Diet problems research
This page of the diet problems and cancer section is about research into the causes, prevention and treatments of diet problems. There is information about
All treatments have to be fully researched before they can be adopted as standard treatment for everyone. This is so that
- We can be sure they work
- We can be sure they work better than the treatments that are available at the moment
- They are known to be safe
First of all, treatments are developed and tested in laboratories. For ethical and safety reasons, experimental treatments must be tested in the laboratory before they can be tried in patients. If a treatment described here is said to be at the laboratory stage of research, it is not ready for patients and is not available either within or outside the NHS.
Tests in patients are called clinical trials. The trials and research section has information about what trials are including information about the 4 phases of trials. If you are interested in taking part in a clinical trial, visit our searchable database of clinical trials recruiting in the UK. If there is a trial you are interested in, print it off and take it to your own specialist. If the trial is suitable for you, your doctor will need to make the referral to the research team.
All the new approaches are the subject of ongoing research. Until studies are completed and new treatments are found to work, these treatments cannot be used to treat diet problems in people with cancer.
A lot of research in nutrition and cancer is into preventing cancer through diet. Over the past 20 years scientists have developed better drugs to help control sickness. But there hasn’t been much research into controlling cachexia. This is changing and doctors are trying hard to find new methods of helping people with this condition.
One new trial is looking for biochemical markers in the blood that will help identify people who are likely to develop cachexia. Early treatment might then prevent the symptoms of cachexia.
The types of drugs being tested include
- Drugs that block cytokines
- Drugs that improve appetite
- Non steroidal anti inflammatory drugs
Drugs that block cytokines
Scientists already know that natural chemicals made by cancers called cytokines are involved in causing weight loss and cachexia. This has led to research into finding drugs to help block cytokines. These drugs may help to reverse the wasting and weight loss that happens in cachexia. This research is still in very early stages of development and no one is sure how successful it will be. The key is likely to lie in blocking several of these cytokines at once because they all interact with each other.
Thalidomide is being used in clinical trials to help people with cachexia. This drug was responsible for birth defects in the late 1950s and early 1960s and so got a bad name. Despite this, it is only dangerous if taken in pregnancy. The drug seems to work in cachexia by interfering with certain cytokines. Early trial results suggest that thalidomide improves appetite and helps control sickness in people with cachexia. A Cochrane review of the research so far says that there is not enough information to recommend it as a treatment at the moment. There is a larger UK trial looking at thalidomide for cachexia. The researchers hope to find out if it helps people who have cachexia due to stomach, oesophageal, pancreatic or small bowel cancer.
A recent review of research showed that megestrol acetate inceases appetite and weight gain, but is no more effective than steriods. As both types of drugs have side effects, more research is needed to find out how much megestrol acetate improves overall quality of life.
Other appetite stimulants being tested include cannabinoids. These drugs are made from the cannabis plant, also known as marijuana. Some studies have found that smoking cannabis or eating it can help to control sickness and pain and increase appetite. But one recent phase 3 trial failed to show that cannabinoids improved appetite or quality of life. Neither does it seem to help people put on weight. We have more information about cannabinoids in our sickness section.
Ghrelin is an appetite regulating hormone found in the stomach lining. Early clinical trials show that ghrelin helps to improve appetite and weight in people who have cancer. More research is needed to see if these are lasting effects.
Steroids can help improve appetite, food intake and sense of well being in people with cachexia. But they don't tend to help you put on weight, except from fluid retention.
Some scientists believe that malnutrition and cancer cachexia may be a response to inflammation caused by the presence of a tumour in the body. This has led to research into using non steroidal anti inflammatories (NSAIDs) to help prevent and treat malnutrition in people with cancer.
One small trial of 135 patients with cancer who had severe malnutrition showed that an NSAID called indomethacin may help. Half the patients were given indomethacin and half were given a dummy pill (placebo). The people who took indomethacin had better overall survival. More trials are needed in this area before we know how well this type of treatment will work.
Remember - anti inflammatory drugs can be dangerous. You should not take them regularly without checking with your doctor. This is particularly true if you have a history of stomach ulcer, bleeding disorders or are taking drugs to thin your blood (Warfarin, heparin or Coumadin).
