Julian Whitaker, MD
Life expectancy has increased dramatically over the past century, from 47 years in 1900 to approaching 80 years today.
Life expectancy has increased dramatically over the past century, from 47 years in 1900 to approaching 80 years today. But before you jump to the reasonable conclusion that life expectancy might increase another 30 years over the next century, consider that most of this remarkable decline has little to do with maximum lifespan.
The infectious diseases that a century ago killed one in four children before they reached their fifth birthday have largely been tamed (in developed countries, anyway). Advances in childbirth, trauma care, and above all, water quality and basic sanitation have prevented many more premature deaths. So although fewer people are dying young, we're not really pushing the envelope on lifespan.
We may one day be able to manipulate genetic influences and postpone aging. Until then, we'll have to be content with working on the four known and modifiable mechanisms associated with aging and disease.
1. Shield cells from oxidative damage
Oxidative or free radical damage is the dominant theory of why we age. Free radicals, which are byproducts of normal cellular metabolism, are highly reactive atoms or molecules that bind to and destroy healthy cells. Breathing, extracting energy from food just living creates free radicals.
Years of accumulated free radical damage, accelerated by environmental sources of oxidative stress such as pollution, smoking, radiation and poor diet, take a tremendous toll on our bodies. Free radical damage is a well-recognized player in heart disease, cancer, arthritis, Alzheimer's and other age-associated diseases. And because the mitochondria your cells' energy-producing factories are bombarded by free radicals, it also leads to a loss of cellular energy.
Mother Nature has devised an elaborate system of antioxidants to neutralize free radicals, and you can give her a hand by eating lots of antioxidant-rich vegetables and fruits and supplementing with vitamins C, E and A, beta-carotene and selenium. This is the first step you should take, regardless of your age, to retard degenerative changes.
2. Maximize methylation
The internal processes that keep you alive also produce a lot of "garbage," or waste products that must regularly be detoxified and cleared out. Your body's chief mechanism for cellular housekeeping is methylation, a crucial chemical reaction that occurs billions of times every second. When methylation becomes inefficient and sluggish, toxic compounds build up like dust balls under the sofa. Most significant among them is homocysteine, a byproduct of normal amino acid metabolism. Elevated homocysteine harms the arteries and impairs circulation. It also damages your cells' DNA and contributes to atherosclerosis, heart disease, cancer, Alzheimer's and other diseases of aging.
Because methylation defects become more common as we age, it's important to consume adequate amounts of vitamins B6, B12 and folic acid. Making sure your cells have enough of these "housecleaning tools" is one of the simplest steps you can take to slow the aging process.
3. Protect yourself against AGEs
Crack an egg into a hot skillet and the clear part turns opaque as the proteins (egg whites are pure protein) undergo chemical changes. Likewise, the proteins in your body are chemically altered by sugars, a process called glycosylation. It's what happens when the protein-dense lens of the eye clouds over with cataracts. It occurs in the skin as collagen breaks down, causing wrinkling and sagging. It manifests in the joints, which stiffen as cartilage undergoes changes.
Glycosylation results in the appropriately named AGEs (advanced glycosylation end products), which gather in the tissues and interfere with normal function. AGEs also damage your immune system and kidneys, and are believed to play a role in Alzheimer's disease. Glycosylation is particularly problematic for people with diabetes or insulin resistance, conditions affecting at least a quarter of the population and which are increasingly common with advancing age.
Keeping blood sugar levels in the normal range may retard glycosylation and its consequences. The easiest way to maintain these levels is to watch what you eat. Steer clear of refined carbohydrates, such as sugar, sodas, cold cereals, most breads and snack foods, as they flood the system and drive up blood sugar. In contrast, fibre-rich plant foods cause a slow, sustained release of glucose. Making these slow burners the basis of your diet will ward off some of the degenerative changes of aging.
Everyone has experienced inflammation a swollen ankle resulting from a sprain or strain, or the redness and swelling around a wound. But you may not realize that inflammation is your body's response to any injury or insult, external or internal. It is an integral part of the immune response, and once the healing process begins, inflammation subsides.
However, as you get older, your body's ability to remove the byproducts of inflammation is impaired. Furthermore, the signaling mechanisms of the immune system become less efficient, and even healthy tissues may be misidentified as foreign and attacked. The result is chronic inflammation. Recent research has uncovered strong links between chronic inflammation and cardiovascular disease, autoimmune disorders, arthritis and Alzheimer's disease.
