DEAR DR. BLONZ: I prefer brown rice to white because of the fiber and additional nutrients, but I recently saw on a cooking show that brown rice must be refrigerated or else it will become rancid. In the markets, it is sold in sealed packages, but is often available for less from bulk bins. I want to save money, but not if it means the product is less safe. -- J.K. Deerfield, Illinois

DEAR J.K.: Brown rice is a whole grain, the seed of the rice plant. It contains a starchy endosperm pellet which, after the milling process, becomes what we know as “white rice.” Brown rice also has a seed germ surrounded by layers of fibrous bran, and in the plant, all this is surrounded by a protective husk.

Some of the oils that would nourish the growing seed are in the germ, but most are in the inner layers of the rice bran. The composition of the oil is 47 percent monounsaturated, 33 percent polyunsaturated and 20 percent saturated. (This is very similar to the profile of peanut oil.)

The unsaturated bonds are the part of an oil that are most susceptible to oxidative attack, so the more highly unsaturated an oil, the greater the risk of oxidation. Temperature is also a factor, with higher temps facilitating the oxidation reaction.

While there is a protective bran coat surrounding the whole-grain rice, it is not airtight. Then there is the fact that some of the oil is in the inner layers of the bran. All this explains why brown rice has a shelf life. Six months is often used, but there are manufacturers that put a “Best by” date on their product with an 18-month window from the date of manufacture.

When buying in bulk, I would make purchases consistent with a six-month use pattern, and I would opt for a store with a consistent flow of customers through the sold-in-bulk section. This makes it less likely that the products have been sitting in the bins for too long. A great practice is for the store to post “Best by” dates on the bulk bins themselves.

While refrigeration is not essential for brown rice, it can extend shelf life up to a year. Absent that, brown rice should be kept in a cool place in a well-sealed container, away from any source of moisture.

Rice oil, usually called rice bran oil, has many healthful attributes. As mentioned above, it has a good fatty acid composition, but it also has some other components that are receiving attention lately. The phytochemicals of note include the tocopherols and tocotrienols (vitamin E and its relatives), and certain triterpene alcohols, most notably a compound named gamma oryzanol. We are not talking large doses of any of these healthy compounds, here, but assets are assets. And this speaks to the big-picture healthfulness of opting for whole foods whenever possible.

Rice bran oil has a high smoke point (490 degrees F), which makes it good for cooking and frying. (Note: The smoke point is the temperature at which an oil will begin to break down. At or about that point, it tends to give off a bluish-grey, acrid-smelling smoke. Food cooked in such oil will have an “off” taste and be unhealthful to eat.)

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: The parents of our son’s soccer team bring the halftime refreshments. Typical items are water and orange slices. Recently a parent brought sweetened juice-flavored drink packets that he claimed would be better than water because they would drink more. It wasn’t a sports drink. An animated discussion followed. It has all been resolved, but I wanted to know your thoughts. -- M.V., Walnut Creek, California

DEAR M.V.: Our bodies work best within a narrow temperature range. There are automatic processes designed to conserve body heat when temperatures fall. If our core body temperature drops, we instinctively reach for some kind of cover or warm layer; if it drops too low, we begin to shiver, which is a purposeful activity that takes advantage of the heat given off by working muscles. But when we engage in continuous physical activity, it’s an excess of heat that becomes the issue. When that happens, the body’s largest excretory organ -- the skin -- assumes center stage.

Small blood vessels dilate near the skin’s surface to radiate heat into the ambient air. The skin will dampen with perspiration, purposely losing heat through the water’s evaporation. With a long, intense workout, electrolyte loss -- mostly sodium, but also potassium -- can become an issue. These minerals are normal elements in bodily fluids and flow out with perspiration, helping to explain the salty nature of skin that has been sweating.

Being overheated and short of water at the same time will place an extra burden on the heart: It’s forced to work harder to pump blood into the working muscles while also pushing fluids out to the skin surface to maintain the cooling process. If the body is not well-hydrated, it can begin to overheat, which can impact athletic efforts as well as the post-workout recovery. In the extreme, it can progress to a dangerous condition known as heatstroke.

