Muscle cramps

In a nutshellLeg cramps are common in pregnancy, the elderly, some medical conditions and as exercise/heat cramps. Although they can be due to deficiencies of nutrients such as electrolytes (e.g. magnesium, calcium, sodium and potassium), there is not much evidence to suggest this is true in most cases.Supplement trials of these nutrients and others (such as carnitine), paint an inconsistent and incomplete picture. The current evidence does not provide clear guidance to clinicians.

Statin myopathy and nutrition

In a nutshellStatin drugs can be associated with myopathy of various degrees from mild to severe. Mild symptoms are not uncommon.Coenzyme Q10, vitamin D, vitamin E, carnitine and creatine have all been mentioned as being nutrients that may be involved in this myopathy and potentially therapeutic.Whilst deficiencies of some of these nutrients have been found with statin and/or in statin myopathy cases, only CoQ10 has any degree of RCT evidence, and only a little at that.

Can folate supplements be dangerous? - part 2

In a nutshellWhilst adequate folate is protective against cancer, there are theoretical grounds and some clinical evidence to suggest that, in people with existing pre-cancerous or cancer cells, folate supplements could stimulate their growth.However, more studies have failed to show this than have reported it, and so the hypothesis remains neither confirmed nor refuted. Until this matter is resolved, some caution is appropriate, particularly in those who may already have early stage tumour.

Can folate supplements be dangerous? - part 1

In a nutshellConcerns have been raised over potential adverse effects of folic acid supplements, particularly in countries where food is fortified with folic acid. The concerns include masking B12deficiency, increased risk of multiple birth, allergic disease, and the appearance of unmetabolised folic acid in the blood.At this point in time we lack solid evidence that any of these is a significant practical clinical problem, although neither has it been ruled out that some individuals might be affected.

Iodine and the brain

In a nutshellIodine is required for thyroid hormone production, which is crucial to brain development. Iodine deficiency is widespread throughout the world, and mild deficiency is surprisingly common in developed countries.There is some good evidence that even milder deficiencies are associated with cognitive deficit. Public health policy is important (e.g. iodine fortification of salt), but also clinicians should be aware of individual iodine status, especially in pregnant women and children.

Infertility and overweight

In a nutshellExcess fatness adversely affects fertility, decreasing pregnancy rates by approximately 30%, both for natural and assisted reproduction. It does so by changing the hormonal, inflammatory and energetic environment in both men and women.There is some evidence that weight reduction (including through bariatric surgery in the obese) can help reverse this. However, we lack RCTs to confirm this.

Infertility, zinc and other metals

In a nutshellPhysiological but not excessive levels of zinc, copper and other essential metals are required for human fertility, and may also help protect against accumulation of reproductively toxic heavy metals, e.g. lead and cadmium.There is limited RCT evidence for zinc supplements in treating infertility, and very little for other essential metals. Nevertheless, clinicians treating infertility should pay attention to the patient's mineral status.

Nuts - an update on their CVD impact

In a nutshellNuts contain a rich mixture of mainly MUFA and PUFA fat, antioxidants, fibre and minerals.Observationally, nut intake is associated with less CVD. Many recent RCTs have shown that they reduce total and LDL-cholesterol and have some benefit for other metabolic CVD risk factors, e.g. insulin resistance and hypertension. They do not appear to have adverse impact on weight or lipid peroxidation.

Poststroke nutrition - part 2

In a nutshellMalnutrition after stroke is common, and affects recovery. As well as inadequate protein-energy, vitamin D deficiency is often present and contributes to osteoporosis and high fracture rates.A few RCTs of poststroke supplementation of energy-protein, vit.D and folate/B12 have had quite positive outcomes. More are needed.

Stroke prevention - other nutrients

In a nutshellObservational evidence links many of the nutritional factors associated with atherosclerosis and hypertension to risk of stroke, e.g. calcium/vitamin D, antioxidants, PUFA, salt restriction, Mediterranean diet etc.Only a minority of RCTs using nutrition to prevent stroke had significant benefit. This may be due to methodological issues.