Dietary Methionine Restriction and Cancer
Methionine is an essential amino acid. Amino acids are considered the building blocks used to make proteins. Amino acids including methionine are also used for many other processes within the body. Some of these other processes that methionine is involved in makes it an interesting target in terms of cancer treatment.
Several recent studies, both human and animal, show that methionine restriction inhibits cancer growth and can actually increase lifespan. One of the major mechanisms by which methionine restriction is thought to work is by limiting a process called methylation. Methylation occurs when a chemical group consisting of one carbon atom and 3 hydrogen atoms (-CH3) is attached to some other molecule. In cancer cells too much methylation, termed hypermethylation, can cause problems.
When the DNA in cancer cells become hypermethylated this can cause several cancer promoting changes. There is a silencing of certain growth inhibitory and pro-apoptotic genes. These genes would typically limit the growth of cancer cells and cause them to self destruct. When hypermethylation occurs these genes dont work the effect is increased cancer growth. Additionally, hypermethylation of a cancer cells DNA can also make those cancer cells less susceptible to DNA damaging agents, ie. chemotherapy or radiation. For these reasons restricting methionine intake and thus the hypermethylation it promotes can be advantageous for people fighting cancer.
Methionine restriction has another interesting cancer fighting effect. Methionine contains sulfur and can provide a cancer cell with a steady supply of this mineral. Sulfur is an essential component of a potent antioxidant called glutathione. This is important because the more glutathione cancer cells can store inside of themselves the more resistant they may be to cancer treatments. Many therapies, both conventional and alternative, work by creating a high level of free radicals within cancer cells. These treatment-induced free radicals steal electrons from the cancer cell, and if enough electrons are stolen then cell can be terminally damaged. Glutathione, being an antioxidant, can supply the treatment-induced free radicals with the electrons they desire, ultimately sparing the cancer cell and making treatment less effective.
Avoiding dietary methionine in the diet typically involves adopting a nearly vegetarian diet. Foods with the highest amount of methionine include animal meats such as chicken and fish. Red meat, eggs, and dairy products also contain high levels of methionine. Almonds, Brazil nuts, and soybeans also contain methionine and their intake should be limited when following this diet.
It is important to work closely with your doctor when starting this diet while undergoing cancer treatment. Fighting cancer is a physiologically demanding process, and as such it is very important that people dont deprive themselves of healthy nutrition during cancer treatment. One strategy that has been used is to cycle on and off a methionine restricted diet. Timing the methionine restriction along with treatment may provide an additive cancer-killing effect.
Dietary manipulation in cancer treatment is an important and often overlooked way to positively impact cancer treatment. The video below is a great explanation of all this and its importance. For more information about naturopathic and integrative cancer therapies contact Longevity Medical Health Center today.
Article contributed by Dr. Jonathan Psenka