The Secret of Longevity

UltraFit Magazine - Annual 2007, Page 14

by Paul Taylor

Standfirst

Ageing is an unavoidable process of nature, but we now know that the rate at which we age is variable. When we talk about longevity, what we’re really talking about is delaying this ageing process.

The anti-ageing arena has become big business. In 2007, spending in this area is projected to reach a whopping US$42 billion. We are constantly bombarded with marketing messages about anti-ageing creams, antioxidant tablets and other pills and potions that are purported to enhance longevity. But do any of them really work? And how much does our lifestyle really influence our longevity?

To answer these questions properly, we need to examine the scientific research, including data on human longevity throughout history, plus the more cutting-edge molecular research of the last couple of decades.

As we look back through human history, we see that our average lifespan has steadily increased pretty much since accurate records began. In ancient Rome, average lifespan was only around 22. By the mid-1800s, this had increased to around 43. In developed countries today, it has peaked at 70 to 80. These increases are due to a combination of factors, including a dramatic reduction in infant mortality rate, eradication of major disease epidemics and, more recently, better treatment for degenerative diseases. Interestingly, however, our maximum lifespan has stayed pretty much consistent, at around 115-120 years.

As our understanding of the inner workings of the human body has improved, a lot of theories have been put forward to explain the mechanisms of ageing, each with varying degrees of scientific support. The four leading theories are:

1. Telomere Shortening

This theory is all about ‘cell-cycle control’. The body is basically a huge ecosystem of around 50 to 70 trillion cells that interact to make us function the way we do. However, all our cells have a finite lifespan. The longest-living cells in our body are liver cells, which last around two years, whereas half the mass of our heart is renewed every 40 to 45 days. Our cells are ‘programmed’ to die at a certain point in time. A process known as ‘cell division’, or ‘mitosis’, is what keeps us alive and healthy. What basically happens is that the cell ‘divides’ just before it dies, ‘giving birth’ to two daughter cells.

Cell-cycle control refers to the whole process of cell division and cell death and telomeres play a key role in this. They do this by protecting the chromosomes that encode our DNA, which subsequently ensures that the daughter cells are ‘born’ with the right characteristics. Think of telomeres as the plastic tip on the end of your shoelaces; with each act of cell division, the telomeres become a little shorter. When they become too short, the chromosomes get damaged (the shoe lace starts to unravel). This results in DNA damage, which ultimately leads to ageing.

Good evidence for the critical impact of telomeres on the ageing process can be seen with the congenital disease, Progeria. The telomeres of the cells in people with this disease are ‘shortened’ at a very early age, to such an extent that Progeria sufferers generally die of ‘age-related’ illnesses by the time they reach puberty. Further evidence of the importance of telomeres is emerging from AIDS victims, in whom the telomeres of the ‘CD8 lymphocyte’, vital for functioning of the immune system, are equivalent in length to those of the average 100-year-old, meaning their immune system is barely functioning.

2. Free Radical Damage

Free radicals are unstable molecules (for science buffs, they are lacking an electron) that are created in our bodies through oxygen consumption and metabolism of fats, carbohydrates and protein. So it stands to reason that we have significant amounts of free radicals in our bodies. In fact, each cell in our body produces around 2-3 billion free radicals per day. When you consider that the average human body contains 50-70 trillion cells, that’s an awful lot of free radicals roaming around! Normally, that’s not a problem, since the human body has a sophisticated defence mechanism to either prevent free radicals from causing damage or to counter their damaging effects.

However, if we produce too many free radicals or have a poor defence system, the free radicals roam unchecked through our body and attack molecules by stealing electrons from them, making the victim molecule also unstable. This damage can spread like a domino effect.

So how are free radicals produced in the first place and how can we defend against them? There are two sources of free radicals:

Endogenous – produced inside our body, both from by-products of normal metabolism and from by-products of our body’s immune system.
Exogenous – caused by pollution, cigarette smoke, radiation (sun, x-rays, etc), certain foods (especially processed) and excessive alcohol consumption.

As mentioned previously, our bodies have a highly developed, layered antioxidant defence system to combat the harmful effects of free radicals.

