14. Sugar and Cancer.

     

     The Government's new guidelines on sugar consumption and obesity provide disturbing reading for those with a sweet tooth.  The report published today by the Scientific Advisory Committee on Nutrition, (SACN), recommends that no more than 5% of our daily energy in a healthy diet should come from sugars, including those 'free sugars' naturally present in unadulterated honey, fruit juice and other foods. This is a 50% reduction on the previous nutrition guidelines published back in 1991 and nutritionists warn that people conforming to the new guidelines, (which also recommend a 50% increase in fibrous foods consumed), will need to make extreme changes to their present diet.
     The problem with our sugar consumption has been that few have stuck even to the old guidelines of 10%, causing an obesity and diabetes crisis across the entire age spectrum, and the necessity of a new government strategy to tackle childhood obesity and tooth decay. 
     The chart below shows the recommended daily 5% sugar intake:

Maximum sugars intake per day (source: SACN report)

	Grams	Sugar cubes	Teaspoons (4g-6g in a teaspoon)
4 to 6 years	19	5	3 - 5
7 to 10 years	24	6	4 - 6
11 years and above	30	7	5 - 7

      For a child under 11 years of age, 24g or 4-6 tsp of sugar recommended is the equivalent of just two bowls of a cereal like Frosties or  2/3rds of a can of coke and no other sugary food or drink at all for the day.   The 30g limit for adults is down from the old guidelines of 70g for men and 40g for women and is equivalent to one bar of chocolate a day and no other sugar.
     The Government organisation Public Health England, (PHE), is particularly focused on the childhood statistics which show one in three children aged 10 or 11 to be overweight or obese. They point to sweetened fruit juices, squash and fizzy drinks as being a major contributor to this.  
     PHE don't mention cancer in their deliberations but I will, since this blog is all about diet and cancer.  Excessive sugar intake must be regarded as a direct route to cancer because it leads to the Obesity'Clapham Junction' from which we travel on to at least 10  cancerous destinations.  Clinical studies have shown that obesity can lead to non-Hodgkin’s lymphoma, leukemia, multiple myeloma, and cancers of the kidney, colon, rectum, breast (in postmenopausal women), pancreas, ovary, and prostate. 
     So cut out those fizzy drinks and beware the sugar content when you buy tomato based pasta sauce, coleslaw, flavoured water, low fat yoghurt and French Fries! 

Update 11.11.15. 
I have followed Jamie Oliver's campaign to reduce sugar intake by persuading the government to introduce a sugar tax. I confess I thought the idea had merit, but the results of a sugar tax imposed in Denmark make me wonder.
Check out this <iframe src="https://embed.theguardian.com/embed/video/commentisfree/video/2015/nov/11/sugar-tax-facts-need-to-know-video" width="560" height="315" frameborder="0" allowfullscreen></iframe> youtube before you make up your own mind.


Dr. Ian Hampson, Reader in Viral Oncology, Institute of Cancer Studies, University of Manchester, comments:  
     One of the most obesity-related cancers in post-menopausal women is endometrial (uterine) carcinoma which is increasing rapidly.        
     In the UK the incidence has increased by half from early 1990's and in 2012 there were 8,500 cases in the UK (23 women every day).  This is actually the cancer which has the strongest link to obesity with type II diabetes also being a major contributory factor. 
     The problem is that obesity disturbs and de-regulates the effects of insulin and this in turn leads to a greater risk of cancer. Curiously, if the process is reversed by exercise, diet etc this often cures the type II diabetes and the risk of cancer also declines!

Further Reading
Association of Obesity and Cancer Risk in Canada
Obesity and Cancer Risk: Recent Review and Evidence
Obesity and post-menopausal breast cancer 
   

13. Diet and Cancer: a clinical research problem.

     It struck me very early on when writing this blog on nutrition and cancer that I had stepped into a virtual minefield; a field sown in the shifting sands of informed opinion that is littered with the bones of once-considered truths that have since been abandoned by dieticians in the light of new and often apparently conflicting evidence. Clinical research on nutrition and cancer prevention is regrettably sparse and is sadly lacking in trial depth in comparison to similar research and trials on drugs for a cancer cure. I wondered why this should be and invited Dr. Ian Hampson of the Institute of Cancer Sciences at the University of Manchester to discuss this anomaly.  This is his illuminating reply: 

     Diet is one of many environmental factors that combine with the genetic hand we have been dealt to promote the development of cancer. The problem with nutrition and diet, however, is that we keep getting it wrong.

