Island Sun Times

TOMATOES COULD BECOME MORE NUTRITIOUS

SCIENTISTS FOCUS ON COLOR TO IMPROVE BENEFITS

Research that has focused on making tomatoes disease resistant and easier to ship could also one day improve their taste and make them more nutritious, researchers say.

At Ohio State University, scientists are working with seeds from hundreds of tomato plants to learn more about how a tomato’s color can improve its nutritional value.

“Their appearance may be uniform, but as you dive down deeper you find they are quite different,” said David Francis, who breeds tomato seeds. “One gene can make all the difference.”

Jay Scott, a breeder at the University of Florida, has spent seven years studying how to improve flavor through taste tests and genetic analysis.

Scott said many factors influence taste, including the tomato’s balance of sugar and acid. He said producers first want a tomato that resists diseases and ships easily.

“I don’t think anybody’s against better flavor,” Scott said. “It’s a question of can they do that and provide everything else.”

Francis noted that breeding has created more diverse tomatoes, with most supermarkets today carrying grape, cherry, roam, beefsteak, cluster and hydroponic tomatoes.
The research also has made tomatoes that are less expensive to produce and purchase.

Advances include tomatoes that ripen after they’re picked, so they can survive on longer shipping routes; are firmer, to withstand bruising during shipment; and are more resistant to fungus and bacteria.

The biggest complaint about the modern tomato is lack of taste. Consumers say today’s varieties are not as juicy or sweet and they sometimes blame the breeders.

Taste tests show that some new varieties rate better than heirloom tomatoes despite a popular opinion that older is better, Scott said.

“I’m not sure if the public has been dumbed down so much that they don’t know what tomatoes are supposed to taste like,” he said.
The different shapes, colors and sizes created by breeding are mainly designed to catch the eye of the shopper, a development that has come at a time when tomato consumption has risen steadily in the last four decades.

Americans eat about 92 pounds of tomatoes annually in everything from ketchup to pasta sauces and salsa, according to a report from the U.S. Department of Agriculture released in 2000. The report attributed the climb to interest in Italian and Mexican food and awareness of the tomato’s health benefits.

Tomatoes are an excellent source of lycopene, which fights some types of cancers, including prostate cancer, and beta-carotene, or pro-vitamin A, which is important for the eyes.

Francis said not enough is known to say whether new varieties of tomato, such as the cherry tomato, are more or less nutritious.
One way to develop a more nutritious tomato would be to solve what causes the fleshy part of some tomatoes to turn yellow, researchers say.

Ohio State student researcher Audrey Darrigues hopes the wild tomatoes in the university’s greenhouse will provide a resistant gene that will ward off the color disorder.
“Color is a very important element in the tomato,” she said.

Dear Dr. Mirkin:

If cooking destroys nutrients, shouldn’t we eat only raw foods?

Raw fruits and vegetables have many phytochemicals that help to keep you healthy, but those frozen soon after harvest may have higher levels of phytochemicals than those that take days or weeks to be transported to your supermarket. Frozen and cooked vegetables can be just as healthful as fresh ones.

Many people believe that fresh fruits and vegetables always contain more nutrients than cooked ones, but cooked carrots have higher levels of antioxidants than fresh carrots. Cooking carrots in the presence of a small amount of oil or butter increases the amount of two antioxidants called beta carotene and phenolic acid. Cooking also increases the amount of lycopene you get from tomatoes. Cooking breaks the plant cells open to increase the absorption of these antioxidants and other beneficial plant chemicals. Adding a little oil or butter increases absorption of fat-soluble chemicals.

Some vitamins may be lost in cooking, but you still get plenty if you have a reasonably varied diet. The enzymes in food that are destroyed by heat are of no use to you; you make your own enzymes for digestion of your food. Most of the nutrients in your food (minerals, proteins, fats, carbohydrates) are not destroyed by heat, and many common foods are unpalatable or unsafe if they are not cooked. I recommend eating the widest possible variety of fruits and vegetables, raw or cooked, and fresh, frozen, canned or dried.

This health info is provided with the permission of Dr. Gabe Mirkin, M.D. Dr. Mirkin has practiced medicine for more than 40 years and is board-certified in four specialties: Allergy and Immunology, Sports Medicine, Pediatrics and Pediatric Immunology. Visit www.drmirkin.com.

Eating Eggs Okay for the Healthy Heart

In healthy adults, consuming two eggs daily for 6 weeks does not have a harmful effect on endothelial function – an aggregate measure of cardiac risk – nor does it increase cholesterol levels, research shows. This suggests that eating eggs may not be as bad for the heart as many people contend.

