Evan Watson, NatureCity author & contributor

Studies have shown that consuming foods with a low glycemic index (GI) before exercise increases the amount of fat burned.

However, most of these studies have included high intensity exercise and trained athletes.  None of them looked at the effects the pre-exercise meal has on metabolism during and after exercise.

To fill this gap in knowledge, Dr. Emma Stevenson at the University of Nottingham recently conducted a study to determine the effect of low glycemic meals on more typical (sedentary) individuals. The study was published in the May 2009 issue of the Journal of Nutrition.

For the study, 8 healthy, sedentary women completed 2 exercise trials. For one trial, the participants were provided with a high glycemic index breakfast.  For the other trial, they were provided with a low glycemic index breakfast.

The participants walked for 60 minutes 3 hours after consuming the breakfasts.

The researchers found that low GI foods resulted in an increase in fat oxidation during exercise and improved satiety during recovery.

They concluded that people trying to shed pounds should consider eating foods with a low glycemic index before exercising.

The GI value of a food is calculated by measuring how fast the carbohydrates it contains raise blood sugar levels. Foods such as artichokes, avocados and peanuts are low GI foods and therefore have little impact on blood sugar fluctuations.  Some high GI foods are white bread, pretzels, potatoes and dates.

Sarah McGowan-Freije, NatureCity author & contributor

A new Japanese study found that being too skinny may actually be more dangerous than being obese, and that slightly overweight people actually live longest.

The study, which included 50,000 people between 40-79 years of age, was conducted by the Japanese Health, Labor and Welfare Ministry research team.

The researchers divided the participants into four groups based on body mass index (BMI):

1. overweight (more than 30 BMI)

2. slightly overweight (BMI between 25 and 30)

3. normal (BMI between 18.5-25)

4. thin (less than 18.5 BMI)

The participants were followed for a 12 year period.

BMI is a measure of an individual’s weight in relation to their height. The formula used to calculate BMI is Weight (lb) / (Height (in) x Height (in)) x 703

The researchers found that slightly overweight individuals lived an average of 6 to 7 years longer than thin people.

Furthermore, the researchers found that the life expectancy of the thinnest people in the study was about 5 years less than the overweight participants.

It has been hypothesized that thinner peoples lives were shorter because they may have been more likely to be sick or smoke. However, when the researchers eliminated those factors, the results barely changed.

The researchers theorize that the main contributor to the lower life expectancy of thin people is their higher susceptibility to contagious diseases.

The researchers note that these findings should by no means encourage people to eat as much as they want.  However, they recommend that very thin people strive to achieve a normal BMI.

Evan Watson, NatureCity author & contributor

The risk of developing age-related macular degeneration (AMD) can be significantly reduced by a combination of higher intakes of omega-3 fatty acids and a supplement called the age related eye disease and nutrition (AREDS) supplement.

The study, led by researchers from Tufts University and the University of Wisconsin, was published in the June 2009 issue of the British Journal of Ophthalmology.

AMD is a progressive disease that attacks the macula of the eye and affects over 15 million Americans.  It is the leading cause of severe vision loss and blindness in the Western world.

Experts are expecting to see a virtual epidemic of AMD due to the aging of the US population. Currently, 20% of people aged 65-74 years and 35% of people aged 75 years or more in the US have the disease.  Scientists predict these numbers will double by 2020.

AREDS is a patented formula meant to fight the onset and progression of AMD. The formula includes vitamins C and E, beta carotene, zinc and copper.

For the study, researchers analyzed data of 2,924 individuals who participated in the 8 year Age-Related Eye Disease Study. The Age-Related Eye Disease study was a major clinical trial sponsored by the National Eye Institute.

According to the National Eye Institute website, the goal of this extensive study was to “learn more about the natural history and risk factors of age-related macular degeneration (AMD) and cataracts and evaluate the effect of high doses of antioxidants and zinc on the progression of AMD and cataracts.”

The researchers found that the highest average intakes of DHA (over 64 mg p/day) were associated with a 27% reduction in advanced AMD, compared to intakes of less than 25 mg per day. Moreover, EPA intakes over 42.3 mg per day were associated with a 26% reduction, compared to intakes of less than 12.7 mg per day.

In light of these findings, the company holding the AREDS patent, Bausch and Lomb, is now developing an AREDS2 formula which will contain antioxidant carotenoids, lutein, and the omega-3 fatty acids DHA and EPA.

Consuming more protective nutrients and foods with a low glycemic index are two effective ways to reduce the risk of developing AMD.

There are also several foods sources that have been shown to promote good eye health including citrus fruits, vegetable oils, nuts, whole grains, dark leafy vegetables and cold water fish.

Evan Watson, NatureCity author & contributor

A study published in the June 2009 issue of the journal Cancer Prevention Research found that active compounds in green tea, called polyphenols, may lower the risk of prostate cancer and slow the progression of the disease.

Polyphenols are compounds found naturally in plants and fruit. They have strong antioxidant properties which allow them to neutralize destructive free radicals and decrease oxidation damage in the body.

Louisiana State researchers recruited 26 men aged 41 to 72 for the study. The participants were all scheduled to have radical prostatectomies.

