Busting nutrition myths
This is a guest blog from Victoria Nelson, Registered Dietitian in London. Victoria offers expert evidence-based nutrition advice that is tailored to you, to help you achieve your lifestyle goals. Her specialities are cancer and gastrointestinal issues. She says, “My passion is dispelling common nutrition myths which can often lead to confusion. Misinformation can be damaging and dangerous and it is my mission to tackle this and spread fad free advice. The ‘one size fits all’ or ‘superfood’ approach to nutrition advice is too simplistic therefore, I aim to deliver evidence-based nutrition advice that is tailored to you, your lifestyle and health conditions.”
Deciding what to eat can be difficult and confusing with headlines such as ‘drinking milk causes cancer’ and ‘Cancer alert over salad rocket’ spreading fear and misinformation. This can be further exacerbated by well-intentioned friends and family members sharing the latest rumour around cancer and nutrition on their social media which can leave you feeling barraged with advice. Therefore in this blog I want to bust the most common nutrition and breast cancer myths.
There have been a number of reports in the media that have encouraged women to reduce their intake of dairy foods due to concern over the high dietary fat content of dairy foods, contaminants in milk and hormones such as oestrogens and insulin like growth factor (IGF-1).
However studies have failed to provide a link between the consumption of dairy foods and recurrence of breast cancer. The World Cancer Research Fund (WCRF) concluded there was insufficient evidence to advise women to avoid dairy foods.
The’ Life After Cancer Epidemiology’ (LACE) study looked at dietary intake over 12 months and found that dairy intake was unrelated to breast cancer. High fat dairy intake was shown to have a small increase risk while low fat dairy intake decreased risk.
Dairy foods include milk, yoghurt, butter and cheese. Dairy is an important food group and good source of calcium. The advice would be if you enjoy dairy foods continue to eat them but if you don’t ensure you use suitable alternatives to get your calcium intake.
Soy foods may contain phytoestrogens which are plant based substances that bind to oestrogen receptors. Eating soy in moderate amounts does not increase the risk of breast cancer recurring. The human evidence shows that soy intake is not harmful, and may even benefit, patients with breast cancer. A diet survey of American and Chinese women showed those that ate the most soy were 25% less likely to have cancer recurrence compared to those that had the least. It has been suggested soy could interfere with breast cancer drugs that lower oestrogen levels such as tamoxifen, but the study showed soy was still protective in this group.
Soy foods include soybeans (edamame), soy nuts, tofu, tempeh, or soy milk and should be enjoyed in the diet as one of your 5 a day or as a vegetarian source of protein. It is advised to avoid soy supplements.
Consumption of alcohol has been identified as a risk factor for the cause of breast cancer but the mechanisms are unclear. Little is known about the influence of alcohol on breast cancer recurrence and survival.
The After Breast Cancer Pooling Project which looked at women diagnosed with Stage I – III breast cancer. They concluded that regular alcohol intake of 2-3 glasses of wine when compared to non-alcoholic intakes was not associated with the risk of recurrence. However, risk of recurrence increased with post-menopausal women who regularly consumed alcohol but alcohol intake was not associated with mortality.
The recent WCRF guidance indicated that the evidence was limited with no conclusions regarding the consumption of alcohol after diagnosis of breast cancer therefore it would be recommended to limit alcohol intake and not consume beyond the recommended maximum 14 units a week.
Organic fruit and vegetables are grown without using artificial fertilisers, pesticides or other chemical. The UK has regulations on the amount of pesticides in food to ensure the levels are well within safe limits. There is no evidence that organic food is more nutritious than none organic foods and nutrient content is more likely to vary depending on the cooking method used.
The most important thing is to ensure you get plenty of fruit and vegetables whether they are organic or none organic in your diet.
All our cells, cancerous and healthy cells, use sugar (glucose) for energy. Glucose is the basic building block of carbohydrates. Our body cannot pick and choose which cells get what food and energy, therefore when we consume carbohydrates, we can’t control which cells get the glucose.
There is no evidence to prove that cancer cells grow faster in people who consume more sugar. The diet termed the ketogenic diet which involves cutting out sugar and forcing the body to use ketones as fuel has been shown to result in weight loss and muscles mass due to the reduced amount of food. Constipation is also high if those that chose to follow the diet as fibre is extremely limited and there are many questions about the nutrient content of the diet and if this impacts the immune system due to the lack of fruit and vegetable consumption.
Unfortunately there is no one miracle super food and an overall balanced diet is what has been shown to be of the most beneficial. Therefore the recommendations are to eat at least your five recommend fruit and veggies a day, consume whole grains, limit red meat (no more than 3 portions a week) and avoid processed meat, limit alcohol (max 14 units a week) and high sugar products (defined as >22.5g sugar per 100g).
The information and content provided in all guest blogs is intended for information and educational purposes only and is not intended to substitute for professional medical advice. Please seek professional advice or speak to your medical team if you have any questions about the issues raised in this guest blog.