6 Quick Heart-Healthy Habits

Cutting your risk for cardiovascular disease doesn't necessarily require a total lifestyle overhaul. Many heart-healthy habits are surprisingly easy to adopt.

"There are plenty of small changes you can make in your day that can have a big impact on your heart health," said Dr. Richard Becker, a professor of medicine at Duke University Medical Center, and a spokesman for the American Heart Association.

Here are six quick fixes that can help your heart:

Quick Fixes to Benefit the Heart

Do Your Ohm Work

Research supports the idea that yoga can help reduce such cardiovascular risks as insulin resistance, high blood pressure and blood vessel inflammation. For the 2.7 million Americans diagnosed with atrial fibrillation in which the heart's upper chambers flutter randomly instead of contracting normally, yoga may be especially helpful.

A new Washington University School of Medicine study found that AF patients who did yoga in addition to taking medication reported half the number of heart quivers compared with patients who only took meds. While not a cure for AF, regular yoga practice -- at least twice a week for three months -- also improved the subjects' heart health by easing anxiety levels and significantly lowering resting heart rates.

"It doesn't necessarily have to be yoga. Any way you reduce stress is good for the heart," Becker said.

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Quick Fixes to Benefit the Heart

Be a Friend

Absence makes the heart grow fonder, but togetherness strengthens heart health.

Having a close relationship with another person, be it a friend, lover or relative is so heartwarming it can halve the risk of a heart attack in someone who has already had a heart attack, a 2004 heart study suggests. And one State University of New York at Oswego investigation found that blood pressure dropped when one spent time with a spouse or partner.

Becker pointed out that whether in pairs or in groups, engaging with other people does seem to help the heart, though it's not exactly known why.

"It could be that secure social ties lead to better health habits and less depression," he said. "It could also be due to neurological and hormonal changes that lessen stress and anxiety."

Toxic associations do the heart no favors, though. In one 12-year study, British civil servants in bad relationships were 34 percent more likely to have heart attacks or heart trouble than those in happier relationships.

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Quick Fixes to Benefit the Heart

Indulge in the Dark

It's no accident that chocolate hearts are associated with Valentine's Day.

Dark chocolate contains high concentrations of cocoa. Intake of this anti-oxidant rich substance appears to relax blood vessels, lower blood pressure and control blood sugar.

Just don't get carried away. Becker said that a single 1.5 ounce serving of the sweet stuff will bestow all its heart-healthy benefits without adding an overabundance of fat, sugar or calories to your diet.

Quick Fixes to Benefit the Heart

Take a Break

When researchers from the University of South Carolina analyzed the daily movement patterns of adult men, they found that those who were the least active throughout the day had a 64 percent greater risk of dying from heart disease compared with men who reported living a less sedentary lifestyle.

Spending too much time rooted to the couch or chair may pack on unhealthy fat around the heart and lead to less desirable levels of cholesterol, blood sugar, triglycerides and waist size, research suggests. This appears to be true even for people who maintain a regular exercise routine.

However, taking even short breaks can counteract some of sitting's negative impact on heart health, one European Heart Journal report found. Becker agreed.

"Taking advantage of opportunities to move has benefits that are well documented," he said. "Any effort is good, and all efforts count."

Quick Fixes to Benefit the Heart

Have a Hearty Salad

Amp up salads with good-for-the-heart ingredients. Start with a base of leafy greens, an excellent source of vitamins and phytochemicals associated with a lower risk of heart disease and depression. Toss in a half cup of steamed asparagus or a couple of slices of avocado. These are two veggies packed with folate, a vitamin that helps head off blood-vessel inflammation. To lower LDL, or "bad cholesterol," swap out the croutons for a handful of almonds or cranberries. Finally, top it all off with a vinaigrette dressing. Harvard research suggests two tablespoons daily can cut the risk of heart disease in women.

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Quick Fixes to Benefit the Heart

Dream On

Too much or too little sleep can hurt your heart.

Findings released last year by Chicago Medical School suggest that people who catch fewer than six hours of Zs a night are twice as likely to have a stroke or heart attack, and one-and-a-half times more likely to have congestive heart failure, whereas people who slumber more than eight hours a night are more likely to experience chest pain and coronary artery disease.

