Cancer, Diet and Lifestyle: What We Know

Cancer, Diet and Lifestyle

Cancer develops by complex processes that are not yet fully understood. It is thought that the risk of development begins when the DNA is damaged possibly by reactive oxygen molecules, toxins, viruses and other reactive substances within cells. This is called the initiation phase. Most of the time, DNA is successfully repaired. When that does not occur, the next phase called promotion occurs where cells with damaged DNA divide into localized areas of the body. This process can occur from 10 to 30 years (“lag time.”). If there is still no repair, the next phase called progression can result with uncontrolled growth and spread of abnormal cells (metastasis) to other parts of the body (lung, liver, breast, bone, prostate, e.g.}.

According to Robert H, Lustig, MD, in his new book, Metabolical: The Lure and Lies of Processed Food, Nutrition, and Modern Medicine, epigenetics plays a strong role in gene expression. “Epigenetics refers to changes in the areas around our genes that can cause them to be turned on or off. Think of it this way: epigenetics is the on-off switch attached to the dimmer in your living room chandelier. The gene is the lightbulb, the epigene is the light switch. If the light bulb is defunct or the switch is frozen in the “off” position, the dimmer function is useless.” This may partly explain whether a disease or its risk is turned on or off. (SJF)

The eight leading environmental factors (other than genetic) related to cancer development are:

Obesity

Low vegetable and fruit intake

Physical inactivity

Smoking

Excess alcohol intake

Unsafe sex

Air pollution

Hepatitis B or C viral infection

DIET MODIFICATIONS

Consume a nutrient dense, whole-foods diet that predominantly includes plant foods. As Michael Pollan puts it, “Eat food, not too much, mostly plants.” Plant foods are rich in nutrients and phytochemicals that work synergistically to prevent many chronic diseases, primarily heart disease and cancer. Evidence exists that up to 45% of colon cancer cases could be avoided through diet and lifestyle changes alone.

Limit your consumption of high-calorie dense foods, primarily in the form of ultra-processed foods that are major contributors to weight gain leading to type 2 diabetes, or insulin resistance.

Cancers of the liver, pancreas, endometrium, colon, rectum, breast, and bladder are at higher risks for developing in obesity. Being overweight also raises the risk of developing non-Hodgkin’s lymphoma, multiple myeloma and gallbladder, liver, cervical, ovarian, and aggressive prostate cancers.

Be as lean as possible without becoming underweight. . The increased risk of disease appears to be due to a higher prevalence of metabolic disorders in many obese people. Approximately 70% of obese persons have two or more metabolic abnormalities such as:

Hypertension

Elevated triglycerides, glucose and/or insulin

Low HDL cholesterol (“good cholesterol”)

High C-reactive protein (a key marker of inflammation)

It may be helpful to be able to calculate your own weight status by using the Body Mass Index (BMI)You simply divide your weight in pounds by your height in inches squared X 703.

For example: BMI =140 pounds divided by 64 inches squared (4096) X 703 = 24.0. A healthy BMI is 20 – 24. Being underweight is considered a BMI of less than 19.0.

Limit your consumption of red meat (including beef, pork and lamb).  There are several reasons:

The International Agency for Research on Cancer (IARC) classifies red meat as a “probably carcinogen”.  You don’t need to give up meat; however, an intake of up to 18 ounces a week can be safely consumed without too much concern. BTW, 4 oz. is about the size of a deck of cards.

Another factor that raises cancer risk is the overcooking of red meat that produces charred areas of the meat – goodbye grill marks?). These create carcinogenic hetero cyclic amines (HCAs) that have been linked to pancreatic and colon cancers.

Another carcinogenic compound comes from burning the fat from meat when grilling that produce polycyclic aromatic hydrocarbons (PAHs), linked to stomach cancer.

Hint: Both compounds can be lessened by using a marinade on the meat.

Highly processed meats such as bacon, hot dogs, and lunch meats are known for their nitrite and nitrate content used as preservatives.  Smoking meats can lead to the formation of N-nitroso compounds which are considered carcinogenic.

Avoid deep-fried foods. When cooked in this manner, foods are exposed to a chemical called acrylamide that increases the risk of prostate cancer.

