Heart disease risk of chemical used in food
and drink containers
Jeremy Laurance

One of the world’s most widely used chemicals, a key constituent of plastic food and drink containers, has been linked for the first time with increased rates of heart disease and diabetes in adults.

Bisphenol A (BPA) is one of the 10 most common chemicals produced worldwide and gives plastic its rigidity, durability and light weight.

Researchers now fear that tiny amounts which leach out of plastic containers into food and drink may cause harm to health.

A team of British toxicologists analysed findings from an American survey of 1,455 adults and showed that the 25 per cent with the highest levels of the chemical were more than twice as likely to have heart disease and/or diabetes compared with the 25 per cent with the lowest levels. They also had higher levels of liver enzymes indicative of metabolic abnormalities.

The scientists from the Peninsula Medical School in Exeter and the University of Iowa have presented their findings to a panel of the US Food and Drug Administration which is hearing evidence on the risks of BPA.

Ninety per cent of the population were exposed to BPA, which is ubiquitous in products such as CD cases and dental sealants, the researchers said. Vast quantities were buried in landfill sites which could potentially have leached into drinking water and was also present in the air around manufacturing facilities.

Iain Lang, an epidemiologist from Peninsula Medical School and lead author of the study, said: “This is something everyone is exposed to. It is the first ever study in a large human population. But this is a single scientific study and we would not want to leap to conclusions on the basis of it.”

Critics said there could be a more “commonsense” explanation for the findings – that people who consumed a lot of canned drinks would increase their risk of heart disease and diabetes from the sugar, incidentally exposing themselves to higher levels of BPA from the can. Younger people showed the highest levels of BPA, lending support to the hypothesis.

Asked if the consumption of sugar in canned drinks could explain the findings, Dr Lang said: “It is possible [but] we have done all we can to exclude that possibility.”

The study is published in The Journal of the American Medical Association, which carries an editorial calling for further regulation of BPA in the wake of the findings. The authors of the editorial have made extensive studies of BPA and have called for curbs on its use in the past.

Dr Lang said: “The editorialists are more bullish than us. A single study is not enough to justify a change in policy.”

The findings show that those with the highest levels of BPA, measured in their urine, had exposure to about 35 micrograms a day, compared with 20 micrograms a day for those with the lowest exposure.

These levels are at least 100 times below the level currently regarded as “safe” in the US and Europe of more than 3,000 micrograms per day.

Professor Richard Sharpe, of the Medical Research Council’s Human Reproductive Sciences Unit at the University of Edinburgh, said the study showed an association, not a causal link, between BPA and heart disease and diabetes, and it was too easy to jump to the “obvious scary conclusion”.

Professor Sharpe added: “There may be an altogether more commonsense (although still scary) explanation... that if you drink lots of sugary canned drinks you will over time increase your risk of cardiovascular disease and diabetes (I think we already suspect this) and incidentally you will be exposed to more BPA (from the can lining). Our present understanding, and this study, do not allow us to choose between these two explanations.”

A spokeswoman for the Chemical Industries Association said the European Food Safety Authority had reviewed the use of BPA in products in contact with food and drink this year and found it to be safe: “This new study will be subject to the same scrutiny to see if further research is required.”

The UK Food Standards Agency said it would “continue to closely monitor scientific reports about the health effects of BPA”.

Popular plastic building block

Bisphenol A is a chemical building block, mainly used to make polycarbonate plastic and epoxy resins. It was first created in a laboratory by the German scientist Thomas Zincke in 1905, and is now one of the most extensively tested materials in use today, after becoming increasingly popular throughout the 20th century.

Polycarbonate plastic – which has been widely manufactured in the US since 1957 – is light, tough and heat resistant, and is used in many everyday products including CDs, DVDs, electronic equipment and food and drink containers.

Epoxy resins are chemically resistant, adhesive and can be easily moulded, and are often used as protective coatings for electronic circuit boards inside electrical equipment, but are also widely used to line metal cans and tins to protect the food or drink stored inside. — The Independent

Waddling gait — it may be knee arthritis
Dr Ravinder Chadha

It is a common sight — scores of people walking with a limp in parks, shopping malls, offices, almost everywhere. Causes could be as varied as obesity, a knee problem, back or hip pain. Knee arthritis is the most common cause of waddling gait.

Arthritis patients, in order to avoid pain (which usually occurs on the inner side
of the knee joint), try to transfer weight on the outer side of the leg and foot
causing waddling gait.

When they walk thus for prolonged periods of time their lower leg bones become bow-shaped and the outer edge of the shoe heels get worn-out very quickly.

Gait alterations/disturbances often are a result of knee pain, back pain and sometimes foot pain.

Feet are held wide apart and the individual walks somewhat like a duck. This also happens during later stages in pregnancy.

Waddling is, in fact, a distinctive duck-like walk that also appears in childhood or later in life.

