Is Marathon Good for Health ?

By Syed K Haque, MD
Image Credit: KJohansson
The Fresh Air Fund is inviting runners to 13.1-mile marathon that takes you through beautiful Central Park, action-packed Times Square and ends with breathtaking finish-line views of the New York City harbor. So the question is, " Is it Good for health?".

Role in Weight Loss

In a study, published in Journal Obesity, researchers followed 6406 runners over 7.4 years. What they found would be useful in motivating many to take to running.
They found that when initially sedentary men and women started running regularly, they lost weight at the rate of 0.017 kg/km per week in case of men and 0.023 kg/km per week in case of women(1). Should this now be used to decide how much to run per week to achieve our desired weight loss goal in a short time ?

American Heart Association recommends, "..perform any moderate-to-vigorous-intensity aerobic activity for at least 30 minutes on most days of the week at 50–85 percent of your maximum heart rate". They caution, "...But don't overdo it. Too much exercise can give you sore muscles and increase the risk of injury." According to them, the maximum heart rate is 220 minus your age(2).

What after having achieved your desired weight loss goal ?

The above study on 6406 runners, having found weight loss with regular running, also found that those who quit running gained weight at a rate of 0.005 kg/km per week in men and 0.018 kg/km per week in women. So to maintain weight, it suggests regular exercise.

How to avoid dehydration ?

Another study has found that during a marathon the maximum weight loss occurs in the first 4 hours (3). This suggests proper fluid intake right from the start to avoid dehydration.Some people suggest taking weight before and after a marathon, and making up for the loss through drinking water.

Could rehydration, the solution to dehydration, be harmful ?

Sometimes, athletes consume too much water leading to low sodium in the blood. While researchers have argued on what causes low sodium in marathon runners ? They generally believe that it's overdrinking which dilutes the blood, and blame the global sports drink industry for continuing to promote overdrinking. Some also believe in the role of loss of sodium in sweat(4). Many sports specialist recommend fluid intake ad libitum ( "at one's pleasure"). So listening to the body's own alarm "thirst","thirst","thirst" should be a useful guide to fluid intake .

What should we do ?

Measure your weight before and after exercise. Drink in moderation. Consult your physician if you have headache, confusion or any other new symptom. Follow the advice of American Heart Association regarding physical activity.

References:

1.Williams PT, Thompson PD.Dose-dependent effects of training and detraining on weight in 6406 runners during 7.4 years.Obesity (Silver Spring). 2006 Nov;14(11):1975-84.

2. Physical Activity-American Heart Association.http://www.americanheart.org/presenter.jhtml?identifier=4736.Accessed Feb 19,2011.

3.Kao WF, Shyu CL, Yang XW et al.Athletic performance and serial weight changes during 12- and 24-hour ultra-marathons.Clin J Sport Med. 2008 Mar;18(2):155-8.

4.Yoram Epstein and Yoav Cohen‐Sivan.Exercise‐associated hyponatraemia: facts and myths.Br J Sports Med. 2007 February; 41(2): 111.

Eating Too Quickly Will Make You Fat

Dr.Kristie Leong
Many people have busy schedules that don’t allow them the luxury of sitting down to a leisurely meal. Instead, they grab something fast from a drive-through window - or scarf down a brown bag lunch before returning to their to-do list. Not only does eating too fast lead to indigestion, it also contributes to weight gain – and the growing problem of obesity. Is speed eating causing you to gain weight?


Does Eating Too Fast Really Cause Weight Gain?

Eating too quickly leads to weight gain, mainly by causing you to overeat. In a study published in the Journal of Clinical Endocrinology and Metabolism, men who devoured a large serving of ice cream in five minutes had lower levels of hormones that cause satiety than men who took thirty minutes to finish their treat. Despite eating a big bowl of ice cream, the men who ate in only five minutes weren’t full.

When you eat too fast, you don’t give the stomach time to tell the brain that it’s had enough – so you keep on eating. It takes twenty minutes for brain-signaling hormones to signal the brain that it no longer needs food. The key is not to eat too much during that twenty minute time period.

Eating Too Quickly is an Unconscious Habit for Some

Some people aren’t aware that they’re eating too fast - so ingrained is the speed-eating habit. They’re so used to wolfing down food that the experience of tasting what they’re eating no longer registers. This type of mindless eating is sure-fire recipe for weight gain – as well as indigestion and heartburn. The health consequences of eating too quickly go beyond simple weight control.

How to Stop Eating Too Fast

Make a conscious effort to slow down the pace of a meal until it becomes second nature.

Train yourself to set down your fork after each bite, and pick it up again only when your mouth is empty.

Focus on the taste and smell of what you’re eating and describe the flavors in your mind.

Cut back on the size of each bite or use chopsticks instead of a fork to train yourself to put smaller portions in your mouth.

Pay attention to signals that indicate you’re full, and don’t eat past that point.

If you’re eating with someone, focus on the conversation rather than on what’s on your plate.

Play slow, new age music in the background during a meal to set the pace. It’s hard to speed-eat when Yanni is playing in the background.

