Feedback—Your FAQs Answered

What effect good or bad, can a GI diet have on prostate cancer patients undergoing hormone treatment to limit testosterone?
We couldn’t find any published research on the links between the GI of your diet and hormone treatment for prostate cancer patients to limit testosterone. There are however, well established dietary guidelines for men to reduce their risk of prostate cancer by reducing the amount of red meat and high-fat dairy foods they eat and making sure they eat five or more servings of vegetables and fruits each day. Reducing the GI of your diet is now added to the ‘reduce the risk’ list as prostate cancer has been linked to high circulating levels of insulin. A study from Italy and Canada reports a direct relationship between dietary GI and GL and prostate cancer risk – men whose diets were highest in GI and/or GL were more likely to develop prostate cancer even after adjusting for all other factors. The researchers explain that low physical activity levels together with high GI carbohydrate and hence higher blood insulin levels were likely responsible for the increased cancer risk (International Journal of Cancer ( 2004; 112(3):446-50). The strength of this particular study is the large number of participants and controls and the use of a reproducible and validated questionnaire. For additional information, contact Claudio Pelucchi, Istituto di Ricerche Farmacologiche Mario Negri, Via Eritrea 62, 20157 Milan, Italy. E-mail: pelucchi@marionegri.it.

I enjoy brown rice and always assumed it had a lower GI than any kind of white rice, but I see that Basmati’s is lower. Why’s that?
The GI group is on the hunt for a brown low GI rice – stay tuned! Rice can have a very high GI value, or a low one, depending on the variety (there are around 2000 varieties worldwide) and its amylose content. Amylose is a kind of starch that resists gelatinisation. Although rice is a wholegrain food, when you cook it, the millions of microscopic cracks in the grains let water penetrate right to the middle of the grain, allowing the starch granules to swell and become fully ‘gelatinised’, thus very easy to digest. So, if you are a big rice eater, opt for the low GI varieties with a higher amylose content such as Basmati. These high-amylose rices that stay firm and separate when cooked combine well with Indian, Thai and Vietnamese cuisines.
Brown rice is an extremely nutritious form of rice and contains several B vitamins, minerals, dietary fibre and protein. Chewier than regular white rice, it tends to take about twice as long to cook. The varieties that have been tested to date have a high GI, so enjoy it occasionally, especially combined with low GI foods such as legumes.

Sushi rice (Koshihikari rice GI 48) is a short-grain rice with a slightly, sticky soft texture when cooked. Wild rice (GI 57) is not actually rice at all, but a type of grass seed.
Arborio rice releases its starch during cooking and has a medium GI.

Does it matter if you eat carbs after 5pm? Will this affect your fat metabolism?
The first point to make is that people with diabetes who are taking insulin or other blood glucose lowering medication should definitely not practice a carb curfew – they could develop a hypo. The second point is that there’s no scientific evidence yet to support the carb curfew theory. It’s certainly not endorsed by health authorities.

‘I think the “carb curfew” myth for weight loss arose from the body builders on one their pre-competition regimes,’ says dietitian Catherine Saxelby (www.foodwatch.com.au). ‘They are heavily into protein and denial and usually follow a semi-fast before a competition to remove surface fat and better define their muscles. Cutting out carbs like potato, pasta or rice with dinner is simply a way of cutting down on kilojoules (calories). That’s all. Here’s what you’ll save:

• Cut out a large baked potato and you reduce your dinner intake by 580 kilojoules.
• Cut out a cup of steamed white rice and you’re down 770.
• Cut out a cup of cooked spaghetti and you’re down 840.

So out of a total dinner intake of say 1200 kJ for grilled steak, potato and a salad, you can knock off over 50% if you say No to the carbs. That’s why you lose weight! But there’s no point in eating an unbalanced meal – it only sets you up to snack the night away because you’re still hungry. A steak or fish fillet with non-starchy vegetables is not a balanced meal. Add a small carb portion and you’ll feel a lot better and you’ll feel satisfied. Just half of cup of rice or pasta or a small potato or even a slice of grainy bread will balance things out nicely.’

Dispelling some myths about … Hypoglycemia

Hypoglycemia is a condition in which the glucose level in the blood falls below normal levels. It derives from the Greek words “hypo” meaning under and “glycemia” meaning blood glucose – hence blood-glucose level below normal. People with diabetes know all about it. If you don’t have diabetes, but you have vague health problems ranging from tiredness to depression and think you may have hypoglycemia or someone tells you that you probably have ‘low blood sugar’, see your doctor and get a proper diagnosis.

• Hypoglycemia is far less common that once was thought in people who do not have diabetes.
• Hypoglycemia due to a serious medical problem is rare.
• The most common form is reactive hypoglycemia, which occurs after eating.

What you need to know about reactive hypoglycemia
What is it?
If you have reactive hypoglycemia, it means that your blood-glucose level rises too quickly after you have eaten causing the release of too much insulin. This then draws too much glucose out of the blood, your blood-glucose levels fall below normal and you suffer a variety of unpleasant symptoms from sweating, tremor, anxiety, palpitations, and weakness to restlessness, irritability, poor concentration, lethargy, and drowsiness.

How is reactive hypoglycemia diagnosed?
Diagnosis is difficult because there are no clear diagnostic criteria. Your doctor may:

• ask you about signs and symptoms
• test your blood glucose while you are having symptoms (The doctor will take a blood sample from your arm and send it to a laboratory for analysis. A personal blood glucose monitor cannot be used to diagnose reactive hypoglycemia.)
• check to see whether your symptoms ease after your blood glucose returns to 70 mg/dl or 3.5 mmol/L or above (after eating or drinking)

If your doctor uses an oral glucose tolerance test (OGTT) to diagnose hypoglycemia you have to continue it for at least 3-4 hours (the normal time is 2 hours). Your insulin levels would be measured at the same time.

How is it treated?
The aim of treating reactive hypoglycemia is to prevent sudden large increases in your blood-glucose levels so you won’t produce excessive, unnecessary amounts of insulin and your blood-glucose levels will not plunge to abnormally low levels.

You can achieve smooth, steady blood-glucose levels by changing from high- to low-GI foods. This is particularly important when eating carbohydrate foods by themselves. Low GI foods like wholegrain bread, low-fat yogurt, and low GI fruits are best for snacks. If you can stop the big swings in blood-glucose levels, then you will not get the symptoms of reactive hypoglycemia and chances are you will feel a lot better.
—Source: The New Glucose Revolution

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