Not enough shut-eye seems to trigger the nervous system to release high levels of "fight-or-flight" stress hormones that raise blood pressure, heart rate and blood sugar. Short sleepers also tend to be heavier, which can take a toll on the heart.

While it's not clear why hitting the snooze button once too often affects the heart, some studies indicate oversleepers may be susceptible to depression and unmotivated to exercise. Or they may run out of time and energy to keep up with heart-friendly habits.

"Somewhere around eight hours seems optimal," Becker acknowledged. "But sleep alone won't necessarily impact heart health unless it's put in context with nutrition, activity, stress management and all of your other health habits."

Mid-life stress linked to dementia risk

A large, long-term study reveals that dealing with stress during middle age may trigger lasting physiological brain changes, increasing the risk of developing dementia later in life.
This finding comes from the Prospective Population Study of Women in Gothenburg, Sweden, which started in 1968 and followed over 800 Swedish women for around 40 years. Results of the study were published online in the journal BMJ Open.
Researchers from the study looked at previous studies showing how stress can cause both structural and functional brain damage, as well as promote inflammation.
They say stress hormones can remain at high levels, long after a traumatic event has passed.
Previous studies looked at the effect of severe psychological stressors in adulthood, such as combat, natural disasters and the Holocaust, and they revealed that mental and physical health were affected decades later.
However, the researchers say that although mild psychosocial stressors are a regular part of life, the "long-term consequences of these more common stressors" have remained unclear.

Data over 40 years shows increased risks

Women who experienced certain stressors during middle age had a 21% increased risk for Alzheimer's and a 15% increased risk for dementia, according to the study.

The women who were part of this recent study were all born in 1914, 1918, 1922 and 1930. They underwent neuropsychiatric tests and exams in 1968, and then again in 1974, 1980, 1992, 2000 and 2005.
In 1968, at the start of the study, the women were asked about the psychological impact of 18 common stressors, including divorce, widowhood, illness or death of a child, mental illness or alcoholism in a family member, unemployment and poor social support.
At each follow-up visit, researchers documented how many symptoms of distress - irritability, fear or sleep disturbances - each woman had experienced in the preceding 5 years.
One in four of the women had experienced a minimum of one stressful event at the start of the study. The most common stressor was mental illness in a close family member (sibling 32%, mother 27%, father 19%).
Between the monitoring period of 1968 and 2006, about one in five - 153 in total - of the women developed dementia, and 104 of them developed Alzheimer's disease.
Dementia was diagnosed at an average age of 79, and it took 29 years for it to develop, the researchers say.
The number of stressors the women reported in 1968 was associated with a 21% increased risk of developing Alzheimer's disease and a 15% increased risk of developing any kind of dementia, according to the study.
The researchers note that these findings remained the same, even after factoring in elements that could influence the results, such as a family history of mental health problems.

'More research needed'

Though the study concludes the research does indeed show that common psychosocial stressors have long-term consequences, the authors say that more studies are needed to confirm the results.
They also recommend further study of interventions, such as stress management and behavioral therapy, to see whether these could be useful for people who have experienced the contributing stressors.
Dr. Lena Johansson, co-author of the study, told Medical News Today that she and her colleagues are planning to continue the research project and extend it to a sample of men in a study taking place in Gothenburg, in order to further analyze the relationship between stressors and dementia.

Anti-Cancer Drug Reverses Alzheimer's Disease In Mice

An anti-cancer drug may reverse memory problems in an Alzheimer's Disease mouse model, according to new research carried out at the University of Pittsburgh Graduate School of Public Health.

The study, published in the journal Science, examined previously published outcomes on the drug bexarotene - which is approved by the U.S. Food and Drug Administration for use in cutaneous T cell lymphoma.

The researchers established that the drug does notably improve cognitive deficits in mice expressing gene mutations associated with human Alzheimer's disease, however, they could not verify the effect on amyloid plaques.

Four comments in the journal Science mention that several teams of scientists have been unable to replicate the medication's (bexarotene's) effect on amyloid plaques.

Senior author Rada Koldamova, M.D., Ph.D., associate professor in Pitt Public Health's Department of Environmental and Occupational Health, said, "We believe these findings make a solid case for continued exploration of bexarotene as a therapeutic treatment for Alzheimer's disease."

