The Truth About Diet and Cancer

Top dietitian JANE CLARKE reveals what to eat (and what to avoid) to beat the disease

The Mediterranean Diet has recently been found to reduce the risk of contracting one of the most dangerous forms of breast cancer by 40 per cent

There doesn’t seem to be a day that passes without a new cancer statistic being published — one of the most alarming from recent years is that one in two of us will go on to develop the disease.

It makes so many of us feel vulnerable, and naturally we want to know what — if anything — we can do to protect ourselves. As a dietitian and nutritionist for the past 25 years, I have treated hundreds of people, young and old and often a key question, even if I was seeing them for a different issue entirely, was what we should and shouldn’t eat to reduce the likelihood of developing cancer, and how can food help us fight the disease if we are diagnosed?

The incidence of different cancers varies hugely but, worryingly, the numbers of people affected are on the rise.

Bowel cancer is now the third most common cause of cancer death in women in the UK, according to the charity Bowel Cancer UK. And it is increasingly affecting younger people, with a 45 per cent increase in those under 50 being diagnosed.

Breast cancer, the most common cancer in women in the UK with around 54,000 new cases each year, is also on the rise.

Latest figures from the Office for National Statistics show an 8 per cent rise in the number of people with pancreatic cancer since 2012.

Better detection and our longer lives play a part in rising cancer rates, but our lifestyle and environment must also be part of the picture — what we put into our body has a profound impact, with many cancers, from stomach to bowel, linked to diet and weight gain.

A massive two-thirds of bowel cancer cases could be prevented by eating, drinking and living well according to the NHS.

Weight gain is strongly linked to an increased risk of stomach and oesophageal cancer, according to a new study from the National Cancer Institute in the U.S.

Meanwhile, the Mediterranean Diet — a long-time staple of healthy eating lore — has recently been found by the World Cancer Research Fund to reduce the risk of contracting one of the most dangerous forms of breast cancer by 40 per cent.

The same study also found a strong relationship between weight gain around the waist and incidence of womb cancer — even a small increase in waist size can lead to a 21 per cent increase in risk of the disease.

The foods and nutrients we eat — and what we avoid — can have a huge impact on our wellbeing and cancer risk.

And if someone already has a diagnosis of cancer, what they eat is also incredibly important, especially as cancer treatment can make eating difficult, causing nausea and vomiting, diarrhoea, loss of appetite, mouth ulcers and extreme exhaustion. Unfortunately there are many misconceptions about food and cancer.

So here, I’ll separate the wheat from the chaff — I’ll also show you the tweaks to your diet that could help reduce your risk.

There are all sorts of ‘miracle’ anti-cancer diets out there but I strongly advise anyone against embarking on a dramatic ‘clean eating’ or exclusion eating plan.

Not only do they add to the fear of anyone worried about developing cancer, they can also worsen the outcomes of those living with the disease.

People end up malnourished and there just isn’t the evidence to support such extreme strategies. So let’s look at the biggest myths around food and cancer and see what adds up…

Myth: Meat will give you cancer

Fact: Several studies have suggested that a high consumption of red or processed meat — bacon, ham — is linked with an increase in the risk of bowel cancer. But the evidence for the risks is greater for a diet heavy in processed meat than having good-quality lean steak a couple of times a week — and the latter will provide all the eight essential amino acids our bodies need for growth, brain development, healthy bones and endorphins (happy hormones).

studies suggest that eating about 50g of processed meat a day may increase the risk of bowel cancer by around 20 per cent

Overall, studies suggest that eating about 50g of processed meat a day (around two slices of ham or a slice of bacon) may increase the risk of bowel cancer by around 20 per cent — one theory is that nitrosamines, compounds formed when we eat meat, damage the DNA in our cells.

Current guidelines are to eat 500g or less of red meat a week, which gives us real scope for enjoying some delicious meat-based meals.

Bear in mind that a bolognese sauce made with 500g of lean, good-quality beef mince should serve a good six hungry adults.

Studies find a convincing relationship between drinking too much alcohol and the development of mouth, throat, oesophageal, liver and bowel cancers

Myth: Wine protects you

Fact: Studies have shown the antioxidants in wine may protect against cancer and other serious illnesses — but it’s only in a laboratory setting that red wine’s antioxidants offer any real benefits. In fact, studies find a convincing relationship between drinking too much alcohol and the development of mouth, throat, oesophageal, liver and bowel cancers.