Because of the cholesterol content of eggs, limiting their consumption is generally recommended as a way to reduce cardiac risk, say the investigators. However, emerging evidence suggests that dietary cholesterol has a much smaller effect on this risk than does saturated fat.

Dr. David L. Katz and colleagues, from the Yale Prevention Research Center in Derby, CT, evaluated the effect that egg or oat consumption had on endothelial function in 49 healthy adults. Poor endothelial function is suspected of being an early sign of artery disease.

During the study period, flow-mediated dilation (FMD), a measure of how well the endothelium, the lining of the blood vessel, acts to keep blood moving by widening the vessel, was stable in both groups and did not differ significantly between them.

Egg intake did not cause an increase in either total or LDL cholesterol levels. By contrast, oat consumption significantly lowered levels of both.

“Usually, people are saying ‘you can’t eat this or you can’t eat that,’” Katz told reporters. “It’s nice to have findings that exonerate a food, like eggs.”

Nevertheless, this may not be the case in patients who already have elevated lipids, a group at increased risk for endothelial dysfunction. “We’ve now started a study of adults with hyperlipidemia,” Katz added, “to determine if the current results apply to this group as well.”

The study was funded, in part, by the American Egg Board.
SOURCE: International Journal of Cardiology March 10, 2005.

Forget the Breath Mints,

EAT YOGURT INSTEAD

New study findings suggest that yogurt may be another weapon in the battle against bad breath.

“Yogurt intake may improve oral hygiene, namely tongue-coating bacteria and halitosis,” study author Dr. Kenichi Hojo of Tsurumi University in Yokohama, Japan told reporters.

He and his colleagues found that study participants who consumed 90 grams of yogurt twice a day for six weeks tended to have lower levels of hydrogen sulfide and other volatile sulfide compounds that contribute to bad breath.

They presented their findings during the 83rd General Session of the International Association for Dental Research held in mid-March in Baltimore.

Previous studies have also pointed to the benefits of regular yogurt consumption. One report found that women who ate yogurt at least three times a week were less likely to have recently developed a urinary tract infection than women who ate such probiotic bacteria-containing foods less than once a week.

Other studies have found that yogurt plays a role in the prevention and management of bowel disease and other gastrointestinal conditions. Furthermore, another study showed that people who eat yogurt regularly might have a lower risk of cavities.

Hojo and his team also have not yet determined how or why yogurt consumption had such an effect on halitosis. “In the future,” he said, “I will focus on the mechanism of that effect.”

In fact, high caffeine consumption only seems to cause bone loss in elderly women who don’t get enough calcium. As long as elderly women get the recommended 1,200mg of calcium a day, it should be safe for them to drink up to 300mg caffeine, or about 18 ounces of coffee or its equivalent. Caffeine does not appear to adversely affect the bones of premenopausal women at all.

At one time, some consumer advice claimed that caffeinated drinks deplete the body’s fluid levels because caffeine increases urination. More recent research shows that a person’s fluid balance is not significantly affected by a moderate use of caffeine.

Bad for High Blood Pressure?
Since some studies suggest that two to three cups of coffee can raise blood pressure around 10 points, many physicians limit people with high blood pressure to 200mg (two six-ounce cups of coffee) per day or less. However, regular caffeine consumers may develop a caffeine tolerance that prevents blood pressure elevations, according to other studies.

The greatest reason people drink caffeinated beverages is to increase their energy and alertness. Studies show that 100 to 200mg of caffeine (about 1 to 2 cups of regular coffee) are enough to achieve these results. When caffeine consumption climbs to 250-700mg per day, people may experience nausea, headaches, sleep difficulties or increased anxiety. People may have heart palpitations with more than 1,000mg.

Some day, there may be individual advice for everyone about how much caffeine they can safely consume. Research, however, is only beginning to explain why caffeine’s influence varies so much. For instance, genetic differences in the enzymes that metabolize caffeine cause some people to process caffeine quickly, thus reducing their exposure to caffeine’s effects sooner. There are also inherited differences in cell receptors.

For now, you should stick to moderate amounts of caffeine. For an adult, that means no more than 300mg daily, which is three 6-ounce cups of coffee, four cups of regular tea, or six 12-ounce colas.

A person may want to have even less, depending upon how caffeine affects their sleep, blood pressure, digestive system and overall well-being. Children, nursing mothers or pregnant women, on the other hand, should have much less because caffeine will have stronger effects in smaller bodies.

WHAT’S IN THAT WEIGHT
LOSS SUPPLEMENT?

