Smoking accounts for more than a third of cases of the most severe and common form of rheumatoid arthritis, indicates research published online in the Annals of the Rheumatic Diseases. And it accounts for more than half of cases in people who are genetically susceptible to development of the disease, finds the study.
The researchers base their findings on more than 1,200 people with rheumatoid arthritis and 871 people matched for age and sex, but free of the disease. The patients came from 19 health clinics in south and central Sweden, while their healthy peers were randomly selected from the population register. All the participants were aged between 18 and 70. They were quizzed about their smoking habits and grouped into three categories, depending on how long they had smoked. Blood samples were taken to assess all the participants' genetic profile for susceptibility to rheumatoid arthritis and to gauge the severity of their disease, as indicated by their antibody levels.
More than half of those with rheumatoid arthritis (61%) had the most severe form of the disease, which is also the most common form, as judged by testing positive for anticitrullinated protein/peptide antibody (ACPA). Those who were the heaviest smokers – 20 cigarettes a day for at least 20 years – were more than 2.5 times as likely to test positive for ACPA. The risk fell for ex-smokers, the longer they had given up smoking. But among the heaviest smokers, the risk was still relatively high, even after 20 years of not having smoked.
Based on these figures, the researchers calculated that smoking accounted for 35% of ACPA positive cases, and one in five cases of rheumatoid arthritis, overall. Although this risk is not as high as for lung cancer, where smoking accounts for 90% of cases, it is similar to that for coronary artery heart disease, say the authors. Among those with genetic susceptibility to the disease, and who tested positive for ACPA, smoking accounted for more than half the cases (55%). Those who smoked the most had the highest risk.
The authors point out that several other environmental factors may contribute to an increased risk of rheumatoid arthritis, including air pollutants and hormonal factors. But they suggest that their findings are sufficient to prompt those with a family history of rheumatoid arthritis to be advised to give up smoking.
The researchers analyzed data from the National Health and Nutrition Examination Survey (2003-2006) which consisted of 4,528 US adults 18 years of age or older that had no previous hypertension diagnosis. The survey asked about dietary habits and what foods and beverages that they consumed. The researchers said that those who ate 74 grams (about 2.5 cans of sugared soda) or more each day of fructose sugar, had shown an increased risk for developing hypertension. There was a 26 percent chance for these individuals to have high blood pressure reading at 135/85mmHg , a 30 percent higher risk to have high blood pressure measured at 140/90, and a 77 percent higher risk for having blood pressure measured at 160/100 mmHg. A normal blood pressure reading is under 120/80 mmHg.
The researchers point out that even though this shows a potential trigger for high blood pressure, a randomized clinical study would need to be conducted in order to prove that a low fructose diet would prevent hypertension.
In most women folate, a type of B vitamin, reduces the risk of breast cancer. However, in women with a certain genetic make-up it has shown to be the opposite: folate raises the risk of breast cancer.
“Therefore I think it is too soon to introduce a general fortification of foodstuffs with folic acid”, says nutrition researcher Ulrika Ericson of Lund University.
Neither does she think it is a good idea to take multivitamin tablets and other dietary supplements containing folic acid (the synthetic form of folate) without special reason.
“It is better to eat a diet containing a lot of fruit, vegetables, legumes and wholemeal products. Then you get sufficient quantities of the natural form of folate, other vitamins and dietary fibre.”
In her doctoral thesis, Ulrika Ericson has taken as her starting point the major study from the 1990s, Malmö Diet and Cancer, which gathered information and blood samples from over 17 000 women. At the end of 2004, just over 500 of these women had developed breast cancer. Folate levels, genetic make-up and food habits in the breast cancer patients have then been compared with the corresponding data from the healthy women.
Those women whose intake of folate corresponded to the level recommended in Sweden had only half as great a risk of getting breast cancer as those who had the lowest intake of folate. This was the overall finding, which shows that folate generally protects against breast cancer. However, the breast cancer risk increased in line with folate levels for a specific sub-group among the women – those who had inherited a certain variant of an enzyme that affects how folate is used in the body.
The ten per cent of the women who had inherited this variant from both of their parents had the highest risk of breast cancer, particularly if they also took vitamin tablets containing folic acid.