A radical prostatectomy is an operation performed on prostate cancer patients which involves removing the prostate gland and the tissue surrounding it.

Each man took four capsules of Polyphenon E, the equivalent of drinking 12 cups of green tea, for an average of 35 days through the day before surgery.

At the end of the supplementation period, the researchers observed significant reductions (up to 30%) in a number of prostate cancer indicators including serum levels of PSA, HGF, and VEGF.  Few side effects were reported.

The researchers note that these findings support a potential role for tea polyphenols in the treatment or prevention of prostate cancer.

The powerful antioxidants in green tea have already been shown to decrease the risk of certain cancers and neurodegenerative diseases as well as helping to balance blood sugar levels.

Evan Watson, NatureCity author & contributor

Postmenopausal women may be able to protect themselves from bone loss by combining antioxidant supplementation and resistance training, according to a pilot study to be published in the July 2009 issue of the journal Osteoporosis International.

A team led by Isabelle Dionne, PhD, from the University of Sherbrooke in Quebec, recruited 34 postmenopausal women with an average age of 66 for the study.

The women were randomly assigned to one of four groups for a period of 6 months:

1) placebo and no exercise

2) antioxidants and no exercise

3) placebo plus exercise

4) antioxidants plus exercise

The women in the antioxidant groups received 600 mg vitamin E and 1,000 mg vitamin C on a daily basis.

The researchers measured bone mineral density of the hip and spine and dietary intakes (3-day food record) before and after the intervention.

They found that the only group to lose bone mass was the placebo and no exercise group.

The mechanisms behind these results are still somewhat unclear.  However the researchers said a study published earlier this year may provide some insight.

Researchers from Tufts University, Hebrew SeniorLife, and Boston University, conducted the previous study which was published in the January 2009 issue of the American Journal of Clinical Nutrition.

They found that increased intakes of antioxidants called carotenoids resulted in a decrease in bone resorption.

Bone resorption is the process by which bones are broken down and dissolved into minerals like calcium, phosphates and salts, thereby weakening the bones.  Studies have shown that oxidative stress, which can be reduced by antioxidants, may increase bone resorption.

Bone resorption is natural, but can be accelerated as you age, potentially leading to osteoporosis and fractures.  Women are four times more likely to develop osteoporosis than men.

Getting more antioxidants in your diet via increased consumption of fruits and vegetables may be a good way to boost bone health and offset bone resorption.

Maintaining balanced acid-alkaline levels and consuming more calcium and vitamin D have also been shown to support healthy bones.

Scott Greenberg, NatureCity author & contributor

A number of novel findings were presented at the annual meeting of the Associated Professional Sleep Societies the week of June 14th, 2009 in Seattle.

One of the main studies unveiled was presented by Dr. Plamen Penev, from the University of Chicago.  The study found that failure to get a full night’s sleep (approximately 8 hours) can lead to weight gain and cancel out the benefits of dieting.

The study included nine overweight volunteers with an average age of 40.

The volunteers completed two separate 14 day trials conducted 3 months apart.

For both trials, the researchers had the participants consume a nutritionally balanced diet containing calories up to 90% of their resting metabolic rate.

The participants were told to stay in bed 5.5 hours a night for the first trial and 8.5 hours per night for the second trial.

The weight loss during each trial was similar; 6.4 pounds for the 5.5 hour trial and 6.6 pounds for the 8.5 hour trial.  However, the amount of weight loss from fat was drastically different, with 26% of the weight loss from fat during periods of sleep restriction compared with 57% from fat during regular sleep.

This indicates an extreme increase in loss of lean body mass when sleep is restricted.  The goal of most dieters is to lose as much fat as possible, rather than lean body mass.

The researchers note that lack of sleep can become counterproductive when trying to lose weight.

Lack of sleep has many other negative effects on the mind and body including increased risk of diabetes, high blood pressure, increased stroke risk, increased risk of depression and a general decrease in alertness.

Evan Watson, NatureCity author & contributor

University of Cincinnati researchers have found that Bisphenol  A (BPA), a chemical found in many household plastics, may be harmful for the heart, particularly in women.

The results of this and several other studies relating to BPA were presented in Washington, D.C., at ENDO 09, the Endocrine Society’s annual meeting, June 10-13, 2009.

The researchers with the Department of Pharmacology and Cell Biophysics found that exposure to BPA resulted in the same abnormal heart activity in female rats and mice that was observed with exposure to estrogen.

BPA is an environmental pollutant that has been shown to mimic estrogen.

Head researcher, Scott Belcher, PhD, stated “both BPA and estrogen rapidly stimulated contraction by altering control of the concentrations of free calcium inside the heart cell but only in heart muscle cells from females, showing that these effects were sex-specific.”

They determined that estrogen receptors that are only present in women were responsible for making the heart muscles act abnormally.

The researchers are going to attempt to recreate these findings with human studies.  Meanwhile, they warn that detriments to cardiovascular health may soon be added to the increasingly long list of potential health hazards associated with BPA.

