the same chronological age ,look younger or older than their peers Here, it is important to introduce the fact that human body two types of age – chronological age and biological age. Chronological age is the one we all are familiar with, as the number of years denoted by Earth’s revolutions around the sun. It is the current age in years, calculated from the birth date.
Chronological age is the actual number of years a person has lived in years, months, days, or a combination of all of these; for example 15 years, 3 months, and 12 days. Biological age, on the other hand, represents the biological status of maturity referring to how old a person seems to be. It is an individual’s development based on certain biomarkers – a recordable molecular or cellular event. Biological age, also called physiological age, determines the extent of body functioning relative to actual calendar age. For example, one may have a calendar or chronological age of 65, but because of healthy and active lifestyle, avoiding longevity threats like consumption of tobacco or subjection to obesity, that person is physiologically more similar to someone with a chronological age of 55. In that case, his/her biological age would, therefore, be 55. So, the biological age is a measure of how time and lifestyle have affected the organs and cells compared to other people of the same chronological age.
Experts consider telomeres (the protective ends of chromosomes) while calculating the age difference between the chronological and biological age. Telomeres prevent chromosomal ends from deteriorating or fusing with a neighboring chromosome, affecting the tempo of ageing of cells. It implies that greater the chronological age, the shorter the total length of telomeres will be. However, maintaining a healthy lifestyle, inclusive of a healthy diet and regular exercise, may also maintain telomere length.
Factors determining Biological Age
There exist several factors that can determine/ influence the biological age of an individual, but none of these are definitive or accurate, rather that would give years on an average life expectancy.
- (a) Lifestyle : Healthy living habits have significant impact on longevity and extended biological age. These majorly include exercise/physical activeness, eating/dietary habits(Antioxidants- fruits and vegetables), stress levels, alcohol/tobacco consumption, level of education, amount of sleep, sexual/romantic relationships. Enough of physical activity, dietary pattern constituting more of nutrient-rich content and less of fatty entities, less or no stress and keeping it away from drinking and smoking tend to influence longevity in positive terms. Decreased biological age has been found associated with lower educational background and lesser hours of sleep.
- (b) Heredity : Genetic predisposition/vulnerabilities are another major factor responsible for influencing biological age. Heredity/gene pool contributes to increased biological age that has nothing to do with lifestyle habits. Just as the way specific diseases run in families, longevity also does. If a person has family members who have lived longer than 96 years, chances are that the person would also lead a longer life even if his/her lifestyle patterns are less than healthy.
- (c) Habitat/ geographical nativity: (forest, mountains, deserts, cold climates) Another important factor influencing biological age is the place where you live. There lies no secret in the fact that the environment and culture one lives in is directly linked to the person’s healthy living.
Why biological age matters?
Everyone ages, but the health problems that we must deal with as we age make a remarkable difference in our biological age and quality of life. Assessing biological age helps to find out in moments what a person’s biological age is and how this age is changing. To some, this might mean they are aging too rapidly. For others, good habits may reveal that their biological age is progressing slowly, making them healthier and more youthful. It is never too late to make changes in life either. No matter what the results are, being able to track one’s biological age will help finding out whether one is heading in the right direction for health or if the person needs to turn around and ask for help/suggestions.
There resides a direct link between vitality and behavioral changes. Healthy living is equated with slow aging, whereas unhealthy lifestyle choices are equivalent to rapid aging. Knowing one’s biological age is the same as knowing how healthy and strong a person is, and whether he/she is at risk for life threatening diseases such as high blood pressure or diabetes.
What if one’s biological age is higher than the chronological age? It acts as an indicator that it is a crucial time to make positive changes which can make positive difference in the individual’s life. The aim here is to put a focus on those habits that lessen age expectancy, changing them into healthy habits that can add some more years to the life. This is possible by addressing some of the following issues:
- Quit smoking, and consumption of alcohol.
- Add more fruits, vegetables, lean meats, and water to your daily diet.
- Practice good sleep, hygiene, by turning off screens and relaxing an hour before you go for the night sleep.
- Get more exercise done by starting a fitness program.
- Learn techniques for stress reduction and management, such as meditation or deep breathing.
Following all or even some of these basic suggestions, one is sure to be healthier than most adults and thus be younger than the chronological age. And exercise is just one area of simple lifestyle changes one can make to grow younger and healthier.
Aging process is something one can have an influence on because lifestyle-related factors play a very crucial part in determining the health and biological age of a person. In order to slow down the aging clock, one needs to find out where it’s currently set by determining the biological age versus the chronological age. By getting an accurate assessment of where problems lie, an individual will gain the motivation to work to improve upon these areas. People are living longer these days and are concerned about being able to afford health care as they live longer. They are looking for ways to lower health care costs and take hold of personal responsibility for their health. That is why it is important to know your biological age. Knowing where the problems exist, one can initiate the lifestyle modifications necessary to improve health and increase vitality.
Determining biological age and matching it with chronological age is also very important among growing children and adolescents in order to prevent atrocities ,injustice against the minor children, e.g., asylum detention, matters related to court of law, to name a few.