     We are now beginning to appreciate that early foetal or newborn dietary programming must be taken into account, (see link to the US National Library of Medicine below).  It seems that the diet to which we are exposed in early life, and even in the womb, fixes the goalposts for what our bodies regard as normal. Our response to nutrients in early life can therefore influence how we will respond to these in later life. This in turn determines our susceptibility to many cancers and, indeed, to a whole range of diseases.  Superimpose this on the worldwide differences in youth and adult lifestyles, diet, exercise and ethnicity and you have created a complex equation, which probably explains why there are so many conflicting studies and calls for further research. It also explains why the success of clinical trials that embrace all parts of this equation would be impossible within a reasonable human timeframe, ethnic spectrum and realistic budget.

      Our newfound appreciation of the impact of early foetal and newborn nutrition and diet on our susceptibility to cancer and other diseases in later life does however open up the possibility of some disease preventive control in the future by the administration of prenatal or postnatal dietary supplements.  But that calls for yet further research!

     Meanwhile, eat a diet which is abundant in fruits, vegetables, whole grains, nuts, legumes and olive oil. Choose fish and poultry, lean sources of protein, rather than red meat, which contains more saturated fat.  This is what is known as the Mediterranean diet.  Also observe moderation in all things! Even exercise – too much is actually bad for you!

Dr Ian Hampson,

Reader in Viral Oncology,

University of Manchester

I was interested to read Dr Hampson's Mediterranean diet recommendation in his final paragraph.  The 'Mediterranean diet'  has  recently been pronounced as beneficial, not only in risk reduction of a growing number of cancers such as uterine cancer, (see my blog  12),  but is also associated with good general health, a healthy heart and weight control or obesity - itself a potential cause of some 22 different cancers according to studies published in The Lancet, including liver, colon, ovarian, breast and prostate cancers, (see my blog 3).

Further reading

US National Library of Medicine

Institute of Cancer Sciences

The Mediterranean Diet

12. Mediterranean diet cuts uterine cancer risk

     

Photo: Nazarethhealthcare.com

     A new study published in the British Journal of Cancer has shown that women who eat a Mediterranean diet could cut the risk of uterine cancer by over half.
     Pooled data from a number of case-control studies in various areas of Italy and Switzerland show that consuming food high in unsaturated fatty acids, fibre, phytochemicals and antioxidents, (as found in what we know as a 'Mediterranean diet'), dramatically reduce the odds of contracting cancer of the womb by over 50%.  
     What do researchers mean by a 'Mediterranean diet'?  They characterise it by nine dietary components: a high intake of vegetables, fruits/nuts, cereals, legumes, fish; low intake of dairy products and red meat, (see my previous blogs 11 and 1); a high monounsaturated to saturated fat ratio; and low alcohol intake.
     Study researcher Dr Cristina Bosetti, from Mario Negri Institute for Pharmaceutical Research in Milan, said, "Our study provides evidence for a beneficial role of the Mediterranean diet on endometrial [uterine] cancer risk.  It adds more weight to our understanding of how our everyday choices, like what we eat...effect our risk of cancer."
     The 'Mediterranean diet'  has  recently been pronounced as beneficial, not only in risk reduction of a growing number of cancers but is also associated with good general health, a healthy heart and weight control or obesity - itself a potential cause of some 22 different cancers according to studies published in The Lancet, including liver, colon, ovarian, breast and prostate cancers, (see my blog 3).

The Mediterranean diet Pyramid

Further Reading:
British Journal of Cancer Mediterranean Diet and Womb Cancer
Womb (uterus) Cancer All about Womb Cancer. NHS pages.
Mediterranean Diet All about the Mediterranean diet. 
How to follow a Mediterranean diet Patient Information and Support.
The Lancet Body mass and cancer risk.