Tuesday, December 30, 2008

Farmed Tilapia and Catfish are More Like Chicken than Fish

Fish are heart-healthy foods because they usually have high levels of omega-3 fatty acids and low levels of omega-6's.. However, researchers at Wake Forest University School of Medicine show that farm-raised tilapia and catfish contain less than one-eighth the amount of omega-3's found in farmed salmon or trout. The tilapia and catfish also had much larger amounts of omega-6 acids than salmon or trout. The ratio of omega-6 to omega-3 in tilapia and catfish averaged 11 to one, about the same as that of chicken (Journal of the American Dietetic Association, December 2008).

A crucial part of a healthful diet is the ratio of omega-6s to omega-3s. Your immunity is supposed to be good for you by killing gems before they can harm you. However, if your immunity stays active, it starts to attack your own body to increase risk for heart attacks, certain cancers and even asthma and some types of arthritis. Omega-3 fatty acids produce prostaglandins that turn down your immunity to help prevent inflammation and the health problems it can cause. Omega-6 fatty acids promote inflammation. A major explanation for the high heart attack rate in North Americans is the high ratio of omega-6s to omega-3s in the diet that contains lots of omega-6s from vegetable oils and low amounts of omega-3's found in fish and seeds.

Few species of fish can grow and thrive on a diet of corn and plant oils. Salmon, trout and most other farmed fish must be fed fish meal and fish oils, which are good sources of omega-3's. However, tilapia and catfish can be raised on corn alone. Since corn-fed tilapia are inexpensive and abundant, they are the fifth most popular fish in America and are widely used for fish sticks, fish burgers and artificial crab (surimi). These are perfectly good foods, but to get the full benefit of omega-3's in seafood, choose oily fish such as salmon, trout, tuna, sardines, anchovies, mackerel or herring. More on omega-3's

Friday, December 26, 2008

Nuts Combat Metabolic Syndrome (Syndrome X)

Nuts are concentrated sources of fat and calories, but they are high in monounsaturated fats which are healthful. A new study from Spain shows that adding nuts to a Mediterranean diet helps to reverse Metabolic syndrome, defined as having three or more of the following: 1) abdominal obesity, 2) high triglycerides, 3) low HDL (good) cholesterol, 4) high blood sugar and 5) high blood pressure. More than 20 percent of North Americans have metabolic syndrome and are at high risk for diabetes. Many of these people will die prematurely, usually from a heart attack.

This study involved 1,200 men and women from 55 to 80 who followed one of three diets for one year. Sixty-one percent of the study group had metabolic syndrome. The first group followed a low-fat diet that reduced all types of fats. The second group ate a Mediterranean diet with at least four tablespoons of olive oil a day. The third group ate the Mediterranean diet with extra nuts. At the end of the study all three groups had improved, but those eating nuts had far fewer of the factors that make up metabolic syndrome. Most did this without restricting calories or losing weight, but they were able to reduce belly fat and lower cholesterol and blood pressure (Archives of Internal Medicine, December 2008).

Fats are classified by their chemical structure into saturated, polyunsaturated and monounsaturated. Monounsaturated fats found in olives, avocados and many nuts and seeds help to prevent heart attacks. Before the bad LDL cholesterol can damage arteries, it must first be oxidize in your bloodstream. LDL cholesterol made from monounsaturated fats is highly resistant to oxidation, so it helps to prevent damage to arteries that can lead to a heart attack. The diet I recommend includes plenty of the good fats found in nuts, seeds, beans, whole grains, olives, avocados, fish and shell fish.

Wednesday, December 17, 2008

Understanding Delayed Muscle Soreness

If you exercise properly, you are supposed to work hard enough to damage your muscles so they feel sore on the next day. This is called delayed-onset muscle soreness. You should then exercise at reduced intensity for as many days as it takes for the soreness to go away.

An article from St Mary’s University College in New Zealand reviews scientific studies on exercise-induced muscle damage (Sports Medicine, December 2008). When muscles feel sore from exercise, they are swollen and leak proteins from inside their cells into the bloodstream, and they cannot generate their usual force. You really have no choice. You must put far less pressure on sore muscles or you will injure them, delaying recovery and your ability to exercise intensely again.

Sore muscles heal faster if you take the next day off, but exercising gently during recovery will make your muscles more fibrous so they can withstand more pressure when you take your next intense workout.

Eating foods with protein and sugar within four hours after you finish a hard workout helps muscles recover faster. The sugar raises insulin levels which helps to drive protein into the muscle cells to promote healing.

