The Western diet is the normal diet of Western Europe, North America, Australia and New Zealand. It comprises mainly of refined grains and processed meats, is low in plant foods, and has a high omega 6 to omega 3 fatty acid ratio. Increasingly, the Western diet is being implicated in disease. In particular, the Western diet is increasingly being seens as the causative factor in the high rates of cancer in developed nations.
Plants Protect From Cancer
Plant foods are protective of cancer. This is because there are chemicals in plants that have anti-cancer effects. Polyphenols, stilbenes and carotenoids have all shown anti-cancer effects in animal and humans studies. Epidemiological studies support a role for plant chemicals as a protective agent against cancer. Because the Western diet is low in plant foods, this explains the higher rates of cancer in developed nations.
Processed meats are popular in the Western diet. The long shelf lives of processed meats is due to the addition of nitrites and nitrates that are added to the meat to prevent spoiling. When consumed, reactions in the gastrointestinal tract convert nitrites and nitrates to nitrosamines. Nitrosamines are carcinogenic and are thought to increase the risk of gastrointestinal cancers such as esophageal, stomach, colon and rectal cancers.
Omega 6 Fatty Acids
The Western diet contains too many omega 6 fatty acids and too few omega 3 fatty acids. The unbalanced ratio of omega 6 to omega 3 fatty acids, which may be as high as 20 to 1, is a cause of inflammation and oxidative stress, and this may increase the risk of cancer. Traditionally, the omega 6 to omega 3 ratio was around 3 to 1, and at this ratio anti-inflammatory effects occur that may protect the individual from cancer.
trans Fatty Acids
The processed food that characterises the Western diet contains hydrogenated vegetable oil. As part of the process of forming this toxic oil, trans fatty acids are produced. These fatty acids are similar in shape to many natural fats in the diet, and so they interfere with the metabolism by inhibiting enzymes and transporters. This can result in metabolic dysfunction and disease. Increasingly trans fats are implicated as a causative factor in cancer.
Traditional diets are those historically consumed by populations. Traditional diets differ depending on the geographical region, but all share the common feature of containing no processed foods. This means that they are free from trans fats and processed meat, contain high amounts of plant foods, and have a low omega 6 to omega 3 ratios. This explains the protective effects of these diets against cancer and why those who consume them have a virtual absence of cancer.