Today, we’re talking with Dr. Carol Greenwood - a senior scientist at Baycrest’s Rotman Research Institute and a professor emeritus at the University of Toronto’s Department of Nutritional Sciences. She is a co-author of Mindfull – the first science-based e-cookbook for the brain (for more information click here), and has also co-authored the first Canadian Brain Health Food Guide (English guide download or French guide download).

What we eat plays an important role in fueling our brains, but it is critical that we consider our broad nutritional needs – instead of focusing too much on a single type of food, nutrient or spice. In other words, global diet is more important than individual foods. We will also be talking about the social context in which we prepare and consume our foods, and how that contributes to our brain health.

About Dr. Carol Greenwood:

Dr. Carol Greenwood is a traditional nutritionist, with a PhD in nutrition. She became interested in the role of diet in maintaining brain health about 30 years ago and has been working in that area for most of her professional career. In the last decade, her focus has been at the nutrition-brain interface, and she has been interested in issues around brain aging, maintaining cognition with aging, and looking at ways that we can lower our dementia risk.

Benefits of healthy eating on brain function:

The brain, like every tissue in our body, is reliant on healthy nutrition throughout its life span. And not only, I think, in terms of looking at maintaining the health of what Carol calls “south of the neck” - making sure your blood vessels stay healthy, so that we get a good supply of nutrients to the brain; but, also making certain that the brain has the nutrients that it needs in order to be able to function. It is when these things start to diminish, that we start to run into problems that can actually either be the beginning of early disease, or alternatively, could accelerate any disease that was already present. So, it's really a lifelong issue and it’s important that we recognize that the brain has its own needs for nutrition the same way that our heart and our muscles do.

Note – taking too much of a specific nutrient, can ultimately become toxic for the body. Also, avoid focusing too much on single foods or single nutrients. We really need to have all of the nutrients in our diet and no one single food is going to be able to do that. For instance, Carol is constantly asked if red pepper is healthy for our brain, and the answer to that is yes, but so are green peppers and yellow peppers and broccoli and a whole bunch of other foods, and so it's really trying to pull back and look at the broad context of the food that we're eating, rather than worrying about single foods or single spices or single nutrients.

Also, be sure to consider the social context in which you are eating. The social context is so important because it keeps us engaged, it keeps us connected, it brings joy into our lives. When you think about the components of healthy aging and healthy brain aging, maintaining that social connectedness, keeping yourself cognitively engaged is so important too, and that is very closely connected with food preparation and food consumption. Eating food together keeps your network going and keeps you socially connected. So, Carol would say that the stimulation of the brain around all of those healthy activities that go with eating are also important in terms of ways that our diet can contribute to our health. Healthy tip: consider your social context - engaging with your community and your family and your friends - when planning, preparing and eating healthy meals.

It is also important to remember to keep healthy foods in your refrigerator and pantry - if it's not in the house, you're not going to eat it. And, keep foods that you shouldn’t be eating, out of the house. It is a simple rule, but an extremely useful one. Healthy eating habits begin with how you shop for your groceries. Try to limit how much unhealthy quick foods you have in your house. If you're starving and  the only thing that you can quickly grab and eat at home is unhealthy (e.g., a bag of chips), it will be really hard to say no. In contrast, if that same bag of chips is at the corner store, it will be a lot easier to say no - are you really going to go out and  get the bag of chips or, are you just going to prepare something with the healthy food that you have available in your own home? If that carton of ice cream or bag of chocolate chip cookies is at home, you're going to go to that before you're going to go to carrot sticks. But if you don't have ice cream or chocolate chip cookies in the house, then you're going to reach for the apple or the carrot.

People are now being encouraged to move towards a more plant-based diet; so, it is important that there is a good selection of foods that you can rapidly make into meals that are plant-based. So, whether it's making certain that you 1. have the heartier vegetables, like the cauliflowers and the broccolis that can easily go into a salad or a pasta, or 2. have canned beans that you can mix into salads and soups, it is important to keep your pantry stocked with the core of what's needed for the plant-based diet.

Note: Going towards a plant-based diet, doesn't mean that we have to abstain from meat. It simply means that we should be reducing our reliance on it.

