Back in May I reported the results of a study which found that taking folic acid before pregnancy and during early pregnancy was associated with a reduced risk of premature birth.  A recent study (1) has found that women with high antioxidant levels in their blood seem less likely to give birth prematurely.

The study(1) was a case control study.  It included over 5000 women.  All the women involved in the study had an interview, examination and blood test at week 24-26 of their pregnancy.  Some of the placentas from term and preterm births were also analysed.  There were 207 preterm births in total.  Women with high (above the average) blood plasma concentrations of carotene (both alpha and beta carotene), cryptoxanthin (a type of carotenoid), and lycopene seemed to have a reduced risk of preterm birth.  (I have written about carotenoids a number of times). 

Carotenoids such as alpha and beta carotene, lutein and zeaxanthin are a family of over 700 naturally occurring yellow, red, orange and dark green pigments found in vegetables and fruits.  Good sources include carrots, sweet potatoes, tomatoes, squash, peppers, cantaloupe melons, nectarines, papaya, mango and dark green vegetables such as spinach, kale, watercress and asparagus.  Introducing a good mix of these fruits and vegetables on a regular basis in the diet will help keep carotenoid levels in the body high.  Carotenoids act as antioxidants in the body.  Antioxidants are important to prevent damage to the body cells by naturally occurring unstable oxygen molecules, known as free radicals.  Antioxidants may help to ‘quench’ or mop-up the destructive free radical molecules and therefore protect against cell-damage.

This study found that women with higher blood levels of certain carotenoids were less likely to deliver their babies preterm.  In the study, the one-half of mothers-to-be with the highest blood levels of certain carotenoids were 30 percent to 50 percent less likely to deliver prematurely than women with lower levels. The findings do not prove cause-and-effect. There may be other things about women with high carotenoid levels that explain the association with lower preterm-birth risk but the authors conclude that further studies are certainly warranted to investigate the apparent link found in this study.

If carotenoids, or other antioxidants, do help prevent premature delivery, the reasons are not yet entirely clear.  The authors speculate that it could be related to protection from any ill effects of environmental toxins, like air pollution, or exposure to bacteria or other infectious agents.

Eating a healthy diet during pregnancy, and indeed at any time, is crucial.  Ensuring that you achieve the minimum 5 portions of vegetables and fruits daily is a good idea.  Aiming to eat plenty of these foods will mean that antioxidant levels in the body will naturally be high.  In addition, many women may choose to take a multivitamin and mineral supplement specifically designed for use during pregnancy and this may also boost levels of important antioxidants in the body, as well as providing folic acid.

(1)Kramer MS et al.  2009.  Antioxidant Vitamins, Long-Chain Fatty Acids, and Spontaneous Preterm Birth.  Epidemiology. 20(5):707-713.
Written by Ani Kowal

The links between diet and cancer are widely researched.  The World Cancer Research Fund UK (WCRF UK) estimate that lifestyle factors such as being overweight, eating an unhealthy diet and being inactive are responsible for about a third of all cancers in developed countries (1).  The WCRF UK are a charity committed to cancer prevention.

A recently published study (2) has found a significant link between eating a diet high in carotenoid rich fruits and vegetables and a reduction in the risk of breast cancer in premenopausal women.

Carotenoids such as alpha and beta carotene, lutein and zeaxanthin are a family of over 700 naturally occurring yellow, red, orange and dark green pigments found in vegetables and fruits.  Good sources include carrots, sweet potatoes, tomatoes, squash, peppers, cantaloupe melons, nectarines, papaya, mango and dark green vegetables such as spinach, kale, watercress and asparagus.  Introducing a good mix of these fruits and vegetables on a regular basis in the diet will help keep carotenoid levels in the body high.

The study (2) involved 5,707 women with invasive breast cancer (2,363 premenopausal women and 3,516 postmenopausal women) and 6,389 individuals with no breast cancer, control subjects (2,594 premenopausal women and 3,516 postmenopausal women).  In an interview, these women were asked about their intake of carotenoid rich fruits and vegetables.  The researchers found that pre-menopausal women eating high intakes of vitamin A, beta-carotene, alpha-carotene, lutein and zeaxanthin appeared to have a reduced risk of breast cancer.  Eating at least two servings of carotenoid-rich vegetables each day was associated with around a 17% reduced risk of breast cancer.  As an association study the results are positive but further studies would be necessary before any firm conclusions could be drawn about the effect of dietary carotenoids on cancer risk. 

Carotenoids may be acting to prevent cancer via different means.  Carotenoids have been shown to interfere with oestrogen (hormone) signalling which may explain why their cancer-preventing effects would be limited to premenopausal women.  In addition to this, carotenoids act as antioxidants in the body and antioxidants have been linked to cancer prevention.  Antioxidants prevent damage to the body cells by naturally occurring unstable oxygen molecules, known as free radicals.  Antioxidants may help to ‘quench’ or mop-up the destructive free radical molecules and therefore protect against cell-damage (which could lead to cancer formation).

Absorption of carotenoids from foods into the body is greatly affected by fat.  Without a fat source carotenoids are not easily absorbed.  Fat acts as a carrier for these nutrients to allow them passage from the gut into our blood and bodily cells.  This is not a suggestion to drown your vegetables or salads in gallons of oil, however, I am a firm believer in using small amounts of olive oil in dressings and cooking.  Including some nuts, seeds or olives in salads may also be helpful in order to gain maximum absorption of these important nutrients. 

