Depressing title?

 It was even more depressing before I changed it from 'fifty' to 'forty-five'.

 Forty-five is about the age I find people start mentioning things like, “I pulled a muscle in my calf last week and it is still not better!”  Or,  “I'm eating less than I ever have, but still I have this roll around my waist!”  Someone told me last year that he had 'cinema knee'.  “What's that?” I asked, thinking I needed to brush up on my orthopaedics.  “It's when you've been to a movie, and you get up and your knees are really stiff”.  Very apt.

 What people certainly do notice with the passage of the years is that their muscles and joints are not as 'free'.  We spend so much of our life taking the perfect functioning of our bodies for granted.  You rise easily from sitting on the floor, without making that groaning feeling that you used to hear your grandmother make. You leap out of bed in the morning and nothing hurts.  If you run around with the kids kicking a ball on the weekend, you don't still feel the effects the following Wednesday.  If you kick the ball extra hard, you don't expect to rupture your Achilles’ tendon.  Alas, this does change with age.  I remember, as a student, a casualty doctor telling me over a grim-faced patient: “Here we have the Classic Achilles’ Tendon Tear: A middle aged man (he was 40!) decides to play soccer with the kids over the holidays, he's out of condition but doesn't know it, and he thinks someone has hit him on the back of his ankle with a baseball bat!”

 I hope nothing like this befell you over the Christmas holidays, but I suspect you did find yourself musing at times on the passage of time, seeing all those friends and relatives that you'd not seen for a year, noticing how much they had changed, and realising they were probably thinking the same thing about you. You may well have engaged in some unfamiliar activity, and 'paid' for it the next day. You may simply have sorted through your summer clothes and realised they were all a bit too snug.

 Years ago, not much attention was paid to the medicine of ageing.  People haven't been living beyond 65 for that long, after all.  Our much-increased average life expectancy has changed all that; ‘geriatrics’ is no longer politically correct, and has been renamed ‘aged care’. Senile keratoses, which are those white scaly spots that develop on sun exposed areas of skin, mainly in the over 40s, are now called ‘solar’ keratoses. It’s not surprising then, that the last 20 years have seen a burgeoning of interest and research into how the human body changes as it ages. The spin off from this is that people have been trying to work out if these changes are preventable.  The good news is that to some extent, they are.  I’ve tried to boil the current knowledge down into five basic areas that you should know about.
 

1          Changes in muscle mass

 Loss of muscle starts around the age of 30, and by the time you reach 70, you will have lost about 25% of your muscle mass.  The delightful medical name for this is 'senile sarcopaenia'.  Some of this loss is due to the aging process itself: Muscle fibres and tendons don't repair or reproduce as efficiently.  However, a lot of this is due inactivity and disuse.  Studies have shown that older adults who do strength training regularly, say,  twice per week, can regain a substantial amount of this loss.

 The benefits of this are not only added strength (handy for lifting the grandchildren), but also toned muscles.  Muscles burn almost ten times as many calories when they are at rest, as does fat.  Therefore, upping your muscle mass makes it easier to keep your weight under control.

 It is now known that muscles also help insulin to do its job efficiently.  Insulin is the hormone that drives sugar from the bloodstream into the cells, thus reducing blood sugar level.  The muscles of physically active people are more sensitive to insulin, so this in turn helps to prevent type 2 diabetes.

 Disappointingly, the muscle mass lost as people age is typically replaced with fat.  Extra fat stores, in turn, make the body more resistant to the action of insulin, again increasing the risks of becoming diabetic.

 Strength training is any exercise that uses resistance, either from your own body weight, weight machines or free weights.  More muscle also means that your blood pressure and cholesterol are more likely to be normal.

 2          Aerobic capacity

 This refers to your ability to use oxygen during exercise, and declines with age, starting as early as your 20s.  This is because the lungs stiffen and the posture may change so that it is harder to completely expand the lungs; the heart muscle weakens and pumps less strongly. Studies show that people who have higher aerobic capacity when they reach mid life, and who maintain physical activity, have better fitness on multiple measures at all points of the ageing process. Regular aerobic activity, and walking for 20-30 minutes to a 'slightly puffed' stage is a great start, and can increase your aerobic capacity by 15-25 per cent, which may be the equivalent ot being 10-20 years younger. If you were not active in your youth, it is not too late to take up some form of regular movement which gets your heart rate up to the point where you are slightly short of breath. 

