Aging is a complex, multifaceted process that is influenced by both genetic and environmental factors.
The processes underlying aging are common to many age-related illnesses. The risk of cancer, heart disease and other chronic diseases increases as we move through middle age and beyond.

Aging, or senescence, is an inevitable, ultimately destructive process that affects all of us. However, its underlying mechanisms are multifaceted and various tissue and cell types tend to start aging at different stages during our lives. There are a number of ways in which we can interfere with these factors and thereby retard the overall process of aging. In so doing, not only do we assist our bodies to continue to function for longer, but we increase our chances of good health well into old age by protecting ourselves against debilitating and often deadly chronic diseases.

Aging and disease 
There is a very close relationship between aging and degenerative diseases:  the processes underlying aging inflict damage that increases susceptibility to disease; and many of the pathological agents and processes that are the direct causes of degenerative diseases also expedite, and are integral to, the aging process. An appreciation of this two way relationship and of the numerous, inextricable links between aging and degenerative diseases is critical to understand how to prolong life and sustain good health. The aging-disease relationship is particularly relevant to the role of spice-derived phytochemicals as many of the mechanisms through which these substances exert disease-preventing properties can also help to slow aging.

How and Why We Age  
Aging involves numerous, complex processes but it ultimately manifests itself in several broad ways: a declining ability to respond appropriately to all types of stresses, homeostatic imbalances, an increased risk of disease and eventually death. The effects of aging become most evident in the deteriorating appearance and function of tissues and organs that ultimately affects the whole organism. However, the less obvious biochemical processes of aging occur at cellular level. The cellular processes underlie the visible effects of aging and while their causes are not fully understood, we know that some are programmed into our genes; others – in the form of DNA mutations, toxin damage, and the general stresses of life – are the “un-programmed” consequences of wear and tear and the sundry destructive processes that occur over time.

Genetically Programmed Processes
A key way in which our genes effect and coordinate cellular aging is thought to involve the segments of DNA at the end of chromosomes called telomeres. The majority of cells in our body replicate through mitosis, with each division producing a near exact copy of the parent cell. This process enables our body to grow, and to replenish damaged or diseases cells. With time, however, the rate of division slows and, eventually, many cells stop replicating altogether. Telomeres are believed to underlie this replicative senescence, as with each division they shorten, thereby imposing a limit to the number of divisions that can occur. In addition to a finite replicative capacity, our cells have a finite lifespan, exhibiting cellular senescence. As lost cells are no longer replaced by mitosis, total cell numbers in certain key tissues, including the heart, may decrease with time.

Given our body’s numerous repair and defence mechanisms, it is not unreasonable to ask why our cells are ultimately designed to die. Senescence is certainly not an inevitable feature of cellular life: it is not, for example, observed in single-celled organisms that reproduce through mitotic cell division; nor does cellular senescence exist in many other simple organisms, such as sponges, corals and even lobsters whose cells are said to be biologically immortal. The reason for the cellular senescence exhibited by complex organisms is not fully understood but is thought, at least in part, to be a built-in control against cancer which relies on uncontrolled cell proliferation and cell immortality.

Degenerative Processes
In addition to its programmed facets – in the form of cellular and replicative senescence – aging involves general damage and wear on our cells, tissues and organs. Caused by DNA mutations, toxins and other destructive agents, these degenerative processes, that include oxidation and inflammation, are in many cases common to both aging and chronic diseases. 

DNA mutations that induce cell immortality are, for example, integral to the development of cancer. And while mutations may occur at any time, the likelihood that they will overcome the immune system and cause disease increases exponentially as we enter middle age and beyond. This is owing to the fact that when cells divide by mitosis, they replicate their entire complement of chromosomal DNA and mutations that occur before or during replication are passed on to the next generation of DNA.

While a single mutation may not cause cancer or other diseases, over time and many generations, mutations accumulate thereby increasing the probability that they will trigger cancerous and other pathological processes. The number of divisions a cell has gone through is one risk factor for disease-inducing mutations in DNA; another is the exposure to external or internally produced toxins that can damage many other cellular structures in addition to DNA.