BPA is used to make the hard clear plastic used in many food containers, water bottles and the lining of food cans. Beyond its potential to cause negative heart affects in women, the chemical has already been shown to increase the risk of neurological defects, diabetes and breast and prostate cancer.

Evan Watson, NatureCity author & contributor

A study published in the June 2009 issue of the journal Archives of Internal Medicine suggests that low-carb diets high in plant-based proteins may have the potential to improve cholesterol while losing weight.

The researchers from the University of Toronto also assert that low-carb weight loss diets with primarily meat protein can lead to adverse affects due to their higher levels of unhealthy saturated fats and cholesterol.

For the study, the researchers randomly assigned 47 participants to either an “Eco-Atkins” diet or a high-carb diet for a period of 4 weeks.

The Eco-Atkins diet was a low-carbohydrate diet (26% of total calories) high in vegetable protein whereas the high-carb diet was 58% carbohydrates, 16% meat protein, and 25% fat.

At the end of the four weeks, both groups experienced similar weight loss (average of 8.8 pounds).

However, there was a significantly higher reduction in blood pressure for the Eco-Atkins group and reductions in LDL-C (bad cholesterol) levels were higher as well.

Furthermore, there were improvements in the ratios between total cholesterol and HDL-C for the Eco-Atkins diet but no differences were observed for the high-carbohydrate group.

The researchers say these findings can lead to higher protein diets that promote weight loss without sacrificing heart health.

They also noted that larger studies with more diverse and higher risk populations are necessary before this new diet can be recommended to the larger population.

Evan Watson, NatureCity author & contributor

Scientists with the International Life Sciences Institute of North America have determined that the science behind the heart health benefits of omega-3s is so “remarkable” that the establishment of a Dietary Reference Intake (DRI) for EPA and DHA is highly recommended.

The scientists came to this conclusion after a large comprehensive review of 15 prospective-cohort studies on the benefits of omega-3 consumption. The review was published in the June 2009 issue of The Journal of Nutrition.

Based on the review, the scientists determined that a mere 250-500mg of DHA and EPA markedly reduces the risk of cardiac death.

In fact, the large body of research shows that omega-3s have more of an impact on reducing the risk of chronic disease than any other dietary factor for which a DRI has already been set, including saturated fat, dietary cholesterol, salt, and dietary fiber.

The setting of a DRI for DHA and EPA would let the general public know that they should be a component of their daily diet.

There was, however, a more modest relationship between omega-3 consumption and other cardiovascular risks such as blood pressure, resting heart rate, triglyceride levels and heart rate variability.

The scientists also looked into the cognitive and cancer reduction benefits of omega-3.

They found that omega-3s ability to reduce dementia risk was “promising but limited” and hope further studies, some of which are already in progress, will serve to further knowledge in this field.

Despite a few studies backing the cancer benefits of omega-3, there is still not enough evidence to conclude any relationship between omega-3 consumption and cancer risk.

While more studies will help define the cognitive and cancer benefits of omega-3s, the cardiovascular benefits are proving to be far ranging and real.

Eating more oily fish is one way to increase your omega-3 levels, however, many people have trouble consuming enough of these essential fatty acids through diet alone to see any real health benefits.  In addition, depending on the type of fish and how the fish is raised, mercury levels in the fish may be a concern.

For most people, the easiest way to get more of these essential fatty acids is by taking a high quality fish oil supplement. When choosing a supplement, be sure that it is high in EPA and DHA and certified for purity.

Evan Watson, NatureCity author & contributor

A study published in the May 2009 issue of the Journal of the American Dietetic Association shows that the absorption of a new calcium-fortified ice cream is just as good as fortified low-fat milk.

16 volunteers between 25 and 40 years of age from the Netherlands were recruited for the randomized, double-blind cross-over study.

The participants consumed either ice cream formulated with 3% butter fat, ice cream formulated with 9% coconut oil or low-fat milk with 1.7% milk fat together with a light standard breakfast on three separate occasions.

The researchers from the Unilever Food and Health Research Institute found no significant difference in calcium absorption between the ice cream products and the milk.  Actual absorption was measured to be 26%, 28% and 31% respectively.

Many people fail to consume adequate amounts of calcium and these findings show that ice cream may provide another way to get more calcium in your diet, particularly among picky children and adolescents.

The researchers also note that the unhealthy reputation of ice cream is somewhat unfounded, highlighting the fact that in terms of calorie content, a serving of ice cream is comparable to the nutritional value of a banana, a bowl of yogurt with muesli, or half of a chocolate chip cookie.

Early research has also indicated that ice cream shows good potential for supporting probiotic strains.

Further research is necessary, however, to overcome some of the hurdles ice cream presents, such as long term refrigeration, which can easily kill probiotics.

Getting enough calcium in your diet is essential, as it is the mineral responsible for bone building, muscle contraction, central nervous system function and hormone secretion.

Since calcium absorption decreases and bone loss increases as you age, it is particularly important for anyone over 50 years of age to consume the recommended daily intake of 1200mg of calcium per day.

Calcium has been shown to aid bone health, help with weight loss, skin health, and reducing the risk of ccolorectal cancer and stroke. Some studies have even suggested that calcium intake is associated with longevity.