Dr. Koldamova and her team were studying mice expressing human Apolipoprotein E4 (APOE4) - the only known genetic risk factor for late-onset Alzheimer's disease, or APOE3 - known not to raise the risk for Alzheimer's disease - when a Case Western Reserve University study was published last year.

It claimed that bexarotene elevates memory and rapidly cleared amyloid plaques from the brains of Alzheimer's model mice expressing mouse Apolipoprotein E (APOE).

Amyloid plaques are made up of toxic protein fragments known as amyloid beta that are known to damage neurons in the brain and are believed to result in the memory deficits linked to Alzheimer's disease, and eventually death.

Bexarotene is a compound chemically associated with vitamin A that triggers Retinoic X Receptors (RXR) found all over the body including neurons and other brain cells. Once they are activated, the receptors bind to DNA and control the expression of genes that guide many different biological functions.

Elevated levels of APOE are one result of RXR activations by bexarotene. The researchers started examining similar compounds over 10 years ago.

Co-author Iliya Lefterov, M.D., Ph.D., associate professor in Pitt Public Health's Department of Environmental and Occupational Health said:

"We were already set up to repeat the Case Western Reserve University study to see if we could independently arrive at the same findings. While we were able to verify that the mice quickly regained their lost cognitive skills and confirmed the decrease in amyloid beta peptides in the interstitial fluid that surrounds brain cells, we did not find any evidence that the drug cleared the plaques from their brains."

The Pitt investigators believe that the drug functions through a different biological process, possibly by decreasing soluble oligomers which, like the plaques, are made up of the toxic amyloid beta protein pieces. Even though the oligomers are made up of amyloid beta they are able to move, unlike the plaques.

Dr. Koldamova explained:

"We did find a significant decrease in soluble oligomers. It is possible that the oligomers are more dangerous than the plaques in people with Alzheimer's disease. It also is possible that the improvement of cognitive skills in mice treated with bexarotene is unrelated to amyloid beta and the drug works through a completely different, unknown mechanism."

In the current study experiments, mice with the Alzheimer's gene mutations expressing human APOE3 or APOE4 were able to complete cognitive tests just as well as their non-Alzheimer's counterparts 10 days after starting treatment with bexarotene.

The mice underwent a spatial test that used cues to detect a hidden platform in a water maze, and a long-term memory test of the mouse's skills in distinguishing between two familiar objects following introduction to a third, new object.

Bexarotene treatment has no impact on the weight or general behavior of the mice. The drug was was successful in both male and female mice.

Exercise to a Healthy Heart

A sedentary (inactive) lifestyle is one of the top risk factors for heart disease. Fortunately, it's a risk factor that you can do something about. Regular exercise, especially aerobic exercise, has many benefits. It can:

• Strengthen your heart and cardiovascular system
• Improve your circulation and help your body use oxygen better
• Improve your heart failure symptoms
• Increase energy levels so you can do more activities without becoming tired or short of breath
• Increase endurance
• Lower blood pressure
• Improve muscle tone and strength
• Improve balance and joint flexibility
• Strengthen bones
• Help reduce body fat and help you reach a healthy weight
• Help reduce stress, tension, anxiety, and depression
• Boost self-image and self-esteem
• Improve sleep
• Make you feel more relaxed and rested
• Make you look fit and feel healthy

How Do I Get Started Exercising?

Before starting an exercise program, talk to your doctor about:

• Medication changes. New medications can greatly affect your response to exercise; your doctor can tell you if your normal exercise routine is still safe.
• Heavy lifting. Make sure that lifting or pushing heavy objects and chores such as raking, shoveling, mowing, or scrubbing aren't off limits. Chores around the house can be tiring for some people; make sure you only do what you are able to do without getting tired.
• Safe exercises. Get the doctor's approval before you lift weights, use a weight machine, jog, or swim.

What Type of Exercise Is Best?

• Stretching the arms and legs before and after exercising helps prepare the muscles for activity and helps prevent injury and muscle strain. Regular stretching also increases your range of motion and flexibility.
• Cardiovascular or aerobic activity strengthens the heart and lungs and improves the body's ability to use oxygen. Aerobic exercise has the most benefits for your heart. Over time, aerobic exercise can help decrease your heart rate and blood pressure at rest and improve your breathing.
• Strengthening, repeated muscle contractions (tightening) until the muscle becomes tired; for people with heart failure, many strengthening exercises are not recommended. (See below)

What Are Examples of Aerobic Exercises?

