Four More Biomarkers

posted by Pilar Gerasimo 07/01/2002 0 comments

7. Cholesterol/HDL Ratio

By now you probably know that the balance of certain classes of lipoproteins in your bloodstream has a lot to do with your risk of heart and arterial diseases. “Lipoprotein” just means a fatty substance (like cholesterol) combined with some kind of protein substance. Cholesterol in itself is not a bad thing (your body requires it to function and produces its own supply), but under some circumstances, an excess or imbalance of certain lipoproteins can be a very bad thing indeed.

Specifically, an excess of low-density lipoproteins (LDL, or “bad cholesetrol”), particularly when out of balance with the presence of high-density lipoproteins (HDL, or “good cholesterol”), appears to have a dreadful effect on your cardiovascular health. Doctors used to think that excess LDL caused fat-laden deposits to build up on arterial walls, clogging them, causing blockages and thus blood-starving the surrounding tissues (an effect that, if those tissues happen to be in your brain or your heart, can cause you to drop dead). Now though, they’ve realized that LDL actually causes arterial inflammation. The fatty plaque stuff builds up not so much on the surface, but within the tissues of the artery itself, where it sets off an immune response, causing those tissues to swell, stiffen and in some cases rupture. The blood clotting that occurs as the result of these ruptures is, in many cases, what ends up blocking the artery (read “Atherosclerosis: The New View” in the May 2002 issue of Scientific American at

In any case, an excess of LDL is still a bad thing. And an ample amount of HDL (which docs now believe not only helps to remove cholesterol from arteries, but also intervenes in the LDL inflammation process) is still a good thing. To keep your LDL/HDL ratios in order, you need – you guessed it – plenty of cardiovascular exercise (which helps raise HDL) and a diet low in saturated fat, high in live foods, healthy fatty acids and whole grains (all of which are believed to help lower LDL). Both these diet and exercise strategies help lower body fat and maintain a healthy body composition, which in turn further improves your LDL/HDL situation. This keeps your circulatory system healthy – which keeps you looking, feeling and functioning younger, for longer.

8. Blood Pressure

Enough has been written about the dangers of high blood pressure that we won’t go into great detail about it here (for more on the importance of maintaining a healthy cardiovascular system, see “Full Circuit” in this issue of EL), but suffice it to say that if your arteries and heart are put under too much pressure too often (as they are with hypertension), it predisposes you to heart attack, aneurysm stroke, kidney failure and all sorts of other undesirable experiences that, if they don’t kill you immediately, will most certainly reduce your vitality and cause you to age at an accelerated rate.

Your best bet for managing and reducing blood pressure? No big surprise here – once again, it’s mostly healthy diet and adequate exercise, plus quitting smoking, reducing body fat, reducing stress, and for some, going off birth control pills. There’s also evidence that, for some people, other strategies (moderate intake of red wine, an aspirin a day, anger management – even forgiveness) can have a significant lowering effect. But you can save yourself a whole lot of worrying about how to lower your blood pressure if you never let it get high in the first place. Translation: Cut the crap out of your diet and get your body moving!

9. Bone Density

Doctors know that the mineral content in our bones tends to decline with age, causing our bones to become porous and more brittle (a condition known as osteoporosis). They don’t all agree on why, and probably there is no single reason, but rather many reasons. What they do know is that our bones, like the rest of our tissues, are dynamic; they are constantly reforming and regenerating themselves. But as we age, that regeneration process often becomes a degeneration process. The two chief causes of degeneration appear to be: 1) diet-related (when we aren’t getting enough bio-available minerals from our diets to support vital functions, our bodies make up the difference by robbing the mineral stores in our bones); and 2) activity-related (when we don’t do enough weight-bearing exercise – like running, walking, manual labor – our skeletons adapt and get weaker.)

According to the Tufts studies cited by the Biomarkers authors, popping mineral supplements alone is not the answer. Your body requires the presence of many other substances (vitamin D, certain hormones, etc.) to make use of those minerals, and interestingly, exercise appears to be one critical factor in whether or not those substances are present. In other words, your activity levels can affect whether or not available minerals are absorbed in adequate quantity.

The authors recommend a brisk, daily walk as the best osteoporosis preventative. They also point out a couple of other interesting bone-loss/exercise connections. For example, if we reduce our weight-bearing activity as we get older, we are not only more likely to lose bone, we’re also more likely to lose strength, balance and agility, and thus are more likely to fall. If we fall and break a hip or other bone, we are less likely to be able to move or exercise, thus setting up an even more accelerated cycle of infirmity and ill health (for all the reasons described in the previous sections). Even more good reason to invite your older friends and relatives along on your daily walk!

10. Body-Temperature Regulation

Every time there’s a heat wave or cold snap, you hear about how dangerous these temperature fluctuations can be for older folks. That’s because as we age, our internal temperature regulators tend to fritz out on us – but again, this is not purely an inevitable result of old age.

To be sure, several factors in older peoples’ reduced ability to regulate body temperature do occur with age. For example, many older people experience reduced thirst and reduced kidney efficiency, both of which can contribute to chronic dehydration and an impaired ability to self-cool by sweating. But both this affliction and its counterpart – impaired ability to self-warm by shivering – are also byproducts of reduced fitness. So once again, by maintaining a high level of cardiovascular fitness, you have a good shot at staving off or minimizing such problems.

Gains in fitness can actually help repair your body’s temperature-control mechanism. Keeping your metabolism high helps ensure that you’ll hang onto your thermogenesis (heat-generating) abilities longer. Maintaining healthy circulation will help you keep cozier in cold weather, too. Regular exercise also increases the amount of water in your blood, helping you maintain higher body-water and electrolyte levels, and thus retain more of your sweating abilities. Still it’s a good idea to drink more as you age, and to get into the habit of drinking even when you aren’t thirsty. That goes double when you are exercising or facing warm temperatures.

To learn more about aging and biomarkers, visit, or the Human Nutrition Research Center on Aging at Tufts University at

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