Prevention – this system works by inactivating molecules that are likely to produce free radicals, such as certain trace metals.
Enzymatic antioxidants – the cornerstone of our antioxidant defence system, these enzymes are located within the cells and neutralise free radicals as soon as they appear. Our genetics largely determine how robust this system is. As we age, our cells make inferior copies of these enzymes, giving free radicals more opportunities to create damage.
Chain-breaking antioxidants – these are obtained from our food and work by neutralising free radicals that have escaped through the other two lines of defence. Vitamins A, C and E, the mineral selenium and bioflavonoids (from fruit and vegetables) are examples of these types of antioxidants.

If this antioxidant defence system fails to neutralise any free radicals, we have other layers of defence:

The P53 gene produces a protein (imaginatively named the P53 protein) that repairs ‘coding’ DNA that has become mutant due to attack by free radicals. (If ‘non-coding’ DNA is attacked, there are no genetic mutations).
Our immune system contains ‘natural killer cells’ which roam throughout our body, seeking and destroying mutant cells that have slipped through the previous layers of defence.

Strong evidence for the free radical theory of ageing comes from laboratory experiments in which control of free radicals has extended the life of multi-cellular organisms by up to six times. This is augmented by research conducted by Dr Pearls from the Harvard Medical School who found that centenarians (people aged 100 or older) had much higher than average levels of blood antioxidants.

3. Inflammation

This is increasingly recognised as one of the key processes in the development of degenerative diseases and the ageing process as it occurs at a cellular level. Basically, when our cells get sick, we get sick. Paradoxically, the release of inflammatory agents is a mechanism by which our body protects itself when our immune system is fighting foreign invaders, infections and injury. This inflammation creates stiffness and swelling to maximise the time for immune cells to do their job.

The key variable, in terms of the impact on our health, is the duration of the inflammation. When the underlying cause of the inflammation is not removed, the inflammatory response becomes chronic, or longterm. Most degenerative diseases, such as cardiovascular disease, diabetes, cancer, Parkinson’s disease and Alzheimer’s disease, are now thought of as being at least partly caused by chronic inflammation. This is why age researchers say that one of the best ways to improve longevity is to simply stay free of illness as much as possible, not because minor illnesses and infections kill us, but because they induce a state of inflammation and there appears to be a cumulative effect.

So what are the major culprits in terms of inflammation?

Free radicals are a major cause, while other factors that cause inflammation directly or indirectly through production of more free radicals include:

Stress
Cigarette smoke
Over-exposure to radiation
Exposure to drugs and chemicals
Trans-fats and chemicals in processed foods
Elevated blood sugar
Excess weight (especially fat around the stomach)
Nutritional deficiencies (such as Vitamin D)
Nutritional excesses (such as iron)
Sleep deprivation

4. Hormonal Changes

Recent research on longevity is focusing on the importance of agerelated changes in our hormonal profile. As we grow older, the levels of some of our hormones undergo a steep decline that has very strong parallels to many of the signs and symptoms of ageing. These hormones include DHEA, oestrogen, progesterone, testosterone and human growth hormone. Within the brain, there are age-related declines in certain neurotransmitters (dopamine, acetylcholine, norepinephrine, GABA and serotonin) which reduce cognitive function and impact on our quality of life.

To better understand the effects of these hormonal changes, let’s take a brief look at their roles within the body:

DHEA – the building block for oestrogen and testosterone, this also acts to boost our immune system and brain function.
Oestrogen, progesterone and testosterone – often referred to as the ‘sex hormones’, these do much more than simply provide sex drive. They also help build muscle, bone and connective tissue, keep us mentally alert and protect us from heart disease.
Human growth hormone – often referred to as the ‘longevity hormone’ due to its anabolic (growth and repair) effects on the body, this hormone stimulates our bones, nerves, muscle, skin and organs to regenerate. Its full effects are not yet completely understood.

To make matters worse, levels of two hormones that act to accelerate ageing tend to increase as we get older:

Insulin – high levels of circulating insulin generally leads to insulin resistance in our cells. When this occurs, blood glucose levels tend to become chronically elevated. As well as predisposing us to diabetes, this leads to damage of body tissue by nasty substances known as ‘Advanced Glycation End-products’ (fittingly abbreviated to AGEs).
Cortisol – is our body’s major stress hormone. Chronically elevated levels lead to numerous negative effects, including increased inflammation, weight gain, lower basal metabolic rate, suppressed immune function and unprogrammed cell division.