Some food supplements may help people with cachexia. One promising nutrient is fish oil, which contains omega-3 fatty acids. These fatty acids are important chemicals that the body needs to function normally. But they are not made naturally in the body and we have to get them from our diet. Foods rich in omega 3 fatty acids include oily fish, such as mackerel, salmon, tuna and sardines. They are also in several oils, including rapeseed, linseed, walnut, soya and flax. Dark green vegetables contain a little too. The 3 fatty acids that make up omega 3 are
- Alpha linolenic acid
- Eicosapentaenoic acid and
- Docosahexaenoic acid
These fatty acids can prevent cancer in animals and this may also be the case with humans but we have no evidence of that yet. In early stage clinical trials, fish oil supplements have stabilised or increased the weight of people with pancreatic cancer who have cachexia. The fatty acids may decrease some of the toxins made by the cancer that are believed to cause cachexia. The side effects of these supplements are mild to moderate and include
- Loose, fatty looking bowel motions
- Fishy tasting burps
A product called ProSure has been developed from this line of research. ProSure is a high protein drink with the fish oil eicosapentaenoic acid (EPA) added to it. Some people with cachexia who drank between 1.5 and 2 packs a day of ProSure did gain fat and muscle bulk. So far, ProSure is only available in a few hospitals in the UK, but it can be prescribed by your GP. Another omega 3 enriched supplement is Forticare. It is more concentrated and claims not to have such a fishy after taste. It's only available for people with pancreatic cancer.
NOURISH is a trial to see if taking a supplement powder helps improve the problem of weight and muscle loss in people with lung cancer.
Cochrane Reviews published in the Cochrane Library pull together the results of several research studies to see how well treatments work. One review, published in 2009, found that there was not enough evidence to support the use of EPA supplements in improving the symptoms of cachexia. We need more research before we will know if these supplements really do help people with cachexia.
Some scientists believe that antioxidant vitamins and minerals may help to prevent cancer when included in a healthy, balanced diet. There have also been some very early stage trials suggesting that antioxidants may help prevent cachexia in people with cancer. We don't know for sure whether any of this is true because it is very difficult to prove. In theory, antioxidants help protect body cells from damage by oxygen particles called free radicals.
Antioxidants, vitamin and mineral supplements are not routinely advised for people with cancer as there is no proof that they help, especially not single nutrients or supplements that are a higher dose than the Recommended Daily Allowance (RDA). In 2008, an overview of studies of giving antioxidants to prevent illness found that people who took antioxidants (Vitamin A, beta-carotene, and vitamin E) actually had a higher risk of becoming ill or dying. Another overview in 2004 looked at studies where antioxidants had been used to try to prevent digestive system cancers. The review found a higher risk of dying in people who took
- Beta-carotene with vitamin A
- Beta-carotene and vitamin E
One unpublished trial found some evidence to suggest that the antioxidants lipolic acid (ALA) and N-acetyl cysteine (NAC) helped to prevent cachexia in people with lung cancer, when taken in combination with the appetite stimulant medroxyprogesterone. But we need a lot more research into these agents before we can tell how useful they really are. Cachexia in people with cancer is a very complex problem. Finding ways to successfully manage and control it will need a lot more research. Many scientists believe that combinations of treatments will be needed.
Recent studies show that exercise may help to control muscle wasting linked to cachexia. Data suggests that progressive resistance exercise training (PRT) may increase muscle mass and strength. It may also improve physical functioning and quality of life. PRT involves a low number of muscle movements performed against increasing levels of resistance. More research is needed to see how well this type of exercise works.
We have information about a study looking at the role of exercise in people with lung or digestive system cancer who have weight and muscle loss.
About 4 out of 10 people are underweight when they are admitted to hospital. But many people lose weight during their hospital stay. So overall, nearly 6 out of 10 people in hospital (60%) at any one time are poorly nourished (malnourished).
People who are most at risk of being malnourished are those who have
- Had treatment for cancer
- Had major surgery to the digestive system - the stomach, bowel or gullet (oesophagus)
- Serious bone fractures and
- Chronic illness (long term heart disease or lung disease for example)
The Government has recently drawn up some proposals aimed at structuring meal times on hospital wards including
- No visitors during meal times so that patients can concentrate on eating
- No staff meal breaks during patient meal times so that there are more staff around to help We have more information here about hospital meals.
Being poorly nourished is known as malnutrition. About 2 million people in Britain are malnourished and this affects their health and ability to work. Some people are more at risk than others. To help improve things, the Malnutrition Advisory Group (MAG) of the British Association for Parenteral and Enteral Nutrition (BAPEN) have launched a programme called the ‘Malnutrition Universal Screening Tool’ (MUST). This tool is simple to use and available to GPs and other people working in health care. They should use the tool to identify adults who are at risk or already malnourished and may benefit from help with their diet. There is detailed information about MUST on their website.
Question about cancer? Contact our information nurse team