How Does Food Impact Our Health?

What Does Food Do In Our Bodies?

The nutrients in food enable the cells in our bodies to perform their necessary functions. This quote from a popular textbook describes how the nutrients in food are essential for our physical functioning.

"Nutrients are the nourishing substances in food that are essential for the growth, development and maintenance of body functions.” Essential” - meaning that if a nutrient is not present, aspects of function and therefore human health decline.

When nutrient intake does not regularly meet the nutrient needs dictated by the cell activity, the metabolic processes slow down or even stop."

- Perspectives in Nutrition, Wardlow and Insel

In other words, nutrients give our bodies instructions about how to function. In this sense, food can be seen as a source of "information" for the body.  Thinking about food in this way gives us a view of nutrition that goes beyond calories or grams, good foods or bad foods. This view leads us to focus on foods we should include rather than foods to exclude.  Instead of viewing food as the enemy, we look to food as a way to create health and reduce disease by helping the body maintain function.

Why Should We Care?

The nutrients in food give our bodies the information and materials they need to function properly. But our daily diets may not always be providing all the information our bodies need.

We all know that we need to get a basic balance of nutrients every day. But we may not be aware that our standard daily diet lacks nutrients. Moreover, some of our processed foods include chemically-altered fats and sugars that give our bodies the wrong signals.

If you are interested in more specific information on the nutrients you need and how best to get them.  This information springs from research coming out of an area of healthcare called Functional Medicine, which is a dynamic approach to assessing, preventing, and treating complex and chronic diseases, and includes research about the role that nutrition plays.

What Is The Connection Between Food and Disease?

As a society, we are facing significant health problems.

  • Our work forces are plagued with absenteeism and reduced productivity because of chronic health problems, including depression.
  • A large percentage of all countries healthcare expenditures is for the treatment of chronic disease.

Many researchers now believe that these problems are partly related to diet. While they used to believe that diseases-such as type II diabetes, obesity, heart disease, stroke, and certain cancers - were caused by a single gene mutation, they are now generally attributing these conditions to a network of biological dysfunction. And the food we eat is an important factor in that dysfunction, in part because our diets lack the necessary balance of nutrients (Proceedings of the Nutrition Society, 2004).

To prevent the onset of these diseases, we need to know how multiple nutrients in a diet interact and affect the human body's functions, according to the Nutrition Society, Europe's largest nutritional organization.

The Functional Medicine Perspective on Food and Health

One component of Functional Medicine focuses on how diet impacts health and function. When Functional Medicine practitioners examine the role of nutrition in chronic disease, they look at multiple systems, such as the digestive system, the immune system, and the detoxification system, because of the interconnections between those systems. For instance, because 80% of the immune system is contained in the gastrointestinal system, a person's issues with immunity could be related to faulty digestion.

Functional Medicine maintains that chronic disease is almost always preceded by a period of declining health in one or more of the body's systems. Thus, these practitioners seek to identify early the symptoms that indicate underlying dysfunction, possibly leading to disease.

One of the ways Functional Medicine seeks to address declining health is to provide the foods and nutrients needed to restore function. This is a cost effective, non-invasive intervention that aims to stop the progression into disease.

What Do Specific Foods Do?

You need only to view the movie Super-Size Me to understand how foods impact the body. In the movie, the director Morgan Spurlock chronicles the adverse health outcomes he experienced from eating nothing but fast food for several weeks. He not only gained weight, he experienced alarming metabolic changes that put him at risk for heart disease, diabetes, and hypertension.

Spurlock was eating foods that gave his body the wrong messages. For instance, in just a few weeks, the excessive amounts of saturated and trans-fatty acids in the fast food diet led to inflammation and higher blood cholesterol. In addition, the fast food diet failed to provide the information necessary for normal metabolic function, which also contributed to the health changes.

Morgan Spurlock is an example of what happens when food is broken down into nutrients, which then impact the metabolic programming of cells and the homeostasis (balance) in the body.   There is a growing realization that the effects of nutrition on health and disease cannot be understood without a profound understanding of how nutrients act at this molecular level (Nature Reviews Genetics, 2003).


This section looks at how food influences the maintenance of health and the prevention, alleviation, or cure of disease.  With knowledge, we can allow food to be our medicine and medicine to be our food as Hippocrates recommended so long ago.   THIS by the way, is the definition of MEDICINE. 

What is The Role of Fruits and Vegetables?

While the health-related benefits of a diet rich in fruits and vegetables is known to most, the scientific literature in the last nine to ten years has increasingly pointed out the influence of these food groups on a variety of diseases. For example, several studies, such as one recently published in the American Journal of Clinical Nutrition, show that the higher the consumption of fruit and vegetables, the lower the incidence of cardiovascular disease, including stroke.

