Paging Dr. Frischer - Medical facts and factoids

Let’s focus on ten more of those always fascinating medical facts and factoids.  Every day, my patients bring more to me.  Are they true or false? Is it safe to follow the “five-second rule”? Let’s think about this logically. If there are harmful germs on the ground, does it take five entire seconds for them to attach onto your food? Despite what we have heard, there is no such thing.  Further, even washing the food immediately will not necessarily clean off all of the bacteria. Of course, the key question is whether the item picks up enough pathogens to worry about.  That depends on the food item and the surface it lands on. So let’s conclude with: When in doubt, throw it out!

Does eating too much candy cause cavities?  The answer is yes, but not directly.  Sugar doesn’t hurt teeth, but bacteria sure do. Sugar in the mouth feeds bacteria, which in turn produce acid, which then breaks down the enamel in the teeth, allowing cavities to form.

Are carrots good for our eyesight? Yes they are. They contain high levels of vitamin A, which helps the retina to function, promoting better eyesight and night vision. Other foods with lots of vitamin A include liver, butter, sweet potato, pumpkin, broccoli, kale, spinach, and other leafy vegetables.

Must we wait 30 minutes after eating to go for a swim?  There is actually no medical evidence to support this for casual exercise. The theory is that we will get cramps because the act of digestion demands increased blood flow to the stomach and intestines, leaving too little blood flow to the muscles.  At issue here is gentle verses vigorous exercise. When eating before exercise, I always recommend eating foods that give quick energy and are easily digested. Still, even after a heavy meal, a walk is always nice!

Is drinking eight glasses of water a day good for our health? This is a long-held belief by many in the health field, but has not been substantiated. A higher fluid intake is critical to reducing kidney stone formation, and a lower intake will reduce the risk of congestive heart failure, so the correct answer is…it depends. In general, my answer is to drink enough to keep your urine a light yellow color.

Can sitting in hot water affect a man’s ability to reproduce? When we think about the male anatomy, the answer seems obvious. The scrotum is actually a clever method of keeping sperm outside of the body and consequently at a lower temperature. Higher temperatures impede sperm development. If you are a male interested in fathering a child, avoid temperatures above 100 degrees. Do NOT, on the other hand, consider long periods in the hot tub a reliable form of birth control!

Do we shrink as we age? As we are all well aware, a number of things change with age.  Among them are hearing, vision, memory…and of course, men’s hairlines. Height is certainly included on that list as well.  Men can lose up to an inch in height between the ages of 30 and 70.  Women may lose two inches during that same time period. There is further loss in height after the age of 80 for both genders. Where and why?  The cartilage between our joints gets worn out and causes the spinal column to compress. We can slow this process by maintaining physical activity, not smoking, drinking alcohol moderately, limiting caffeine intake, and consuming a nutritious diet, including foods rich in calcium and vitamin D (dairy, fruits and vegetables).

Does eating an apple a day keep the doctor away?  Not that I would wish for an empty waiting room, but this is an age-old belief that refuses to go away. Let’s break it down.  Apples are a great source of fiber, they do help maintain good colon health, are filling, and useful in weight control.  They are a great alternative to junk food snacks.  They do not, however, prevent infections, or a host of other conditions.  So, go ahead and eat an apple every day - and see your doctor on a regular basis.

Do children who eat lots of sugar become hyperactive?  There is no hard evidence that a high sugar diet directly induces hyperactivity. Nonetheless, a high sugar diet can cause a long list of other problems including obesity and diabetes, so regardless of a link, let’s do our very best to help children avoid sugar.

Finally, does pulling out one gray hair cause more to grow in its place? Those of you with a few gray hairs will be happy to hear that this is simply not true. Hair turns gray or white when the pigment cells in a hair follicle die. When you pluck that one gray hair from the scalp, a new single gray hair will likely grow in its place, since there is only one hair per follicle. Do be aware, however, that if you encounter a gray hair that you feel must go, repeated plucking over time may cause damage or even infection to that hair follicle.  It is best to cut the hair instead.

Dr. Alan Frischer is former chief of staff and former chief of medicine at Downey Regional Medical Center. Write to him in care of this newspaper at 8301 E. Florence Ave., Suite 100, Downey, CA 90240.

**********

Published: April 10, 2014 - Volume 12 - Issue 52