Dr John Briffa: Eye on the pies

Listening to the radio recently, I caught a report which warned of a mince-pie shortage this Christmas as a result of the growing demand for British lard by Eastern European food manufacturers. Some may believe that the siphoning off of suet to other parts of the world can only bring glad tidings regarding the health of our nation. However, it now seems that cutting back on animal fat might actually have undesirable consequences for heart health in some individuals.

In the study, published last month in the American Journal of Clinical Nutrition, 235 post-menopausal women with known heart disease had the state of the arteries around their hearts assessed through angiography (dye is injected into the arteries while X-rays are taken). Three years later, they had a repeat angiography. Dietary analysis revealed that women with the highest intakes of saturated fat saw no progression on the artery-blocking process known as atherosclerosis. But those with the lowest amounts saw a significant narrowing in their coronary arteries.

This relationship between saturated fat and atherosclerosis might have been due to factors such as age, history of diabetes, smoking, exercise habits and body weight. Yet even with such factors taken into account, the apparent protective effect of saturated fat remained.

These results are in keeping with a growing body of evidence suggesting that the link between animal-fat consumption and heart disease is far from clear, particularly in women. Research published in the New England Journal of Medicine found no significant relationship between saturated-fat consumption and heart-disease risk in a group of 80,000 women. A study published in the journal Diabetes Care found that higher saturated-fat intakes were associated with reduced risk of heart disease in diabetic women.

One potential explanation relates to differences in the consumption of carbohydrate. Lower-fat diets tend to be higher in carb - excesses of which can bring about changes expected to increase heart-disease risk, such as a lowering of 'healthy' high-density lipoprotein (HDL) cholesterol and an increase in levels of unhealthy blood fats, triglycerides. Low-fat diets can have unfavourable effects on these, and other, blood parameters. In keeping with this research, the AJCN study found that a higher carbohydrate intake in women was associated with increased risk of atherosclerosis, particularly for foods that give substantial rises in blood sugar - those rich in refined sugar and flour. For women, it's the sweet, rather than the meat, in mince pies that is best avoided.

Nutrition news

The lens in the eye is composed of a transparent, jelly-like material that can be subject to damage by destructive molecules called free radicals in the body. This damage can ultimately lead to cataract formation, though protection against this is offered by so-called antioxidants, which quench the action of free radicals.

Previous studies have suggested that higher intakes of the antioxidant nutrients lutein and zeaxanthin are associated with a reduced risk of cataract formation. This association was recently investigated in more depth by American researchers. In this study, cells from the human lens were mixed with lutein and zeaxanthin and then exposed to cataract-inducing ultraviolet (UV) light. Compared to lens cells with no added antioxidants, those bathed in lutein and zeaxanthin showed significantly less damage from UV exposure.

This study adds further weight to the notion that eating lutein- and zeaxanthin-rich foods can help protect against cataracts. Foods rich in these nutrients include spinach, broccoli, kale, leeks and peas.

Dear John

I am 78 and have been taking bendrofluazide and telmisartan since January. For three months I've had tingling sensations in my back, arms and hands.

I've seen a physiotherapist, who can find nothing wrong. Your recent answer highlighting the link between bendrofluazide and low potassium and magnesium levels made me think I might have a similar problem. What do you think?
Marion Lewis

Bendrofluazide is a blood-pressure-lowering drug that can reduce potassium and/or magnesium levels. Your symptoms suggest that you might have a raised level of potassium - the medical term for which is hyperkalaemia. Neurological symptoms include tingling, pins and needles, or numbness.

You may be at increased risk of hyperkalaemia, as this is a recognised side effect of the telmisartan and other drugs of this type (aka angiotensin II receptor antagonists). Bendrofluazide can offset the potassium-raising effects of telmisartan.

I suggest you see your doctor for tests. If your potassium level is high, adjusting your medication may be appropriate.

Thanks to guardian.co.uk who have provided this article. View the original here.