Tea to lower your blood pressure, the genetics of eye colour and more of the latest health news

Fish twice a week

Fish has a reputation as being good for your heart, so researchers wanted to test this and they tested it in a big way. They conducted a meta-analysis of studies including a total of 192,000 people from 60 countries across five continents, including people from high-, middle- and low-income countries. Of the people involved, 52,000 already had cardiovascular disease (CVD). The findings showed that eating oily fish regularly helps prevent CVD in high-risk people such as those who have existing heart disease or have experienced a stroke. The crucial ingredients are omega-3 fatty acids found in fish, and when people ate two serves of fish a week these nutrients led to a 16 per cent reduction in risk of stroke or heart attack in these high-risk people. Interestingly, no real benefit was found in people without heart disease or previous stroke.

Sources: JAMA Internal Medicine

Why tea lowers blood pressure

New research shows that the effect of tea on your blood pressure goes deeper than relaxation. Researchers have found that catechins in green tea and black tea activate a specific type of ion channel protein called KCNQ5. The effect is to allow potassium ions to flow out of cells, thus reducing cell excitability. Since KCNQ5 is found in the lining of blood vessels, when it is activated the blood vessels relax, causing a lowering of blood pressure. One interesting finding was that when black tea with milk was applied directly to cells, the KCNQ5 channel as not activated. However, despair not ye milky tea drinkers; the researchers point out that in your stomach the catechins found in tea are separated from proteins in milk that might block their effect. On top of that there is plenty of other research showing that milky tea has the same anti-hypertensive effect as its milkless brethren.

Source: Cellular Physiology and Biochemistry

Refined grains have coarse effects

For this new research, data was analysed on more than 137,000 people followed for 16 years from 21 countries. Despite all that we know about the benefits of whole grains, the researchers found that consumption of refined grains has increased over the years. Grains were categorised into three groups: refined grains, whole grains and white rice. Refined grains included products made with white flour such as white bread, pasta, noodles, breakfast cereals, crackers and bakery goods. The analysis showed that having more than seven serves per day of refined grains was associated with a 27 per cent greater risk of early death, a 33 per cent greater risk of heart disease and a 47 per cent greater risk of stroke. No adverse health outcomes were associated with whole grain consumption or even white rice. It’s a worthy reminder that refined grains can lead to some coarse outcomes.

Source: British Medical Journal

The genetics of eye colour

Remember those Mendelian lessons in science class where you learned that the gene for brown eyes is dominant over the gene for blue eyes? Simple, wasn’t it? Unfortunately, it was also wrong. This has been established by researchers who conducted genetic analysis of 195,000 people across Europe and Asia. Their analysis identified 50 new genes for eye colour and builds on previous research which had shown that dozens of genes influence eye colour. Previously, scientists had thought that variations in eye colour were controlled by just one or two genes. This new research also found that eye colour in Asians with differing shades of brown is genetically similar to eye colour in Europeans, ranging from dark brown to light blue. Aside from the confirmation that our understanding of the body is continually evolving, these findings may also improve understanding of diseases associated with eye pigmentation levels.

Source: Science Advances

Medifact

“5-a-day”, longer life

Research on around two million adults has confirmed that eating five serves of fruit and vegetables a day will lead to a longer life. The study also confirmed that the optimal ratio is two serves of fruit and three serves of vegetables.

Source: Circulation