Aerobic exercises include: walking, jogging, jumping rope, bicycling (stationary or outdoor), cross-country skiing, skating, rowing, and low-impact aerobics or water aerobics.

How Often Should I Exercise?

In general, to achieve maximum benefits, you should gradually work up to an aerobic session lasting 20 to 30 minutes, at least three to four times a week. Exercising every day or every other day will help you keep a regular aerobic exercise schedule.

Reasons to Work Out

Need a reason to work out? Here are Some to start

What if someone told you that a thinner, healthier, and longer life was within your grasp? Sound too good to be true? According to a wealth of research, exercise is the silver bullet for a better quality of life.

Not only does regular exercise aid in weight loss, it reduces your risk for several chronic diseases and conditions. Finding activities that you enjoy and that become part of your daily routine is the key to a long and healthy life.

The list of health benefits is impressive, and the requirements are relatively simple -- just do it.

Ward Off Disease

Research has confirmed that any amount of exercise, at any age, is beneficial. And, in general, the more you do, the greater the benefits. The National Academy of Sciences has recommended that everyone strive for a total of an hour per day of physical activity. Sounds like a lot, but the hour can be made up of several shorter bursts of activity (it can be walking, gardening, even heavy housecleaning) done throughout the day.

Physical activity is an essential part of any weight-loss program, to maximize your fat loss while keeping valuable muscle mass. But exercise has many other health and longevity benefits. It can help prevent or improve these conditions:

1. Heart Disease. Regular activity strengthens your heart muscle; lowers blood pressure; increases "good" cholesterol (high-density lipoproteins or HDLs) and lowers "bad" cholesterol (low-density lipoproteins or LDLs); enhances blood flow; and helps your heart function more efficiently. All of these benefits reduce the risk of stroke, heart disease, and high blood pressure.

Researchers at Duke University suggest that the amount of physical activity, rather than its intensity, has the biggest impact on improving blood lipids (cholesterol). According to The New England Journal of Medicine, these researchers also found that any exercise is better than none -- although more is better.

2. Stroke. In an analysis of 23 studies, researchers found that being active reduces your risk of having and dying from a stroke. According to a study published in the journal Stroke, moderately active study participants had 20% less risk of stroke than less active participants.

3. Type II Diabetes. This disease is increasing at alarming rates -- by 62% since 1990 -- and 17 million Americans now have it. Physical activity can enhance weight loss and help prevent and/or control this condition. Losing weight can increase insulin sensitivity, improve blood sugar and cholesterol levels, and reduce blood pressure -- all of which are very important to the health of people with diabetes.

In a study published in the Annals of Internal Medicine, Frank Hu, MD, of the Harvard School of Public Health found that a brisk walk for one hour daily could reduce the risk of type II diabetes by 34%.

4. Obesity. Overweight and obese conditions can be prevented or treated with exercise along with a healthy diet. Activity helps to reduce body fat and increase muscle mass, thus improving your body's ability to burn calories. The combination of reduced calories and daily exercise is the ticket to weight loss. And controlling obesity is critical, as it is a major risk factor for many diseases. Lowering your body mass index (BMI) is a sure way to reduce your risk of dying early and to live a healthier life.

5. Back Pain. Back pain can be managed or prevented with a fitness program that includes muscle strengthening and flexibility. Having good posture and a strong abdomen is the body's best defense against back pain.

6. Osteoporosis. Weight-bearing exercise (such as walking, jogging, stair climbing, dancing, or lifting weights) strengthens bone formation and helps prevent the osteoporosis or bone loss often seen in women after menopause. Combine a diet rich in calcium and vitamin D with regular weight-bearing exercise for maximum results.

According to The Journal of the American Medical Association, data from the Nurses' Health Study showed that women who walked four or more hours per week had 41% fewer hip fractures than those who walked less than an hour a week.

7. Psychological Benefits. Improved self-esteem is one of the top benefits of regular physical activity. While exercising, your body releases chemicals called endorphins that can improve your mood and the way you feel about yourself. The feeling that follows a run or workout is often described as "euphoric" and is accompanied by an energizing outlook. Exercise can help you cope with stress and ward off depression and anxiety.

And these are just a few of the ways exercise improves your health. Studies have suggested it can also help with certain types of cancer, improve immune function, and more.

