OnCore Nutrition - Two Peas in a Podcast

Episode 33: Busting cancer nutrition myths

Episode Summary

Does sugar feed cancer? Do I need to avoid dairy, soy or start juicing? Should I go alkaline, eat only organic or start fasting? Your OnCore Nutrition oncology dietitians separating fact from fiction with some common cancer nutrition myths.

Episode Notes

Common cancer nutrition myths

Sugar feeds cancer

More info here

Juicing

No evidence to support it’s use

Can lead to deficiency in valuable nutrients, weight loss, protein energy malnutrition

Antioxidant load can be potentially detrimental during radiotherapy and certain chemotherapy regimens. More information here.

Alkaline diet

More info here

Organic

Studies on the foods themselves in terms of nutritional content, levels of chemicals and resistant bacteria
Studies on the health of humans long term
When we look at organic vs non-organic there may be slightly higher concentrations of antioxidants in organic produce. This is only in general, as organic milk has been found to have lower mineral content, and varies depending on the source.
When we look at chemicals and pesticide residues, organic produce may reduce exposure to these but important to note that the levels of toxins in non-organic produce is generally well below safe limits
When we look at health overall, in particular long term health of individuals that eat organic vs non organic produce, the benefits are far less clear.
No difference in cancer risk (studies of >600,000 women)
Huge systematic reviews show no difference
Some studies that report a difference need to be careful of other confounding factors. If we think about the profile of someone who may eat organic - they have chosen to and have the means to do so. In general,this often means they are more likely to be of a higher SES/income, better living environments, higher education level, health conscious therefore choose more fresh produce overall, get regular health check ups and screen for chronic diseases. It’s really difficult to attribute health benefits to the organic produce when there’s a whole bunch of other health-promoting behaviours, environmental and lifestyle factors contributing.
Bottom line: if you’ve got the means and it’s a priority for you - by all means! If you don’t - just keep aiming for your 5 serves of veggies and wash them well.

Soy

Legume - soybeans or edamame - eaten whole or processed in numerous ways - fermented to produce tofu, tempeh, miso, natto.
Rich - rich in phytooestrogen ‘Isoflavens - which act like a weak oestrogen in the body.
Since many breast cancers need oestrogen to grow, it would stand to reason that soy could increase breast cancer risk. However, this isn’t the case in most studies.
Most studies linking soy consumption to an increased risk of breast and other forms of cancer are
done in laboratory animals. But because humans metabolize soy differently than rodents, these findings might not apply to people.
Most observational studies indicate that consumption of soy products may reduce the risk of hormonally driven cancers such as breast, prostate, or endometrial (lining of the uterus), and there is some evidence it may lower the risk of certain other cancers. This might be because the isoflavones can actually block the more potent natural oestrogens in the blood.
Exposure early in life is beneficial and a change in soy intake in either direction, may be responsible for change in risk
Additionally, soy has been linked to a longer lifespan after breast cancer diagnosis.
In a review of five long-term studies, women who ate soy after diagnosis were 21% less likely to have a recurrence of cancer and 15% less likely to die than women who avoided soy.

Dairy

Dairy has been associated with reduced risk of colorectal cancer, but an increased risk of prostate cancer. Individualised advised, tailored to you, is key,

Fasting

ESPEN Nutrition guidelines

Anti-cancer diets

There is no diet or food that has been proven to prevent or cure cancer

ESPEN Nutrition guidelines

Other resources

https://www.wcrf-uk.org/uk/recipes/diet-cancer-myths-debunked

http://www.espen.info/wp/wordpress/wp-content/uploads/2016/11/ESPEN-cancer-guidelines-2016-final-published.pdf