Case study : Minors used in crimes , sexuality before 18 years etc.. All required to amend laws based on biological age
Determining Biological age
(a) From Anthropological assessment
Weight and height are physical manifestations of growth and development. They are utilized the most in diagnostic procedures and in assessment of growth and development. Body mass is probably the best criterion of nutrition and growth because it sums up all increments in size. By comparing the height and weight of a child of a given age with the standard height weight values of the same age group ,one can assess the relative growth rate as well as the factors responsible. By comparing the sexual maturity indices like breast development stages ,penal development stages, appearance of facial and body hair, one can fairly assess and match the biological and chronological age of growing children.
(b) Skeletal Assessment
The skeletal maturity of the individual is known as bone age. Bone age is an appropriate indicator of physiological development and is distinct from the chronological age. Appearance and fusion of different skeletal centers of ossification follows a fairly definite pattern and time schedule from birth to maturity. Roentgenographic study of these skeletal maturational processes provides valuable criterion of a child′s level of osseous maturation. This helps in assessing whether the child is advanced in skeletal maturity as compared to his/her peers of the same chronological age or is lagging behind..
(c) Dental Assessment
The development and eruption of teeth are part of child′s total development. Tooth eruption and development is a useful measure of maturity as it represents a series of recognizable events which take place in the same sequence from birth to maturity. Estimation of dental age is based upon the pace of development and calcification of tooth buds along with their progressive sequence of eruption in the oral cavity. Tooth calcification provides a valuable indicator of dental age, serving as an index of maturation of child. Tooth calcification, being a continuous development process, should be considered a better measure of physiological maturity than dental emergence. Hence, several methods have been developed in order to assess dental age according to the degree of calcification observed on permanent teeth.
| 1st Premolar | 10-11 Years |
| 2nd Premolar | 10-12 Years |
| 1st Molar | 6-7 Years |
| 2nd Molar | 11-13 Years |
| 3rd Molar | 17-21 Years |
Physical characteristics comprising of weight, height, skeletal maturation and dental development are subjected to biometric tests and compared with standards based upon large groups of healthy subjects in order to evaluate the growth and maturational status of people. Differences between dental, skeletal and chronological age is of great interest in ascertaining an advancement or delay compared to standard growth. Besides bone age, dental age is also used to study somatic maturity. Eruption and calcification of dental tissues is used to determine dental age. Tooth calcification is superior to tooth emergence because emergence of a tooth a fleeting event and its precise time is difficult to determine, whereas calcification is a continuous process that can be assessed by permanent records such as X-ray films.
Concept of Chronological Age and Biological Age in Sports
Development and maturity appear at different chronological ages. Chronological age of a person may be lesser than his/her biological age making him/her an early maturer. While for late maturers, biological age is generally lower than chronological age. In sports, biological age refers to the biological status or maturity of the athlete depending on whether he/she is a pre-adolescent, adolescent, or an adult. Technical training age refers to an athlete’s technical ability in a given task, strength training or sport specific to name a few. In most cases, particularly in team sports, athletes are grouped purely on their chronological age. The term ‘age’ is described as typical or ideal group training category in which athletes are separated. For example, team sport athletes are typically separated by chronological age, and in some circumstances based upon technical training age. However, athletes are rarely separated by biological age.
Over past few decades sports science and, strength and conditioning have become increasingly popular professions that has led to many practical and scientific progressions. One of which is the understanding of ‘individuality’ which infers that no two athletes are the same and that they can vary by gender, age, ability, physical and psychological maturity, anthropometrics, and training necessities, for example. This implies that training programmes must be individualized in order to maximize the athleticism of each athlete and protect them from any personal predisposing injuries. For this reason, exercise specialists have begun to categorize their athletes not only on the basis of their chronological age but also by their biological and technical training age.
(a) Chronological Age in sports
This form of categorization is most commonly adopted when working with athletes. However, the primary issue in doing so is the large variance between individual abilities that is often exaggerated in young athletes due to differences in both their biological and psychological maturity. For example, in an under-17 boys’ rugby team, some players may have almost reached full physical maturity while others may have yet to undergo their peak height velocity. This can result into large variances in physical and psychological maturity, limiting the physical potential of the athletes by potentially increasing risk of injury, reducing inter-group competition and generating distractions, failing to cater training necessities for each individual.
(b) Biological Age in sports
In comparison to chronological age, the classification of biological age is far more complex as it is often determined differently depending on whether the exercise professional is calculating the biological age or status of a pre-adolescent, adolescent or adult. Biological status of adults can be accurately estimated only with medical expertise and extensive assessments. On the other hand, biological age or maturity offset of youths can be determined using non-invasive anthropometric measures that require minimal equipments.
Analyzing biological status of a young athlete is typically done by calculating the maturity offset of the individual, predicted years from peak height velocity, by using several anthropometric measures-using age, standing height, sitting height and leg length, most of the times. By objectively measuring maturity offsets of a group of young athletes, training groups can be restructured according to their biologic status. This enables young athletes to be categorized based upon their physical and psychological status and/or training goals.
Availability is often the primary issue with categorizing athletes based upon their biological age, especially when working with youth team-based athletes who have set sport-specific technical training timings based on their chronological age.