Healthy food substitute: Mix tuna with some white beans (instead of mayonnaise) and some chopped red onion, and a little bit of red wine vinegar and olive oil.

Taking leftover lentils from one night and turning them into a salad the next:

Carol sautéed carrots, celery and onion, and added in the leftover lentils. She then chopped some tomatoes, peppers and celery, added some roasted salmon and used everything to make a large salad.

What are healthy fats?

Quick tip: heart healthy = brain healthy. A lot of that comes back to what Carol said before about keeping our blood vessels healthy, because if we start to get any kind of blockage, obviously our brain is not going to be well fed. So, it is important to keep away from the saturated fats, going more towards the mono-unsaturated fats, the types of fats that are in olive oil, which are key to a lot of what is considered “heart healthy” (maintaining the blood vessels is really why we're doing it in terms of brain health).

What about omega-3s?

If you look uniquely at the brain, that's really when the story of the omega-3s come in, because the brain is made up of a lot of fat, and - of any organ in the body - it has the highest concentration of omega-3 fats. We have to consume omega-3 fats, because we can't make them in our body.

Sources of omega-3s: e.g., fish, nuts, flax seeds.

In addition to consuming omega-3 fatty acids, it is also very important that you avoid saturated fats. These are predominantly any kind of fat that is hard at room temperature. This latter part relates more to maintaining the health of our blood vessels.

What about olive oil? We know that olive oil is good for us, but is cooking with olive oil bad? In fact, cooking with any oil at a high temperature is bad and here’s why: When we talk about fats either being saturated or unsaturated, it really is referring to whether or not they have something that we call a double bond. So, the double bond is what makes a fat unsaturated. And those double bonds can be broken in the face of a lot of heat, and then they turn into compounds that are less healthy for the body.

Any oil that you would heat to a high temperature that would have those double bonds in it, you're going to get them broken. And that fat is going to deteriorate with cooking. The fact is: some fats are better able to withstand heat, as compared to others.

Is olive oil one of those fats that doesn't withstand heat as well as some of the others?

The reality is, it's probably middle of the road in terms of its ability to withstand heat. So, as long as you're not frying at ultra high temperatures, you're fine with the olive oil. NOTE: what you shouldn't be doing ever, when you're cooking with oil, is allowing it to heat to get to the point where it's smoking. Once it's smoking, you know it's breaking down. Medium heat, olive oil is fine.

Rule of Thumb: At the end of the day, the more whole foods we are eating, the better off we are. If you look at where we get the saturated fats and the salts and the simple sugars in our diet, it's generally in pre-packaged foods, many of which are sweet or salty in terms of our snacks.

Highlights from the new Canadian food guide:

• Eat mostly whole foods

• Half of our plate should be plant-based vegetable, fruit

• A quarter of our plate should be sources of protein (vegetable- or animal-based proteins)

• Add in some grains

Carol says that if you focused on the above, then you won’t have to worry as much about the saturated fats, the salts and the simple sugars, because you're only going to buy those cookies and potato chips and pretzels on occasion and use them as a treat.

What research is Carol working on at Baycrest?

In the last little while, they’ve developed the Brain Health Food Guide (English guide download or French guide download), which draws on the scientific evidence in terms of what diets seem to be best associated with retention of cognitive function as we age, and it's very similar to our new Canadian food guide.

At Baycrest, they’re currently in the process of running a clinical trial, where they're combining healthy eating with exercise and looking at whether or not that can do two things:

1. Improve blood flow to the brain

2. Improve cognitive performance, including memory and higher level thinking abilities– aka executive functions

The clinical trial is six months that they're having people come in and helping support in terms of changing lifestyles as it relates to diet and exercise.

There are also other trials going on at Baycrest, many of which are focusing on prevention or retaining cognition with aging. Specifically, they are looking at certain aspects of lifestyle that they know are important and then evaluating ways that they can support people to adoptive healthier lifestyles.

To find our more, you can visit the Baycrest website or call Kaljani Mahalingam at 416-785-2500 x3315, and be sure to indicate that you are interested in the diet and exercise study or the study on lifestyle behaviours.

To access the Brain Health Food Guide - you can download the guide in English (click to download) or in French (click to download).

Click here for more information on Mindfull (co-authored by Dr. Carol Greenwood), the first science-based e-cookbook for the brain.