Fat and protein

Looking for the right balance

Fat and protein are essential parts of any balanced diet — but they're also key elements in the development of prostate cancer.

Although your body needs some fat to function properly and absorb nutrients from the foods you eat, there's a strong link between dietary fat intake and the risk of developing prostate cancer. There's convincing evidence that men with prostate cancer who eat higher amounts of fat experience more rapid cancer growth.

Getting enough protein is also crucial, and that can be diffi-

cult — especially if you're cutting down on meat and dairy products, the traditional sources of protein in Western diets. These so-called animal proteins, while high in protein, are also high in fat. The solution? Plant protein — a low-fat and versatile source of the protein your body needs. Of all the plant proteins available, soy is the most complete, offering a full range of essential amino acids and "cancer-fighting" isoflavones.

The fat factor

A low-fat diet is the first step on the road to prostate health. In China and Japan, the traditional diet has 15 to 20 percent of calories from fat. In North America, the typical diet includes 38 to 40 percent of calories from fat. Interested in this possible link between diet and prostate cancer, researchers have been putting the theory to the test — and the results are very convincing.

Recent studies have shown that fat or fatty foods are associated with the development of prostate cancer. When researchers put human prostate cancer cells into mice, the cancer grows faster if the mice eat a high-fat diet. It looks like the same might hold true for humans: At least one study suggests that prostate cancer is more likely to progress in men whose diet has a high fat content. And at New York's Sloan-Kettering Cancer Center, even men without established prostate cancer managed to reduce their prostate-specific antigen (PSA) values by eating a low-fat diet.

Hormones and fat

Dietary fats and cholesterol are part of the building blocks of androgens — male hormones associated with prostate-cancer development. It's theoretically possible that chronically elevated levels of testosterone, the major male androgen, can lead to prostate cancer. There's increasing evidence that high-fat diets can increase levels of

In China and Japan, the traditional diet has 15 to 20 percent of calories from fat. In North America, it includes 38 to 40 percent of calories from fat.

Get in the habit of reading food labels and choosing lower-fat options when you shop.

androgens. For example, vegetarians (who tend to consume less dietary fat) often have lower levels of testosterone than meat-eaters.

Steps to a low-fat diet

Eating a low-fat diet isn't hard to do. Start by avoiding fried foods, eating smaller (palm-sized) portions of meat (especially red meat), and cutting down on butter, margarine, oils and cream. Opt for more fruits and vegetables, beans and pasta, whole-grain breads, leaner cuts of meat and low-fat dairy products. Just be aware of what you're eating — and get in the habit of reading food labels and choosing lower-fat options when you shop for groceries. Pretty soon, making healthier choices will become a habit.

Protein: animal vs plant

Our bodies need protein to build tissue for growth and repair. The two sources of protein in our diets are either animal- or plant-based. We traditionally associate eating meats, fish and dairy products with good sources of protein. But the problem with these foods is that protein isn't always the main ingredient — fat is.

While meat is protein-rich, most cuts of meat are also high in fat: A T-bone steak, for example, provides only 20 percent of its calories from protein — fully 80 percent is from fat. Fish is a better source of protein because most types are naturally low in fat. Be careful, though: Canned tuna packed in oil has a 64-percent fat content, and frying any type of fish will ruin even the best of intentions (steaming, broiling or barbecuing are better options). Milk and dairy proteins, the final animal protein source, can also be very high in fat, most of it saturated (the "bad" kind).

Plant power

The solution to finding the right fat-protein balance is plant protein. If we could design a perfect food, this would be it — full of vitamins and minerals, low in fat and sodium, and high in protein, carbohydrates and fibre. Best of all, plant proteins taste good and they're inexpensive. And unlike meat, they deliver carbohydrates instead of fat along with the protein. The richest sources of these amazing vegetable proteins are legumes — dried split peas and beans.

There are literally hundreds of varieties of beans. Depending on the kind, one cup of beans has 150 to 300 calories and a healthy 12 to 25 grams of protein. Kidney beans, for example, provide 25 percent of their calories from protein and 70 percent from carbohydrates. But by far the best source is the soybean, commonly consumed in the form of tofu. It's the only plant protein that contains sufficient amounts of all nine essential amino acids.

There are at least two good reasons to add soy to your diet: It's a great source of low-fat protein and it also contains special ingredients called isoflavones, including genistein and daidzein — compounds likely to play an important role in holding off the growth of prostate tumours.

Studies based on the Asian population's lower prostate cancer rate show that Asians typically consume a low-fat diet filled with lots of tofu, tempeh and soy milk — all excellent sources of soy protein. Blood and urine analyses of Asian men have revealed that the samples contain anywhere from seven to 100 times more isoflavones than the samples of North American men. Plus, lab tests on

There are at least two good reasons to add soy to your diet: It's a great source of low-fat protein and it also contains special ingredients called isoflavones.

genistein, the type of isoflavone found abundantly in soy foods, show that it's a potent inhibitor of cancer cells, including prostate cancer.

■ Adding soy to your diet

After lowering your fat intake, the second most important step in a prostate-friendly diet is adding soy. Nutritionists recommend 40 grams daily, a figure established from laboratory research: Tumours grew more slowly when nutrition included 40 grams of soy protein. Yet the typical Canadian diet contains virtually no soy products. To learn more about the different types, see the box on the facing page.

Before you buy...

Keep in mind that adding soy to your diet may cause you to gain a few pounds if you don't adjust your regular eating habits, although lowering your overall fat intake may help counteract any weight gain.

Men who are on protein-restricted diets for medical reasons (diabetes, liver or kidney disease) should consult their doctors before adding soy to their diet.

Levels of isoflavones, number of protein grams, and fat and calcium content vary widely across different brands. Read the labels carefully to select the soy products best for you.

A GLOSSARY OF SOY PRODUCTS

Tofu — a semi-soft food made from adding mineral salt to soy milk — is a handy and nutritious substitute for meat. Like all soy products, it's an excellent source of protein and is low in fat. Surely the most versatile form of soy, tofu has varying degrees of firmness (the firmer it is, the higher the fat content). The softer form is best for sauces and dips; the denser type for grilling, baking and stir-fry-ing. Tofu lends itself well to a variety of recipes because it absorbs any flavours that are mixed in with it.

Soy milk is made from ground and cooked soybeans. The soy "milk" is filtered out during this process. It can be used as a dairy substitute — drink it straight from the carton, put it on your breakfast cereal, or use it as a replacement for milk in cooking or baking. It also comes in flavours like vanilla, strawberry and chocolate. Note: Avoid non-fat soy milk, since soybeans lose some of their beneficial properties when completely defatted. Opt for regular or low-fat varieties.

Tempeh, a textured vegetable protein (TVP) made from cooked and fermented soybeans, can also be used as a meat substitute. It's high in calcium, iron, zinc, fibre and it's cholesterol-free. Another TVP, miso, made from fermented soybean paste, is commonly used in soups.

Soy powder is available as flour (whole ground soy flour is best), granules or isolate. It's easy to use in cooking (just add water) and it also comes in different flavours: Mix it with fruit juices, soy milk or skim milk as a refreshing drink.

Soy sauce and Tamari: Most types of so-called "soy sauce" aren't made from soybeans at all — they're just coloured and flavoured water. To get the real benefit of soy, use tamari instead, which is a fermented brew made from soybeans.

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