Staying Healthy Archive

Choline may labor in obscurity — if you haven't heard of it, you're in the majority — but it's an essential nutrient that does important work in the body.

And now there's some research that lends some credence to claims that the nutrient may be something of a "brain food" that fends off cognitive decline in old age.

Q. Is it true that you can get a tingling feeling from taking too much vitamin B₆?

A. Vitamin B₆ is a water-soluble vitamin that's involved in over 100 different enzyme reactions in the body, many of them involving protein metabolism. Adults need just a small amount — less than 2 milligrams (mg) a day — and a wide variety of foods contain B₆, so a reasonably balanced diet provides most people with all they need.

Q. I've always enjoyed fruit with my breakfast cereal. Over the past year, my family seems to have shifted from bananas and strawberries to a steady diet of blueberries "because they'll keep you healthy." I love blueberries, but I do miss variety. So I want to know if blueberries really are good for our health.

A. Native to North America, blueberries have been popular here ever since our earliest days. Their flavor and color justify this popularity, but as people have become interested in the health benefits of "functional foods," blueberries have become as prized for their chemicals as their taste — and production has soared to over 200 million pounds a year.

Q. I recently brought a nice bouquet of flowers for my elderly aunt, who was hospitalized for a broken hip. She was quite depressed, and I thought the flowers would brighten her day, particularly since she is a dedicated gardener. To my surprise, the hospital had a policy against bedside flowers, and I could not deliver my gift. What's behind this policy, and is it reasonable?

A. The main worry is infection. Flowers harbor bacteria, and so does the water in a vase. But the presence of bacteria does not automatically translate into the risk of infection. Bacteria, after all, are everywhere; in fact, the human body is home to 10 times more bacterial cells than human cells. Most of these microbes are quite wimpy and pose little risk to healthy individuals. But some hospitalized patients are particularly vulnerable. That's why fresh flowers are typically excluded from the rooms of patients with impaired immune systems; cancer chemotherapy patients are a prime example.

Q. I was very interested in your article on how obesity seems to spread through social networks. I understand that it's a new type of research, but I wonder if it might have overlooked the possibility that obesity might also be spread by an actual virus.

A. Obesity in America has increased steadily since 1960, with a particularly dramatic increase between 1980 and 2010. Because genetic changes cannot explain the obesity epidemic, scientists have considered other causes. At least five animal viruses can cause obesity, but these infections cause many serious, often fatal abnormalities in addition to excess body fat. Only one human virus, adenovirus 36, has been linked to obesity in people, but the link is indirect: individuals with evidence of previous adenovirus 36 infection are more likely to be obese than people who have never been infected. But even if it's confirmed, this type of research can establish an association but not a cause-and-effect relationship between the virus and obesity.

Scientists have long known that certain nutrients are essential for brain development and function. There's also evidence that good nutrition can help stave off cognitive decline in older people. But studies of single nutrients have largely been disappointing, and research on the relationship between overall diet and brain function generally relies on food frequency questionnaires, which can be misleading because of faulty memories and the inability to take account of nutrient absorption. Now researchers have conducted the first study using nutrient biomarkers and brain imaging to analyze the effect of diet on cognitive function and brain volume. Their main finding is that higher blood levels of omega-3 fatty acids and vitamins B, C, D, and E are associated with better memory and thinking in older people. The study was published in Neurology (Jan. 24, 2012).

The study. Researchers at Oregon Health & Science University measured the blood levels of 30 nutrients in 104 people (64 of them women), average age 87, who were participating in the Oregon Brain Aging Study. For the Neurology study, the scientists administered tests of mental function (including memory, learning, and spatial relations), and, for a subgroup of 42 participants, used MRI imaging to measure cerebral brain volume.

Departures from the familiar yellow are often harmless but should be discussed with a doctor.

Most of the time, urine is a pale-yellow color because it contains urochrome, one of the substances produced when hemoglobin gets broken down. Hemoglobin is the protein in red blood cells that sticks to oxygen so it can be ferried around the body.

Occasionally, though, urine turns a very different color. Men may notice the change as their urine enters the toilet bowl or urinal. Women may be more likely to observe it after wiping. Seeing red or orange instead of the usual yellow can be alarming, especially if there are also symptoms like a burning sensation or pain with urination. The alarm may be justified: an abnormal urine color can be an early sign of a serious medical condition. To be on the safe side, it should be discussed with a doctor or another clinician.

Regular marijuana use does not appear to have a negative effect on lung function.