“No-one knows which genetic variant of this enzyme they have. This is why I think people should only take dietary supplements if there is a particular reason to do so, not just because 'it's probably a good idea'”, says Ulrika Ericson.
She considers that there are two groups who could have a particular reason to take a folic acid supplement. These are people with a certain type of anaemia and low folate levels and women who are trying to become pregnant (folate reduces the risk of neural tube defects in babies).
To be on the safe side, others should avoid vitamin tablets containing folic acid while it is still unclear what the link is between folate and different types of cancer. Mandatory folic acid fortification of foodstuffs, which has been discussed in many countries including Sweden, is not appropriate in the current situation, according to Ulrika Ericson.
“This protein is present in the part of the brain in which memories are stored. We have found that in order for any memory to be laid down this protein, called the M3-muscarinic receptor, has to be activated.
“We have also determined that this protein undergoes a very specific change during the formation of a memory – and that this change is an essential part of memory formation. In this regard our study reveals at least one of the molecular mechanisms that are operating in the brain when we form a memory and as such this represents a major break through in our understanding of how we lay down memories.
“This finding is not only interesting in its own right but has important clinical implications. One of the major symptoms of Alzheimer's disease is memory loss. Our study identifies one of the key processes involved in memory and learning and we state in the paper that drugs designed to target the protein identified in our study would be of benefit in treating Alzheimer's disease.”
Professor Tobin said there was tremendous excitement about the breakthrough the team has made and its potential application: “It has been fascinating to look at the molecular processes involved in memory formation. We were delighted not only with the scientific importance of our finding but also by the prospect that our work could have an impact on the design of drugs for the treatment of Alzheimer's disease.”
When it comes to buying fruits and vegetables, many factors play a role in which types consumers choose, including nutritional value. Are there significant differences among fresh, frozen, canned or dried? The American Dietetic Association says no matter what form they take, fruits and vegetables are good-for-you foods that can be enjoyed at any time.
Kidney stones are small, hard deposits of minerals and salts that can form in the kidneys when urine becomes concentrated. Specific treatment beyond increasing water intake is usually not needed, but a kidney stone can be very painful to pass, as anyone who has had one can tell you. While anyone can get kidney stones, there are multiple risk factors that can potentially increase your chances of acquiring them, including:
- Family history of kidney stones.
- Being over 40 years old.
- Being male.
- High protein, high sodium and high sugar diets.
- Being obese.
- Digestive diseases such as inflammatory bowel disease or surgeries such as gastric bypass.
You can reduce your risk of getting kidney stones by:
- Drinking water throughout the day. For those with a history of kidney stones, doctors usually recommend passing approximately 2.5 litres of urine daily. In summer months you need to consume considerably more fluids to stay well-hydrated.
- Eating fewer foods containing high amounts of oxalate. Kidney stones can form due to a build up of calcium oxalate. Foods rich in oxalate include spinach, beets, rhubarb, okra, tea, chocolate and soy products.
- Limiting salt and animal protein in your diet. Reduce the amount of salt in your diet and choose non-animal protein sources such as nuts to reduce your chances of getting kidney stones.
- Watching out for stealth sources of sodium. Some energy and sports drinks contain high levels of sodium and/or caffeine. While they may quench your thirst, you may also be increasing your risk of stone formation.
- Re-hydrating often if engaged in strenuous activity if you have long-term exposure to the heat. Painters, roofers, landscapers, marathon runners and people who enjoy outdoor sports activities that last several hours at a time need to pay special attention to their water intake and watch for signs of dehydration. Health experts recommend at least 16 to 32 ounces of water per hour of heat exposure. A lack of sweat or urination, dizziness, weakness, headache, muscle cramps, nausea or vomiting are possible signs of heat-related illness or dehydration.
- Avoiding calcium supplements, but calcium-rich foods are OK. Calcium in the food you eat does not increase your risk of getting kidney stones. Keep eating calcium-rich foods unless your doctor advises you otherwise. However, calcium supplements have been linked to higher risk of kidney stones. Consult your physician before starting a calcium supplement.
A dietitian like Nastaran can help those at risk to plan meals that will reduce the chance of getting kidney stones.