Processed red meat isn’t just bad for your heart, it’s also associated with dementia

Less red meat is good for the planet and a growing number of people have started the new year resolving to pursue a meat-free diet.

Besides being good for the planet and kinder to animals, eating less red meat is also better for your health. Reducing consumption of red and processed meat could reduce your risk of diabetes, cancer and heart disease. These diseases share risk factors with dementia, including the most common type, Alzheimer’s disease.

Alzheimer’s and other types of dementia are the UK’s leading cause of death. With Alzheimer’s, memory problems are often the first issue to become apparent and these are later followed by other cognitive impairments significantly affecting daily life and social interactions.

A large US-based study investigated different foods and their associated dementia risk in over 133,000 healthcare professionals who did not have dementia when the study started. They were tracked for over four decades. In that time, just over 11,000 developed dementia.

Eating processed red meat (such as sausages, bacon, hotdogs and salami) was linked to a 16% higher risk of dementia and a faster rate of cognitive ageing. Eating about two servings of processed red meat a week raised the risk of dementia by 14% compared with those who ate less than about three servings a month. (A serving is a piece of meat roughly the size of a deck of playing cards – around 85g.)

If people substituted processed red meat protein for that found in nuts, tofu or beans, they could reduce their dementia risk by 19%, the study found. The rate of cognitive ageing was also reduced.

In this same sample, eating less red and processed meat was shown to substantially reduce the risk of death from cancer and heart disease. The researchers estimated that almost one in ten deaths could have been prevented if everyone had eaten less than 42g of red meat (less than half a serving) a day throughout the study.

Red or processed meat can result in high levels of “bad fats” in the blood because of its saturated fat and cholesterol content. This can result in fatty deposits building up in the blood vessels, explaining some of the association with heart disease deaths.

High blood pressure can result from the high salt content in processed meats. The fat around the tummy caused by these calorific foods combined with a sedentary lifestyle is also linked to high blood pressure, in addition to inflammation of the blood vessels and diabetes.

These factors are all also associated with Alzheimer’s. “Good fats” found in nuts, fatty fish, olive oil and avocado could help reduce these mechanisms and may protect against dementia and memory decline.

Gut health

Scientists increasingly recognise the role of the gut in brain disorders.

Gut health can be improved with prebiotics, such as fibres in plants, and probiotics (the helpful bacteria that can be found in fermented foods such as tempe, sauerkraut, kefir, kombucha and yoghurt).

Plants and beans that contain lots of fibre were associated with less risk of dementia in the studies mentioned. Conversely, gut health can be negatively affected by ultra-processed food, such as crisps, fizzy drinks, breakfast cereals and ready meals.

A review of studies, published in 2023, found that people who ate lots of ultra-processed foods (of all kinds – not just processed meats) had a 44% higher risk of dementia. So, do we need to cut out all processed foods?

This is a difficult topic, and it is also very hard to implement. Much of what most of us eat is processed, from tinned vegetables to bread and milk. Many of these foods have health benefits. The above-mentioned review found that eating moderate amounts of ultra-processed food was not associated with an increased risk of dementia.

Moderation is key

As always, moderation is key in any diet. Any food or drink – even water – in the wrong dose can harm the body. So be wary of recent diet trends suggesting we need to eat loads of protein.

Too much protein can be tough on the kidneys, leading to their dysfunction. This is a problem as you need your kidneys to remove toxins from your body, get rid of excess fluids and waste. They help regulate blood pressure and support bone health, among other important functions. Not having good kidney function can lead to serious health problems.

Read more: Does taking part in Veganuary put people off meat in the long term? Here's what the evidence shows

Besides going meatless, many people want to lose weight in the new year. Keto diets with lots of protein and fat, while popular, have low adherence and the same weight loss as other diet programmes in the long term.

Eating a healthy, balanced diet that includes lots of plants, beans and good fats (such as those found in nuts and fish), and exercising regularly will help to reduce your risk of dementia and heart disease.

Eef Hogervorst has received funding from British Council/Newton trust to investigate whether tempe could promote brain health. She also acted as consultant by Proctor on the effects of omega 3 and folate on brain function. Eef is affiliated with Loughborough University.

Emma D'Donnell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.