The following is a list of resources that fruits and vegetables provide to the body:

  • Vitamins and minerals (including antioxidants, such as vitamin A, vitamin C, vitamin E and selenium).
  • Vitamins and minerals are found in all foods, but fruits and vegetables are a particularly good source for some vitamins and minerals. 
  • Fibre, which assists digestion, slows carbohydrate absorption, and promotes satiety. (See the whole grains section for more information on the benefits of fibre.).
  •  Phytonutrients.

What Vitamins and Minerals Do?

Vitamins and minerals are found in most foods, but fruits and vegetables are particularly good sources of many of these valuable compounds. Vitamins and minerals play a vital role in most metabolic processes. Complex interactions make it essential that the status of all vitamins and minerals be kept at optimal levels. Below are examples of the role vitamins and minerals play in your body:

Vitamin C helps:

  • Prevent cell damage from free radicals    
  • Boost iron absorption     
  • Enhance immune function, which increases resistance to disease   
  • Promote healthy gums and wound healing
  • Resolve bruising and recurrent infections

Sources of vitamin C:

citrus fruits, tomatoes, green leafy vegetables, parsley, cabbage, asparagus, avocados, cantaloupe, currants, mangos, kiwi, papaya, peppers, pineapple, and strawberries.

Vitamin A helps:

  • Prevent cell damage from free radicals
  • Maintain the tissue of the skin and gastrointestinal and respiratory tracts   
  • Enhance immune function natural killer cells and T-cells  
  • Heighten resistance to infection  

Sources of Vitamin A:

carrots, apricots, sweet potatoes, yellow squash, pumpkin, watercress, Swiss chard, greens, eggs.

Folic acid, Vitamin B-6 and Vitamin B-12 (three of the B-vitamins) are:

  • Vital for central nervous function  
  • Necessary for immune system function  
  • Needed for the metabolism of amino acids and the synthesis of proteins
  • Used in managing elevated homocysteine (an independent risk factor for heart disease)

Sources of B-vitamins:

dark green leafy vegetables, legumes, whole grains, nuts, and seeds.

To read more on these vitamins visit: Foods For Life: Natural Sources

What Do Phytonutrients Do?

In addition to vitamins and minerals, plants contain compounds called phytonutrients (sometimes referred to as phytochemicals). Essentially, these compounds are the plants' protection. A plant cannot fight or flee, so it is equipped with "phyto" or plant nutrients that defend against disease, blight, radiation, weather, insects and anything else that may threaten the plant's survival.

When we eat the plants, we not only benefit from the vitamin and mineral content of the plant, but from the protection these phytonutrients provide. Phytonutrients are considered anti-inflammatory and have been shown to possess anti-cancer properties, repair DNA damage, aid detoxification, enhance immunity, and influence insulin glucose balance.

How do you know if you are getting enough phytonutrients?

Hundreds of phytonutrients have been discovered thus far. Because fruits and vegetables contain different amounts of these beneficial compounds, it is best to eat a variety of plants. Phytonutrient content is categorized by colour (dark green, light green, red, orange, and purple.) If you get at least one from each of these colour groups daily, you will not only be getting a variety of beneficial phytonutrients, but meeting the recommended minimum of 5 to 13 servings of fruits or vegetables a day. (Note: while colour indicates the predominant phytonutrient content, most fruits and vegetables contain multiple phytonutrients.)

Examples of sources of beneficial phytonutrients

  • Cabbage, Brussels sprouts, broccoli, kale, cauliflower and turnips all contain the phytonutrient indole-3-carbinol.
  • Oranges, tangerines, lemons, and limes all contain a flavonoid called limonene.
  • Grapes, apples, cherries, blueberries, and raspberries contain anthocyanins.
  • Onions and garlic contain the phytonutrient quercetin.
  • Tomatoes, red pepper, watermelon and radishes all contain lycopene.
  • Peaches, carrots, apricots, pumpkin, squash; the phytonutrient carotenoids
  • Swiss chard, kale, parsley contain the phytonutrient lutein

What should you do?

Include from 2.5 to 3 servings of fruit daily and at least 4 servings of vegetables daily.  For more information on serving sizes visit our: 4-Food-Groups page and take a look at our: Eat From The Rainbow page.

What is the Role of Whole Grains?

Whole grains have long been recognized as containing beneficial nutrients vital to a healthy diet. Whole grains include vitamins and minerals, which are stripped out during food processing and may or may not be replaced by manufacturers supplementing the final product. Whole grains also include fibre, which is not replaced when refined, and which offer many essential benefits.