Aspirin and nonsteroidals such as ibuprofin may help reduce muscle soreness, but they can delay healing. Stretching and massage make your muscles feel better but there is little evidence that they make you recover faster. Studies of electrical muscle stimulation and cold therapy (ice packs) are so inconsistent that most exercise researchers do not recommend them. On the other hand, virtually everyone agrees that each bout of intense, muscle-damaging exercise followed by reduced intensity exercise makes muscles stronger.

Sunday, December 14, 2008

Cold weather may increase risk for various health problems

Nobody really knows why, but recent research show that sudden drops in environmental temperature are associated with increased risk for disease and death (American Journal of Epidemiology, December 2008).

Researchers at the University of Athens in Greece studied people in 15 European cities. They plotted the average temperature for that day against the number of deaths in that city and showed that a 1?Centigrade decrease in temperature from one day to the next is associated with a 1.72 percent increase in daily heart attack deaths, a 3.30 percent increase in respiratory deaths, and a 1.25 percent increase in stroke deaths.

This study does not tell you to move to warmer climates because those who live in warmer cities are far more susceptible to dying from sudden drops in temperature. This study does suggest that you should try to avoid chilling and cold weather if you suffer from heart, lung or blood vessel disease.

Tuesday, December 09, 2008

Exercisers Age Better

Athletes who compete into their eighties suffer few medical problems, but those who lapse into inactivity regress toward the general population norms for fitness, weight control and health problems, according to a study in the Clinical Journal of Sport Medicine (November 2008).

People who compete into later life in sports such as running or cycling can maintain their competitive edge into their eighties. Each muscle is made up of millions of muscle fibers. With aging, particularly after age 50, you lose muscle fibers so you become weaker. You cannot slow the loss of muscle fibers, but you can compensate for the loss of fibers by increasing the size of each remaining muscle fiber with regular vigorous exercise. If the results of this study can be extended to all regular exercisers, you can also expect to live longer and suffer fewer health problems than your non-exercising peers.

Monday, December 08, 2008

Eggs Increase Risk for Diabetes?

Research from Harvard Medical School suggests that eating an egg a day may increase a person’s risk for developing diabetes (Diabetes Care, December 2008). This is the first large study to support the general belief that eating eggs frequently may harm you. However, animal studies have failed to show any association between eating eggs and diabetes, and the authors of this study did not offer any explanation for the increased risk.

The authors studied 20,703 male physicians without diabetes from the Physicians' Health Study (1982-2007) and 36,295 non-diabetic female health professionals from the Women's Health Study (1992-2007). The men were followed for 20 years and the women for 11 years. Men who ate seven or more eggs per week were 58 percent more likely to develop type 2 diabetes, and women eating a similar amount were 77 percent more likely to become diabetic than those who did not eat eggs. Risk for diabetes was lower when fewer eggs were eaten (9 percent for one egg per week, 18 percent for two to four eggs and 46 percent for five to six eggs).

This was a self-reported study so it is possible that the people who eat eggs also have other habits that increase their risk. For example, they may be more likely also to eat meat, which may increase diabetes risk, as I reported in the November 9 issue of the eZine.

An egg is a very rich source of saturated fat (1.5 grams) and cholesterol (200 mg), but adding three eggs per day to the average Americans’ diet does not raise cholesterol levels. Cholesterol in eggs has very little effect on blood cholesterol levels in healthy adults. Several studies show no relationship between eating eggs and increased risk for heart disease or stroke and most people can eat one egg a day without increasing heart disease risk. (Journal references for these studies) I eat eggs 2-3 days per week and will continue to do so unless more persuasive research comes along.

Thursday, December 04, 2008

Eating Before Exercise OK for Most People

Many people believe that exercising right after you eat will cause stomach cramps, but that doesn't usually happen. Whenever your stomach fills with food, its muscles contract and require large amounts of blood. When you exercise vigorously, your heart pumps large amounts of blood to your skeletal muscles. If your heart is not strong enough to pump blood to both your stomach and your skeletal muscles, blood is shunted from your stomach muscles, the muscles lack oxygen, lactic acid builds up in muscles and they start to hurt. However, most people can exercise after eating without suffering cramps because their hearts are strong enough to pump blood to both their exercising muscles and their stomach muscles.

Some researchers believe that you shouldn't eat sugar before you exercise because it will cause your blood sugar level to rise and your pancreas to release insulin, which will cause your blood sugar to drop too low so you will feel tired during exercise. However, the major cause of tiredness that you feel in your muscles during exercise is lack of stored sugar in muscles. Taking any extra calories before and during exercise helps to preserve the sugar that is stored in muscles and help you to exercise longer. If you are going to exercise for more than an hour, eat or drink anything you like before and during your exercise. Most people will not get stomach cramps while exercising, no matter what or when they eat.