Putting It All Together: Exercise and a Healthy Diet

Exercise alone produces modest weight loss; when combined with a reduced-calorie diet, the effects are much more impressive.

In a study published in The Journal of the American Medical Association, University of Pittsburgh researchers found that people who exercised regularly and ate a healthy, modest-calorie diet lost weight and improved cardiorespiratory fitness regardless of the length or intensity of their workouts.

Another study published in JAMA showed that it is never too late to reap the benefits of physical activity. Sedentary women 65 years and older who began walking a mile a day cut their rates of death from all causes by 50%.

Resistance, Resistance

If exercise is so good for us, why aren't people doing it?

Some 64% of men and 72% of women fail to fit in activity on a daily basis, according to data from the 2000 National Health Interview Survey. Americans today are no more active than they were a decade ago.

VEGETARIANS DIET

The simplest definition of vegetarianism is a diet free of meat, fish, and fowl flesh. But eating habits of vegetarians cover a wide spectrum. At one end are lacto-ovo vegetarians who avoid animal flesh but eat eggs and milk products. At the other end are vegans, who forego eating (and often wearing) all animal-based products, honey included. Raw foodists are vegans who eat mainly raw fruits, vegetables, legumes, sprouts, and nuts.

There are also pescatarians, vegetarians who eat fish and seafood, and lacto-vegetarians, who eat dairy products but not eggs. Fruitarians follow a diet that includes fruits, nuts, seeds, and other plant food. Those who follow a macrobiotic diet eat mostly grains but can also eat fish. They don't necessarily identify as vegetarians.

Reasons for Becoming a Vegetarian

Many adherents of vegetarianism and veganism -- Beatle Paul McCartney and actor Alec Baldwin are a few celebrities who happily promote the cause -- regard a flesh-free diet not only as more healthful, but as a more ethical way to live. They point to the cruel practices and the high environmental cost of raising animals for food as a few reasons for excluding meat from the diet.

Most Americans, however, continue to eat some form of meat or fish. A 2008 Harris Interactive survey commissioned by Vegetarian Times put the number of Americans who do not eat meat or fish at 3.2%, or 7.3 million adults.

Vegetarianism and Health

Most doctors and nutritionists agree that a low-fat diet high in fruits, vegetables, and nuts can be a boon to health. There is also widespread acknowledgment that reducing or eliminating red meat from the diet cuts the risk of heart disease.

Research also has shown that a plant-based diet can improve the health of people with type 2 diabetes. A study in 2004 and 2005 showed that people with diabeteswho followed a low-fat vegan diet had less of a need for diabetes medications. They lost weight and their insulin sensitivity increased. They had improved glycemic and lipid control.

Does Being a Vegetarian Lower Cancer Risk?

Whether being a vegetarian or a vegan lowers cancer risk is less clear. This is mainly because of the diversity within the vegetarian population. Studies, however, have suggested that people who do not eat meat have a lower risk of prostate and gastrointestinal cancers.

Many of the cancer/vegetarian studies often conclude that diets rich in fiber, carotenoids (found in carrots, sweet potatoes and spinach), vitamins, minerals, and isoflavones (found in soybeans and legumes),seem to protect against disease, including cancer. This is in concert with a health-conscious lifestyle.

A British study of 11,000 vegetarians and healthy eaters concluded that daily consumption of fruit was associated with a 20%-plus reduction in mortality from heart disease, cerebrovascular disease, and cancers of the stomach, lung,pancreas, large intestine, and rectum. Researchers, however, didn't account for the kind of diet practiced by study participants (whether they ate dairy and fish or drank alcohol, for example). They also didn't check to see if their diets had changed over the course of the 17-year study.

Does Being a Vegetarian Lower Cancer Risk? continued...

A 1998 Dutch survey of 150,000 vegetarians concluded that the benefit of a vegetarian diet comes not just from excluding meat but in eating more whole grains,fruits and vegetables, legumes, and nuts.

Researchers who conducted an 11-year study in Germany came to a similar conclusion. They examined the relationship between a vegetarian diet and coloncancer among 1,900 vegetarians. Researchers noted fewer deaths from cancers of the stomach and colon and even the lung in study participants -- particularly among those who practiced some form of vegetarianism for at least 20 years. They suggested, however, that other factors, like body weight and amount of exercise, likely affected mortality rates in the vegetarians they studied.