Whole grains provide information and materials to help the body do the following:

  • Regulate blood sugar (because complex carbohydrates are metabolized more slowly)
  • Aid digestion by producing good bacteria in the gut
  • Control appetite (because the fibre in the grains signals satiety-the sense of being full) 
  • Reduce cholesterol
  • Remove toxins (because fibre binds to toxins in the gut and removes them during elimination 
  • Improve digestive system function
  • Synthesize neurotransmitters (the chemical messengers made by the body, such as serotonin for sleep and mood) 

Sources of beneficial whole grain

  • Whole Wheat
  • Whole Rye
  • Oats
  • Brown Rice
  • Wild Rice
  • Spelt
  • Amaranth
  • Buckwheat
  • Buckwheat Groats
  • Bulgur
  • Kamut
  • Millet
  • Barley
  • Wheat Germ
  • Quinoa

What you should do?

Increase whole grains and limit refined grain products. When choosing grain products, be sure it says "whole grain" on the ingredients list. If it doesn't, it isn't whole grain.For more information on serving sizes visit our: 4-Food-Groups page.

What is The Role of Protein?

Contrary to popular belief protein does NOT mean MEAT.  The human body requires only 10% of its daily caloric intake in the form of protein.  A WFPB (Whole Food Plant-Based) diet, can easily provide 10-12% protein which meets the long established recommended daily allowance (RDA) of 9-10% protein.  In a WFPB diet beans are key sources of protein. Less is known about protein and its relationship to health and disease than fats or carbohydrates. It is known that protein is abundant in the body and regulates multiple messengers that keep us functioning.  Protein provides the body with amino acids, which we need daily because the body does not store them.  

Proteins provide information to help the body do the following:

  • Regulate blood sugar and insulin balance
  • Produce hormones that regulate mood and sleep
  • Detoxify  (during the second phase of detoxification in the liver, protein attaches to waste molecules and escorts them out of the body)
  • Make connective tissue for skin, cartilage and bone
  • Build muscle 
  • Promote wound healing
  • Aid adrenal and thyroid function
  • Produce and maintain a feeling of satiety (feeling full)

Some Sources of Protein

  • Almonds
  • Amaranth
  • Artichokes
  • Asparagus
  • Beans
  • Black eyed peas
  • Broccoli
  • Brown rice
  • Buckwheat
  • Chia seeds
  • Chickpeas
  • Green beans
  • Green peas
  • Hemp milk
  • Hemp seeds
  • Lentils
  • Nutritional yeast
  • Nuts
  • Oatmeal
  • Pumpkin seeds
  • Quinoa
  • Spinach
  • Tahini (sesame seed paste)

Visit these pages to gain more insight into the value of these foods: 

What you should do?

  • Get a good mix of proteins, from all WFPB and vegetarian foods.  Eat from the rainbow and ensure you eat from the 4-Food Groups.   Eating a variety of proteins will ensure that you get all of the amino acids (building blocks of protein) you need. 
  • Include beans, nuts, and whole grains, which offer protein without much saturated fat and with plenty of healthful fibre and micronutrients.

What is The Role of Fats and Oils?

The prevalence of low-fat diets in our culture leads many of us to assume that eating any fat is bad, but our bodies require some fat to be healthy. As scientific and public opinion of fats is slowly shifting, the emerging consensus is that eating the right kind of fats is important to health and the prevention of disease. 

Fats provide information to help the body do the following:

  • Provide insulation for the organs
  • Transport fat-soluble vitamins (A, D, E, K)
  • Provide materials critical to the integrity of cellular membranes
  • Lubricate mucous membranes and skin
  • Provide materials used to make hormones
  • Utilize glucose more effectively
  • Contribute to healthy joints
  • Enjoy efficient gut health 
  • Facilitate immune system function
  • Increase or decrease inflammation (depending on type of fat). Generally, we want to eat fats that decrease inflammation, such as oils from plants, nuts, and seeds and fats from fish whose diet is made up of algae (these all contain a predominance of omega 3 fatty acids).


we would prefer that you NOT eat fish, but of all the animal proteins, this one is probably the best of the worst.

Sources of Beneficial Fat

  • Flaxseed
  • Cereal grasses, such as wheat or barley grass
  • Dark green vegetables
  • Avocado
  • Seeds
  • Nuts
  • Coconut oil
  • Organic cacao nibs

Visit this page for more information on Fats, Oils and Omegas

Issues of mercury contamination

In Eat Drink and be Healthy, Walter Willett discusses issues of contamination in certain fish. He says that farm-raised fish are less likely to be contaminated by mercury and other toxins, but they may not be as high in omega 3 fatty acids, depending on what they have been fed. "If the fish are fed other fish or algae they will have a higher content of omega 3 fatty acids, but if they are fed wheat and corn they won't contain much.


Mercury contamination of fish is just ONE of the reasons why we do not include fish in our programs.

What you should do?

Enjoy beneficial fats. Get the majority of your fats from plants, nuts and seeds and remove saturated animal fats.  For more information, also visit: Micro and Macro Nutrients