Tuesday, June 26, 2012

Why I'm Still Stretching

Stretching has gone out of fashion in recent years.  Formerly touted as a way of improving your workout and preventing injuries, the practice, particularly static stretching, has been shown in some studies to decrease power in activities such as running and jumping and to have no benefit in preventing injuries.  The new thinking is that workouts should be preceded by a warm-up, such as jogging in place, and ballistic stretches like goose-stepping.  Some recommend avoiding static stretching altogether on the grounds that it tends to tighten muscles, while others would give it a role in a post-workout routine.  The current situation was discussed in a New York Times blog post by Gretchen Reynolds.

For a few months I tried ballistic stretching before working out on the elliptical and I was not impressed.  It did not raise my heart rate high enough to prepare me for the workout nor did it improve my flexibility by extending my range of motion.  These days I do a warm-up consisting of jumping jacks and jogging in place; I don’t do any stretching at before a workout.  In the evenings, especially on days when my muscles are sore from resistance training, I use a foam roller, then do a series of resistance stretches.  These exercises, which I learned from Anne Tierney and Steve Sierra, involve pulling against the stretch which is supposed to avoid tightening the muscle.  Stretching makes me more comfortable, more relaxed, and probably lets me sleep better.  

The stretches I learned in years of yoga classes helped me to recover full range of motion after having a frozen shoulder.  I am now applying the same type of technique to my hands, which have scar tissue at the knuckles because of arthritis.  I’ve been in enough yoga classes to believe that what happens to the body happens to the mind as well.  A calm, relaxed body is probably conducive to an open, percipient mind.  New research also shows that a flexible body can mean flexible arteries, lower blood pressure, and a reduced risk of cardiac problems, findings that are of great interest to me because of my family history of heart disease. 

Monday, June 18, 2012

When Emotion Trumps Science: the Latest on Hormone Therapy

Let’s imagine that there is a new medication available for post-menopausal women.  It is an effective remedy for hot flashes and osteoporosis and lowers the risk of diabetes and colon cancer.  In younger women, it may protect against heart disease.  One version of this drug can also diminish a woman’s risk of dying of breast cancer.  Potential downsides include a small increased risk of having a stroke (12 more per 10,000) or of dying of breast cancer (about 1 more death per 10,000 with the drug). 

This blog has a feature called “Should I Be Taking This?” in which the potential side effects of a particular medication are listed first, followed by ostensible benefits.  Often the first list is quite long and the second rather short and tentative.  Some of the medications have only been on the market for a short time so the full extent of the risks and benefits may not yet be apparent, a situation I discussed in “Statistics and the Twenty Year Rule.”  

Against this background hormone therapy seemed like a pretty good deal:  substantial and proven benefits associated with risks that amount to tenths or hundredths of a percent.  And some hormone medications had been around for decades.  I started taking Premarin, an estrogen-only version of hormone therapy, in 1979 after a complete hysterectomy at age 32.  The initial dosage of 1.25mg was too high and was later reduced by half.  I tried taking even less but started getting hot flashes.  Then in 2002 the Women’s Health Initiative study of estrogen-plus-progestin therapy was halted because of higher-than-expected rates of breast cancer and heart attack in women using the medication; the risks of the therapy were deemed to outweigh the benefits.  When this news was released, widespread panic ensued among women using hormone therapy.  Many abandoned it altogether.  WHI was taken as a blanket rejection of hormone therapy by the medical community, whether researchers intended it or not.

The women who discontinued taking these medications avoided risks but they also lost substantial benefits.  Many undoubtedly experienced hot flashes which disturbed their sleep and interfered with their ability to concentrate.  People tend to joke about hot flashes but insomnia is a big deal.  Sleep is right up there with air, water, and food among the essentials for survival.  That’s why sleep deprivation is used as a form of torture.  These women were also more likely to get osteoporosis.  Sometimes their doctors prescribed bisphosphonates to protect from bone loss but these have been related to a rare type of femur fracture and, in a few cases, with osteonecrosis of the jaw (disintegration of the jaw bone), although the nature of the association is not yet clear.   

Women with a higher risk of breast cancer or stroke may not want any additional risk, however small.  My situation is different.  The Cleveland Clinic’s online calculator of stroke risk puts mine at 3.6% over 10 years, about half the average for women my age.  Taking estrogen may increase that risk to 3.60432%, an increment too tiny to worry about.  Decisions about medical treatment should be made on an individual basis: one size does not fit all.  The hormone therapy saga is a good illustration of this point.  

For those of us on hormone therapy, the medical discussion of this issue has been like an extended good news/bad news joke.  In a recent issue of the Wall Street Journal the invaluable Melinda Beck brings us up to date on the most recent findings.  The current notion is that for younger women the benefits may outweigh the risks.  Did doctors overseeing WHI anticipate the extreme reaction to their study? Did they consider what the consequences would be for women who stopped taking hormones?  Some of them, when quoted, sound a bit defensive.  In the WSJ article Rowan Chlebowski, a WHI investigator, asks:  “Why would anyone want to double their risk of dying from breast cancer?”  If the additional risk is tiny and the benefits include protection from hot flashes, osteoporosis, colon cancer,and diabetes, I’d say it was worth it.   

Women are still being advised to take these medications for the shortest time possible because of the risks, but how much is known about longer term use of these medications? I’ve met or read about many women like me who have taken them for decades and are doing fine.  When is someone going to study us?

Thursday, June 7, 2012

Fat Gain Versus Weight Gain: All Calories Are Not Created Equal

In January of this year I read about a new study on how calories from different types of food affect fat gain and weight gain, but until I heard Dr. David Crabb’s discussion of the study on WFIU’s medical program “Sound Medicine” I didn’t appreciate how counter-intuitive and downright strange the results were.  Dr. George Bray of the Pennington Biomedical Research Center in Baton Rouge began by determining the daily caloric needs of 25 healthy men and women.  Then, over an eight-week period, he fed them 1000 calories more.  

The participants were divided into three groups according to the type of diet they were fed during the study.  Some received a diet low in protein - about 5% - and high in fat; others ate a normal protein diet of roughly 15%, an average of 139 grams per day; while the third group consumed a high protein diet of 26%, about 228 grams per day, and very little fat.  Carbohydrate levels for all three groups were the held constant.
At the end of the eight weeks all the groups had put on the same amount of fat but weight gains varied among the groups in an unexpected fashion.  The low protein/high fat group put on the least amount of weight and those on the high protein/low fat diet put on the most but the normal and high protein groups gained lean body mass in addition to fat and increased their energy output, while the low protein group actually lost lean body mass.  In his commentary Dr. Crabb notes that it is surprising that the protein in the diet alone produced an increase in lean body mass without any sort of physical training.  (The study did not involve any exercise for any of the participants.)  Presumably the loss of lean body mass would make it harder for the high fat group to lose the weight they had gained once they started to do this, though the study did not address that point.

Some commenters on the research see the study as further evidence of the unreliability of BMI as an index of good health.  At the end of the study the low protein group weighed less but were also less fit.  One aspect of the study seems to confirm a point made by nutrition researcher Douglas Paddon-Jones, that the body does not absorb more than a certain amount of protein, about 30 grams per meal maximum for most people.  Those on the high protein diet did not gain much more lean body mass than those on the normal protein diet.