Vegetarianism and Nutrition

A vegetarian diet can be a healthy diet, but vegetarians -- especially vegans -- need to make sure they're getting enough vitamin B12, calcium, and iron.

The Academy of Nutrition and Dietetics warns of the risk of vitamin B12 deficiencies in strict vegetarians (vegans). Vitamin B12 is found naturally only in animal products. A lack of vitamin B12 can lead to anemia and blindness. It can also cause muscle weakness, tingling, and numbness.

Calcium is another nutrient that may be lacking in some vegetarian diets. Ovo-vegetarians, who eat eggs but not dairy, need to find foods that compensate for the missing calcium from their diets. Dark green vegetables are a good source of calcium.

Lacto-vegetarians (who don't eat eggs) also need to boost their intake of B12 and iron.

A vegan diet, in particular, may lead to an increased risk of deficiencies of vitamin B12, vitamin B2, calcium, iron, and zinc. To counteract the increased risk, vegans should include B12 supplements, or fortified cereals and veggie burgers in their diets.

Is a Vegan Diet Safe During Pregnancy?

The warnings are a bit more urgent for pregnant and lactating women who are vegan. Having a vitamin B12 deficiency, particularly, has been shown to impair neurological development in infants nursed by vegetarian mothers. A lack of vitamin D and calcium also can result in bone demineralization in breastfeeding women.

Similarly, young children (under 5) reared on vegetarian and vegan diets can suffer impaired growth. That's because of a vitamin B12 deficiency, which can also result in anemia and rickets. Yet a well planned diet can meet all the nutritional needs.

Absorbable calcium is critical, too, for vegans and ovo-vegetarians to protect against weak bones that can lead to osteoporosis.

Key Nutrients for Vegetarians and Vegans

The U.S. Department of Agriculture offers dietary guidelines for vegetarians of all stripes on its web site. The Academy of Nutrition and Dietetics (formerly the American Dietetic Association) is also a good source for dietary recommendations.

Regardless of the kind of meat-free diet practiced, vegetarians should focus on getting enough protein, iron, calcium, zinc, and vitamin B12. They also need riboflavin, linolenic acid, and vitamin D.

Here are some ways for vegetarians to incorporate these nutrients into their diets:

• Protein: Is found in tofu, tempeh, veggie burgers, beans, nuts and nut butters, eggs.
• Iron: Eggs, fortified breakfast cereals, soy-based foods, dried prunes and apricots, nuts beans, legumes, whole-wheat bread, and baked potatoes are rich in iron.
• Calcium, which builds bone, is plentiful in cheese, yogurt and milk. Ovo-vegetarians and vegans can get it in soy products, legumes, almonds, sesame tahini, calcium-fortified orange juice, and dark, leafy vegetables like collard greens and bok choy.
• Zinc, which boosts the immune system, is ample in soybeans and soymilk, veggie "meats," eggs, cheese and yogurt, fortified breakfast cereals, nuts, breads, mushrooms, and peas. Wheat germ and pumpkin seeds also have high zinc content
• Vitamin B12: Soy-based beverages, some breakfast cereals, and fortified veggie "meats" are all good sources of vitamin B12
• Riboflavin: Almonds, fortified cereals, cow's milk, yogurt, mushrooms, and soy milk are riboflavin-rich foods.
• Linolenic acid (omega-6): Canola oil and flaxseeds and flaxseed oil contain linolenic acid, along with soybeans, tofu, walnuts, and walnut oil.
• Omega-3 Fatty Acids: Cold-water fish, such as salmon and mackerel, are high in omega-3 fatty acids For vegetarians who do not eat fish, good sources of omega-3s are flaxseed, walnut, soy and canola oils. Supplements are fine, too.

Fluctose may affect hunger cues

Fluctose may affect hunger cues

Jan. 2, 2013 -- All sugars are not created equal, at least when it comes to the brain, a new study shows.

For the study, which is published in the Journal of the American Medical Association, researchers asked 20 healthy men and women to sip a cherry-flavored drink sweetened with either pure glucose or pure fructose.  

Both glucose and fructose are simple sugars. People rarely take in either one by itself. Instead, they’re usually added to foods and drinks as mixtures. Table sugar is about half glucose, half fructose, for example, while high-fructose corn syrup is about 55% fructose and 45% glucose.