(1)WCRF/AICR.  2009.  Policy and action for cancer prevention.  Food, nutrition and physical activity: a global perspective.  Washington DC: AICR, 2009.
(2) Mignone LI et al.  2009.  Dietary carotenoids and the risk of invasive breast cancer.  International Journal of Cancer.  124:2929-2937
Written by Ani Kowal

In October of last year I wrote about eating for bone health and mentioned the clear and positive associations between fruit and vegetable consumption and strong bones (1).  The post concentrated mainly on the way these foods act to effect the pH balance within the body.  Fruits and vegetables contain a huge array of vitamins, minerals and phytonutrients/flavonoids (chemically active plant compounds) that may also act to strengthen bone.

Last month a paper was published in the American Journal of Clinical Nutrition (2) which points toward the bone protective effects of carotenoids.  Previous evidence suggests that carotenoids may be acting to prevent bone loss and also to stimulate bone cell growth. Carotenoids, found abundantly in fruit and vegetables, act as antioxidants in the body and it is this mechanism that may be protecting the bones from damage by naturally occurring unstable oxygen molecules in the body, known as free radicals.  Antioxidants may help to ‘quench’ the destructive free radical molecules and therefore protect against damage.  As nutrients, antioxidants are ingested in the diet and are then distributed via the blood into various parts of the body tissues, including the bones.  

The researchers involved in this latest study (2) looked at the potential effects on bone mineral density of overall and individual intake of several carotenoid compounds, including alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein and zeaxanthin.  The study scientists tracked the bone mineral density in the hip and spine of 213 men and 390 women over the course of four years.  They found that carotenoid intake was associated with some levels of protection against bone mineral density losses at the hip in men and at the spine in women.  The results suggest that carotenoids, especially lycopene, may be protective against bone loss in older adults.  Further studies are certainly needed but the evidence adds further weight to the mounting data which shows just how important fruits and vegetables are to the whole body, including our bones.

A diet rich in colourful fruits, vegetables will provide plentiful amounts of antioxidants.  Carotenoids are a family of over 700 naturally occurring yellow, red, orange and dark green pigments found in vegetables and fruits.  Good sources include carrots, sweet potatoes, tomatoes, squash, peppers, cantaloupe melons, nectarines, papaya, mango and dark green vegetables such as spinach, kale, watercress and asparagus.  Introducing a good mix of these fruits and vegetables on a regular basis in the diet will help keep carotenoid levels in the body high.

Absorption of carotenoids from foods into the body is greatly affected by fat.  Without a fat source carotenoids are not easily absorbed.  Fat acts as a carrier for these nutrients to allow them passage from the gut into our blood and bodily cells.  I am certainly not suggesting that you drown your vegetables or salads in gallons of oil, however, I am a firm believer in using small amounts of olive oil in dressings and cooking.  Including some nuts, seeds or olives in salads may also be helpful in order to gain maximum absorption of these important nutrients. 

If you are looking at carotenoid supplements, especially lycopene, look for those that contain an oil carrier, these will aid maximum absorption.  Of course fruits and vegetables contain far more than just carotenoids and a supplement cannot be seen as a substitute for good dietary habits, but if you feel that you do not get a good variety of vegetables and fruits in your daily diet you may wish to consider a supplement to help make up for any short-fall.

It is particularly important that young people look after their bone health, a balanced diet as well as exercise is vital in this respect.  Recently the National Osteoporosis Society (NOS) produced a press release and report regarding their findings that young people in the UK are endangering their health by not looking after their bones.  Prevention is the key to osteoporosis which affects up to three million people in the UK.

The NOS found that (3) that less than a quarter of people knew they should start looking after their bones before the age of 30, despite the fact that bone strength actually peaks during our 20s. Younger people need to ‘bank’ plenty of bone by the age of 30 as bones tend not to regenerate as quickly after that.  
• Almost half (49%) of young people (18-24 yrs) did not know there were any steps they could take to keep their bones healthy;
• More than half were unaware that exercise can help reduce the risk of osteoporosis;
• One in three did not know about the positive role diet can play.

Professor Roger Francis, Chair of the charity’s Medical Board, states(3):
 
“Our bones are living tissue, much like our skin. New bone replaces old throughout our lives. But the most crucial years are when we’re young as this is when the cells building new bone are most active. Until our mid 20s our bones are gaining density and strength. From our 30s onwards our bones gradually lose their density. The more we can build up our bones when we are young the better we can help to protect ourselves against osteoporosis and fragility fractures in later life.” (3)

Women are more at risk of developing osteoporosis since their bones are smaller and also more vulnerable to hormonal changes.  Being underweight, and having a low BMI (body mass index) is also a big risk factor.  Currently many girls and women are striving to reach a low bodyweight and achieve the size zero that is touted by so many celebrities.  The report found that only 21% of people knew that being underweight was a significant risk factor for osteoporosis development (3).

Encouraging young people to eat fruit and vegetables, as well as foods rich in calcium, magnesium and other minerals is very important for bone strength and development.  Please visit the National Osteoporosis Society website for more information about bone health. A very informative document about osteoporosis can be downloaded from the site and my post about eating for strong bones may also be of interest.

(1) New SA.  2003.  Intake of fruit and vegetables:implications for bone health.  Proc Nutr Soc.  62:889-899
(2) Sahni S et al.  2009.  Inverse association of carotenoid intakes with 4-y change in bone mineral density in elderly men and women: the Framingham Osteoporosis Study. Am J Clin Nutr 89: 416-424
(3) NOS press release

Written by Ani Kowal