
Ageing is any change in an organism over time. It refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing increase over time, while others decline.
Reaction time, for example, may slow with age, while knowledge of world events and wisdom may expand. Research shows that even late in life potential exists for physical, mental and social growth and development.
There are several scientific theories on ageing. The telomere theory of cell death, mitochondrial degeneration, AGEs (advanced glycation end-products) and DNA mutation are among the most popular. In simple language, however, ageing is due to the cell’s decline and lowered productivity. Ageing is not a particular malady. It’s a distinct process, a progressive decline in function that makes us more vulnerable to crippling or fatal age-related illnesses.
So why do our bodies gradually fail? Cells die off and new cells are created by copying themselves, much like a photocopy of a photocopy of a photocopy. Each time it is copied it loses some of its sharpness. Eventually the copy is no longer readable and there is no more copy.
CHOICES
But there is a choice with regard to what one eats, how much one eats, what nutrients are in abundance (antioxidants, trace minerals and essential nutrients) and which nutrients are in excess (fats, simple carbohydrates or chemical contaminants). All these factors promote or retard gene expression. Genetics really only plays a 25% role in determining human longevity and the balance of the critical factors affecting lifespan are environmental – what we do, what we eat, and how we stay enlivened. The American essayist Henry David Thoreau said, ‘None are so old as those who have outlived enthusiasm.’
Extended lifespan can be achieved by genetic alteration or environmental manipulation and almost always equates, at least in a laboratory environment, to a reduced incidence of potentially fatal diseases (e.g. cancer), slower onset of age-related senescent changes (loss in cognitive ability, slower mobility, greater fragility) and, of course, increased vitality. In other words, don’t get sick, don’t age and don’t die.
Dying is inevitable, or at least it is for multi-cell animals, but ageing, how we age and the manner of dying is a choice. Researcher Ülo Kristjuhan says, ‘It is possible to decrease the rate of damage in humans. Our research shows that it is possible to postpone age-related changes by up to 20 years, by using what is already known about avoiding discomfort and risk factors to health in practical application.'1 In other words, stay thin, eat well, relax and stay free of stress, don’t smoke or use drugs and exercise regularly.
STRESS
Today stress plays a critical role in premature ageing. Elissa Epel2 of the University of California points out that women with the highest levels of perceived stress have telomeres shorter on average by the equivalent of at least one decade of additional ageing compared with low-stress women. These findings have implications for understanding how, at the cellular level, stress may promote earlier onset of age-related diseases. Stress leads to compensatory overeating, drug use, poor exercise regimens, depression and imbalances in the neuroendocrine system.
OBESITY AND NUTRITION
Besides stress, poor nutrition plays a critical role in ageing. Overeating and eating nutritionally empty foods play a central role.3 Central body fat as estimated by waist-hip ratio is related to risk of myocardial infarction, stroke, non-insulin-dependent diabetes mellitus, hypertension, endometrial carcinoma, and polycystic ovary syndrome. Central body fat also predicts mortality.4
The 14 reasons why we get fat
- Less exercise, more leisure.
- Poor diet, overeating.
- Less sleep – we’ve gone from an average of nine to seven hours of sleep a night. Sleep deprivation is linked to increased appetite.
- Exposure to xenoestrogens – pesticides and other chemicals in foods can change hormonal activity, which can boost body fat.
- Air conditioning and heating – we don’t sweat and shiver as much as our ancestors, so we don’t burn as many calories.
- Greater use of medications – anti-depressants and diabetes drugs have weight gain as a potential side-effect.
- Stress – exposure to cortisol and other stress hormones increases blood sugar and creates more adipose tissue.
- Older birth mothers – children born to older mothers are more prone to excess weight gain than the offspring of younger mothers.
- Genetics – obese moms may pass the trait on to their children in utero.
- Poverty and education – poorer, less educated people tend to eat more junk food.
- Assortative mating – heavy people tend to mate with each other and produce heavy children.