The impact and risk posed by toxins and other damaging environmental stresses increases steadily with age. The older our body gets, the less effective is its defence against toxins, such as free radicals, and the less efficient it becomes at repairing cell and tissue damage. This increases the likelihood that toxins will cause harm through oxidative, inflammatory and other degenerative processes. For example, the older we get the less effective our bodies are at preventing the oxidation involved in the formation of atherosclerosis; this puts older individuals at an increased risk for heart attacks and strokes. The abnormal chronic systemic inflammatory response, which underlies a number of chronic diseases, is also more likely to occur as we grow old.

Two Examples of Environmental Factors that Accelerate Aging and Cause Disease
Our skin provides an excellent, visible example of the integral relationship between aging and degenerative disease. Older individuals, and in particular women, who have smoked regularly and over a long period – thereby chronically exposing their body to myriad toxins – have much older looking skin than non-smokers of a similar age. Compared with their non-smoking counterparts, smokers also have much higher incidences of various forms of cancer, heart disease and other disorders.

Chronic exposure to ultraviolet light, usually in the form of sunlight, has a similar effect; accelerating the aging of skin cells and increasing the risk of skin cancer. Both the aging and mutagenic effects of ultraviolet light are due to its oxidative effects and free radical production. Beneath skin, the association between aging and degenerative diseases – due to shared degenerative processes – is less visible, but just as strong.

Retarding the Aging Process
There is, at present, little we can do to change the programmed mortality of our cells. And even if we eventually discover how to do so, we would need to proceed with great caution and moderation: given the potential for increasing the risk of cancer, we may do ourselves a disservice by extending cell life indefinitely. However, where we can effectively counter aging – and do so without risk to our health – is by protecting our DNA and other cellular components from toxin damage and the wear and tear to which all of us are subject to lesser or larger degrees. In doing so, we can prevent premature aging and retain good health for longer.

The range in longevity within species and between populations attests to the fact that while aging is inevitable, the rate of aging is certainly not invariable. Partly responsible for this variation are individuals’ genetic differences and, in general, people with long-lived relatives tend to live longer themselves. However environmental factors also have a strong influence on the rate of senescence. While our genes remain beyond our control, we can do much to ensure that we will live as long as they allow us to. We can achieve this by avoiding the environmental factors that are known to reduce life expectancy. These include obesity, smoking, alcohol, drugs, environmental pollutants, lack of exercise, and physical and emotional stress.

Dietary factors also play a crucial role in aging and the influence of diet on life expectancy can be either positive or negative. The excessive consumption of red meat may, for example, increase our susceptibility to some cancers like cancer of the colon; more broadly, excessive calorific intake increases general systemic stress and wear and tear on the body. Resveratrol, an antioxidant found in grapes and wine, is one example of a phytochemical that has been found to substantially extend the lifespan of several animal species; and evidence is mounting that other phytochemicals have potent anti-aging properties too.

Spices and Aging
Preventing oxidation (a key degenerative process) is one of the most effective ways in which aging can be combated and the compounds in spices provide the ideal dietary means to do so. In addition to their numerous antioxidants which mop up free radicals, spices contain different classes of compounds that indirectly protect against oxidation, by stimulating and protecting other dietary and internally produced antioxidants.

Another indirect antioxidant effect of phytochemicals involves dietary sugars such as glucose and fructose. These sugars can react with amino acids in a process called glycation that is believed to lead to accelerated aging via an oxidative process (and associated free-radical production) called glycoxidation. This process damages structural proteins thereby weakening many different tissue types – including those of blood vessel walls and kidneys – and reduces the production of DNA-repair enzymes.

The regular intake of spices like cinnamon and fenugreek that lower blood glucose levels can help protect against excessive glycation, and the antioxidants in most spices help to counter glycoxidation and other age-related processes.

Not all of the ways in which phytochemicals slow down aging are well understood. But given the close relationship between aging and degenerative diseases, it is likely that most phytochemicals exert their retarding effect on aging via the same mechanisms responsible for their protective effects against degenerative diseases; including heart disease, cancers, arthritis and Alzheimer’s disease. By increasing our intake of the spice based compounds that prevent degenerative diseases, we simultaneously benefit from the deceleration of aging, helping us to look and feel younger, for longer.