Last week we discussed the benefits of a predominantly plant-based diet in protecting our bodies from breast cancer – but actually in promoting health of all our organs, and protecting against most cancers.  Plant foods have hundreds of thousands of phytochemicals, many of which are only beginning to be understood for their role in promoting health.  No wonder the western highly-processed diet has been associated with all manner of ill-health, stripped as it is of all these natural life-supporting properties.

ALSO READ : Turning the Tide – Lifestyle Medicine and Breast Cancer (Part 3)

This week we will again garner relevant information from the chapter on what not to eat in Kristi Funk’s book “Breast’s, the owner’s manual”.  There is so much soundly researched information to be found in her book – we can only hope to whet your appetite to purchase the book for yourself.

Around the world there is increasing evidence to suggest that the consumption of animal products  is strongly associated with many of the lifestyle diseases so prevalent in our modern world, particularly cancers.  Breast cancer is one of those cancers that shows rapid rise in incidence as cultures move away from more traditional plant-rich, minimally processed diets to the animal product-rich diets typical of western countries.  The World Health Organization (WHO) has identified processed meat as a Group 1 carcinogen for colon cancer (“there is convincing evidence that the agent causes cancer”). But WHO also states that evidence suggests that all red meat is probably carcinogenic to humans (WHO bulletin October 2015).

This blog is far too brief to go into all the scientific studies mentioned in Kristi’s book.  Some of the factors in red meat, white meat and even in fish associated with increased cancer rates are:  natural and synthetic oestrogens (often used in farming methods to boost growth – banned in many countries but still used in South Africa -), heme iron, N-nitroso compounds and saturated fat.  How do these substances increase the risk of cancer?

• Increase insulin-like growth factor-1 (IGF-1) – a growth stimulator, strongly influencing cancer cell growth
• Producing carcinogenic heterocyclic amines (especially through high-heat food preparation)
• Stimulation of inflammation
• Stimulation of oxidative stress

Critics of plant-based advocates quote studies showing minimal increase in cancer in heavy meat eaters, compared to those who eat less meat.  However studies that have looked at comparisons between meat-eaters and non-meat eaters have shown very significant reduction in breast cancers.  One such study is the Adventist Health Study-2 which has followed 69,000+ participants over many years.

Let us examine some of the above factors in a bit more detail:

• Hormone additives to animal farming. One of the hormones used in the US, Canada and in South Africa, but banned in the EU is Zeranol, a potent oestrogen which stimulates growth in calves.  The reason it was banned in the EU is because of proven association between consumption of meat from Zeranol treated calves and precocious breast development in girls and even young boys.  There is also evidence that it is associated with increase in breast cancer risk through a number of pathways.
• Increase in production of IGF-1 is strongly associated with consumption of animal protein – meat, eggs and dairy. Yet eating protein of plant-origin does not have this effect.  Interestingly people who have a genetic defect in which they do not respond to IGF-1 never get breast cancer or type 2 diabetes.  A fibre-rich diet high in whole plant-foods and low in fats, and a lifestyle which includes regular exercise, is a potent way to reduce excessive IGF-1.
• Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) are cancer-causing compounds that form on the surface of well-done and grilled, smoked, roasted, pan-fried and braaied meats. They form within minutes at high temperatures. There are strong statistical associations with breast cancer – up to 121% higher risk for beefsteak lovers.  Burnt meat is bad for your risk of breast cancer (apart from its effect on your heart and blood vessels).
• Nitrates often added to processed meat to maintain pink colour and to prolong shelf life. When combined with meat these often transform into carcinogenic nitrosamines or nitrosamides.
• Saturated fat as found in animal products is a problem. Dairy is a primary source, especially full-fat dairy, and concentrated dairy as found in cheese.  Modern cows are genetically bred to produce milk for much of their lives – even when they are pregnant.  Pregnancy and post-pregnancy are hormone-rich seasons of a cow’s life, and thus their milk is laced with hormones – concentrated in the milk fat.  Cheese is highly concentrated milk so has up to 10 times more hormones than fresh milk.  So it is not surprising that there is a strong correlation in studies that have looked at breast cancer incidence amongst dairy consumers vs those who consume little or no dairy.  Another source of harmful fat is trans-fat or partially hydrogenated fat – as found in so many processed foods, as well as meat and dairy.  A major source of dietary saturated fat in the USA is cheese/pizza.  Judging by how many pizza outlets occur in S Africa, I imagine there is a close contest between meat and pizza.  Saturated fats are also found in palm and coconut oil.  In fact coconut oil has 90% saturated fat.  Palm oil is now in just about every processed food – even peanut butter!  Look at any list of ingredients and you are sure to find palm or palm-fruit oil in there.
• Another problematic fat is omega-6. Although an essential fatty acid, in excess it displaces omega-3 which has so many health-promoting effects.  Modern western diets have far too much omega-6 in a ratio up to 16:1 omega 3.  This ratio should be around 1:1.  This imbalance promotes inflammation that feeds a host of chronic illnesses, including heart disease and cancer.
• There is much controversy about the role of eggs in disease promotion. Harvard researchers have found a strong correlation with the consumption of as little as 2,5 eggs per week and 81% increase in mortality from prostate cancer, so it is likely to have a similar effect in breast cancer.  Eggs are also the main source of dietary cholesterol for many people.
• Alcohol has many adverse effects on breast health through various pathways. Just one drink per day increases your risk by 10%, 2 drinks by 30%, etc.  If you must drink make sure you eat plenty of leafy greens to counteract the negative effect on folate metabolism by alcohol.  However some recent very large multi-centre studies have shown no health benefit from any amount of alcohol.

Does this article leave you feeling flat and discouraged – have we challenged your favourite eating habits?  Well, it is good to take time to reflect on what you really want out of life – short term pleasure, or the benefits of a long and productive life, full of zest for living.  It is not about bad and good, as much as it is about what is best for you, your family and your future.

Next week we will look at other factors that are correlated with the high incidence of breast cancer within the environment and lifestyle related.

This article is meant to remind us all that we don’t have to be powerless to defeat cancer – there is so much we can do to prevent and restore our health through positive choices.

Have a great week.

Dave Glass

Dr David Glass graduated from UCT in 1975.  He spent the next 12 years working at a mission hospital in Lesotho, where much of his work involved health education and interventions to improve health, aside from the normal busy clinical work of an under-resourced mission hospital. 

He returned to UCT in 1990 to specialise in obstetrics/gynaecology and then moved to the South Coast where he had the privilege of, amongst other things, ushering 7000 babies into the world.  He no longer delivers babies but is still very clinically active in gynaecology.

An old passion, preventive health care, has now replaced the obstetrics side of his work.  He is eager to share insights he has gathered over the years on how to prevent and reverse so many of the modern scourges of lifestyle – obesity, diabetes, ischaemic heart disease, high blood pressure, arthritis, common cancers, etc.

He is a family man, with a supportive wife, and two grown children, and four beautiful grandchildren. His hobbies include walking, cycling, vegetable gardening, bird-watching, travelling and writing.  He is active in community health outreach and deeply involved in church activities.  He enjoys teaching and sharing information.

HAVE YOUR SAY

Like the South Coast Herald’s Facebook page, follow us on Twitter and Instagram