Fructose is sweeter than glucose. It’s also less expensive. So over the years, the balance of calories from added sugars in the American diet has shifted to favor fructose.

“People consume a lot more fructose now than they used to, because it’s cheaper to put high-fructose corn syrup in the foods we eat,” says researcher Robert S. Sherwin, MD, an endocrinologist at the Yale University School of Medicine, in New Haven, Conn. 

Whether that shift may be contributing to our nation's growing obesity problem has been an open question.

Animal studies have shown that glucose and fructose can have different effects on appetite and metabolism. Sherwin and his team set out to see if that might also be true for humans.

Sugars in the Brain

Each person in the study completed the experiment twice with a gap of a few weeks to a few months between lab visits. They weren’t told which sugar they were given to drink.

Each time, they were given a scan that allowed researchers to watch what was happening to their brains in real time.

Study scientists were particularly interested in changes to a region called the hypothalamus, which helps to control appetite. They also took blood samples to check levels of hormones that control feelings of hunger and fullness, and asked the study participants how satisfied they felt after drinking the different sugar solutions.

As quickly as 15 minutes after people in the study finished the drinks, researchers began to see changes in brain blood flow and activity.

After the glucose drink, the body seemed to recognize and respond to the extra calories with an increase in glucose and insulin levels. That response, which blunts hunger, was significantly greater than fructose's. Brain activity also slowed in the hypothalamus, the region that stimulates appetite.

After the fructose drink, on the other hand, the hypothalamus continued to stay active. There was little increase in insulin, and study volunteers said they felt hungrier, even though they weren’t told which sugar they’d had.

Other hormones that are known to regulate hunger, such as ghrelin and leptin, were unchanged after ingestion of either type of sugar.

Sugars in the Brain continued...

“When we eat, the body recognizes that food is coming in, and ultimately the brain is trying its best to regulate how many calories we need and how much fat we have in our bodies, and trying to maintain a balance so that we’re not overeating or under-eating,” Sherwin says. 

Fructose seems to upset that balancing act, though researchers aren’t sure why.

One theory is that when humans evolved, the problem wasn’t overeating, but not getting enough calories. In that case, it wouldn’t have been a good idea for fructose, which is the primary sugar in fruit and fruit juices, to make us feel full since fruits may have been a primary food source.

That may have worked fine for cavemen, but it may not be so great for our sugar-saturated modern diets.

Advice to Dieters

So what does the study mean for health-conscious eaters?

That’s harder to say, says Jonathan Purnell, MD, an endocrinologist at Oregon Health & Science University in Portland.  Purnell wrote an editorial on the study but was not involved in the research.

“This study didn’t prove that fructose causes weight gain,” Purnell says. “It doesn’t reflect real-world conditions.”

Industry representatives agree.

“When consumed together, as they almost always are, fructose and glucose balance each other out and would likely have no effect on normal hypothalamic blood flow,” says James Rippe, MD, professor of biomedical sciences at the University of Central Florida and a paid consultant for the Corn Refiners Association, the group that represents manufacturers of high-fructose corn syrup.

“Any suggestion that this artificial experiment has implications for human nutrition or obesity is unwarranted speculation,” says Rippe, in a statement prepared in response to the study.

Ideally, Purnell says, the next phase of studies would test the kinds of sugar mixtures found in foods, like table sugars and high-fructose corn syrup, against a comparison condition like water or an artificial sweetener.

“This study shouldn’t, all by itself, lead people to cut back on this food or that food,” Purnell says.

It would be a mistake, he says, to give up fruit, which has naturally occurring fructose.

“We don’t recommend limiting fruit intake. Although there’s fructose there, it’s also present with water and fiber that alter the characteristics of straight fructose alone. We think that doesn’t make fruit as much of a bad actor,” Purnell says.

What’s probably more practical, says Rachel Begun, RD, a spokeswoman for the American Academy of Nutrition and Dietetics, is to try to limit added sugars.

Americans take in nearly 150 pounds of added sugars per year, according to the U.S. Department of Agriculture, an amount that breaks down to nearly 28 teaspoons or 440 calories every day.

“It's safe to say that Americans are consuming too much sugar in all forms and we need to significantly reduce our intake," says Begun, who wasn’t involved in the research.