As one of its special reports titled "Machigai darake no kenko joshiki" (error-strewn common wisdom about health), Shukan Shincho (Sept 13) runs five articles that examine the phenomenon of "natsu-bate" (weariness from the prolonged heat).
The first is a warning over acute diabetes that develops through overconsumption of sweetened soft drinks -- referred to by some as the "PET bottle syndrome."
This is not to say that getting sufficient liquids is a mistake. Indeed, one of the characteristics of "natsu-bate," says Dr Tsuyoshi Kawamura, is chronic dehydration. If neglected, this may cause the pulse rate to increase and blood pressure to rise, and if prolonged, may also lead to hardening of the blood vessels.
"Capillaries in the skin account for about 1% of body mass," neurologist Shoichi Sanada tells the magazine. "When perspiration causes the amount of water in the body to decline, the capillaries dilate, resulting in insufficient blood circulation. The brain and heart demand blood, so the insufficiency might occur in other organs such as the duodenum or stomach, leading to digestive problems."
Along with water, people who imbibe soft drinks are going to absorb a lot of sugar," notes Dr Miyuki Kurachi. "A 500ml PET bottle is about 10% sugar -- the equivalent of 17 or 18 commercially sold sticks of sugar (of the type provided in coffee shops). Isotonic sports drinks contain about one-half that amount.
"This is one reason why blood sugar levels tend to show a rise around the end of summer. Even among middle- and high-school students, quite a few develop acute diabetes due to the PET bottle syndrome."
Internist Kazunori Koyama concurs. "Due to heavier consumption of soft drinks, ice cream and fruits, the number of new cases of diabetes jumps from late August through September." He advises anyone who notices weight loss, dry throat and frequent urge to urinate to seek medical advice.
Diabetes is bad news, since among other things, it leads to increases in cardiac and cerebral infarctions. Dr Zohei Kaku suggests diluting sports drinks at a 1:1 ratio with water and adding a teaspoon of table salt. He adds that gulping it down rapidly won't relieve chronic dehydration.
"Drink slowly, ingesting it at the same rate you'd imagine for an intravenous drip," he advises.
After 40 or more days of constant exposure to air conditioning, people should also be concerned about the so-called "disuse syndrome."
Think of astronauts, who during extended periods of weightlessness in space are unable to make full use of their muscles. Upon returning to Earth, they notice that unused muscles have become atrophied.
A similar phenomenon can be found among the couch potatoes who loaf around the house all summer. "Among some men in their 40s and 50s, as autumn arrives they start going out again and suffer from falling accidents," warns Dr Toshihiko Iwamoto.
The functions of the bones and joints decline. Along with increasing their physical activity, people should consume more milk and yogurt to boost their calcium and also eat eggs and other sources of vitamin D.
Dr Kotaro Yokode observes that autonomic nerve function becomes degraded through consistent exposure to air conditioning.
"Compared with half a century ago, diabetes has increased several-fold. The rate of occurrence overlaps perfectly with the increase in automobile ownership," says Yokode. "People who ride in taxis because of the hot weather and who spend their summer in front of the air conditioner need to be careful. To prevent lifestyle diseases, people should walk at least 8,000 paces per day. This will burn off body fat and sugars and blood sugar levels will decline."
"The worst thing you can do in terms of endangering good health and longevity is to laze about all day doing nothing," warns director emeritus Hideo Yamanaka of the Toranomon Hibiya Clinic -- who himself is a hale and hearty 85 years old.© Japan Today