Eating Too Fast: The Bottom Line?

Learn how to take it slow at meal time. You’ll consume fewer calories – and actually taste your food again.

References:

Men's Health. "6 Mistakes That Keep You Fat"

The copyright of the health article, "Eating Too Quickly Will Make You Fat," in "Interesting Health Articles" is owned by Dr.Kristie Leong M.D. Permission to republish this article in print or online must be granted by the author in writing.

Does Milk Cause Weight Gain?

Image Credit:Janine Chedid
On the contrary, it prevents weight gain. However, infants and bodybuilders do gain weight from drinking milk. But such weight gain is mainly because of the protein content of milk rather than fat. Fat loss regimens help shrink the fat cells in the body. Research shows that milk helps maintain the fat cells in shrinked state, thus preventing or slowing the fat cells from bouncing back to its initial size.


Studies on rats have shown that rats-on-diet have lower fat mass when they take dairy proteins and high calcium then when they consume whey, soy or casein protein and low calcium(1).Now moving on to humans, we know that weight loss increases appetite so much that we tend to rebound back or sometime gain even more weight than what we started with. Studies show that milk supplementation diminishes this effect(2).


Why Not Take Calcium tablets Instead of Milk ?

Studies on fat cells show that calcium plays a key role in it's metabolism. While it's true that high calcium diet prevents synthesis of fat cells and helps in it's shrinkage, dairy sources of calcium has shown even greater effect. Milk not only prevents weight gain in those who are dieting and have lost weight but also those who are not dieting(3).

What Should We Do ?

Milk is a super nutrition. If you are afraid of the fat in the milk then buy fat-free milk. Calcium in the milk is more effective than calcium in tablets. Try milk and see it for yourself if it helps you keep your weight in check.

References:

1.Eller LK, Reimer RA.A high calcium, skim milk powder diet results in a lower fat mass in male, energy-restricted, obese rats more than a low calcium, casein, or soy protein diet.J Nutr. 2010 Jul;140(7):1234-41.

2.Gilbert JA, Joanisse DR, Chaput JP et al.Milk supplementation facilitates appetite control in obese women during weight loss: a randomised, single-blind, placebo-controlled trial.Br J Nutr. 2011 Jan;105(1):133-43.

The Personality of Chronic Fatigue

Studies suggest that chronic fatigue may not only have the power to change a person’s personality but that certain personality traits may also put a person at higher risk of developing chronic fatigue. One recent study, in particular, examined the personalities of both people diagnosed with chronic fatigue syndrome and victims of medically unexplainable chronic fatigue not meeting criteria for chronic fatigue syndrome.

Study participants diagnosed with chronic fatigue syndrome had to have experienced medically unexplainable fatigue that limited their daily activities for at least six months with four of the following symptoms: headache, muscle pain, joint pain, sore throat, tender lymph nodes, significant impairment of memory or concentration, unrefreshing sleep, and unusual postexertional malaise.

The study, published in Psychotherapy and Psychosomatics, found that chronic fatigue syndrome victims scored higher in neuroticism, a measure of vulnerability to negative emotional states such as anxiety or depression, than both people without fatigue and people with medically unexplainable fatigue. Victims of medically unexplainable fatigue, however, still scored higher in neuroticism scores than people without fatigue. The researchers also found a reverse pattern with extraversion, one’s level of activity and sociability. Chronic fatigue syndrome victims were the least extraverted, and people without fatigue were the most extraverted. Although these results were solely correlational, in another study, chronic fatigue syndrome patients rated themselves as higher on neuroticism and lower in extraversion when they were ill then when they were well.

The reduced levels of extraversion may indeed be a result of fatigue rather than a risk factor for fatigue. It is possible that neuroticism is also either a result of the fatigue itself or a result of the same factors which are causing the fatigue. On a psychological level, chronic fatigue may lead to greater emotional burden due to feelings such as worry, frustration, and aloneness that victims of chronic unexplainable fatigue often experience. This emotional burden might, in turn, lead to higher neuroticism scores. Chronic fatigue could alse cause or be the result of an impaired physiological response to stress.

The two groups of participants with chronic fatigue had similar levels of agreeableness and conscientiousness which were lower than the scores of people without fatigue. Agreeableness is a measure of the tendency to be cooperative and compassionate towards others, and conscientiousness is a measure of such traits as being organized, planful, and self-disciplined. Whether agreeableness and conscientiousness decrease after onset of the chronic fatigue or are risk factors for chronic fatigue is unclear.

The study also found that a disproportionately large number of chronic fatigue victims had personality disorders, or maladaptive behavior patterns. Twenty-nine percent of people with unexplainable fatigue and 28 percent of people with chronic fatigue syndrome had at least one personality disorder. The most common personality disorder found among people with chronic fatigue syndrome was obsessive-compulsive personality disorder, a personalitydisorder involving a maladaptive obsession with perfection, rules, and organization. Maladaptive behavior patterns may in fact be risk factors for developing chronic fatigue. A past study followed sets of twins for 25 years and found that high stress and emotional instability, which are both causes and results of maladaptive behavior patterns, increased the risk for developing chronic fatigue-like illness.