LONGEVITY PLAN

It is clear that there is no single process of ageing, rather it is the cumulative effect of multiple processes occurring at the same time.

The following longevity plan acts on two fronts to reduce damaging agents and increase damage repair. You don’t need to be a rocket scientist to work out that acting on both fronts simultaneously will yield the best results.

Part 1: Reduce the Damage

Obviously the most effective way to enhance longevity is to maintain our body in pristine condition. It has been demonstrated that cellcycle control is very well regulated in young people, but becomes increasingly volatile as we age. Dr Pearle from Harvard estimates that less than 30% of our longevity is controlled by our genetics. This view is backed up by the US Centre for Disease Control, which estimated the key determinants of health in 1995. They attributed roughly the same proportions to genetics as the environment (18% and 19% respectively), with the highest proportion (57%) attributed to lifestyle factors.

Researchers in the Okinawa Study spent 25 years studying the lifestyle habits of the inhabitants of an island that has the highest concentration of centenarians anywhere on the planet. They concluded that cardiovascular disease and most cancers are 80% preventable.

Results from this research and conclusions from other molecular studies have contributed to the formation of my science-based, 10-step Longevity Plan.

The prevention part of my plan involves 3 steps:

Step 1: Limit Exposure to Toxins

The greatest threat to longevity comes from tobacco. Only 26% of smokers live to 80, compared to 57% of non-smokers. In short, anyone who smokes is bonkers!
We absorb significant amounts of toxins from the environment, including pollution, pesticides and insecticides (from non-organic food), and chemicals in cleaning products, so ‘going organic’ reduces our exposure to these nasties.
Radiation is another major source of damage and we get it from many places, including over-exposure to the sun (we only need about 20 minutes of exposure per day to get adequate Vitamin D), X-rays, mobile phones (it is my personal belief that the risk from mobile phones is currently very understated), computers, television and other electrical equipment. The major point here is that it’s all cumulative!
Recreational drugs, although a source of relaxation for some people, damage our bodies in different ways. Alcohol, caffeine and all classes of drugs (cocaine, heroin, cannabis, stimulants, barbiturates, etc) have various adverse effects on the body. Suffice to say that none of them are good for you (except the small positive effect on cardiovascular health of moderate consumption of alcohol, especially red wine).

Step 2: Manage Stress

Some stress is necessary to keep us motivated and increase our capacity (known as ‘eustress’), but excessive stress wreaks havoc on our immune system, messes with our hormones and can slow our metabolic rate, while increasing fat storage. Chronic stress can be extremely debilitating for our health, so stress management techniques are crucial for anyone experiencing significant stress on a regular basis. Techniques such as progressive relaxation, autogenic relaxation, transcendental meditation (or any other type of meditation), prayer, guided imagery, tai chi, yoga and exercise are all proven interventions for stress management.

Step 3: Control Blood Sugar and Improve Sensitivity to Insulin

Think of the damage that sugary drinks do to our teeth (despite their tough enamel coating) and you start to get some idea of the effect that high circulating blood glucose can do over the years to our vulnerable organs and cells. Controlling our blood sugar and insulin levels involves a pretty straightforward process of regular exercise and a healthy diet. There is much debate over what constitutes a ‘healthy diet’, but steering clear of refined carbohydrates is the most important for controlling blood sugar. Every bout of exercise can improve insulin sensitivity for over 24 hours, so the key to exercise in this context is regularity.

Part 2: Increase Repair of Damage

The remaining 7 steps in my plan are all about enhancing the mechanisms that repair the damage that is constantly occurring within our bodies.

Step 4: Build Immune System and Antioxidant Defences

It is clearly very important to protect and support our immune system and other body defences as much as possible. In terms of nutritional support, there is much we can do. The following is a list of foods (by no means exhaustive) that are good for immune function, antioxidant defences and processes of digestion:

Antioxidants – help to combat one of the biggest accelerators of the ageing process – free radicals! Antioxidants are abundant in fresh fruit and vegetables, wholegrains, nuts and seeds. Happily, chocolate is also high in antioxidants, as is tea (especially green tea) and coffee (preferably decaffeinated). Particularly if you’re over 50, you should consider taking a multivitamin supplement on a daily basis to improve immune function, due to a combination of natural decline and a tendency towards a restrictive diet from this age.
Omega-3 fats – there is increasing amounts of data about the anti-inflammatory properties of omega-3 fats, sourced from fatty fish (easily the best source), flaxseed, pumpkin seeds, canola oil, soybeans, dark green vegetables and walnuts.
Fibre – this keeps our digestive tract in good order, enhancing absorption of nutrients and avoiding toxin release from the buildup of rotting foods in our suboptimal digestive tract. The best sources of fibre are psyllium husk, bran, grains, corn and vegetables (insoluble), as well as oats, rice, legumes, fruit and vegetables (soluble). Both types are required to keep things moving along smoothly.

Step 5: Get Regular Health Checks (Especially After Age 40)

Advances in medicine are such that many degenerative diseases can be eradicated or at least controlled if they are detected early in their development. Your doctor can perform a variety of tests to check your overall health. In addition to the standard tests of blood glucose, cholesterol and blood pressure, it’s a good idea to have your doctor perform a thyroid check, liver and lung function tests, a test for inflammation (such as ESR or, preferably, C-Reactive Protein) and homocysteine (an amino acid linked to heart disease). Although these tests often don’t point to anything specific, you will know that something is wrong on your inside if levels are elevated.

As you approach middle age, it may be worthwhile to check your hormone levels. Hormone replacement therapy and its natural alternatives is not just for women. (Your doctor will advise you on the pros and cons). Anyone over 40 (especially males) should ideally undergo a 12-lead ECG stress test, the best way to pick up early heart abnormalities. Other important tests are a skin cancer check (everyone), uric acid and prostrate check (males) and a mammogram, pap smear and iron check (females).

Step 6: Get Plenty of Cardiovascular Exercise

Ideally, include at least five 30-minute sessions per week. If you don’t like gyms or dedicated exercise, ensure you take at least 70,000 steps per week. Being physically fit is one of the most effective ways to reduce chronic inflammation and reduce our speed of ageing. Recent research has confirmed what many experts have believed for years – that intense interval exercise (anaerobic in nature) is more beneficial to the body than long-duration, lower-intensity aerobic exercise. Having said that, you must build up to this intensity level if you’re not accustomed to strenuous exercise, since a heart attack will undo all your good work!

Cardiovascular exercise also has massive benefits for your mood and has been shown to improve cognitive functioning. These benefits appear to be more significant as you age. Remember that levels of neurotransmitters (communication hormones) decrease as we get older. Low levels of two of these (norepinephrine and serotonin) are strongly linked with depression, which may explain why rates of depression increase with age. The good news is that exercise boosts the levels of both these neurotransmitters and has been shown to help alleviate depression and help prevent Alzheimer’s disease.

Cardiovascular exercise also has a strong anti-inflammatory effect. Fit and lean people produce much less inflammatory agents than unfit and overweight people. They also have much less risk of heart disease, diabetes, dementia and other degenerative diseases. Exercise also helps improve our body’s antioxidant defence mechanism, which counters the harmful effect of free radicals, unless you’re an endurance athlete, in which case very high levels of exercise significantly increase free radical production and thus inflammation. This is why endurance athletes should consume lots of extra antioxidants, preferably in the form of fruit and vegetables.

Step 7: Perform at Least 2 Strength Training Sessions Per Week

One of the most significant conditions in the ageing process is sarcopenia or muscle wasting disease. As we age, most people respond by becoming more sedentary. This accelerates the ageing process and particularly the development of degenerative diseases, such as cardiovascular disease and diabetes. Additionally, this loss of muscle strength, power and coordination makes us more susceptible to falls, which often result in serious fractures in older people. One frightening statistic is that around 70% of people aged 70 or over who suffer a fractured hip will die within 5 years!

Other benefits of strength training include improved body composition, increased metabolic rate and, most importantly, it helps prevent your levels of anabolic hormones (growth hormone, testosterone, DHEA) from falling too low. If you don’t like strength training, then learn to, because you’ll like chronic disease even less!

Step 8: Drink Plenty of Water

Being dehydrated puts stress on all our cells. We can go for months without food, but only a few days without water. Enough said! Aim for 30ml per kilo of bodyweight per (ie. if you weigh 70kg, drink about two litres). Remember that caffeine (in coffee, tea and soft drinks) and alcohol are diuretics, so you must drink extra water to counter the dehydrating effects of these drinks.