Being well-nourished before the event, and resupplying what’s being lost in the process -- including water, energy and electrolytes -- can help during the workout and afterward. Plain water is fine for shorter efforts, such as those under an hour, and adding oranges provides flavor and a source of energy and nutrients from real food.

Sports drinks, which usually include sweet flavorings and some electrolytes, do encourage young athletes to drink more; this works well for those who play sports for extended periods of time, or who sweat excessively. That parent was correct in saying that some sugar can improve palatability and encourage consumption.

Beverages with added sugar are not cast in a positive light these days. But this is an exception, in that the muscles are at work. A small amount of sugar in a drink can help performance by helping maintain blood glucose, a key source of energy for muscles involved in athletic efforts. But “small” is the operative word here, as too much sugar slows absorption and leads to bloating and cramping.

Sweetened juice drinks not specifically designed as sports drinks can be too sweet, tend to contain artificial colors and flavors, and are unlikely to include electrolytes (check the Nutrition Facts label).

Water and oranges make practical sense for team events, such as your son’s soccer games. For individual athletes, I favor homemade sports drinks made from water and fresh fruits. My recipe can be found at: tinyurl.com/krkj8mx.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I see so much info online stating that canola oil, also called rapeseed oil, is not fit for human consumption, even after manufacturers address the toxic substances found in the original seed. This information says not to believe the canola proponents, insisting that this oil can cause blindness and other severe health problems. What are your feelings on this? Could this be the initial stage of another trans-fat-like trend -- something that people should avoid now, rather than waiting for all the chips to fall? -- R.H., San Francisco

DEAR R.H.: Misinformation on the internet can be like a pesky weed that keeps coming back. An already-debunked item gets found by a search engine and passed around anew, forcing a replay of the “Who do you trust?” game. I am glad that you wrote, because we each have the responsibility to exercise due diligence and find out the facts before we spread a bogus message of fear to others.

One way is to use a search engine, searching for the term in question, coupled with the term “urban legend” in quotes. Another is to limit your search to academic sites (those ending with .edu) or ones known to be evidence-based, such as berkeleywellness.com (I am on their editorial board). You can find Berkeley’s take on canola myths at tinyurl.com/yd865u5k.

Doing these searches for “canola” would have filled your pantry with more rational takes on the anti-canola nonsense. There is nothing wrong with canola oil; it does not contain, nor represent, an impending “trans-fat-like” dark spot on our food supply.

DEAR DR. BLONZ: You had recently reassured a reader who questioned the safety of cooking raw chicken in a slow cooker. I have another question about my son’s method for cooking chicken on the grill. He puts frozen chicken breasts on the hot grill and cooks them for about 15 minutes, turning frequently. He believes that the meat stays juicier than if he started with thawed pieces. I have eaten his grilled chicken, which did, indeed, seem to be quite moist. It appeared to be adequately cooked; at least, I did not suffer any ill effects. But is this a safe method of grilling? -- G.T., Pinole, California

DEAR G.T.: It can be safe if done carefully, but I don’t see the advantage here. Your son, the chef, has to walk the line between an overcooked, leathery outside and undercooked meat at the center. The thicker the piece of meat, the smaller the gap between these extremes. It’s all a matter of timing and a quick hand on the flipper. Constant attention is the name of the game. Lowering the grill temperature can provide more time for the heat to penetrate. It would also help if you had a good meat thermometer, and a grill that allows you to cook with indirect heat.

It is best to check the meat before you eat, checking the thickest part of the largest pieces. Undercooked chicken has a translucent quality to it. Care is also needed to avoid under- or overcooking when you start with poultry at refrigerator temperature, but it is much easier than starting with frozen. The USDA information page on freezing and food safety is at tinyurl.com/y9axm7qd. Their recommended minimum temperature for cooked poultry is 165 degrees F.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.