Interestingly, another study examined patients with multiple sclerosis, a fatiguing illness which, like chronic fatigue syndrome, has an unknown cause, and found that the multiple sclerosis patients had about as many personality disorders as the chronic fatigue syndrome patients. Maladaptive behavior patterns thus may be risk factors for both chronic fatigue and multiple sclerosis.

Although about a quarter of people with chronic fatigue syndrome are disabled enough that they are either unemployed or receiving disability compensation, only about half of people with this disorder actually consult a physician about their illness. This can perhaps be partly attributed to the lack of knowledge among physicians about the nature of unexplainable chronic fatigue as well as to the limited number of current treatments. Understanding the personality behind chronic fatigue will bring the victims of medically unexplainable chronic fatigue one step closer to getting proper help.

References

Buckley L, MacHale SM, Cavanagh JT, Sharpe M, Deary IJ, & Lawrie SM (1999). Personality dimensions in chronic fatigue syndrome and depression. Journal of psychosomatic research, 46 (4), 395-400 PMID: 10340240

Johnson SK, DeLuca J, & Natelson BH (1996). Personality dimensions in the chronic fatigue syndrome: a comparison with multiple sclerosis and depression. Journal of psychiatric research, 30 (1), 9-20 PMID: 8736462

Kato K, Sullivan PF, Evengård B, & Pedersen NL (2006). Premorbid predictors of chronic fatigue. Archives of general psychiatry, 63 (11), 1267-72 PMID: 17088507

Magnusson AE, Nias DK, & White PD (1996). Is perfectionism associated with fatigue? Journal of psychosomatic research, 41 (4), 377-83 PMID: 8971668
Nater UM, Jones JF, Lin J-MS, Maloney E, Reeves WC, & Heim C (2010). Personality Features and Personality Disorders in Chronic Fatigue Syndrome: A Population-Based Study. Psychotherapy and Psychosomatics, 79 (5), 312-318 PMID: 20664306

Pepper CM, Krupp LB, Friedberg F, Doscher C, & Coyle PK (1993). A comparison of neuropsychiatric characteristics in chronic fatigue syndrome, multiple sclerosis, and major depression. The Journal of neuropsychiatry and clinical neurosciences, 5 (2), 200-5 PMID: 8508039

Taillefer SS, Kirmayer LJ, Robbins JM, & Lasry JC (2003). Correlates of illness worry in chronic fatigue syndrome. Journal of psychosomatic research, 54 (4), 331-7 PMID: 12670610

White C, & Schweitzer R (2000). The role of personality in the development and perpetuation of chronic fatigue syndrome. Journal of psychosomatic research, 48 (6), 515-24 PMID: 11033370

What Stem Cells Need to Survive in the Brain

Stem cells have been a hot and also controversial topic in research and in the media for the last few years, as they might be used in the future to repair injured tissue in such diverse disease like heart attacks, strokes, Alzheimer’s disease, Parkinson’s disease and many more. But, there are also unsolved ethical issues about their procurement. There is a lot of confusion about what is meant by the expression “stem cells” in the media.

In principal there are three kinds of stem cells:

    * Embryonic stem cells. These cells are present in an embryo. They have the ability to develop into all of the different tissues types within the embryo. To use these cells in research (or in the future for therapies) embryos have to be destroyed which makes the use of these cells highly controversial.
    * Adult stem cells. These are cells isolated from adult tissues that retain the ability to develop into a limited number of different kinds of cells. These stem cells are the cells that repair injuries in adult organs.
    * Induced stem cells. In theory, cells from any tissue can be reprogrammed to go back to a state in which they behave like embryonic stem cells. While this has been understood in principal, and there are many examples of them in research, the reprogramming involves the use of genes that can also cause cancer, so that the use of induced stem cells still is hampered by safety issues.

Many adult organs such as the liver contain adult stem cells which give these organs impressive regenerative capacity. Most areas of the adult brain, however, do not contain any stem cells, which is most likely the reason, why brain injuries are so hard to repair. In a recent publication, researchers from the University of California, Berkeley, showed that stem cells in the brain of juvenile fruit flies need two different signals to persist into adult life: a signal from insulin which acts as a growth factor and the disruption of signals that lead to programmed cell death (apoptosis). If these findings hold true for the survival of stem cells in mammalian brains, they could be used in the future to re-introduce stem cells into a injured or diseased area of an adult brain and keep them alive long enough for tissue repair to happen. Remaining stem cells could then be starved off the insulin to remove them and thus reduce the risk that they will develop into cancer cells later on. However, since the brain cannot act as a source for adult brain stem cells, these stem cells would need to be induced or embryonic stem cells. Even if ethical concerns are not considered, much research is still necessary before these stem cells are safe enough to be used in humans.

Reference

Siegrist SE, Haque NS, Chen CH, Hay BA, & Hariharan IK (2010). Inactivation of both Foxo and reaper promotes long-term adult neurogenesis in Drosophila. Current biology : CB, 20 (7), 643-8