August 2007 Newsletter

Prof Mark Wahlqvist AO, MD, FRACP Immediate Past President International Union of Nutritional Science

Welcome to the August edition of the HEC newsletter Fruit and vegetable extracts (Juice Plus) raise blood antioxidant levels and reduce oxidative stress Diabetes needs more magnesium and thiamin Regular/Diet soft drinks and caffeine linked to metabolic syndrome? The MEATRIX and STOREWARS video clips about sustainable farming

Dr Antigone Kouris BSc (Biochem) (Melb), Hons (Nutrition) (Deakin), Grad Dip Diet (Deakin), PhD Med Nutrition (Monash) Honorary Nutrition Research Fellow, Monash Asia Institute

Asia Pacific Journal of Clinical Nutrition Read abstracts of the edition vol16 (3) Subscribe to APJCN for only $195 hardcopy and online or $150 on-line only

WHAT'S NEW IN RESEARCH

Fruit and Vegetable Extract (Juice Plus+®) improved serum

antioxidant levels and reduced oxidative stress in Japanese men and women

In the September Issue of APJCN Kawashima et al tested whether dehydrated concentrates from mixed fruit and vegetable juices (Juice Plus+®) consumed for 28 days affected serum antioxidant and folate status, plasma homocysteine levels and markers for oxidative stress and DNA damage. Japanese subjects (n=60; age 27.8 yrs; BMI 22.1) were recruited to participate in a double-blind placebo controlled study and were randomized into 2 groups of 30, matched for sex, age, BMI and smoking status (39 males, 22 smokers; 21 females, 13 smokers).
In the absence of dietary modification, supplementation with the fruit and vegetable juice concentrate capsules proved to be a highly bioavailable source of phytonutrients significantly increasing the concentration of serum beta-carotene by 528%, lycopene by 80.2%, vitamin E by 39.5% and serum folate by 174.3% (which correlated with a decrease of 20% in an undesirable amino acid homocysteine which research has shown is linked to heart disease).
Markers of oxidative stress were also reduced with serum lipid peroxides declining -10.5% and urine 8OHdG decreasing -21.1%. Evaluation of data from smokers only (n=17) after 28 days of active supplementation showed comparable changes.
These findings have important implications for conditions where oxidative stress or excessive free radicals are generated e.g excessive exercise/athletes, cancer, diabetes, heart disease, smoking, pollution exposure.
However, this product should not replace fresh fruit and vegetable consumption.
This product has been studied by other research groups with promising findings and there are more studies underway. To date, this product has been shown to positively affect markers of proper immune function, to reduce DNA damage and to improve elasticity of arteries after a high fat meal.
More info go to: http://www.juiceplus.com.au

Diabetes needs more Mg and Thiamin

Magnesium
The newest magnesium/diabetes research comes from the Karolinska Institute in Stockholm, Sweden published in the Journal of Internal Medicine in 2007. The Karolinska team (Larsson et al) reviewed seven large studies. In each study, dietary and medical records were followed over a long period. Four studies tracked diet only, while three studies reviewed dietary habits and supplement intake. The combined studies included more than 286,000 subjects. Six of the studies found a significant association between high magnesium intake and reduced risk of type 2 diabetes. The sources of magnesium - whether from diet or supplements combined with diet - were equally effective. Diabetes risk dropped by 15 percent for every 100 mg increase in magnesium intake.
Elevated blood sugar levels can increase the excretion of magnesium, chromium and thiamin and there is emerging evidence that levels of magnesium have declined in vegetables and fruits over the last 50 years further compounding the problem.
We need about 400mg magnesium daily (and people with diabetes or people on diuretics or certain heart medications probably need more than this). An easy way to get 100mg of magnesium is to include about
20 almonds or cashews or 30g pumpkin seeds or 30g dark chocolate or 1 cup dark green leafy vegetables. Interestingly, 1 cup of Turkish/Greek coffee (but not instant coffee) has 90mg of magensium.
Food sources of magnesium from "Food Facts" by Professors M Wahlqvist and D Briggs
More info on Magnesium

