It's a diet that's been shown over and over again to protect your heart. Plenty of research has revealed that the Mediterranean diet - rich in fruit, vegetables, nuts, beans and olive oil - helps lower cholesterol and blood pressure, and reduces the risk of dying from heart disease.
Now, a study published today in the Journal of the American Medical Association has found that a pattern of eating that's good for your heart may also ward off Alzheimer's disease, a degenerative brain disease that causes thinking and memory to become seriously impaired.
The findings make a strong case for swapping our North American diet, heavy in meat and processed foods, for one rich in plant foods that's been the focus of research for more than 50 years.
In the study, researchers from the Columbia University Medical Center in New York set out to examine the relationship between diet and exercise on Alzheimer's disease in 1,188 elderly adults, average age 77, without dementia who were living in Manhattan.
Previous research has explored the role of diet and exercise in the development of Alzheimer's. A 2006 report conducted in the same group of study participants found that adhering to a Mediterranean-style diet was protective.
While studies have hinted that physical activity can slow cognitive decline, its relationship with Alzheimer's remains unclear.
The current study expands on earlier findings by evaluating the association between Alzheimer's and both physical activity and diet.
When physical activity was considered alone, exercise was protective. And the more exercise, the greater the protection. Compared with those who were inactive, folks who reported the most physical activity each week - 1.3 hours of vigorous, 2.4 hours of moderate or four hours of light exercise - were 37 to 50 per cent less likely to develop Alzheimer's disease.
The researchers found that both diet and physical activity were significantly associated with protection from the disease.
People who adhered most closely to a Mediterranean-style diet had a 32 to 40 per cent reduced Alzheimer's risk. (Adherence to a Mediterranean-style diet was scored as low, medium and high.)
What's more, the risk of Alzheimer's gradually decreased with more exercise and higher diet adherence. Individuals with the highest scores for both physical activity and Mediterranean-type diet were 67 per cent less likely to be diagnosed with Alzheimer's during the study.
There are a number of ways in which exercise and diet may guard against Alzheimer's disease. Cardiovascular (aerobic) fitness has been related to less age-related brain deterioration, increased blood flow in the brain, reduced inflammation and increased levels of certain brain chemicals.
A Mediterranean-style diet combines several foods and nutrients such as fish, monounsaturated fat, vitamins B12 and folate, vitamin E and flavonoids that may reduce free radical damage and inflammation, two factors that contribute to the development of Alzheimer's.
The Mediterranean diet may also keep your brain healthy through its protective effects on blood vessels. The diet has been shown to protect from obesity, Type 2 diabetes and hypertension, risk factors that damage blood vessels and that have also been linked to a greater risk of Alzheimer's.
It may be premature to recommend adopting a Mediterranean diet to help fend off the disease. But the mounting evidence that it offers so many other health benefits and may even prolong your life makes it, in my opinion, one of the healthiest eating patterns.
The following tips will help you incorporate elements of the Mediterranean diet into your own eating pattern:
Grains, vegetables, fruit
These foods should be eaten at most meals. Choose whole grains that are minimally processed such as brown rice, barley and whole grain pasta.
While all vegetables are nutritious, spinach, eggplant, tomatoes, broccoli, peppers, mushrooms, garlic and green beans are staples in Mediterranean cuisine. Fruit is typically served for dessert; choose whole fruit over fruit juice to increase fibre intake.
Olives, olive oil
This monounsaturated fat is the principal fat in the Mediterranean diet, replacing butter and margarine. Choose extra virgin olive oil, which is higher in phytochemicals, compounds thought to reduce inflammation.
Fish, shellfish
These high-protein foods are low in saturated fat. Salmon, tuna, sardines and herring are rich in omega-3 fatty acids. Eat grilled, sautéed or baked fish or shellfish two times a week.
Cheese, yogurt
These dairy products are eaten daily in the Mediterranean diet, but in low to moderate amounts.
Legumes, nuts, seeds
These foods add protein, healthy fats, fibre, vitamins and minerals to the diet. Use them to add flavour and texture to dishes.
Eggs
The Mediterranean diet includes up to four eggs a week, including those used in cooking and baking.
Meats
Lean cuts of meat, only a few times a month. In Mediterranean cuisine, veal and lamb are most often consumed. Poultry is also a lean protein choice.
Sweets
Desserts such as sorbet and gelato are served only a few times a week, in small portions.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Her website is lesliebeck.com .
Leslie Beck