That doesn\u2019t mean omega-3s aren\u2019t important. \u201cThey\u2019re an essential nutrient and there\u2019s good evidence supplements can benefit heart health, particularly in people who eat very little fish,\u201d says Manson. \u201cHeart disease and stroke are closely related to cognitive decline so what\u2019s good for the heart is usually good for the brain. But the benefits are not guaranteed.\u201d<\/p>\n
Scientists believe omega-3s may be more effective for brain health when consumed as part of a Mediterranean-style diet which is naturally rich in omega-3s from fish, nuts and dark green leafy vegetables.<\/p>\n
The bottom line:<\/strong> Focus on getting omega-3s from your diet rather than relying on a supplement. \u201cI recommend eating two or more servings of oily fish a week as part of a Mediterranean-style diet rich in vegetables, fruit, whole grains, nuts and healthy fats,\u201d says Manson. \u201cDietary supplements should never be a substitute for a healthy diet.\u201d If you don\u2019t eat fish, or have very little, she recommends a daily supplement containing 1g of marine omega-3s, ideally with a ratio close to 50:50 of DHA.<\/p>\n Vitamin B12Vital if you\u2019re deficient<\/p>\n If you\u2019re struggling with brain fog or poor memory<\/a>, one of the first things to check is your vitamin B12 level<\/a>.<\/p>\n \u201cVitamin B12 deficiency is one of the few, potentially reversible causes of cognitive decline,\u201d says Manson. \u201cTreating a deficiency with supplements can improve symptoms.\u201d<\/p>\n Our body needs vitamin B12 to keep nerve cells healthy and make neurotransmitters, the chemical messengers that allow brain cells to communicate. Chronic deficiency can lead to memory problems, depression and, eventually, brain atrophy.<\/p>\n B12 is found only in animal products or fortified foods, meaning vegetarians and vegans are at greater risk of deficiency. Our ability to absorb it also declines as we get older. According to NHS figures, around one in 20 people aged 65 to 74 and one in 10 people aged 75 and older have B12 or folate deficiency.<\/p>\n Yet, despite the link between low levels of B12 and cognitive decline, clinical studies, including those involving Alzheimer\u2019s patients, haven\u2019t found taking B12 supplements improves cognition in people whose levels are already adequate.<\/p>\n \u201cSome people genuinely need extra B12,\u201d says Manson. \u201cThat includes those with pernicious anaemia or who are taking medications such as metformin that reduce absorption. Otherwise, I wouldn\u2019t routinely recommend high-dose vitamin B12 supplements.\u201d<\/p>\n The bottom line:<\/strong> Don\u2019t take B12 in the hope it will sharpen your memory. If you\u2019re suffering symptoms or are at risk of deficiency, ask your GP about a blood test. \u201cFor most healthy people, a multivitamin provides sufficient B12,\u201d says Manson. \u201cA healthy diet including meat, fish, eggs, dairy and fortified foods should cover your daily needs. If you\u2019re vegan or eat a largely plant-based diet, consider a B12 supplement, and discuss the dose with your GP.\u201d<\/p>\n Vitamin DOnly if you\u2019ve got low levels<\/p>\n One in six people in the UK have low levels of vitamin D \u2013 often called the sunshine vitamin because our bodies make it when sunlight hits the skin.<\/p>\n Not just important for healthy bones, vitamin D also protects our brain health. Low levels have been linked to poor memory and thinking skills and studies suggest deficiency may increase the risk of dementia.<\/p>\n A large trial of more than 1,600 people, in Neurology<\/a>, found those with moderate vitamin D deficiency were more than 50 per cent more likely to develop Alzheimer\u2019s or dementia. For those with severe deficiency, the risk was 125 per cent higher.<\/p>\n However, that doesn\u2019t mean everyone benefits from taking a high-dose supplement. In the five-year VITAL trial of more than 25,000 people, Dr Manson and colleagues found taking 2,000 IU of vitamin D3 a day failed to significantly slow cognitive decline in adults whose vitamin D levels were already adequate.<\/p>\n \u201cWe saw benefits only in those who started out with lower levels,\u201d she says. \u201cThat tells us the issue is correcting a deficiency rather than <\/strong>benefits from giving everyone extra vitamin D.\u201d<\/p>\n The bottom line:<\/strong> The Government recommends UK adults take a daily 10mcg (400IU) vitamin D supplement during autumn and winter. \u201cPeople at high risk of deficiency, such as those with osteoporosis, fat malabsorption or who get little sunlight exposure, may benefit from 1000-2000 IU a day,\u201d says Manson. \u201cFor everyone else, the evidence for brain health benefits is much less convincing.\u201d<\/p>\n GlucosamineBe cautious<\/p>\n Recent research has raised fresh questions about glucosamine, one of the most popular supplements for joint pain.<\/p>\n