Thiamin
Thornalley et al found people with diabetes expelled thiamin - vitamin B1 - from their bodies at 15 times the normal rate in a study of 94 people (published in Diabetologia). The Warwick University team said thiamine helped ward off complications such as heart disease and eye problems. It is the first time a deficiency of the vitamin, which is found in meat, yeast and grains, has been identified in people with diabetes.
The authors concluded that supplementing diets could be an effective way of minimising the risk of these complications since the requirement for thiamin would be much higher in diabetes if excessive amounts are excreted. It has been missed in the past because of the way thiamin levels were measured. Traditionally, the activity of an enzyme called transketolase in red blood cells has been used to indicate thiamin levels. But the researchers found that increased activity - usually a sign of high thiamine levels - was also associated with the body's response to deficiency. Instead, the team measured thiamin levels in blood plasma and found concentrations were 76% lower in people with type 1 diabetes and 75% lower in people with type 2.
Thiamin is key to warding off vascular problems such as kidney, retina and nerve damage as well as heart disease and stroke. It works by helping protect cells against the effect of high glucose levels. Trials are now being carried out to see if supplementing diet with thiamine could return levels to normal.
Food sources of thiamin from "Food Facts" by Professors M Wahlqvist and D Briggs

Regular/diet soft drinks and caffeine linked to metabolic syndrome?

Coffee's impact on sugar metabolism is currently unclear.
Coffee has been linked to both a reduced risk and increased risk of developing diabetes in the general population but it is not yet known whether this is due to the caffeine content or other compounds in coffee.
Furthermore, caffeine may behave differently in people with diabetes. The Canadian Diabetes Association says the following about coffee "Drinking caffeine in large amounts as coffee over a short period of time has been shown to raise blood sugar. Caffeine does this by enhancing the effect of two hormones (adrenaline and glucagon). These two hormones release stored sugar from the liver resulting in high blood sugar". This can be advantageous in very active people like athletes who need a surge of glucose (atheletes been known to take caffeine supplements for extra "energy") but may be undesirable in the inactive person.
Emerging studies are shedding more light on caffeine metabolism.
In the July 23, 2007 online issue of the journal Circulation, Dhingra et al linked the consumption of more than one soft drink per day to the risk of developing metabolic syndrome or high levels of blood insulin (a precursor to developing diabetes). The association was found to be true for diet soft drinks (i.e. zero calorie) as well as those packed with sugar. The investigators suggest that the culprit might not be the soft drinks themselves, but instead the eating habits that soft drink consumption reflect. This study has fueled speculation by suggesting that some unknown ingredient (like caffeine) in diet sodas might be contributing to metabolic syndrome in susceptible individuals. The sweet taste in the mouth (from sugar or artificial sweeteners) may trigger the pancreas to release insulin which could result in hyperinsulinaemia (leading to metabolic syndrome) if intake is chronic.
In 2006 Rush et al from the Auckland University of Technology in New Zealand published a study in Asia Pacific
Journal of Clinical Nutrition showing that an energy drink containing sugar and added caffeine caused the body to convert sugar into fat more rapidly than lemonade. The energy drink tested by Rush's team contained 28g sucrose and 81mg caffeine per 250ml can, which is similar to the amount of sugar in soft drinks and caffeine in a brewed cup of coffee. The author believes these results could have huge implications when you think about how much sugar and caffeine people consume these days, and the high rates of inactivity. For the study, the New Zealand team recruited 10 healthy women aged 18 to 22 from a range of ethnicities. The subjects fasted overnight and were randomly given either 250ml of an energy drink or lemonade on the first day and the alternative on the second day of testing. The sugar in both drinks was absorbed rapidly into the bloodstream - within a minute and when caffeine is also present the sugar is more quickly converted to fat.
Sugar is a simple carbohydrate and evidence from this study shows that, coupled with a large amount of caffeine, the body rapidly turns it into stored fat. Professor Rush highlights that simple carbohydrates and caffeine were not such a large part of our diet in the past. Inactive people have trouble burning off excess energy and this leads to weight gain.
The findings are supported by a recent UK study, which found that caffeine increased cyclists' absorption of carbohydrates from a sports drink. But for those consumers not doing much exercise, these carbohydrates will be turned into fat.
The study also raises questions about the effects of consuming high-sugar foods and highly caffeinated drinks together in a short period of time. Caffeine lasts in the body for four to six hours, so people who have caffeinated drinks, including sugar-free energy drinks or coffee, and then eat sugary food within this time frame, may experience similar effects. This study is limited by its small sample size and the fact that the subjects were all young women. But the results are important as this area has not been explored before. This area needs further research, as well as the long term effects of combined caffeine and sugar on sedentary people's health.

The Healthy Eating Team suggest you limit caffeine containg beverages (to about one serve a day) and have more organic herbal and green tea - organic teas have less pesticides and green tea has 80% less caffeine than coffee.

More info on coffee
More info on soft drinks

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NUTRITION RESOURCES ON THE WEB

Funny but clever and insightful cartoon video clips about sustainable animal and

organic farming and what we can do to help the planet

The MEATRIX - http://www.themeatrix.com/

STOREWARS - http://www.storewars.org/flash/index.html

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HEC PRODUCTS