Many common ingredients pose potential health risks

Americans spend billions of dollars each year on weight-loss supplements. Although we wouldn’t buy a car or a dinner without knowing some details, many who purchase these supplements have no idea what is in them, or what independent reports say about their safety and effectiveness.

Even though the Food and Drug Administration has charged some companies with using banned ingredients, and the Federal Trade Commission has successfully prosecuted marketers who made illegal claims, the same products, or copycat versions, still remain available.

Some weight loss supplements contain ingredients meant to suppress the appetite. Caffeine and its herbal counterparts, guarana, bitter orange and yerba maté, as well as ephedra (ma huang), fall into this category. Animal studies suggest that they may slightly suppress the appetite, but the limited human studies lasted only a few months. All these ingredients are nervous system stimulants, so they commonly produce side effects like headaches, insomnia, elevated blood pressure and heart palpitations.

Deceptive Labeling
Product labeling can be deceptive: Weight-loss supplements labeled ephedra- or caffeine-free may contain other ingredients from the list above, which may pose the same health risks. Although ephedra (ma huang) has been banned by the FDA, you may still see it in some supplements. In a summary of more than 50 trials, this substance created a 2 to 3.6-fold increase in the risk of psychological, heart and digestive system problems.
Supplement manufacturers claim other ingredients aid weight loss by speeding up the metabolism. For example, EGCG, a phytochemical found in green tea, is being studied for its potential to reduce cancer risk. Some initial studies suggest it could slightly increase the rate at which calories burn. Now it can be found in many weight-loss supplements and “weight-loss vitamins.”
However, since there are only extremely short initial studies so far, the body might adapt to EGCG, reducing its effect over time. In addition, the weight loss benefit seen with EGCG amounts to about 60-70 calories a day. This small difference is more likely to help prevent a gradual yearly weight gain than reverse excessive weight gain. Third, the effect of EGCG appears to depend on the dose. Supplements with amounts of 30-40mg of EGCG, which is commonly seen in these products, may not have the same effect as a dose over 250mg used in the studies.

Few Significant Effects
Supplements may also contain ingredients that manufacturers state will block the absorption of fat or carbohydrates. Chitosan is a common example, and a few preliminary studies made it appear promising. However, several controlled studies found that chitosan had no significant effect on fat absorption. In the most recent study, men would need seven months to lose one pound of body fat. There was no fat loss for women.

Another group of ingredients are said to increase the feeling of fullness and decrease eating. Guar gum appears safe for this purpose, but 11 well-controlled studies show it has no benefit for weight loss. Psyllium can help control blood sugar and blood cholesterol, but studies do not support its reputed ability to reduce eating and assist weight loss.

There are more than 50 individual supplements and 125 combination products now available for people who want to lose weight. Yet a Harvard Medical School review of these products that set standards for product quality, safety and effectiveness concluded that none of them met all three standards.

Future research may identify some safe and effective ingredients for weight loss, but for now it seems smarter to invest in walking shoes, a gym membership, or healthier food instead.

Dear Dr. Mirkin:

Are colon cleansers necessary for good health?

No. The latest research shows that regular use of laxatives or colon cleansers can harm you by blocking the absorption of nutrients from your colon into your bloodstream. There are two absorption systems in the digestive tract. First, the food that you eat passes from your stomach to your upper intestines, where secretions from your stomach, liver, intestines and pancreas break down carbohydrates, fats and proteins into their building blocks. Only these building blocks – basic sugars, amino acids, fatty acids and glycerol – are absorbed from your intestines into your bloodstream. The food that is not broken down cannot be absorbed, so it passes to your colon.

Bacteria in your colon convert undigested starches into short-chain fatty acids that heal ulcers, prevent colon cancer and other cancers, reduce the pain of arthritis, prevent the arterial damage of arteriosclerosis, lower cholesterol, and even lower high blood pressure. Regular use of colon cleansers or laxatives reduces the absorption of these beneficial short-chain fatty acids.
People who recommend these products claim that they remove old feces that get stuck and rot in your colon, but this is ridiculous. Undigested waste products stick together by a physical process called surface tension, so they cannot pass by older stool. Colon cleansers not only have not been shown to help you, they can harm you by depriving you of nutrients that are necessary for health.

This health info is provided with the permission of Dr. Gabe Mirkin, M.D. Dr. Mirkin has practiced medicine for more than 40 years and is board-certified in four specialties: Allergy and Immunology, Sports Medicine, Pediatrics and Pediatric Immunology. Visit www.drmirkin.com