Adapted from a variety of sources5-6
FITNESS
Researchers found that the death rate per 1 000 person-years improved as fitness improved across five groups with incrementally higher fitness levels.7,8 Fitness was found to predict mortality risk. Thus normal-weight adults had greater longevity only if physically fit, while fit, obese individuals had lower mortality risk than unfit, normal-weight individuals.
In a large, long-term cohort study of older individuals, fitness independent of adiposity was a significant predictor of mortality in older adults.9 Stay thin and stay fit – there are no excuses!
Benefits of exercise
- Prevention of bone loss.
- Improvement of postural stability.
- Preservation of cognitive functions, reduced incidence of depression, and enhanced self-efficacy.
- Prevention of colonic cancer possibly due to increased gastrointestinal tract transit time.
- Stimulation of human growth hormone and insulin-like growth factor 1 (IGF-1).
- Metabolic enhancement, increased insulin sensitivity and glucose tolerance.
- Reduces blood pressure, helps vasodilation, reduces incidence of cardiac arrhythmias.
- Enhances brain blood supply and reduces episodes of thrombosis.
- Lower mortality rate.
- Higher high-density lipoprotein (HDL)/ low-density lipoprotein (LDL) ratio.
INSULIN
Dr Andrezej Bartke from Southern Illinois University told Reuters Health: ‘Treatment(s) causing an improvement in insulin sensitivity combined with modest reduction in insulin release would reduce risk of age-related disease and likely also delay ageing.’
This finding, Bartke said, ‘supports our hypothesis that increased sensitivity to the actions of insulin is a very important and perhaps the key mechanism of delayed ageing and prolonged longevity in growth hormone-deficient and growth hormone-resistant mice.’
Other research also suggests that a failure in insulin processing in the brain may contribute to the development of Alzheimer’s disease. So control your sugars, control your insulin, and control your brain.
OXIDATIVE STRESS
Every breath we take hastens our death. Releasing energy through aerobic respiration gives rise to reactive oxygen molecules (called free radicals, oxygen radicals, or oxidants) as an inevitable by-product. Managing oxidative stress is done by means of a diet of fresh fruit and vegetables and good antioxidants.
CONCLUSION
How well you age is up to you, but don’t put it off. Every good effort in early middle age pays dividends in your 80s. If you are young, overweight and unfit, now is the time to make choices and life-enhancing changes.
Ten factors that indicate early ageing
- A poor waist-to-hip circumference ratio.
- Elevated systolic and diastolic blood pressure.
- Elevated urinary cortisol.
- Elevated urinary norepinephrine.
- Elevated urinary epinephrine.
- Low serum dehydroepiandrosterone sulphate (DHEA-S).
- Glycosylated haemoglobin (a long-term measure of blood sugar levels).
- Elevated serum LDL/HDL cholesterol.
- Elevated total serum cholesterol/triglycerides.
- Insulin resistance/metabolic syndrome.
Editor's note: Here are two other excellent articles on ageing: Feeding the Brain and Slowing its Ageing and Sexuality & the Gifts of Ageing
References
- Kristjuhan Ü. Molecular mechanisms and models of aging. Annals of the New York Academy of Sciences 2007; 1119: 122-128.
- Epel ES, et al. Accelerated telomere shortening in response to life stress. PNAS 2004; 101: 17312-17315.
- Lupton D. Food, the Body and the Self. 1st ed. Sage Publications, 1996: 73.
- Lean MEJ. Clinical Handbook of Weight Management. 2nd ed. Informa Healthcare, 2002: 46.
- Bray G. How do we get fat? An epidemiologic and metabolic approach. Clinics in Dermatology 2004; 22:281-288.
- Vogel S. Why we get fat – research on genetics. Discover Magazine, April 1999
- Hooker SP, et al. Cardiorespiratory fitness as a predictor of fatal and nonfatal stroke in asymptomatic women and men. Stroke 2008, August 7
- Mattocks C. Early life determinants of physical activity in 11 to 12 year olds: a cohort study. Br J Sports Med 2008; 42:721-724.
- Sui X, et al. Cardiorespiratory fitness and adiposity as mortality predictors in older adults. JAMA 2007; 298: 2507.
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