3          Flexibility

 Many people have heard that some recent research showed that stretching does not lessen the chances of injury. This is true, but was done on physically fit people who were given a stretching warm up or no warm-up before their usual sporting activity.  In fact, a regular stretching program will help to keep your muscles from shortening and allow a greater range and ease of movement around a joint.  As you age, the water content of your tendons reduces, making them stiffer (you are not just imagining it); the synovial fluid content of your joints is reduced, also making them stiffer, cartilage degenerates, ligaments shorten and lose flexibility.

 Being physically idle accelerates these changes.  An old rheumatologist told my class once:  “when you get to forty, make sure you take all your joints through their full range of movement each day”.  Moving is what joints like to do, and when they are moved, they self- lubricate.  Exercises like yoga, tai chi and pilates are especially good for this.  They also help to maintain agility and balance, therefore reducing the risk of you having a fall when you are (much) older.  Most people have seen groups of ancient- looking Chinese people doing amazing things in the early morning mists; you can do it too.

 4          Bone Mass

 Most people reach their peak bone mass by the age of 30.  Bone is continually remodeled, as dentists are only too aware, but with age, breakdown tends to exceed generation.  The rate at which bone loss occurs differs according to gender.  For men, net bone loss usually begins in the 50s, and progresses more slowly than it does in women, until about 65-70, when it about equals the rate of females. Women tend to start to lose bone mass at menopause, due to the sharp decline in oestrogen.  Post menopause, bone mass is lost at the rate of 2-3 per cent per year. Men are not immune from osteoporosis however, and I will devote a whole article to this in the future.  (One in five man over 70 in Australia has osteoporosis.)   To try to arrest bone attrition, you need to have adequate calcium intake.  This is1000 mg per day for men 50-75, and for women of the same age, 1300 mg per day.  Vitamin D is essential for your body to properly absorb calcium.  You get vitamin D from food, such as eggs and oily fish, but you also need sunlight (or supplements) to make sufficient amounts. For that, you need exposure to indirect sunlight for 5-15 minutes a day, 4-6 days per week; so many more people than was once though do in fact require supplementation. Bone loss is accelerated by smoking, and to a lesser extent by alcohol (more than 2 drinks per day).  Excessive caffeine intake also seems to speed up bone loss, but there is much debate on how much is too much.  The general consensus suggests more than three caffeinated drinks per day.  Weight bearing exercise significantly stimulates bone regeneration; this includes any activity where you defy gravity with your body.  Walking, jogging, weight training are good, cycling less so, and swimming is good for lots things but not bones.

 5          Immune system

 Your immune system becomes less efficient as you get older, so older people are more likely to suffer from infections, inflammatory diseases and cancers. Smaller numbers of a pathogen, such as the food poisoning bug salmonella, are needed for an older person to be severely affected; such a dose would probably not register any symptoms in a younger adult. Older people are more at risk of auto-immune diseases, in which the body begins to treat its own cells as foreign.  These include auto0immune haemolytic diseases, where the body destroys its own blood cells, and thyroid disease.  Many health food shops encourage the purchase of supplements purporting to ‘strengthen’ the immune system.  Things are never this simple.  Evidence again reinforces the importance of eating a wide variety of foods, in a relatively un-processed state, including green vegetables (folic acid), nuts and fish (zinc), eggs and meat (vitamin B12).  Many studies of elderly UK citizens in the 70s consistently found deficiencies in the B group vitamins (cereals, whole-grains), and vitamin C (fresh fruit and veggies).  In these relatively affluent times in Australia, it is less common to find deficiencies.  If one is dedicated to taking supplements, then omega-3 fatty acids and a multivitamin will do no harm, and calcium tablets are useful if there are any doubts about dietary calcium intake.

Finally, bear in mind that “old age is not so bad when you consider the alternatives”! Maurice Chevalier (1882-1972)