Alcohol is also a key factor in increasing the risk of breast cancer in women. We should aim to drink no more than two units per day for men and one for women, with a maximum of 14 units a week.

Myth: Dairy foods cause cancer

Fact: Studies have not yet given clear results. Recent research shows a higher intake of calcium (found in dairy products) can protect against bowel cancer, but some early research also suggests there could be a link between dairy intake and the risk of developing prostate and ovarian cancers.

For breast cancer the evidence is conflicting. A link between breast cancer and dairy products has been suggested, possibly because of the saturated fats they contain, or contaminants such as pollutants and other environmental toxins, but there is no clear evidence to support this.

Recent research shows a higher intake of calcium (found in dairy products) can protect against bowel cancer

Another theory is that dairy products might in fact help protect against breast cancer due to increased calcium in the diet. But again, more research is needed.

For the time being I believe we should continue to include some dairy foods in our diet, as they’re such a good source of calcium. The latest official advice is that dairy should make up no more than 8 per cent of your daily diet.

Myth: Sugar ‘feeds’ cancer

Fact: Sugar doesn’t make cancer grow faster if you have it already. All cells, including cancer cells, depend on blood sugar (glucose) for energy, but giving more sugar to cancer cells doesn’t speed their growth.

Likewise, depriving cancer cells of sugar doesn’t ‘starve’ them. This misconception may be based in part on a misunderstanding of PET (positron emission tomography) scans, which are used to analyse cancers.

Before a PET scan you will be injected with a small amount of radioactive trace, typically a form of glucose.

All tissues in your body absorb some of this tracer, but tissues that are using more energy — including cancer cells — absorb greater amounts, which allows them to be identified by the scan.

For this reason, some people have concluded that cancer cells grow faster when we eat more sugar.

There is some evidence that eating large amounts of sugar is associated with an increased risk of cancer — including pancreatic cancer — developing in the first place: this is linked to weight gain and diabetes.

Lots of sugary foods will make you feel lousy anyway. But sometimes you need a little sweet stuff to give you energy.

Ideally, have something that has nutritional benefits, too, such as a few sticky medjool dates, a slice of date and walnut cake, or a bowl of fruit compote.

You’ll still be getting sugar, but the date, for instance, will provide fibre and vitamins.

Stock up on your tomatoes and turmeric
Fruit and vegetables: We’ve all heard it a thousand times before, but it can’t be stressed enough that eating plenty of fresh foods is proven to reduce the risk of certain cancers, including mouth, throat, stomach and lung. The antioxidants they contain help reduce the impact of free radicals, the damaging molecules linked to cancer.

Eating ten portions of different fruit and veg a day is associated with a 13 per cent reduction in cancer risk, according to a study from Imperial College London published in February.

The deeper red the tomato, the more lycopene it generally contains which is thought to help reduce the incidence of many cancers

A particularly good choice is beetroot. Its rich, purple colour comes from powerful antioxidants called anthocyanins.

And include tomatoes — the deeper red the tomato, the more lycopene it generally contains. This antioxidant is thought to help reduce the incidence of many cancers, including prostate. Lycopene levels intensify even more when the tomatoes are cooked, and they can also become far more appetising and easier to digest this way.

Fibre: This is particularly important in preventing cancer of the digestive system, including bowel cancer.

Fibre bulks up your stools, making them quicker and easier to pass, reducing the number of toxins in the body, which can cause cell changes. You need both soluble fibre, which is broken down in the body and found in fruits, vegetables, pulses and grains, and insoluble fibre, which passes through the body virtually unchanged, and is found in wholegrains.

We need around 18g of fibre a day — to put that into perspective, a slice of wholegrain bread provides around 2g, a bowl of muesli around 4.5g, and a banana, 4.2g.

Turmeric: Recent studies have found lower cancer rates in countries where people eat lots of turmeric over long periods — it’s thought that the active ingredient, curcumin, may reduce the cell changes that increase cancer risk, and that may even kill cancer cells. Curcumin is fat soluble so is better absorbed by the body when it’s eaten as part of a meal, rather than a supplement.

So it’s the perfect excuse to enjoy a delicious curry spiced with turmeric.

Written by Jane Clarke for and published by The Daily Mail ~ May 1, 2017.

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