Q: I have heard that some foods are good to eat if they are related to your blood group. For example I am A positive and it is said that I should not eat too many Brazil nuts as my system does not agree with them nor oranges… Do you agree with this form of belief? That some food should be eaten according to your blood group?

A: The blood type diet was introduced by Peter D’Adamo who suggested that because the cells in our bodies have certain distinct chains of polysaccharides which put us into one of four blood types, O, A, AB or B then we should eat a diet that is right for whichever blood type we are.

The blood type theory is founded on anthropology because it is reasoned that as type O was the first blood type to evolve, then people with this blood type should eat like our hunter-gatherer ancestors. The theory is based on the action of lectins, which are proteins found on the surface of certain foods. So when you eat a food containing lectins that are not compatible with your blood type then the lectins can cause health problems.

I have a problem with the thinking that we can all just be slotted into four groups, according to the four blood types. And in fact there are more than four because with each group there are sub-groups (e.g. rhesus positive and negative) and these differences are not taken into account. The other major problem is the lack of evidence. There has not been any scientific evidence to show that an interaction between blood type and diet has an impact on health. Biochemical research has also found no differences in how lectins react with each different blood type. Even D’Adamo adds a warning to say that even within each blood type there are individual variations so don’t expect all the recommendations to apply to you. The difficulty would then be knowing which ones apply and which ones don’t and then the blood typing theory starts to fall down.

Q: I had a heart attack a few years ago. Should I be taking a supplement of omega 3 fish oils?

A: Numerous studies have shown that omega 3 fatty acids help to protect against heart disease and the National Institute of Clinical Excellence has just recommended that if you’ve had a heart attack you should eat at least 7g of omega 3s per week (that’s two portions of oily fish such as salmon, mackerel, sardines and fresh tuna.

Doctors have also been advised to prescribe 1g of omega 3 daily for anyone who can’t do this, starting from three months after a heart attack, for up to three years.

I suggest that you eat a diet with plenty of whole grains, fresh fruit and vegetables oily fish, nuts, seeds and pulses as these foods are linked to lower heart disease risk. And add in a supplement like Omega 3 Plus to get the correct amount of essential fatty acids in your diet. Reduce the amount of saturated fats in your diet by avoid meat and eating dairy foods in moderation. Avoid trans fats completely as just an increased consumption of trans fats by only 2% increases the risk of heart disease by a massive 30%.

Q: Do we really need to take supplements every day?

A: A healthy diet is always the basis for good health, but because nowadays it is not easy to get all the health boosting nutrients you need from your diet, taking supplements may be extremely beneficial.

With the dominance of supermarket shopping, there’s no way of knowing the freshness or nutritional content of our food. Even if you eat all the right foods modern agricultural and production processes remove much of the nutritional value.

For example, almost 80 per cent of zinc is removed from wheat during the milling process to ensure that bread has a longer shelf life. Part of the problem is that the soil food is grown on today is so lacking in nutrients due to overuse and commercial farming methods, so that even foods we regard as healthy, like vegetables, may not contain the nutrients you expect.

According to joint research by the Royal Society of Chemistry and the Ministry of Agriculture, Fisheries and Food, between 1940 and 1990 vegetables lost 76% of their copper content, 24% of their magnesium and 27% of their iron quotient. From the vitamin point of view, it may be so long since an orange was picked that by the time you eat it has lost most of the vitamin C you bought it for in the first place. 

A recent a Which Magazine report found that one pack of sliced green beans contained only 11% of the vitamin C it should have done. It’s clear that many of us are simply not getting all the nutrients we need to ensure optimum health and fertility from our food. This was confirmed by a National Diet and Nutritional survey published in 2003 which looked at adults aged 19-64 showed that only 15% of women and 13% of men actually ate the five-a- day target for fruit and vegetables.

With vitamins and minerals, 74% of women failed to achieve the Reference Nutrient Intake In an ideal world a healthy diet would provide all the nutrients we need but we don’t live in an ideal world and I do suggest that you take a good quality daily multi vitamin and mineral as an insurance policy instead of high doses of individual nutrients and take one appropriate for your age. So if you over the age of 45 take one designed for leading up to the menopause, through it and beyond (like MenoPlus) or if you are aiming to get pregnant take Fertility Plus for Women.