A new study has revealed that excessive salt consumption, which is well known for causing high blood pressure and heart disease, can also increase the risk of stomach cancer.

The most well-established stomach cancer risk factor is infection with a bacterium called Helicobacter pylori (H. pylori), which causes inflammation within the stomach that can progress to stomach cancer, the Daily Express reported.

Researcher John Atherton of United European Gastroenterology Secretary said that although they don't know exactly why a high salt intake increases the risk of stomach cancer, studies suggest that it may encourage the growth of H. pylori and make it more toxic to the cells of the stomach.

Current guidelines from the World Health Organisation (WHO) suggest that no more than 5g of salt (less than 1 teaspoon) should be eaten per day, which can be a challenging target given that most salt in our diets is not added by us, but comes from processed foods such as bread, cheese, breakfast cereals and ready meals.

Atherton added that in the UK, people's salt target is no more than 6 g per day, which should theoretically reduce the risk of stomach cancer as well as other salt-related health problems.

He continued that they need more studies to confirm that eating a low-salt diet reduces the incidence of stomach cancer, but there is preliminary evidence from Japan to suggest this would be the case.

Adding an avocado to your daily diet helps lower bad cholesterol and reduce the risk of heart disease, a study says.

"Including one avocado each day as part of a moderate-fat, cholesterol-lowering diet provides additional LDL (bad cholesterol) lowering affects which benefit CVD (cardiovascular disease) risk," said Penny Kris-Etherton, professor at Pennsylvania State University.

Known to have originated in Mexico and Central America, avocado is cultivated in a very limited scale in Tamil Nadu, Kerala, Maharashtra, Karnataka in the south-central India and in the eastern Himalayan state Sikkim.

Avocados are known to be a nutrient-dense food, high in monounsaturated fatty acids. Previous studies have suggested that avocados are a cholesterol-lowering food, but this is the first study to look at health implications of avocados beyond monounsaturated fatty acids, the researchers added.

For the study, the researchers tested three different diets, all designed to lower cholesterol: a lower-fat diet, consisting of 24 percent fat, and two moderate fat diets, with 34 percent fat.

The moderate fat diets were nearly identical, however, one diet incorporated one Hass avocado every day while the other used a comparable amount of high oleic acid oils - such as olive oil - to match the fatty acid content of one avocado.

The researchers tested the diets with 45 healthy, overweight adults between the ages of 21 and 70. All participants followed each of the three diets for five weeks.

The avocado diet decreased bad cholesterol by 13.5 mg/dL ( milligram per per decilitre), while LDL was decreased by 8.3 mg/dL on the moderate-fat diet and by 7.4 mg/dL on the low-fat diet.

The study was published in the Journal of the American Heart Association.

Researchers have identified the level of five of the most common food allergens which would cause a reaction in the most sensitive 10 percent of people.

The five foods they considered were -- peanut, hazelnut, celery, fish and shrimp.

Between 1.6 and 10.1 milligrams of hazelnut, peanut and celery protein produced a reaction in the most sensitive 10 percent of those studied.

For fish, it was higher - at 27.3 milligrams - and for shrimp, a significantly higher 2.5 grams of cooked protein produced a reaction - though the researchers did not study raw shrimp which may have a different effect.

"What we wanted was to find a level of allergen which would only produce a reaction in the most sensitive ten percent of people," said lead researcher professor Clare Mills University of Manchester in Britain.

"This sort of data can then be used to apply a consistent level of warning to food products. What we would like to see are warnings which tell people with allergies to avoid certain products completely or just apply to those who are most sensitive," Mills explained.

The researchers analysed data from 436 people across Europe who had allergies to peanut, hazelnut, celery, fish or shrimp.

They were then given small doses of the food they were allergic to and their reactions were monitored.

The study appeared in the Journal of Allergy and Clinical Immunology.

A new study has revealed that women who use a certain type of injectable birth control are at a higher risk of becoming infected with HIV than those who take the pill.

A large meta-analysis of 12 studies in sub-Saharan Africa showed that the use of the contraceptive, depot medroxyprogesterone acetate (DMPA), increases the risk of acquiring HIV by moderately 40% compared with women using non-hormonal methods and those not practicing birth control.

The increased risk was slightly lower, 31 percent, among women in the general population than those already at higher HIV risk.

The contraceptive, depot medroxyprogesterone acetate, is sold under the brand name Depo-Provera, and it is administered as a shot every three months.

The researchers selected the studies based upon methodological rigor, such as whether they accounted for the use of condoms.

In addition to Depo-Provera, the studies also examined other commonly prescribed forms of hormonal contraception, such as the injectable norethisterone oenanthate (sold as NET-EN), combined oral contraceptives and progestin-only pills. The other birth control methods did not appear to increase HIV infection risk for women in the general population.

Study's lead author Lauren Ralph of UC Berkeley, said that the results had potentially broad implications because hormonal contraceptives remain popular for women worldwide.

Approximately 144 million women worldwide use hormonal contraception, and of those about 41 million women use injectable forms of birth control instead of the pill.

It remains unclear why the increased risk was seen among those using Depo-Provera but not the other forms of hormonal contraception, the authors said.

One possibility may be that birth control with higher levels of progestin, the synthetic form of the natural hormone progesterone, changed the vaginal lining or altered local immunity, increasing the risk for HIV infection, though the researchers emphasized that this study did not examine the physiological effects of the different contraceptive methods and more research on potential underlying biologic mechanisms is needed.

The researchers cautioned that the increased HIV infection risk needs to be considered in the context of the risks associated with not using birth control.

The researchers noted that the results highlight the need for more studies among high-risk populations. Among the 12 studies analyzed, only two included sex workers or women with HIV-positive partners.

The study, published in The Lancet, included data from 39,500 women.

Considered to be the most common cause of severe diarrhoea in children, the tummy bug rotavirus attacks cells through carbohydrate receptors present on a child's intestinal cells, a new study has found.

The study could greatly assist in understanding how this virus starts to infect cells and provides new direction in potential drug discovery, said co-senior author Mark von Itzstein, a professor at the Institute for Glycomics, Griffith University in Queensland, Australia.

"Our findings greatly advance our understanding of the sugar receptors used by human rotaviruses and provide clues as to how we might target this virus to stop it infecting cells," he said.

"What we have found is that not all human rotaviruses recognise the same sugar receptor and this important information will be invaluable in the discovery of anti-rotaviral drugs," Barbara Coulson, an associate professor at the University of Melbourne, said.

The findings could also offer potential for new vaccine development strategies.

"We are very excited by our findings, as we now have a much better understanding of the carbohydrates important for the virus to latch on to for successful infection," Thomas Haselhorst from the Institute for Glycomics, Australia, noted.

The study appeared in the journal Nature Communications.