Osteoarthritis of the knee joint entails low grade inflammation in the joint due to the breakdown of the cartilage that under normal circumstances carries and acts as a cushion inside the joint. There is also a decline in the amount of synovial fluid which lubricates the joint.

Prevention and treatment of gait disturbances depend on the cause. Once the cause is treated, the disturbance will often go away.
Reduction in the body weight is a very critical component in treatment and alleviating pain/discomfort in the cases of knee arthritis.
Knee braces/supports as could be used to provide stability to the knee joint.
Shoe modifications i.e. inserting a medial arch in flat feet patients. Medial/ lateral wedge raise could be given to lessen the waddling gait.
Damaged cartilage lacks the ability to produce the lubricating fluid rendering the joint dry, stiff and painful. Hyaluronic acid injections dramatically alleviate symptoms of pain and stiffness. These injections are given every week for three to five week. These, however, do not carry the risks or concerns as in cases of steroid injections.

As the muscles and ligaments hold the knee together, it is critical that they are strong. Mandatory stretching and strengthening of muscles on the front and back of thighs (quadriceps and hamstring) are indeed crucial. To achieve these objectives the following exercises help considerably:
Placing a round pillow/ rolled towel under the knee. Tightening of the muscles of the leg without moving the knee, holding on for a count of 15. Repeat 15 times.
Sitting against the wall, lifting the affected leg 6” above the floor and staying on for a count of 10. Repeat 10 times.
Tie sandbag or a purse filled up with coins over the ankle. Lie with face downwards and lift the lower leg by bending the knee 6”-12” from the floor. Repeat 10 times.

Waddling gait could be lessened/ treated if the cause could be detected and treated at the earliest, otherwise gait disturbances can even lead to back pain or knee pain, causing greater agony.

eYESIGHT
Latest in ARMD management
Dr Mahipal S. Sachdev

Age-related macular degeneration (ARMD) is a leading cause of blindness in the elderly population. The prevalence is reported to be 1.2-1.4 per cent in several population-based epidemiological studies.

Currently 25-30 million people worldwide are blind due to ARMD. With the
ageing world population, it is bound to increase significantly with serious
socio-economic implications.

ARMD is caused by the degeneration of the central portion of the retina called “macula”, which is responsible for fine vision. The exact cause of ARMD is not known but genetics seems to play a significant role.

There are two types of macular degeneration: dry and wet. The dry form is common and accounts for about 90 per cent of all cases. Vision loss from dry macular degeneration occurs very gradually over the course of many years.

Individuals with dry macular degeneration do not usually experience a total loss of central vision. However, it can become difficult to perform tasks that require fine-detail vision.

Wet ARMD accounts for about 10 per cent of cases. In wet macular degeneration, new blood vessels grow (neovascularization) beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive retinal cells, which die off and create blind spots in central vision.

Several strategies are today available to treat the wet form of AMD, which is responsible for significant visual loss. These treatment modalities, however, are aimed primarily at the preservation of vision only.

Treatment decreases the rate of progression of the disease, but this can only partially reverse the degeneration that has already occurred. Treatments for different stages of the disease process include:
1. Vitamin and anti-oxidant supplements
2. Laser photocoagulation can help some patients of wet AMD by destroying or sealing new blood vessels to prevent leakage. This is possible only in cases where the central retina is not involved in the disease process.
3. Photodynamic therapy: With PDT a light-sensitive dye is injected into the bloodstream and is transported to the retina at the back of the eye. This chemical highlights the blood vessels that are growing abnormally. A low energy or “cold” laser beam is then shone onto the macula. This makes the chemical react and destroy the leaking blood vessels without damaging the healthy tissue around the affected area in the back of the eye. More than one treatment is usually required. Low fluence PDT is now used which reduces the damage to the healthy retina.
4. Anti-angiogenic drugs: In recent years a group of drugs (medicines) called anti-VEGF drugs have been developed. VEGF stands for ‘vascular Endothelial Growth Factor’. This is a chemical that is involved in the formation of new blood vessels in the macula in people with wet-ARMD. By blocking the action of this chemical, it helps to prevent the formation of the abnormal blood vessels that occur in wet-ARMD thereby preventing its complications.

These drugs are injected directly into the vitreous of the eye by a fine needle,
and injections may be needed more than once at a few weeks’ interval to keep
on with their effect.

The main aim of treatment with Anti-VEGF drugs is to prevent wet-ARMD from getting worse. However, it seems that in some cases these drugs may actually restore some of the vision that has been lost.

Today, the various treatments available for the management of this blinding condition are used to help in the preservation of vision for as long as possible. It is essential for patients, especially those over the age of 60 years who develop complaints of distortion of vision, decrease of vision for distance and/or near and a feeling of seeing a black spot in the central part of their visual field to have a checkup by an eye specialist to rule out this condition. It is best treated when the effect on the visual function is less.

The writer is Chairman and Medical Director, Centre for Sight, New Delhi. Email: drmahipal@gmail.com.