Originally published in The Ottawa Citizen March 30, 2004
Original Title: The diet of the ages
It seems that every week there is another diet or celebrity offering the Holy Grail of diet and health nirvana. Indeed, nutritional science researchers are casting healthy skepticism on their claims.
The pace of health information and reporting can overwhelm and confuse people who are trying their best to select a proper diet lifestyle.
So, based on the latest evidence, what is the state of our understanding about diet and disease prevention?
Cardiovascular disease and stroke are the leading causes of death in our society. The lifetime risk of dying from cardiovascular disease is one in two for women and one in three for men.
The growing body of evidence suggests that the more raw fruit and vegetables consumed, the less the risk of stroke and heart disease. Studies indicate that people following diets that include five to six servings of cruciferous vegetables such as broccoli, cauliflower, cabbage and brussels sprouts, citrus fruits, green leafy vegetables and vitamin
C-rich fruits and vegetables have the lowest risk of stroke and heart disease. More than six servings per day did not confer any additional risk reduction.
Some of the proposed explanations for these findings are that these foods contain above average amounts of folic acid, potassium, antioxidants and fibre. All of these nutrients seem to offer protection against heart disease and stroke.
High-fibre diets can lower insulin levels, reducing the risk of heart disease and stroke. Cereal fibre has the strongest association with reduced risk. Studies indicate a 40- to 50-per-cent risk reduction for heart attack in high-fibre eaters (greater than eight grams per day) compared to those with a low intake (less than 3.2 grams per day). This has been borne out by the Framingham Heart Study and other research.
It is the soluble fibre found in fruits, vegetables and legumes that will improve the control of sugar levels in diabetics. It can help reduce the risk of obesity. A previous column (http://members.rogers.com/barrydworkin/sugars_not_equal.html) explains why diets rife with high glycemic index (GI) foods can increase the risk of type 2 diabetes. Indeed, the Canadian Diabetes Association dietary plans are based on the consumption of low-GI foods.
Although there is a negative connotation to fat consumption, it is the type of fat consumed, rather than the amount, that is significant. Hydrogenated fats (trans fatty acids) and saturated fats (animal products) increase the risk of coronary heart disease, whereas polyunsaturated fat (e.g. canola and corn oil) and monounsaturated fats (olive oil) lower the risk by decreasing cholesterol levels.
Although there is evidence correlating moderate alcohol consumption with a reduced risk of heart disease, especially among older men and women, a safe maximum has yet to be determined. The confounding factor is that alcohol is associated with an increased risk of breast, colon and liver cancers.
Eating should be an enjoyable experience, not a chore or laden with guilt. The consensus and recommendation for a healthful diet and heart health favours fresh foods over prepackaged and prepared foods.
Try to make fruits and vegetables part of every meal. Eat five to six servings a day (canned and frozen are acceptable alternatives). Choose different colours as each has different nutrients. Add fruit to your cereal and eat vegetables as snacks. Leave a bowl of fruit out for the children to snack on.
Make cereal fibre a dietary staple. Eat folate-rich foods such as fortified high-fibre cereals, oranges, orange juice and green leafy vegetables.
Avoid trans fatty acids (hydrogenated fats) and saturated fat. Choose chicken, fish or beans instead of red meat and cheese. Many store-made baked goods such as crackers, cookies and cakes contain hydrogenated fats. Margarine users should choose Becel because it does not have hydrogenated oils. Use canola and olive oils for cooking.
The evidence suggests that by sticking to low glycemic index foods, reducing your intake of alcohol, saturated fat and processed foods, and increasing your soluble fibre intake, you will have a healthier life. This does not impose insurmountable restrictions, is moderate in scope and is less difficult to implement than a wholesale change in eating habits and food selection as seen in some of the more popular diets. Moreover, it is sustainable and has a better chance of reducing weight and keeping it off.
Diabetics should consult their dietitian or physician before changing their diet to ensure that they will have proper blood sugar control.
© Dr. Barry Dworkin 2004