One thing you can do to help control chronic inflammation is to get rid of the bad fats in your diet and bring in the good ones. Fats are precursors to prostaglandins, powerful chemical messengers with either anti-inflammatory or pro-inflammatory effects. Eicosapentaenoic acid (EPA), a fatty acid found in fish oils, is very effective in controlling inflammation, so I suggest you make fatty fish a regular part of your diet. At the same time, avoid excess saturated fat foundin meat and dairy, which promotes inflammation.
It's Never Too Late...or Too Early
Nutrition should be the foundation of your anti-aging program. Eat a healthful diet centred around nutrient-dense vegetables, fruits, legumes and whole grains. Include omega-3-rich fish (salmon, mackerel, sardines) several times a week and moderate amounts of soy and other lean protein. A little extra-virgin olive oil and expeller-pressed vegetable oils are fine, but stay away from animal fats and processed fats. And don't overeat cutting back on calories has been shown to retard aging.
To counter free radicals, supplement with vitamin C (1,500 mg), vitamin E (800 IU), vitamin A (5,000 IU) and beta-carotene (15,000 IU). To facilitate methylation, take folic acid (800 mcg), vitamin B12 (150 mcg) and vitamin B6 (75 mg). And to curb inflammation, take two fish oil capsules a day. The best way to make sure you're getting adequate amounts of these anti-aging nutrients is to take a high-dose multivitamin and mineral supplement. Check your health food store for premium brands.
While we can't push the envelope of mortality, we can take steps to function at peak capacity throughout life, feel great and be able to do all the things that make life worth living. This is successful aging.
Dr. Whitaker's Biomarkers of Aging: What's your score?
You know your chronological age even if you'd rather not admit to it. But do you know your biological or functional age? Although there is no universally accepted measurement of biological or functional age, experts have identified several biomarkers of aging that can be measured by a physician. These include muscular strength, exercise tolerance, vision and hearing, blood pressure, vital capacity (lung function), heart size and laboratory tests of DHEA, glucose, lipids and creatinine clearance (kidney function). You can do the following tests of functional age on your own. They're a lot of fun, so get the family involved and see how people of different ages score.
If you've ever been bested by your children or grandchildren in a videogame, you know that reaction time slows down as we age. To test yours, take the falling-ruler test. Have someone dangle a ruler from the end, holding it at the 30-centimetre (12-inch) to 50-cm (18-inch) mark (depending on the size of your ruler). Position your thumb and middle finger about eight cm (three inches) apart at equal distance on either side of the bottom of the ruler (the 0-cm/0-inch mark).
As the other person drops the ruler, without warning, catch it between your thumb and finger as quickly as possible, and note where you caught it. Repeat three times and average your scores. Averages generally go from the 15-cm (six-inch) mark at age 20 to 30, to 25 cm (10 inches) at age 40 to 50, and 30 cm (12 inches) or more at age 60.
I was in a restaurant recently when I noticed two couples at an adjacent table passing around a pair of reading glasses none of them could make out the menu without them. As we age, the lenses of our eyes stiffen and lose their ability to accommodate, or change shape, and this interferes
with near vision.
To test your visual accommodation, hold this page at arm's length and slowly move it towards your eyes until the print suddenly begins to blur. (If you wear glasses for distance, you may use them, but do not use reading glasses.) For the average 21-year-old, the blurring point will be about 10 cm (four inches) from the eyes; at age 30, 13 cm (five inches); at 40, 23 cm (nine inches); and at 50, 38 cm (15 inches). By the time you're 60, your arms probably aren't long enough to bring it into focus at all!
One of the most visible markers of aging is the skin. Loss of connective tissue in the skin contributes to the sagging and wrinkling that are characteristic of aging. A reliable test of skin elasticity is to pinch the skin on the back of your hand between your thumb and forefinger for five seconds, then see how long it takes to return to normal.
This will take less than a second for most people under 30, and two to five seconds for those ages 40 to 50. However, by age 60, traces of the skin fold will remain for an average of 10 to 15 seconds, and by age 70, 35 to 55 seconds.
Improve Your Scores
Have fun with these tests, and remember that the results are only broad indicators of where you are right now. Rather than concentrating on the present, think about where you want to be in the future and take steps to improve your health. I suggest you record your results today, then take these tests again in six and 12 months. Don't be surprised if, despite the passage of time, your functional age gets younger.