Step 9: Sleep Yourself to Good Health

There has been a plethora of research into sleep physiology in the last two decades and we now know a lot about the detrimental effects of chronic sleep debt. Our research into sleep is so extensive that we now have an International Classification of Sleep Disorders, totalling 48 different sleep disorders!

Unlike dolphins, which have the unique ability to let their right and left brain hemispheres alternate their sleep cycle, so they’re always awake, we humans have to let both hemispheres sleep at the same time. Our brains can therefore recover from the day’s exertions, but that’s only the start of the story. Sleep is so important to proper bodily function that Dr John Lang, chairman of Good Health Solutions (Australia’s biggest corporate health company), refers to it as the fifth pillar of health (along with exercise, sound nutrition, stress management and avoiding smoking).

Our sleep cycle follows a circadian rhythm (from the Latin ‘circa’ for about, and ‘ada’ for a day) of 24-25 hours. This cycle is regulated by the hormone melatonin, which is secreted by the pineal gland in the centre of our brain. However, within the circadian cycle, an ultradian rhythm of around 90 minutes exists, meaning there is around 90 minutes between peaks of either energy or sleepiness. This ultradian rhythm also governs which stage of sleep we are in at any given moment.

There are five stages of sleep:

Stage 1: Transition from wakefulness to sleep.

Stage 2: Light sleep, characterised by certain brain waves.

Stages 3 and 4: The deep stages of sleep, often called ‘slow-wave sleep’ due to the nature of brain-wave activity. These two stages are crucial for our physical and psychological repair, as the body secretes many growth and repair hormones. The most critical of these is growth hormone, as it has wide-ranging effects on cellular repair and regeneration, immune function, muscle growth, bone density, connective tissue and even asthma.

Stage 5: REM sleep. Characterised by rapid eye movements and increased brain activity, REM sleep is now known to be essential in learning, memory and emotion. We get more of this type of sleep at the end of the night, which is why we function much better if we wake naturally after a full night’s sleep.

In short, sleep is essentially an anti-ageing activity and most of us need 7-8 hours per night to function optimally. It is interesting to note that today we sleep an average of two hours less than we did 100 years ago (7 hours versus 9 hours). The importance of sleep is highlighted by the fact that nearly 2% of all GP consultations are about sleeping problems. Around half of all workplace accidents involve fatigue, while sleep disturbance plays a significant role in disease, injury and poor performance.

A good night’s sleep will come much easier if you develop a bedtime routine, just as it works for babies. Key components to a good routine should involve:

Consistency – try to go to bed and wake up at the same time. Random late nights and early mornings, or lie-ins, can mess with our circadian rhythm of sleep.
Regulate stimulant use – caffeine should be avoided after around 3pm or 4pm, as its stimulatory effects can last for hours. Alcohol has a negative effect on our quality of sleep, so the temptation to drink yourself to sleep should definitely be avoided!
Wind down – dim the lights an hour or two before bed, as this sends a signal to our brain that darkness is approaching. The final 30 minutes before retiring should involve some sort of relaxation.
Make your bedroom a sleep haven – if you have a TV in there, get rid of it. The room should also be dark and cool, as this helps facilitate sleep.
Relax into it – once in bed, methodically relax all your muscle groups and do some deep diaphragmatic breathing (into the belly, rather than the chest) with slow, even breaths.
Plan for disturbances – if you do wake up, do what you need to do on autopilot. Try to avoid turning on lights and resume your relaxation techniques as soon as you can.
Switch off your RAM – many people have problems sleeping because their heads are full of thoughts about the day and what needs to be done tomorrow. It may be helpful to use a ‘dump pad’ - a notebook to write down things of concern, thus allowing a bit of closure to the subconscious.

Step 10: Be Positive

There is an enormous amount of evidence that positive thinking has a beneficial effect on your longevity. A new branch of science known as ‘epigenetics’ is telling us why. We now know that the environment has a huge impact on the functioning of our cells through the production of hormones and electrical signals that influence both cellular actions and our DNA. The ‘placebo effect’ is also an indicator of the success of mind over matter, so if you’re a ‘negative nelly’, then check the resources section below for help in reframing your thoughts!