There are other lifestyle factors that can influence epigenetically the risk of any chronic disease. Alcohol intake, for example is important due to the carcinogenic effects of alcohol itself. 

“Chronic inflammation, which is strongly associated with being overweight, can increase the risk of developing cancer.  Excess belly fat produces hormones that can raise levels of insulin, estrogen and leptin, all of which have been linked to cancer development.” (Finlayson, 2019). 

The interconnected factors that trigger chronic diseases are vast and subject to manipulation by the body as well as our microbial environment. It would be wise to attempt to take the best care of your body as you possibly can and begin at an early age.  Aging as you know itself becomes a central factor in the development of any chronic disease. In 1980, Dr. James Fries, Professor of Medicine, Stanford University introduced the compression of morbidity theory. This theory states that “most illness was chronic and occurred in later life and postulated that the lifetime burden of illness could be reduced if the onset of chronic illness could be postponed and if this postponement could be greater than increases in life expectancy.”). That theory tells it all. (Unknown source). SJF

Source: Judith Finlayson. You Are What Your Grandparents Ate: What You Need to Know About Nutrition, Experience, Epigenetics & the Origins of Chronic Disease, 2019

Judith E. Brown, Nutrition Now, 7th Edition, 2013

Is DNA Your Destiny?

Thinking of getting one of those DNA testing kits?  Aside from the Ancestry tests, the tests for your future health risks may be questionable and at this point you may want to save your money. Here is why.

A new outlook on genetics is called epigenetics  and involves the concept of environmental factors (including diet) affecting how genes are expressed or inhibited. Thanks to this relatively new science, we now know that experiences of previous generations may show up in your health and well-being. Many of the risks for chronic diseases – including obesity, diabetes type 2, high blood pressure, heart disease and dementia can be traced back to your biological roots and the experiences your parent and even grandpaents had. Similarly, the food you eat may affect your children and grandchildren.

Is Your DNA Your Destiny?

Gene Expression: the process by which a cell converts the genetic code into RNA and protein

Epigenetics: the study of heritable changes in gene function that occur without a change in the DNA sequence itself

DNA Methylation: A chemical reaction that occurs in a cell when a methyl group attaches to DNA, changing the expression of the gene to which it is attached.

Methyl Group: A type of molecular structure that occurs in many compounds, CH3, for example.

Methyl Donor: Nutrients, like folate and vitamin B12 that when metabolized can donate methyl groups during the process.

To fully illustrate the epigenetic process, one must tell the story of the agouti gene.

The Result of Methylation

Methylation Effects in the DNA

Both these mice have the gene called the agouti gene that tends to produce fat, yellow pups, so we want to silence the expression of the gene if possible. There is a way.  The mom of the brown mouse was fed B vitamins which silenced the gene. This produced brown pups with normal appetites resulting in a thin, healthy mouse.

Without altering the genomic structure, agouti moms were then able to produce healthy brown pups of normal weight and less prone to diseases. Even more surprising, when the offspring become mothers themselves, their babies can also be healthy, even without further vitamin supplementation. The yellow variant had been silenced, and that muted effect was inherited by the offspring. 

How did this occur?  Some nutrients silence genes by providing methylation (adding a methyl group (CH3); others activate genes by inhibiting methylation. It’s like throwing a wrench into the DNA to stop the expression of a gene or removing the wrench to allow the expression of the gene. The B vitamins acted as methyl donors that caused methyl groups to attach more frequently to the agouti gene in utero, inhibiting its expression. (See the black dots in the diagram above).   Silence or inhibiting depends on what the gene does: e.g., silencing a gene that stimulates cancer growth is beneficial; silencing a gene that suppresses cancer growth would be harmful.

In any case, your lifestyle choices may play a role in your future health status.

It must be remembered that with any new concept, doubts and skepticism will occur. It must be recognized that we are not mice or lab rats, but the same effect has been shown by studying human interactions and is needed for more research to examine this interesting hypothesis. The   implications are enormous in that we may be able to improve our health status by choosing healthy habits and lifestyles such as diet, exercise, stopping smoking, for example.

“The packaging of the gene may be as important as, or even more important than, the gene itself, and these epigenetic changes are predominantly influenced by environmental factors.” The Cancer Code, A Revolutionary New Understanding of a Medical Mystery Dr. Jason Fung, 2020.