Food As Medicine

What's in this section? 

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

After a quick consideration of the role of genes, we look at the role of some categories of foods (click on a link if you want to go directly to that food category):

• Fruits and vegetables
• Whole grains
• Protein 
• Fats and oils

How do nutrients interact with genes?

One of the breakthrough concepts from the Human Genome Project is that "genes in and of themselves do not create disease. Only when they are plunged into a harmful environment unique to the individual do they create the outcome of disease."

An advancing area of study called Nutrigenomics looks at how different foods may interact with specific genes to modify the risk of common chronic diseases such as Type II diabetes, obesity, heart disease, stroke and certain cancers. 

Nutrigenomics also seeks to identify the molecules in the diet that affect health by altering the expression of genes. (For example, by triggering the genes that start the onset of Type II diabetes.)

For example, one study showed that participants who consumed a diet of whole rye (low-insulin-response) experienced changes in their gene expression that reduced their risk of developing diabetes. Participants who consumed an oat-wheat-potato (high insulin response) diet experienced the opposite-a change in their gene expression that increased their risk. 

As an editorial published in the American Journal of Clinical Nutrition (2007) noted in response to this study-we are spending millions to find drugs that can impact our production of hormones such as insulin, when there might already be a simple dietary strategy. The editorial concludes, "The results of the present study emphasize the age old wisdom to use food as medicine.

We cannot change our genes, but we can change the environment which impacts how our genes manifest. One important component of this environment is food.

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, C, E and selium). Vitamins and minerals are found in all foods, but fruits and vegetables are a particularly good source for some vitamins and minerals. 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. 
• Phytonutrients are considered anti-inflammatory and offer many health benefits outlined below.
• Fiber, which assists digestion, slows carbohydrate absorption, and promotes satiety. (See the whole grains section for more information on the benefits of fiber.)

Example: An apple a day

Apples contain a rich source of a variety of phytonutrients. Epidemiological studies have linked the consumption of apples with reduced risk of cardiovascular disease, asthma, diabetes, and some cancers. Apples have been found to have very strong anti-oxidant activity, inhibit cancer cell proliferation, and decrease lipid oxidation and lower cholesterol (Nutrition Journal, 2004).

What is the bottom line about fruits and vegetables?

The bottom line is: include from 5 to 13 servings of a variety of fruits and vegetables daily. A serving is one piece of fruit, ½ cup of vegetable, 1 cup of salad greens, or ½ c of juice (choose juices without added sugar or corn syrup).

For more information, go to the Linus Pauling Institute, which gives scientific information regarding the role of vitamins, minerals, and other nutrients and phytonutrients.

What is the role of whole grains?

Whole grains offer a number of important health benefits, including:

• Regulate blood sugar (because complex carbohydrates are metabolized more slowly)
• Aid digestion by producing good bacteria in the gut
• Control appetite (because the fiber in the grains signals satiety-the sense of being full) 
• Reduce cholesterol
• Remove toxins (because fiber 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) 

What is the role of protein?

Meats, fish, and beans are key sources of protein in our diet. 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)

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).

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." Willett recommends monitoring farm fishing by requiring a label that gives omega-3 content of farm-raised fish. To help choose a fish with lower mercury content, go to the US Environmental Protection Agency fish advisory.